Dipak Sapkota

• Giglio, Daniel; Ganesh, Divya; Bhattarai, Bishwa Prakash; Søland, Tine Merete; Sundberg, Jonas & Thorsell, Annika [Show all 9 contributors for this article] (2026). Biomarkers Correlating With the Development of Oral Squamous Cell Carcinoma From Leukoplakia. Oral Diseases. ISSN 1354-523X. doi: 10.1111/odi.70439. Full text in Research Archive Show summary

  Background We assessed protein biomarkers expressed in oral leukoplakia (OL) that are associated with the risk of transformation into oral squamous cell carcinoma (OSCC). Methods Tissue sections of OL transforming into OSCC (leuko-ca), the corresponding OSCC and OL that did not progress to OSCC (leuko-nonca) were analyzed with global relative quantification to compare proteome profiles. Immunohistochemistry was performed to validate the expression of identified biomarkers. Results The top enriched biological pathways in OL transforming into OSCC within 5–26 months after diagnosis (short duration [SD]-leuko-ca) compared with leuko-nonca were pathways regulating remodeling of the extracellular matrix (ECM) and lipid and cholesterol metabolism/transport. Kininogen-1, apolipoprotein E (ApoE), collagen alpha-1 (XVIII) chain (COL18A1), sortilin, and perlecan were the most downregulated proteins, whereas EEF1D was the most upregulated in SD-leuko-ca compared with leuko-nonca. Immunohistochemistry confirmed the expression of kininogen-1, ApoE, perlecan, and EEF1D in OL and OSCC. In OSCC compared with leuko-ca, enriched biological pathways involved keratinocyte and epithelial differentiation and immune response regulation. Conclusion We identified biomarkers in OL that were associated with the risk of malignant transformation. Our study gives further support for the importance of the immune system, ECM remodeling, and lipoproteins and cholesterol metabolism in the progression of OL to OSCC.

• Ganesh, Divya; Sundberg, Jonas; Dafar, Amal; Kjeller, Göran; Sapkota, Dipak & Öhman, Jenny [Show all 8 contributors for this article] (2026). Expression of intracellular toll-like receptors in leukoplakia and oral squamous cell carcinoma. Acta Odontologica Scandinavica. ISSN 0001-6357. 85, p. 96–103. doi: 10.2340/aos.v85.45423. Full text in Research Archive Show summary

  Objective: Toll-like receptors (TLRs) are a group of pathogen recognition receptors expressed not only on immune cells but also cancer cells, where TLR activation may lead to tumour progression or suppression. At present, little is known about the role of TLRs and their connection with immune responses in precancerous lesions, such as oral leukoplakia (OL). In the present study, we have explored the immune activation and the expression of the intracellular TLRs – TLR3, TLR7, TLR8, and TLR9 in OL without and with dysplasia, and in oral squamous cell carcinoma (OSCC). Patients and methods: Immunohistochemistry was performed on 19 OL patients without dysplasia (OL-no) and 13 patients with dysplasia (OL-dys) and 10 OSCC patients. On digitalised images, TLR3-, TLR7-, TLR8- and TLR9-expressing cells were semi-quantitatively assessed, while the number of CD3- and CD8-expressing cells/mm2 was registered. Results: Nuclear TLR7 appeared in 31% of OL-dys but was absent in OL-no (p = 0.03). Cytoplasmic TLR8 was higher in OL-no than OL-dys (32% vs. 8%, p = 0.02). Similarly, cytoplasmic TLR9 was also higher OL-no than OL-dys (42% vs. 23%, p = 0.01). Conclusions: TLR3, TLR7, TLR8, and TLR9 are all expressed in OL-no, OL-dys, and OSCC. Also, the study provides evidence for possible nucleocytoplasmic shuttling of TLRs.

• Bhattarai, Bishwa Prakash; Singh, Ashutosh Kumar; Mastrogeorgiou, Michalis & Sapkota, Dipak (2026). Oral squamous cell carcinoma (OSCC): An overview. In Chaurasia, Akhilanand & Tavassoli, Mahvash (Ed.), Microbiome in Head and Neck Cancer: Pathogenesis, Diagnosis and Therapeutic Implications: Part B. Elsevier. ISSN 9780443470561. p. 3–33. doi: 10.1016/bs.ai.2026.04.002. Full text in Research Archive Show summary

  Oral cavity cancer comprises malignancies arising from anatomical sites within the oral cavity, including the gingiva, buccal mucosa, anterior two-thirds of the tongue (oral or mobile tongue), hard palate, floor of the mouth, retromolar area, and mucosal surface of the lip. More than 90% of oral cavity cancers are histologically squamous cell carcinomas (oral squamous cell carcinoma, OSCC). Combined with mucosal lip cancer, oral cavity cancer ranks as the 19th most common cancer globally, with approximately 390000 new cases and 190000 deaths annually. However, the burden of OSCC varies geographically, with Melanesia and South-Central Asia showing a much higher disease incidence. Despite advances in diagnostic and therapeutic approaches over recent decades, OSCC mortality has remained largely unchanged, with only approximately 55-60% of patients surviving 5 years after diagnosis. Tobacco use (both smoking and smokeless forms) and alcohol consumption are among the most important risk factors for OSCC. This book chapter aims to provide a general introduction to OSCC, including its epidemiology, associated etiological factors, a proposed model of molecular pathogenesis, the diagnostic pathway, common treatment modalities, and prognostic factors.

• Bhattarai, Bishwa Prakash; Singh, Ashutosh Kumar & Sapkota, Dipak (2026). Oral potentially malignant disorders (OPMDs): An overview. In Chaurasia, Akhilanand & Tavassoli, Mahvash (Ed.), Microbiome in Head and Neck Cancer: Pathogenesis, Diagnosis and Pathogenesis, Diagnosis and Therapeutic Implications: Part A. Elsevier. ISSN 9780443470523. p. 175–191. doi: 10.1016/bs.ai.2026.03.003. Full text in Research Archive
• Osman, Tarig Al-Hadi; Rikardsen, Oddveig Gjertrud; Teh, Muy-Teck; Sapkota, Dipak; Liang, Xiao & Neppelberg, Evelyn [Show all 11 contributors for this article] (2025). Identification of Phenotypically Distinct Cancer Stem Cell Subpopulations in Oral Squamous Cell Carcinoma. Cancers. 17. doi: 10.3390/cancers17213547. Full text in Research Archive Show summary

  Background: Several markers have been shown to define subpopulations enriched for cancer stem cells (CSCs) and correlate with poor clinical outcomes in oral squamous cell carcinoma (OSCC). Objective: To investigate the pattern of expression and correlation with clinical parameters of two CSC markers, namely p75NTR and ALDH1A1, in both patient samples and cell lines. Methods: Archival formalin-fixed paraffin-embedded samples from normal human oral mucosa (NHOM, n = 31), oral dysplasia (OD, n = 10) and OSCC (n = 177) were subjected to multiple immunohistochemistry and some to qRT-PCR for expression of CSC and proliferation-related markers, BMI1 and Ki67. Correlations between CSC marker expression and clinical parameters were investigated. Primary cells and cell lines derived from NHOM, OD or OSCC were FACS-analyzed for the same markers. Results: A higher frequency of cells positive for CSC markers was detected in OD and OSCC compared to NHOM. Co-localization of the two markers was a rare finding in OSCC as compared to NHOM or OD and was more heterogeneous in OSCC cell lines than in OD and NHOM cells. Cells positive for p75NTR exhibited higher expression of proliferative and self-renewal markers in comparison to ALDH1A1+ or double ALDH1A1+/p75NTR+ cells. Cells positive for p75NTR were more frequent in small-size tumors and poorly to moderately differentiated tumors and correlated with poor survival of patients otherwise (clinically) deemed as of better prognosis. Higher frequency of ALDH1A1+ cells was found to be associated with lymph node metastasis. Both p75NTR+ cells and ALDH1A1+ cells could emerge de novo from the respective negative subpopulation after FACS and in vitro growth, but with different kinetics. Conclusions: Here, we show that several stem cell subpopulations with distinct phenotypes co-exist in a tumor, each having impact on different clinical parameters. The cell subpopulations identified by the use of different CSC markers were found to be dynamic populations, able to switch between phenotypes. In addition, our data suggest that the stem cell heterogeneity is acquired and evolves parallel with carcinoma progression.

• Søland, Tine Merete; Ljunggren, A; Abuharb, A; Alaref, F; Kelppe, J & Reibel, J [Show all 14 contributors for this article] (2025). Odontogenic tumors in Sweden, Norway, Finland, and Denmark. A multicenter study. Journal of Oral Pathology & Medicine. ISSN 0904-2512. 54(5), p. 360–370. doi: 10.1111/jop.13635. Full text in Research Archive Show summary

  Background Updated and comprehensive epidemiological data on odontogenic tumors are not available for the Nordic countries. The aim of the study was to retrospectively examine the prevalence and clinical and radiological characteristics of primary odontogenic tumors over a 10-year period in Sweden, Norway, Finland, and Denmark. Methods Primary odontogenic tumors diagnosed by oral pathologists from 2010 to 2020 at nine different diagnostic laboratories in Sweden, Norway, Finland, and Denmark were identified. Using histopathology referrals and their corresponding histopathological reports, age and sex, anatomic site, clinical and radiological findings, tentative diagnosis, histopathological diagnosis, and recurrence of the tumors were recorded. Range, mean, and median for continuous variables and frequency tabulation for discrete variables were used. Results In total, 1139 primary odontogenic tumors (598 in males and 540 in females) were identified during the study period, giving an annual incidence rate of 4.2/million. The mean age of all patients was 29 years. Ninety-nine percent of the tumors were benign, and the mandible was the predominant location. Odontoma, ameloblastoma, and odontogenic fibroma were the three most common tumors. The mixed epithelial and mesenchymal benign odontogenic tumors were more common at a younger age compared with the epithelial tumors and the mesenchymal tumors (mean age 22, 44, and 35 years, respectively). Information on variables other than sex, age, and tumor site was missing in most referrals. Conclusion The annual incidence of 4.2 cases per million indicates that odontogenic tumors are uncommon in Nordic countries. Better practices to improve the quantity and quality of clinical information in the pathology referrals are needed.

• Lipka, Aleksandra; Søland, Tine Merete; Nieminen, Anni I.; Sapkota, Dipak; Haug, Trude Marie & Galtung, Hilde (2025). The effect of extracellular vesicles derived from oral squamous cell carcinoma on the metabolic profile of oral fibroblasts. Frontiers in Molecular Biosciences. 12. doi: 10.3389/fmolb.2025.1492282. Full text in Research Archive Show summary

  Introduction: Oral cancer is one of the most common forms of head and neck cancers. Oral squamous cell carcinoma (OSCC) accounts for more than 90% of the oral malignancies. The molecular pathogenesis of OSCC is complex as it involves altered expression of specific genes and proteins, but also comprises changes in metabolic processes. It is suggested that extracellular vesicles (EVs) released by cancer cells may contribute to cancer development and metastasis by recruiting and changing phenotype of normal cells that surround the tumor. Methods: The aim of the project was to characterize the effect of OSCC EVs on the metabolic profile of normal oral fibroblasts (NOFs). Targeted liquid chromatography mass spectrometry metabolic profiling was performed on control cells and NOFs exposed to OSCC EVs for 24 and 48 h. Results: Analysis of detected metabolites revealed that OSCC EVs affected NOFs the most after 24 h of exposure. Among metabolites that were significantly altered at 24 h, pyruvate, ATP, UTP, coenzyme A, and dihydroxyacetone phosphate were upregulated, while fatty acids such as nervonic acid, linoleate, oleate, palmitoleic acid, and docosahexaenoic acid were downregulated. These findings were supported by Western blotting of pyruvate kinase M2 (PKM2) and aldolase, fructose-bisphosphate A (ALDOA). Conclusion: The metabolic pathways of glycolysis, citric acid cycle, and amino acid metabolism were enriched, suggesting that OSCC EVs cause phenotype switch in NOFs that may contribute to acquiring a pro-tumorigenic phenotype.

• Sapkota, Dipak; Wang, Daxin; Schreurs, Olaf Joseph Franciscus; Vallenari, Evan Michael; Pandey, Sushma & Küntziger, Thomas M. [Show all 9 contributors for this article] (2024). Investigation of Roles of SLC38A1 in Proliferation and Differentiation of Mouse Tongue Epithelium and Expression in Human Oral Tongue Squamous Cell Carcinoma. Cancers. 16(2). doi: 10.3390/cancers16020405. Full text in Research Archive Show summary

  The aerobic glycolytic pathway, boosting lactate formation, and glutamine addiction are two hallmarks of cancer pathophysiology. Consistent with this, several cell membrane glutamine transporters, belonging to different solute carrier (SLC) families, have been shown to be upregulated in a cell-specific manner to furnish the cells with glutamine and glutamine-derived metabolic intermediates. Among them, the system A transporter Slc38a1 has a higher affinity for glutamine compared to other SLC transporters, and it undergoes highly multifaceted regulation at gene and protein levels. The current study aimed to investigate the functional role of Slc38a1 in the proliferation and maturation of the mouse tongue epithelium. Secondly, we aimed to examine the expression of SLC38A1 and its regulation in human tongue oral squamous cell carcinoma (OTSCC). Employing Slc38a1 wild-type and knockout mice, we showed that Slc38a1 was not directly linked to the regulation of the proliferation and differentiation of the mouse tongue epithelium. External transcriptomic datasets and Western blot analyses showed upregulation of SLC38A1 mRNA/protein in human OTSCC and oral cancer cell lines as compared to the corresponding controls. Further, an investigation of external datasets indicated that mechanisms other than the amplification of the SLC38A1 chromosomal locus or hypomethylation of the SLC38A1 promoter region might be important for the upregulation of SLC38A1 in OTSCC.

• Bhattarai, Bishwa Prakash; Singh, Ashutosh Kumar; Singh, Rabindra; Chaulagain, Rajib; Søland, Tine Merete & Hasséus, Bengt [Show all 7 contributors for this article] (2024). Recurrence in Oral Leukoplakia: A Systematic Review and Meta-analysis. Journal of Dental Research. ISSN 0022-0345. doi: 10.1177/00220345241266519. Full text in Research Archive
• Singh, Ashutosh; Alagarsamy, Ragavi; Chaulagain, Rajib; Singh, Abanish; Sapkota, Dipak & Thavaraj, Selvam [Show all 7 contributors for this article] (2023). Does BRAF mutation status and related clinicopathological factors affect the recurrence rate of ameloblastoma? A systematic review, meta-analysis and metaregression. Journal of Oral Pathology & Medicine. ISSN 0904-2512. doi: 10.1111/jop.13494. Full text in Research Archive
• Singh, Ashutosh Kumar; Singh, Rabindra & Sapkota, Dipak (2023). Current trends and themes of oral cancer research: A bibliometric analysis of publications from 2011 to 2022 in prominent oral pathology related journals. Oral Oncology Reports (OOR). 6, p. 1–8. doi: 10.1016/j.oor.2023.100037. Full text in Research Archive Show summary

  Objectives This study presents a comprehensive bibliometric analysis of oral cancer research published in three leading journals (Oral Oncology, Journal of Oral Pathology and Medicine, and Oral surgery Oral medicine Oral pathology and Oral Radiology) between 2011 and 2022 covering oral pathology. Material and methods The study identifies publications and citation metrics and evaluates the performance of journals, authors, institutions, and countries as well as identifies the prevalent topics and trends in oral cancer research through an analysis of article titles using the R-studio Bibliometrix package. Results The USA, India, and China produced the highest number of publications. The annual scientific production of all of the journals in the current study has increased over time, with noticeable peaks in 2013, 2017 and 2020. The study also identifies the most commonly researched topics, such as “potentially malignant,” “lymph node,” “HPV,” “malignant transformation,” and “epithelial dysplasia.” Additionally, a thematic analysis of sliced maps showed changing conceptual structures and themes over the years, with emerging themes like “AI” and “oral microbiome” dominating in recent years. Finally, co-citation and co-authorship analysis were conducted to evaluate the intellectual structure and social collaboration structure of the research. Conclusion Overall, this study provides valuable insights into the evolving research trends in oral cancer. Some specific clusters of research collaboration were observed among certain countries and institutions. The map of oral cancer research is currently leaning towards AI, microbiome and biomarkers.

• Toközlü, Burcu; Sapkota, Dipak; Vallenari, Evan Michael; Schreurs, Olaf Joseph Franciscus & Søland, Tine Merete (2023). Cortactin expression in a Norwegian cohort of human papilloma virus negative oral squamous cell carcinomas of the mobile tongue. European Journal of Oral Sciences. ISSN 0909-8836. doi: 10.1111/eos.12925. Full text in Research Archive
• Sharma, Sunita; Khan, Qalbi; Schreurs, Olaf Joseph Franciscus; Sapkota, Dipak & Samuelsen, Jan Tore (2023). Investigation of biological effects of HEMA in 3D-organotypic co-culture models of normal and malignant oral keratinocytes. Biomaterial Investigations in Dentistry. 10(1), p. 98–108. doi: 10.1080/26415275.2023.2234400. Full text in Research Archive Show summary

  Several in vitro studies utilizing 2-dimensional (2D) cell culture systems have linked 2-hydroxyethyl methacrylate (HEMA) with cytotoxic effects in oral mucosa and dental pulp cells. Although such studies are invaluable in dissecting the cellular and molecular effects of HEMA, there is a growing interest in the utilization of appropriate 3-dimensional (3D) models that mimic the structure of oral mucosa. Using a previously characterized 3D-organotypic co-culture model, this study aimed to investigate the cellular and molecular effects of HEMA on a 3D-co-culture model consisting of primary normal oral keratinocyte (NOK) grown directly on top of collagen I gel containing primary oral fibroblasts (NOF). The second aim was to examine the suitability of a 3D-co-culture system consisting of oral squamous cell carcinoma (OSCC) cells as a model system to investigate the biological effects of HEMA. We demonstrated that HEMA treatment led to reduced viability of NOK, NOF and OSCC-cell lines in 2D-culture. The keratinocytes in 3D-co-cultures of NOK and OSCC-cells reacted similarly with respect to cell proliferation and activation of autophagy flux, to HEMA treatment. Nevertheless, NOK was found to be more susceptible to apoptosis following HEMA treatment than OSCC in 3D-co-cultures. These results indicate that 3D-organotypic co-cultures of NOK might represent an appropriate model system for the investigation of the biological effects of HEMA and other dental biomaterials. Given the challenges in obtaining primary cultures of NOK and issues associated with their rapid differentiation in culture, the possible use of OSCC cells as an alternative to NOK for 3D models represents an area for future research.

• Basnet, Suyog; Vallenari, Evan Michael; Maharjan, Urusha; Sharma, Sunita; Schreurs, Olaf Joseph Franciscus & Sapkota, Dipak (2023). An Update on S100A16 in Human Cancer. Biomolecules. 13(7). doi: 10.3390/biom13071070. Full text in Research Archive Show summary

  S100A16 is a member of the S100 protein family. S100A16 is expressed in a variety of human tissues, although at varying levels. S100A16 expression is especially high in tissues rich in epithelial cells. mRNA and protein levels of S100A16 have been reported to be differentially expressed in the majority of human cancers. Functionally, S100A16 has been linked to several aspects of tumorigenesis, for example, cell proliferation, differentiation, migration, invasion, and epithelial-mesenchymal transition (EMT). Accordingly, S100A16 has been suggested to have both tumour-promoting and suppressive roles in human cancers. S100A16-mediated cellular functions are suggested to be mediated by the regulation of various signaling pathways/proteins including EMT-related proteins E-cadherin and Vimentin, PI3K-AKT, p53, MMP1-1, MMP-2, MMP-9, JNK/p38, etc. In addition to the functional roles, expression of S100A16 has been suggested to have prognostic potential in various cancer types. The aims of this review are to summarise the expression profile, identify common molecular partners and functional roles, and explore the prognostic potential of S100A16 in human cancers.

• GANESH, DIVYA; DAFAR, AMAL; NIKLASSON, JULIA; SANDBERG, INGRID; Braz-Silva, Paulo & Sapkota, Dipak [Show all 9 contributors for this article] (2023). EZH2 Expression Correlates With T-Cell Infiltration in Oral Leukoplakia and Predicts Cancer Transformation. Anticancer Research. ISSN 0250-7005. 43(4), p. 1533–1542. doi: 10.21873/anticanres.16302. Full text in Research Archive Show summary

  Background/Aim: The EZH2 complex is involved in cellular proliferation and modulates the immune response in cancer. Less is known about the importance of EZH2 in precancerous lesions such as oral leukoplakia (OL). The aim of the study was to explore the association between EZH2 expression, immune activation, and cancer transformation in OL. Patients and Methods: Analyses were retrospectively performed on nine OL cases that had undergone transformation to oral squamous cell carcinoma (OSCC; OL-ca) and nine that had not undergone transformation (OL-non). EZH2-expressing cells, CD3+ and CD8+ T cells, and CD1a+ Langerhans cells were visualized with immunohistofluorescence and counted. Results: A moderate positive correlation between CD3− and EZH2-expressing and CD8− and EZH2-expressing cells in the epithelium was found (r=0.57, p=0.01; r=0.59, p=0.01). The number of EZH2-expressing cells in the epithelium of OL-ca was significantly higher compared to OL-non (p=0.0002). Cancer-free survival rates differed significantly between patients with EZH2high compared to EZH2low expression (p=0.001). EZH2high expression in OL epithelium was associated with a 13-fold higher risk for developing OSCC (HR=12.8). Conclusion: EZH2 expression in oral epithelium predicts OSCC transformation of OL and correlates with the level of T-cell infiltration.

• Rajthala, Saroj; Parajuli, Himalaya; Dongre, Harsh Nitin; Ljøkjel, Borghild; Hoven, Kristin Marie & Kvalheim, Arild [Show all 11 contributors for this article] (2022). MicroRNA-138 abates fibroblast motility with effect on invasion of adjacent cancer cells. Frontiers in Oncology. 12. doi: 10.3389/fonc.2022.833582. Full text in Research Archive Show summary

  Background: Recent studies have shown aberrant expression of micro-RNAs in cancer-associated fibroblasts (CAFs). This study aimed to investigate miR-138 dysregulation in CAFs in oral squamous cell carcinoma (OSCC) and its effects on their phenotype and invasion of adjacent OSCC cells. Methods: Expression of miR-138 was first investigated in OSCC lesions (n = 53) and OSCC-derived CAFs (n = 15). MiR-138 mimics and inhibitors were used to functionally investigate the role of miR-138 on CAF phenotype and the resulting change in their ability to support OSCC invasion. Results: Expression of miR-138 showed marked heterogeneity in both OSCC tissues and cultured fibroblasts. Ectopic miR-138 expression reduced fibroblasts’ motility and collagen contraction ability and suppressed invasion of suprajacent OSCC cells, while its inhibition resulted in the opposite outcome. Transcript and protein examination after modulation of miR-138 expression showed changes in CAF phenotype-specific molecules, focal adhesion kinase axis, and TGFβ1 signaling pathway. Conclusions: Despite its heterogeneous expression, miR-138 in OSCC-derived CAFs exhibits a tumor-suppressive function.

• Søland, Tine Merete; Solhaug, Maren Bråten; Bjerkli, Inger-Heidi; Schreurs, Olaf Joseph Franciscus & Sapkota, Dipak (2022). The prognostic role of combining Krüppel-like factor 4 score and grade of inflammation in a Norwegian cohort of oral tongue squamous cell carcinomas. European Journal of Oral Sciences. ISSN 0909-8836. p. 1–11. doi: 10.1111/eos.12866. Full text in Research Archive Show summary

  Krüppel-like factor 4 (KLF4) is a zinc-finger transcription factor involved in inflammation, cancer development, and progression. However, the relationship between KLF4, inflammation, and prognosis in oral cancer is not fully understood. KLF4 expression levels were examined in a multicenter cohort of 128 oral squamous cell carcinoma (OSCC) specimens from the tongue (OTSCC) using immunohistochemistry. In two external KLF4 mRNA datasets (The Cancer Genome Atlas/The Genotype-Tissue Expression Portal), lower KLF4 mRNA expression was found in OSCC and head and neck squamous cell carcinomas (HNSCC) than in control oral epithelium. These data indicate that down-regulation of KLF4 mRNA is linked to OSCC/HNSCC progression. Using Cox-multivariate analysis, a significantly favorable 5-year disease-specific survival rate was observed for a subgroup of patients with a combination of high levels of KLF4 expression and inflammation. OSCC cell lines exposed to IFN-γ showed a significant upregulation of nuclear KLF4 expression, indicating a link between inflammation and KLF4 expression in OSCC. Overall, the current data suggest a functional link between KLF4 and inflammation. The combination of high KLF4 nuclear expression and marked/moderate stromal inflammation might be useful as a favorable prognostic marker for a subgroup of OTSCC patients.

• Sofizadeh, Narmin; Bjerkehagen, Bodil; Solheim, Tore Torsteinson; Sapkota, Dipak & Søland, Tine Merete (2022). The spectrum and frequency of histopathological diagnosis of oral diseases in Oslo: Implications to oral pathology syllabus. European journal of dental education. ISSN 1396-5883. 00, p. 1–7. doi: 10.1111/eje.12808. Full text in Research Archive Show summary

  Introduction To assure knowledge and skills in diagnostic work of oral diseases a continuously updated curriculum is essential. The first aim of the present study was to evaluate the spectrum and frequency of oral histopathological diagnoses signed out by oral pathologists at the Department of Pathology, Oslo University Hospital (OUS), Norway during a two-year period. The second aim was to compare the spectrum of histopathological diagnoses with the content of the current syllabus in oral pathology at the Faculty of Dentistry, University of Oslo (UiO). Materials and Methods In this retrospective cross-sectional study, all histological diagnosis signed out during 2015 and 2016 were included. All histopathological reports were analysed with regard to clinical information and histopathological diagnosis. The spectrum of histopathological diagnoses was compared to the diagnoses presented in lectures and courses for dental and dental hygienist students at UiO. Results Three thousand four hundred and two histopathological reports (47% males and 53% females) were included. The diagnoses were categorised into eight disease groups and the three most frequent disease groups were cysts, benign tumours/reactive lesions, and white, red, ulcerative and vesiculobullous lesions. The lateral periodontal cyst was more frequent than expected. Conclusions We conclude that a minor revision of the syllabus is needed, although the most frequent oral conditions presented in this study are well covered in the oral pathology teaching in Oslo. A more clinical related teaching approach should be considered by categorising oral diseases according to, for example location and age groups.

• Sapkota, Dipak; Vallenari, Evan Michael; Tamatam, Dhanalakshmi; Schreurs, Olaf Joseph Franciscus; Pandey, Sushma & Søland, Tine Merete [Show all 9 contributors for this article] (2022). Investigation of Cross-Reactivity of Anti-Ephrin-B2 Antibody to Other Ephrin-B Members in an Immunohistochemical Study in a Cohort of Oral Squamous Cell Carcinoma. Oral. ISSN 2673-6373. 2. doi: 10.3390/oral2020015. Full text in Research Archive Show summary

  Ephrin-B1,-B2 and -B3 proteins share a high degree of sequence similarity. Investigation of these proteins as putative prognostic markers in human cancers including oral squamous cell carcinoma (OSCC) has been limited by challenges in generating specific antibodies against them. The current study examined the reactivity of a polyclonal anti-human ephrin-B2 antibody (HPA008999) against ephrin-B proteins and investigated the prognostic significance of immunoreactivity of the same antibody at different intra-tumor sites in OSCC specimens. By amino acid sequence comparison, immunocytochemistry and Western blot analysis on cell lysates and precipitates from HEK-293T cells transfected with EFNB1, EFNB2, or EFNB3 expression constructs, we demonstrated that HPA008999 reacted to all ephrin-B proteins. Using immunohistochemistry (IHC) with the HPA008999 antibody in a cohort (n = 131) of OSCC, we showed high immunoreactivity at the tumor center, but not at the tumor invading front, was significantly associated with worse 5-year overall survival probabilities. In conclusion, the HPA008999 antibody reacted to all ephrin-B proteins and the immunoreactivity at the tumor center might be useful as a prognostic marker in OSCC. These data underscore the need for the investigation of antibodies for cross-reactivity to similar protein members for obtaining reliable and meaningful results in IHC based biomarker studies.

• Amornvit, P.; Rokaya, D.; Sapkota, Dipak & Sanohkan, S. (2022). Oral and Craniofacial Anomalies of Fraser Syndrome:Prosthetic Management. Kathmandu University Medical Journal. ISSN 1812-2027. 20(79), p. 391–395. Full text in Research Archive
• Schwab, Gabriela; Palmieri, Michelle; Zerbinati, Rodrigo M.; Sarmento, Dmitry J. S.; Reis, Thais & Ortega, Karem L. [Show all 17 contributors for this article] (2022). Lack of direct association between oral mucosal lesions and SARS-CoV- 2 in a cohort of patients hospitalised with COVID-19. Journal of Oral Microbiology. 14(1). doi: 10.1080/20002297.2022.2047491. Full text in Research Archive Show summary

  Background COVID-19 is a disease affecting various human organs and systems, in which the virus seeks to interact with angiotensin-converting enzyme 2 receptors. These receptors are present in the oral cavity, but the direct relationship between such an interaction and possible oral manifestations of COVID-19 is still unclear. Aim The present study evaluated oral manifestations in a cohort of COVID-19 patients during the period of hospitalisation. Methods In total, 154 patients presenting moderate-to-severe forms of COVID-19 had their oral mucosa examined twice a week until the final outcome, either discharge or death. The oral alterations observed in the patients were grouped into Group 1 (pre-existing conditions and opportunistic oral lesions) and Group 2 (oral mucosal changes related to hospitalization). Results Oral lesions found in the patients of Group 1 are not suggestive of SARS-CoV-2 infection as they are mainly caused by opportunistic infections. On the other hand, oral alterations found in the patients of Group 2 were statistically (P < 0.001) related to intubation and longer period of hospitalisation. Conclusion It is unlikely that ulcerative lesions in the oral cavity are a direct manifestation of SARS-CoV-2 or a marker of COVID-19 progression.

• Sundberg, Jonas; Pandey, Sushma; Giglio, Daniel; Holmberg, Erik; Kjeller, Göran & Kovács, Anikó [Show all 11 contributors for this article] (2021). Expression of p53, p63, podoplanin and Ki-67 in recurring versus non-recurring oral leukoplakia. Scientific Reports. p. 1–12. doi: 10.1038/s41598-021-99326-5. Full text in Research Archive Show summary

  Abstract Oral leukoplakia (OL), a potentially malignant disorder, recurs in 40% of cases after surgical removal. Recurrence is a risk factor for malignant transformation. We aimed to examine the prognostic significance of four biomarkers related to cell proliferation: p53, p63, podoplanin (PDPN) and Ki-67 in predicting recurrence. Formalin-fixed-paraffin-embedded specimens from excised OL (n = 73, 33 recurrent; 40 non-recurrent) were collected in a prospective study. Immunohistochemistry was used to visualise expression of p53, p63, PDPN and Ki-67. Image analysis software was used for quantification of p53-, p63- and Ki-67-expressing cells, while PDPN was analysed visually. The expression of all four proteins were higher in recurrent compared with non-recurrent OL, only expression of p53 was statistically significant. In uni- and multivariable Cox regression analyses of individual markers, expression of p63 was significantly associated with higher recurrence risk ( p  = 0.047). OL with a combined high expression of both p53 and p63 had a significantly higher risk to recur [Log Rank, p  = 0.036; multivariate Cox, HR: 2.48 (1.13–5.44; p  = 0.024)]. Combination of p53 and p63 expression may be used as a prognostic biomarker for recurrence of OL.

• Rajthala, Saroj; Min, Anjie; Parajuli, Himalaya; Debnath, Kala Chand; Ljøkjel, Borghild & Hoven, Kristin Marie [Show all 13 contributors for this article] (2021). Profiling and functional analysis of microrna deregulation in cancer-associated fibroblasts in oral squamous cell carcinoma depicts an anti-invasive role of microrna-204 via regulation of their motility. International Journal of Molecular Sciences. ISSN 1661-6596. 22(21), p. 1–18. doi: 10.3390/ijms222111960. Full text in Research Archive Show summary

  Background: Knowledge on the role of miR changes in tumor stroma for cancer progression is limited. This study aimed to investigate the role of miR dysregulation in cancer-associated fibroblasts (CAFs) in oral squamous cell carcinoma (OSCC). Methodology: CAF and normal oral fibroblasts (NOFs) were isolated from biopsies of OSCC patients and healthy individuals after informed consent and grown in 3D collagen gels. Total RNA was extracted. Global miR expression was profiled using Illumina version 2 panels. The functional impact of altered miR-204 expression in fibroblasts on their phenotype and molecular profile was investigated using mimics and inhibitors of miR-204. Further, the impact of miR-204 expression in fibroblasts on invasion of adjacent OSCC cells was assessed in 3D-organotypic co-cultures. Results: Unsupervised hierarchical clustering for global miR expression resulted in separate clusters for CAF and NOF. SAM analysis identified differential expression of twelve miRs between CAF and NOF. Modulation of miR-204 expression did not affect fibroblast cell proliferation, but resulted in changes in the motility phenotype, expression of various motility-related molecules, and invasion of the adjacent OSCC cells. 3′ UTR miR target reporter assay showed ITGA11 to be a direct target of miR-204. Conclusions: This study identifies differentially expressed miRs in stromal fibroblasts of OSCC lesions compared with normal oral mucosa and it reveals that one of the significantly downregulated miRs in CAF, miR-204, has a tumor-suppressive function through inhibition of fibroblast migration by modulating the expression of several different molecules in addition to directly targeting ITGA11.

• Rajthala, Saroj; Dongre, Harsh; Parajuli, Himalaya; Min, Anjie; Nginamau, Elisabeth Sivy & Kvalheim, Arild [Show all 10 contributors for this article] (2021). Combined in situ hybridization and immunohistochemistry on archival tissues reveals stromal microRNA-204 as prognostic biomarker for oral squamous cell carcinoma. Cancers. 13(6). doi: 10.3390/cancers13061307. Full text in Research Archive Show summary

  Micro-RNAs (miRs) are emerging as important players in carcinogenesis. Their stromal expression has been less investigated in part due to lack of methods to accurately differentiate between tumor compartments. This study aimed to establish a robust method for dual visualization of miR and protein (pan-cytokeratin) by combining chromogen-based in situ hybridization (ISH) and immunohistochemistry (IHC), and to apply it to investigate stromal expression of miR204 as a putative prognostic biomarker in oral squamous cell carcinoma (OSCC). Four different combinations of methods were tested and ImageJ and Aperio ImageScope were used to quantify miR expression. All four dual ISH-IHC methods tested were comparable to single ISH in terms of positive pixel area percentage or integrated optical density of miRs staining. Based on technical simplicity, one of the methods was chosen for further investigation of miR204 on a cohort of human papilloma virus (HPV)-negative primary OSCC (n = 169). MiR204 stromal expression at tumor front predicted recurrence-free survival (p = 0.032) and overall survival (p = 0.036). Multivariate Cox regression further confirmed it as an independent prognostic biomarker in OSCC. This study provides a methodological platform for integrative biomarker studies based on simultaneous detection and quantification of miRs and/or protein and reveals stromal miR204 as a prognostic biomarker in OSCC.

• Pandey, Sushma; Søland, Tine Merete; Bjerkli, Inger-Heidi; Sand, Lars Peter; Petersen, Fernanda Cristina & Costea, Daniela Elena [Show all 8 contributors for this article] (2021). Combined loss of expression of involucrin and cytokeratin 13 is associated with poor prognosis in squamous cell carcinoma of mobile tongue. Head and Neck. ISSN 1043-3074. 43(11), p. 3374–3385. doi: 10.1002/hed.26826. Full text in Research Archive Show summary

  Background This study aimed to evaluate the prognostic significance of expression levels of involucrin (IVL), cytokeratin (CK)-10 and -13 at different intratumor sites (tumor center and invading area) of oral tongue squamous cell carcinoma (OTSCC). Methods IVL, CK13 and CK10 expression levels were examined in a multicenter cohort of 146 OTSCCs using immunohistochemistry. External mRNA datasets were used for expression analysis and/or to validate survival associations. Results External transcriptomic datasets showed downregulation of IVL and KRT13 in oral malignancies including OTSCC as compared to normal controls. The combined loss of IVL and CK13 expression at the invading core but not at the center core was significantly associated with poor differentiation and reduced 5-year overall survival. Multivariate Cox analysis confirmed the loss of CK13 and IVL expression to be an independent prognostic factor. Transcriptomic dataset corroborated immunohistochemistry results. Conclusions Combined expression levlels of IVL and CK13 might be useful as prognostic biomarkers in OTSCC.

• Dongre, Harsh N.; Haave, Hilde; Fromreide, Siren; Erland, Fredrik Atteraas; Moe, Svein Erik Emblem & Manueldas, Sophia [Show all 11 contributors for this article] (2021). Targeted Next-Generation Sequencing of Cancer-Related Genes in a Norwegian Patient Cohort With Head and Neck Squamous Cell Carcinoma Reveals Novel Actionable Mutations and Correlations With Pathological Parameters. Frontiers in Oncology. 11. doi: 10.3389/fonc.2021.734134. Full text in Research Archive Show summary

  Background: Targeted next-generation sequencing (NGS) is increasingly applied in clinical oncology to advance personalized treatment. Despite success in many other tumour types, use of targeted NGS panels for assisting diagnosis and treatment of head and neck squamous cell carcinomas (HNSCC) is still limited. Aim: The focus of this study was to establish a robust NGS panel targeting most frequent cancer mutations in long-term preserved formalin-fixed paraffin-embedded (FFPE) tissue samples of HNSCC from routine diagnostics. Materials and Methods: Tumour DNA obtained from archival FFPE tissue blocks of HNSCC patients treated at Haukeland University Hospital between 2003-2016 (n=111) was subjected to mutational analysis using a custom made AmpliSeq Library PLUS panel targeting 31 genes (Illumina). Associations between mutational burden and clinical and pathological parameters were investigated. Mutation and corresponding clinicopathological data from HNSCC were extracted for selected genes from the Cancer Genome Atlas (TCGA) and used for Chi-square and Kaplan-Meier analysis. Results: The threshold for sufficient number of reads was attained in 104 (93.7%) cases. Although the specific number of PCR amplified reads detected decreased, the number of NGS-annotated mutations did not significantly change with increased tissue preservation time. In HPV-negative carcinomas, mutations were detected mainly in TP53 (73.3%), FAT1 (26.7%) and FLG (16.7%) whereas in HPV-positive, the common mutations were in FLG (24.3%) FAT1 (17%) and FGFR3 (14.6%) genes. Other less common pathogenic mutations, including well reported SNPs were reproducibly identified. Presence of at least one cancer-specific mutations was found to be positively associated with an extensive desmoplastic stroma (p=0.019), and an aggressive type of invasive front (p=0.035), and negatively associated with the degree of differentiation (p=0.041). Analysis of TCGA data corroborated the association between cancer-specific mutations and tumour differentiation and survival analysis showed that tumours with at least one mutation had shorter disease-free and overall survival (p=0.005). Conclusions: A custom made targeted NGS panel could reliably detect several specific mutations in archival samples of HNSCCs preserved up to 17 years. Using this method novel associations between mutational burden and clinical and pathological parameters were detected and actionable mutations in HPV-positive HNSCC were discovered.

• Golburean, Olga; Hagen, Maria Helene; Uncuta, Diana; Tighineanu, Marcela; Manrikyan, Gayane & Vardanian, Izabella [Show all 17 contributors for this article] (2021). Knowledge, opinions, and practices related to oral cancer prevention and oral mucosal examination among dentists in Moldova, Belarus and Armenia: a multi-country cross-sectional study. BMC Oral Health. 21. doi: 10.1186/s12903-021-02011-2. Full text in Research Archive Show summary

  Introduction Moldova, Belarus, and Armenia are post-Soviet countries with a high rate of heavy smokers and a relatively high age-standardized incidence of oral cancer. However, to our knowledge, there is lack of available information on dentists’ knowledge on prevention of oral cancer in the countries in question. Accordingly, this study aimed to assess the knowledge, opinions, and practices related to oral cancer prevention and oral mucosal examination among dentists in Moldova, Belarus, and Armenia. Methods This was a multi-country, cross-sectional study based on a self-administered questionnaire. A structured questionnaire was distributed to 3534 dentists (797 in Chisinau, Moldova, 1349 in Minsk, Belarus, and 1388 in Yerevan, Armenia). Dentists' knowledge about risk factors for oral cancer development and its clinical picture, current practices and opinions with regard to oral mucosal screening and oral cancer prevention, and their consistency to perform oral mucosal examination were assessed. A knowledge score ranging from 0 to 14 points was generated based on each dentist’s answer to the questionnaire. Results A total of 1316 dentists responded, achieving an overall response rate of 37.2% (34.5% in Moldova; 52.3% in Belarus; 24.2% in Armenia). Most dentists in the three countries correctly identified tobacco (83.8–98.2%) and prior oral cancer lesions (84.0–96.3%) as risk factors for oral cancer. Most dentists correctly identified leukoplakia as a lesion with malignant potential (68.7% in Moldova; 88.5% in Belarus; 69.9% in Armenia), while erythroplakia was identified by much fewer in all three countries. Less than 52% of dentists identified the tongue, rim of tongue, and floor of mouth as the most common sites for oral cancer. The mean knowledge score for all countries combined was 7.5 ± 2.7. The most commonly reported barriers to perform oral mucosal examination were lack of training, knowledge, and experience. Conclusions This study highlights the need for improved oral cancer-related education and training on oral mucosal examination for dentists in Moldova, Belarus, and Armenia. Such skills are essential to enhance oral cancer prevention and to improve the prognostic outcome by early detection.

• Skallevold, Hans Erling; Vallenari, Evan Michael & Sapkota, Dipak (2021). Inflammatory Biomarkers in Saliva. Mediators of Inflammation. ISSN 0962-9351. doi: 10.1155/2021/6019791. Full text in Research Archive
• Sapkota, Dipak; Sharma, Sunita; Søland, Tine Merete; Braz-Silva, Paulo & Teh, Muy-Teck (2021). Expression profile of SARS-CoV-2 cellular entry proteins in normal oral mucosa and oral squamous cell carcinoma. Clinical and Experimental Dental Research. p. 1–6. doi: 10.1002/cre2.510. Full text in Research Archive Show summary

  Objective Besides angiotensin converting enzyme 2 (ACE2), an active involvement of proteases (FURIN and/or TMPRSS2) is important for cellular entry of SARS-CoV-2. Therefore, a simultaneous expression profiling of entry proteins in a tissue might provide a better risk assessment of SARS-CoV-2 infection as compared to individual proteins. In an attempt to understand the relative susceptibility of oral squamous cell carcinoma (OSCC) lesions as compared to the normal oral mucosa (NOM) for SARS-CoV-2 attachment/entry, this study examined the mRNA and protein expression profiles of ACE2, FURIN, and TMPRSS2 in the corresponding tissues using public transcriptomic and proteomics datasets. Methods and methods Public transcriptomic and proteomics datasets (the Cancer Genome Atlas (TCGA)/the Genotype-Tissue Expression (GTEx), the Human Protein Atlas (HPA), and two independent microarray datasets) were used to examine the expression profiles of ACE2, TMPRSS2 and FURIN in NOM and OSCC. Results ACE2, TMPRSS2, and FURIN mRNAs were detected in NOM, however, at lower levels as compared to other body tissues. Except for moderate up-regulation of FURIN, expression levels of ACE2 and TMPRSS2 mRNA were unchanged/down-regulated in OSCC as compared to the NOM. Conclusions These results indicate that NOM may serve as a possible site for SARS-CoV-2 attachment, however, to a lesser extent as compared to organs with higher expression levels of the SARS-CoV-2 entry proteins. However, the evidence is lacking to suggest that expression status of entry proteins predisposes OSCC lesions to additional risk for SARS-CoV-2 attachment/entry as compared to NOM.

• Sapkota, Dipak; Søland, Tine Merete; Galtung, Hilde; Sand, Lars Peter; Giannecchini, Simone & To, Kelvin KW [Show all 10 contributors for this article] (2020). COVID-19 salivary signature: diagnostic and research opportunities. Journal of Clinical Pathology. ISSN 0021-9746. 0, p. 1–6. doi: 10.1136/jclinpath-2020-206834. Full text in Research Archive
• Pandey, Sushma; Osman, Tarig Al-Hadi; Sharma, Sunita; Vallenari, Evan Michael; Shahdafar, Aboulghassem & Pun, Chin B. [Show all 12 contributors for this article] (2020). Loss of S100A14 expression at the tumor-invading front correlates with poor differentiation and worse prognosis in oral squamous cell carcinoma. Head and Neck. ISSN 1043-3074. 42(8), p. 1–11. doi: 10.1002/hed.26140. Full text in Research Archive Show summary

  Background We previously showed a tumor‐suppressive function of S100A14 in oral squamous cell carcinoma (OSCC). This study aimed to examine the prognostic significance and differentiation‐related function of S100A14 in OSCC. Methods S100A14 expression was examined in 170 OSCCs from Norwegian and Nepalese populations using immunohistochemistry. Pro‐differentiation function was investigated by overexpressing and silencing S100A14 expression in OSCC‐derived cells. External transcriptomic datasets were used to validate association between S100A14 and differentiation markers in OSCC. Result Loss of S100A14 expression at the invading tumor fronts significantly correlated with poor differentiation and reduced 10‐years survival of OSCC‐patients. Multivariate Cox analysis identified S100A14 to be an independent prognostic factor. Modulation of S100A14 expression in OSCC‐derived cells positively correlated with the expression of differentiation markers. Analysis of external datasets supported the pro‐differentiation function of S100A14. Conclusion These results indicate that S100A14 is a pro‐differentiation protein and its expression might be useful as a prognostic marker in OSCC.

• Yazdani, Mazyar; Shahdafar, Aboulghassem; Reppe, Sjur; Sapkota, Dipak; Vallenari, Evan Michael & Lako, Majlinda [Show all 9 contributors for this article] (2020). Response of human oral mucosal epithelial cells to different storage temperatures: A structural and transcriptional study. PLOS ONE. 15:e0243914(12), p. 1–17. doi: 10.1371/journal.pone.0243914. Full text in Research Archive Show summary

  Purpose Seeking to improve the access to regenerative medicine, this study investigated the structural and transcriptional effects of storage temperature on human oral mucosal epithelial cells (OMECs). Methods Cells were stored at four different temperatures (4°C, 12°C, 24°C and 37°C) for two weeks. Then, the morphology, cell viability and differential gene expression were examined using light and scanning electron microscopy, trypan blue exclusion test and TaqMan gene expression array cards, respectively. Results Cells stored at 4°C had the most similar morphology to non-stored controls with the highest viability rate (58%), whereas the 37°C group was most dissimilar with no living cells. The genes involved in stress-induced growth arrest (GADD45B) and cell proliferation inhibition (TGFB2) were upregulated at 12°C and 24°C. Upregulation was also observed in multifunctional genes responsible for morphology, growth, adhesion and motility such as EFEMP1 (12°C) and EPHA4 (4°C–24°C). Among genes used as differentiation markers, PPARA and TP53 (along with its associated gene CDKN1A) were downregulated in all temperature conditions, whereas KRT1 and KRT10 were either unchanged (4°C) or downregulated (24°C and 12°C; and 24°C, respectively), except for upregulation at 12°C for KRT1. Conclusions Cells stored at 12°C and 24°C were stressed, although the expression levels of some adhesion-, growth- and apoptosis-related genes were favourable. Collectively, this study suggests that 4°C is the optimal storage temperature for maintenance of structure, viability and function of OMECs after two weeks.

• Khan, Ayyad Ahmad Zartasht; Jackson, Catherine; Utheim, Tor Paaske; Reppe, Sjur; Sapkota, Dipak & Olstad, Ole Kristoffer [Show all 8 contributors for this article] (2020). Sericin-induced melanogenesis in cultured retinal pigment epithelial cells is associated with elevated levels of hydrogen peroxide and inflammatory proteins. Molecules. ISSN 1431-5157. 25(19), p. 1–20. doi: 10.3390/molecules25194395. Full text in Research Archive Show summary

  We previously demonstrated that the silk protein sericin promotes pigmentation of retinal pigment epithelium (RPE) by activating the NF-κB pathway. Among numerous agents, NF-κB can be activated by hydrogen peroxide. In the present study, we explored possible associations between reactive oxygen species and sericin-induced melanogenesis in RPE. The proteome of human fetal RPE cultured for seven days with or without 1% sericin was analyzed using ingenuity pathway analysis (IPA). The proteomic data was verified by immunofluorescence and immunoblotting. Light microscopy and scanning electron microscopy were used to assess morphology. Dihydroethidium (DHE) and dihydrorhodamine (DHR) assays were used to measure superoxide and hydrogen peroxide species. Expression levels of proteins related to inflammation, differentiation, cell survival and cell adhesion were higher in cells cultured in Dulbecco’s Modified Eagle Medium (DMEM) with 1% sericin, whereas cells cultured in DMEM alone showed higher expression levels of proteins associated with Bruch’s membrane and cytoskeleton. Despite upregulation of inflammatory proteins, sericin co-cultured RPE yielded significantly higher cell viability compared to cells cultured without sericin. Addition of sericin to culture media significantly increased hydrogen peroxide-levels without significantly affecting superoxide-levels. We suggest that sericin-induced melanogenesis in cultured RPE is associated with elevated levels of superoxide dismutase, hydrogen peroxide and inflammatory proteins.

• Braz-Silva, Paulo; Ana, Mamana; Romano, Camila; Felix, Alvina; Paula, Anderson & Fereira, Noeli [Show all 18 contributors for this article] (2020). Performance of at-home self-collected saliva and nasal-oropharyngeal swabs in the surveillance of COVID-19. Journal of Oral Microbiology. 13(1). doi: 10.1080/20002297.2020.1858002. Full text in Research Archive Show summary

  Background: SARS-CoV-2 quickly spreads in the worldwide population, imposing social restrictions to control the infection, being the massive testing another essential strategy to break the chain of transmission. Aim: To compare the performance of at-home self-collected samples – saliva and combined nasal-oropharyngeal swabs (NOP) – for SARS-CoV-2 detection in a telemedicine platform for COVID-19 surveillance. Material and methods: We analyzed 201 patients who met the criteria of suspected COVID-19. NOP sampling was combined (nostrils and oropharynx) and saliva collected using a cotton pad device. Detection of SARS-COV-2 was performed by using the Altona RealStar® SARS-CoV-2 RT-PCR Kit 1.0. Results: There was an overall significant agreement (κ coefficient value of 0.58) between saliva and NOP. Considering results in either sample, 70 patients positive for SARS-CoV-2 were identified, with 52/70 being positive in NOP and 55/70 in saliva. This corresponds to sensitivities of 74.2% (95% CI; 63.7% to 83.1%) for NOP and 78.6% (95% CI; 67.6% to 86.6%) for saliva. Conclusion: Our data show the feasibility of using at-home self-collected samples (especially saliva), as an adequate alternative for SARS-CoV-2 detection. This new approach of testing can be useful to develop strategies for COVID-19 surveillance and for guiding public health decisions.

• Khan, Ayyad Ahmad Zartasht; Utheim, Tor Paaske; Moe, Morten Carsten; Aass, Hans Christian Dalsbotten; Sapkota, Dipak & Vallenari, Evan Michael [Show all 7 contributors for this article] (2020). The silk protein sericin promotes viability of ARPE-19 and induced pluripotent stem cell-derived retinal pigment epithelial cells in vitro. Current Eye Research. ISSN 0271-3683. 46(4), p. 504–514. doi: 10.1080/02713683.2020.1809001. Full text in Research Archive Show summary

  Purpose Maintaining mature and viable retinal pigment epithelial cells (RPE) in vitro has proven challenging. Investigating compounds that can promote RPE-viability and maturation is motivated by RPE transplantation research, the quest to understand RPE physiology, and a desire to modulate RPE in pathological states. We have previously reported that the silk protein sericin promotes viability, maturation, and pigmentation of human fetal RPE. In the present study, our aim was to uncover whether these effects can be seen in adult retinal pigment epithelial cell line-19 (ARPE-19) and induced pluripotent stem cell-derived RPE (iPSC-RPE). Methods ARPE-19 and iPSC-RPE were cultured with or without 10 mg/mL sericin. After 7 days, viability was assessed with calcein-acetoxymethyl ester (CAM) and ethidium homodimer-1 (EH-1) assays, flow cytometry, and morphometric analysis. Expression levels of RPE65, tyrosinase, and Pmel17 were quantified to compare maturation between the sericin-treated and control cultures. Light microscopy and staining of the tight junction protein zonula occludens protein 1 (ZO-1) were employed to study sericin’s effects on RPE morphology. We also measured culture medium pH, glucose, lactate, and extracellular ion content. Results Sericin-supplemented RPE cultures demonstrated significantly better viability compared to control cultures. Sericin appeared to improve ARPE-19 maturation and morphology in vitro. No effects were seen on RPE pigmentation with the concentration of sericin and duration of cell culture herein reported. Conclusions This is the first study to demonstrate that supplementing the culture media with sericin promotes the viability of iPSC-RPE and ARPE-19. Sericin’s viability-promoting effects may have important implications for retinal therapeutics and regenerative medicine research.

• Pandey, Sushma; Follin-Arbelet, Benoit; Pun, Chin Bahadur; Gautam, Dej K.; Johannessen, Anne Christine & Petersen, Fernanda Cristina [Show all 8 contributors for this article] (2020). Helicobacter pylori was not detected in oral squamous cell carcinomas from cohorts of Norwegian and Nepalese patients. Scientific Reports. 10. doi: 10.1038/s41598-020-65694-7. Full text in Research Archive Show summary

  Helicobacter pylori (HP) infection is an established causative agent for gastric cancer. Although the oral cavity is a part of the gastrointestinal system, the presence and possible causative role of HP in oral squamous cell carcinoma (OSCC) is a subject of controversy. Therefore, the current study aimed to investigate HP infection in two cohorts of OSCC patients with different demographic characteristics, lifestyles and habitual risk factors. A total of 242 formalin-fixed paraffin-embedded OSCC specimens from two different patient cohorts (Norway, n = 171 and Nepal, n = 71) were used to examine HP using immunohistochemistry (IHC) and quantitative polymerase chain reaction (qPCR). Two different HP specific genes (23S rRNA and ureA) were used for TaqMan-based qPCR, and for subsequent verification using HP specific RIDAGENE HP kit and SYBR Green based qPCR. All of the OSCC specimens from both cohorts were found to be negative for HP infection with IHC and qPCR, although the positive control specimens tested positive. Our findings suggest that HP is absent in the examined OSCC cohorts, irrespective of race, lifestyle and habitual risk factors. This indicates that, in contrast to gastric cancer, HP is an unlikely contributing factor for OSCC pathogenesis.

• Gajurel, Rashmi; Gautam, Dej Kumar; Pun, Chin Bahadur; Dhakal, Hari Prasad; Petrovski, Beata & Costea, Daniela Elena [Show all 7 contributors for this article] (2020). Trends and clinicopathological characteristics of oral squamous cell carcinomas reported at a tertiary cancer hospital in Nepal during 1999 to 2009. Clinical and Experimental Dental Research. 6(3), p. 356–362. doi: 10.1002/cre2.278. Full text in Research Archive Show summary

  Objective Reliable data describing the trends and clinicopathological characteristics of oral squamous cell carcinoma (OSCC) in the Nepalese population are very limited. The current study aimed to examine the demographics, trend, and clinicopathological characteristics of OSCC reported to the main referral/tertiary cancer hospital, the B.P. Koirala Memorial Cancer Hospital (BPKMCH) in Nepal for a period of 11 years (1999–2009). Material and methods This is a cross‐sectional study. Data were retrieved retrospectively from hospital register maintained in the Department of Ear, Nose, Throat at BPKMCH, categorized into demographic and clinicopathological variables and SPSS (V25) was used for the analysis. Results In a period of 11 years, 3,452 cases of head and neck cancer were registered at the Department of Ear, Nose, Throat, BPKMCH. Out of 1,111 oral cancer cases, 1,081 (97.3%) were OSCC. A trend for increasing number of OSCCs presenting to BPKMCH was observed during that period. OSCC was found to be more common among males (73.0%), Brahmin/Chhetri ethnic groups (33.0%), in age group of 51–60 years (31.9%), and in Terai region (62.0%). Tongue (42.8%) was the most common site, followed by buccal mucosa (27.2%). Nevertheless, when stratified with respect to the geographical location and ethnicity, buccal mucosa was the most common site for OSCC in Terai region (63.9%, p = .002) and in Madhesi ethnic group (34.2%, p < .001). Majority of OSCC cases were diagnosed at advanced stage (49.7%, Stage IV) and received a combination therapy (42.0%). Conclusions Hospital‐based records can provide valuable information on disease characteristics in countries like Nepal. This study revealed that the clinicopathological characteristics of OSCC in Nepal follow the global trend. Nevertheless, relationship between specific intraoral sites for OSCC with geographic location and ethnic groups is an interesting observation and requires further population‐based studies to clarify these findings.

• Søland, Tine Merete; Bjerkli, Inger-Heidi; Georgsen, Jeanette B; Schreurs, Olaf Joseph Franciscus; Jebsen, Peter Wilhelm & Laurvik, Helene [Show all 7 contributors for this article] (2020). High-risk human papilloma virus was not detected in a Norwegian cohort of oral squamous cell carcinoma of the mobile tongue. Clinical and Experimental Dental Research. 7(1), p. 70–77. doi: 10.1002/cre2.342. Full text in Research Archive Show summary

  Abstract Objectives: The presence of and the causative role of high-risk human papilloma virus (HPV) is a subject of controversy in oral squamous cell carcinoma (OSCC). The disagreement can be related to the misclassification of OSCC as oropharyngeal squamous cell carcinoma and/or lack of standard detection methods. This study aimed to examine the presence of transcriptionally active high-risk HPV in a homogenous Norwegian cohort of primary and second primary OSCC of the mobile tongue (oral tongue squamous cell carcinoma—OTSCC). Methods: Tissue microarrays containing formalin-fixed and paraffin-embedded cores of 146 OTSCC from the anterior 2/3 of the tongue (n = 128 primary and n = 18 second primary) from a multicentric Norwegian cohort were examined for the presence of high-risk HPV by DNA- and RNA-in situ hybridization (ISH) assays and p16 immunohistochemistry. Results: Transcriptionally active HPV (E6/E7 mRNA) was not identified in any of the OTSCC specimens. In parallel, no tumors were positive for HPV by DNA ISH. Although, 61 (42%) OTSCC demonstrated p16 positivity with varying staining intensity and subcellular localization, only two cases demonstrated strong and uniform p16-staining (both cytoplasmic and nuclear) in >70% of cancer cells. The absence of transcriptionally active high-risk HPV in this cohort of OTSCC indicates that high-risk HPV is an unlikely causative factor in the present material.

• Zhuoyuan, Zhang; Gao, Zhenjie; Rajthala, Saroj; Sapkota, Dipak; Dongre, Harsh & Parajuli, Himalaya [Show all 12 contributors for this article] (2019). Metabolic reprogramming of normal oral fibroblasts correlated with increased glycolytic metabolism of oral squamous cell carcinoma and precedes their activation into carcinoma associated fibroblasts. Cellular and Molecular Life Sciences (CMLS). ISSN 1420-682X. p. 1–19. doi: 10.1007/s00018-019-03209-y. Full text in Research Archive
• Basnet, Suyog; Sharma, Sunita; Costea, Daniela Elena & Sapkota, Dipak (2019). Expression profile and functional role of S100A14 in human cancer. OncoTarget. 10(31), p. 2996–3012. doi: 10.18632/oncotarget.26861. Full text in Research Archive
• Sharma, Sunita; Xue, Ying; Xing, Zhe; Yassin, Mohammed Ahmed; Sun, Yang & Lorens, James [Show all 9 contributors for this article] (2019). Adenoviral mediated mono delivery of BMP2 is superior to the combined delivery of BMP2 and VEGFA in bone regeneration in a critical-sized rat calvarial bone defect. Bone Reports. doi: 10.1016/j.bonr.2019.100205. Full text in Research Archive Show summary

  Apart from osteogenesis, neovascularization of the defect area is an important determinant for successful bone healing. Accordingly, several studies have employed the combined delivery of VEGFA and BMP2 for bone regeneration. Nevertheless, the outcomes of these studies are highly variable. The aim of our study was to compare the effectiveness of adenoviral mediated delivery of BMP2 alone and in combination with VEGFA in rat bone marrow stromal cells (rBMSC) seeded on a poly(LLA-co-CL) scaffold in angiogenesis and osteogenesis using a critical-sized rat calvarial defect model. Both mono delivery of BMP2 and the combined delivery of a lower ratio of VEGFA and BMP2 (1:4) led to up-regulation of osteogenic genes (Alpl and Runx2) and increased calcium deposition in vitro, compared with the GFP control. Micro computed tomography (microCT) analysis of the rat calvarial defect at 8 weeks showed that the mono delivery of BMP2 (43.37 ± 3.55% defect closure) was the most effective in healing the bone defect, followed by the combined delivery of BMP2 and VEGFA (27.86 ± 2.89%) and other controls. Histological and molecular analyses supported the microCT findings. Analysis of the angiogenesis, however, showed that both mono delivery of BMP2 and combined delivery of BMP2 and VEGFA had similar angiogenic effect in the calvarial defects. Examination of the key genes related to host response against the adenoviral vectors showed that the current model system was not associated with adverse immune response. Overall, the results show that the mono delivery of BMP2 was superior to the combined delivery of BMP2 and VEGFA in healing the critical-sized rat calvarial bone defect. These findings underscore the importance of appropriate growth factor combination for the successful outcome in bone regeneration.

• Bredrup, Cecilie; Stokowy, Tomasz; McGaughran, Julie; Lee, Samuel; Sapkota, Dipak & Cristea, Ileana [Show all 13 contributors for this article] (2018). A tyrosine kinase-activating variant Asn666Ser in PDGFRB causes a progeria-like condition in the severe end of Penttinen syndrome. European Journal of Human Genetics. ISSN 1018-4813. doi: 10.1038/s41431-018-0323-z. Full text in Research Archive
• Sharma, Sunita; Sapkota, Dipak; Xue, Ying; Rajthala, Saroj; Yassin, Mohammed Ahmed Alamin Yousif & Finne-Wistrand, Anna [Show all 7 contributors for this article] (2018). Delivery of VEGFA in bone marrow stromal cells seeded in copolymer scaffold enhances angiogenesis, but is inadequate for osteogenesis as compared with the dual delivery of VEGFA and BMP2 in a subcutaneous mouse model. Stem Cell Research & Therapy. 9:23, p. 1–13. doi: 10.1186/s13287-018-0778-4. Full text in Research Archive Show summary

  Background: In bone tissue engineering (BTE), extensive research into vascular endothelial growth factor A (VEGFA)-mediated angiogenesis has yielded inconsistent results. The aim of this study was to investigate the influence on angio- and osteogenesis of adenoviral-mediated delivery of VEGFA alone or in combination with bone morphogenetic protein 2 (BMP2) in bone marrow stromal cells (BMSC) seeded onto a recently developed poly(LLA-co-CL) scaffold. Methods: Human BMSC were engineered to express VEGFA alone or in combination with BMP2 and seeded onto poly(LLA-co-CL) scaffolds. Changes in angiogenic and osteogenic gene and protein levels were examined by quantitative reverse-transcription polymerase chain reaction (RT-PCR), PCR array, and alkaline phosphatase assay. An in vivo subcutaneous mouse model was used to investigate the effect on angio- and osteogenesis of VEGFA alone or in combination with BMP2, using microcomputed tomography (μCT), histology, immunohistochemistry, and immunofluorescence. Results: Combined delivery of a lower ratio (1:3) of VEGFA and BMP2 (ad-BMP2 + VEGFA) led to upregulation of osteogenic and angiogenic genes in vitro at 3 and 14 days, compared with mono-delivery of VEGFA (ad-VEGFA) and other controls. In vivo, in a subcutaneous mouse model, both ad-VEGFA and ad-BMP2 + VEGFA scaffold explants exhibited increased angiogenesis at 2 weeks. Enhanced angiogenesis was largely related to the recruitment and differentiation of mouse progenitor cells to the endothelial lineage and, to a lesser extent, to endothelial differentiation of the implanted BMSC. μCT and histological analyses revealed enhanced de novo bone formation only in the ad-BMP2 + VEGFA group, corresponding at the molecular level to the upregulation of genes related to osteogenesis, such as ALPL, RUNX2, and SPP1. Conclusions: Although BMSC expressing VEGFA alone or in combination with BMP2 significantly induced angiogenesis, VEGFA alone failed to demonstrate osteogenic activity both in vitro and in vivo. These results not only call into question the use of VEGFA alone in bone regeneration, but also highlight the importance in BTE of appropriately formulated combined delivery of VEGFA and BMP2.

• Fluge, Øystein; Mella, Olav; Bruland, Ove; Risa, Kristin; Dyrstad, Sissel Elisabeth & Alme, Kine [Show all 26 contributors for this article] (2016). Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy/chronic fatigue syndrome. JCI Insight. 1(21). doi: 10.1172/jci.insight.89376. Full text in Research Archive
• Sharma, Sunita; Sapkota, Dipak; Xue, Ying; Sun, Yang; Finne-Wistrand, Anna & Bruland, Ove [Show all 7 contributors for this article] (2016). Adenoviral Mediated Expression of BMP2 by Bone Marrow Stromal Cells cultured in 3D Copolymer Scaffolds Enhances Bone Formation. PLOS ONE. doi: 10.1371/journal.pone.0147507. Full text in Research Archive Show summary

  Selection of appropriate osteoinductive growth factors, suitable delivery method and proper supportive scaffold are critical for a successful outcome in bone tissue engineering using bone marrow stromal cells (BMSC). This study examined the molecular and functional effect of a combination of adenoviral mediated expression of bone morphogenetic protein-2 (BMP2) in BMSC and recently developed and characterized, biodegradable Poly(L-lactide-co-є-caprolactone){poly(LLA-co-CL)}scaffolds in osteogenic molecular changes and ectopic bone formation by using in vitro and in vivo approaches. Pathway-focused custom PCR array, validation using TaqMan based quantitative RT-PCR (qRT-PCR) and ALP staining showed significant up-regulation of several osteogenic and angiogenic molecules, including ALPL and RUNX2 in ad-BMP2 BMSC group grown in poly(LLA-co-CL) scaffolds both at 3 and 14 days. Micro CT and histological analyses of the subcutaneously implanted scaffolds in NOD/SCID mice revealed significantly increased radiopaque areas, percentage bone volume and formation of vital bone in ad-BMP2 scaffolds as compared to the control groups both at 2 and 8 weeks. The increased bone formation in the ad-BMP2 group in vivo was paralleled at the molecular level with concomitant over-expression of a number of osteogenic and angiogenic genes including ALPL, RUNX2, SPP1, ANGPT1. The increased bone formation in ad-BMP2 explants was not found to be associated with enhanced endochondral activity as evidenced by qRT-PCR (SOX9 and FGF2) and Safranin O staining. Taken together, combination of adenoviral mediated BMP-2 expression in BMSC grown in the newly developed poly(LLA-co-CL) scaffolds induced expression of osteogenic markers and enhanced bone formation in vivo.

• Lunde, Sigrid; Kristoffersen, Einar Klæboe; Sapkota, Dipak; Risa, Kristin; Dahl, Olav & Bruland, Ove [Show all 8 contributors for this article] (2016). Serum BAFF and APRIL levels, T-lymphocyte subsets, and immunoglobulins after B-cell depletion using the monoclonal anti-CD20 antibody rituximab in myalgic encephalopathy/chronic fatigue syndrome. PLOS ONE. 11:e0161226(8). doi: 10.1371/journal.pone.0161226. Full text in Research Archive
• Min, Anjie; Zhu, Chao; Peng, Shuping; Rajthala, Saroj; Costea, Daniela Elena & Sapkota, Dipak (2015). MicroRNAs as important players and biomarkers in oral carcinogenesis. BioMed Research International. ISSN 2314-6133. 2015:186904. doi: 10.1155/2015/186904. Full text in Research Archive Show summary

  Oral cancer, represented mainly by oral squamous cell carcinoma (OSCC), is the eighth most common type of human cancer worldwide. The number of new OSCC cases is increasing worldwide, especially in the low-income countries, and the prognosis remains poor in spite of recent advances in the diagnostic and therapeutic modalities. MicroRNAs (miRNAs), 18–25 nucleotides long noncoding RNA molecules, have recently gained significant attention as potential regulators and biomarkers for carcinogenesis. Recent data show that several miRNAs are deregulated in OSCC, and they have either a tumor suppressive or an oncogenic role in oral carcinogenesis. This review summarizes current knowledge on the role of miRNAs as tumor promotors or tumor suppressors in OSCC development and discusses their potential value as diagnostic and prognostic markers in OSCC.

• Osman, Tarig Al-Hadi; Parajuli, Himalaya; Sapkota, Dipak; Ahmed, Israa A.H.; Johannessen, Anne Christine & Costea, Daniela Elena (2015). The low-affinity nerve growth factor receptor p75NTR identifies a transient stem cell-like state in oral squamous cell carcinoma cells. Journal of Oral Pathology & Medicine. ISSN 0904-2512. 44(6), p. 410–419. doi: 10.1111/jop.12251. Full text in Research Archive Show summary

  Background Although several markers have been used for enrichment of cells with stem cell-like properties in oral squamous cell carcinoma (OSCC), isolation of a pure subpopulation is still a challenging task. Normal oral and esophageal keratinocyte stem cells have been previously isolated using the low-affinity nerve growth factor receptor p75NTR. Objective To investigate the potential of p75NTR as a marker for identification and isolation of oral cancer cells with stem cell-like properties. Methods Subpopulations of cells with high or low expression of p75NTR were sorted from OSCC-derived cells and compared for sphere/colony formation, in vivo tumor formation ability, expression of stem cell-related molecules, cell cycle distribution and drug resistance. Results p75NTRHigh cells exhibited statistically significant higher stem cell properties than p75NTRLow cells in all assays performed. Nevertheless, p75NTRLow subpopulation did also exhibit some stem cell features, but to a lesser extent. Propagation of p75NTRLow cells for several passages in culture showed that the expression of p75NTR could rise spontaneously. This finding was also supported by the similar expression of p75NTR by the xenografts generated by both subpopulations in NOD\SCID IL2Rgnullmice. Conclusion p75NTR can be used for isolating a subpopulation enriched for cells with stem cell-like properties in OSCC. De novo generation of p75NTRHigh cells from p75NTRLow cells suggests either that there is another subpopulation with stem cell features within the p75NTRLow cells, or that the p75NTRLow cells can dedifferentiate due to a contextually regulated equilibrium between stem cell-like cells and transit-amplifying neoplastic progenitors.

• Sapkota, Dipak; Bruland, Ove; Parajuli, Himalaya; Osman, Tarig Al-Hadi; Teh, Muy-Teck & Johannessen, Anne Christine [Show all 7 contributors for this article] (2015). S100A16 promotes differentiation and contributes to a less aggressive tumor phenotype in oral squamous cell carcinoma. BMC Cancer. 15:631. doi: 10.1186/s12885-015-1622-1. Full text in Research Archive Show summary

  Background: Altered expression of S100A16 has been reported in human cancers, but its biological role in tumorigenesis is not fully understood. This study aimed to investigate the clinical significance and functional role of S100A16 in oral squamous cell carcinoma (OSCC) suppression. Methods: S100A16 mRNA and/or protein levels were examined by quantitative RT-PCR and immunohistochemistry in whole- and laser microdissected-specimens of normal human oral mucosa (NHOM, n = 65), oral dysplastic lesions (ODL, n = 21), OSCCs (n = 132) and positive cervical nodes (n = 17). S100A16 protein expression in OSCC was examined for correlations with clinicopathological variables and patient survival. S100A16 was over-expressed and knocked-down in OSCC-derived (CaLH3 and H357) cells by employing retroviral constructs to investigate its effects on cell proliferation, sphere formation and three dimensional (3D)-organotypic invasive abilities in vitro and tumorigenesis in a mouse xenograft model. Results: Both S100A16 mRNA and protein levels were found to be progressively down-regulated from NHOM to ODL and OSCC. Low S100A16 protein levels in OSCC significantly correlated with reduced 10-year overall survival and poor tumor differentiation. Analysis of two external OSCC microarray datasets showed a positive correlation between the mRNA expression levels of S100A16 and keratinocyte differentiation markers. CaLH3 and H357 cell fractions enriched for differentiated cells either by lack of adherence to collagen IV or FACS sorting for low p75NTR expression expressed significantly higher S100A16 mRNA levels than the subpopulations enriched for less differentiated cells. Corroborating these findings, retroviral mediated S100A16 over-expression and knock-down in CaLH3 and H357 cells led to respective up- and down-regulation of differentiation markers. In vitro functional studies showed significant reduction in cell proliferation, sphere formation and 3D-invasive abilities of CaLH3 and H357 cells upon S100A16 over-expression. These functional effects were associated with concomitant down-regulation of self-renewal (Bmi-1 and Oct 4A) and invasion related (MMP1 and MMP9) molecules. S100A16 over-expression also suppressed tumorigenesis of H357 cells in a mouse xenograft model and the resulting tumor xenografts displayed features/expression of increased differentiation and reduced proliferation/self-renewal. Conclusions: These results indicate that S100A16 is a differentiation promoting protein and might function as a tumor suppressor in OSCC.

• Fluge, Øystein; Risa, Kristin; Lunde, Sigrid; Alme, Kine; Rekeland, Ingrid Gurvin & Sapkota, Dipak [Show all 11 contributors for this article] (2015). B-lymphocyte depletion in myalgic encephalopathy/chronic fatigue syndrome. An open-label phase II study with rituximab maintenance treatment. PLOS ONE. 10:e0129898(7). doi: 10.1371/journal.pone.0129898. Full text in Research Archive
• Liang, Xiao; Osman, Tarig Al-Hadi; Sapkota, Dipak; Neppelberg, Evelyn; Lybak, Stein & Liavaag, Per Gunnar [Show all 11 contributors for this article] (2014). Rapid adherence to collagen IV enriches for tumour initiating cells in oral cancer. European Journal of Cancer. ISSN 0959-8049. 50(18), p. 3262–3270. doi: 10.1016/j.ejca.2014.09.010. Full text in Research Archive Show summary

  Background: Although several approaches for identification and isolation of carcinoma cells with tumour initiating properties have been established, enrichment of a population of pure and viable tumour-initiating cells (TICs) is still problematic. This study investigated possibilities to isolate a population of cancer cells with tumour initiating properties based on their adherence properties, rather than expression of defined markers or clonogenicity. Methods: Several human cell lines derived from oral dysplasia and oral squamous cell carcinoma (OSCC), as well as primary cells derived from patients with OSCC were allowed to adhere to collagen IV-coated dishes sequentially. Rapid adherent cells (RAC), middle adherent cells (MAC) and late adherent cells (LAC) were then harvested and further investigated for their morphology, stem cell-like properties and molecular profile while grown in vitro and tongue xenotransplantation in NOD-SCID mice at serial dilutions. Results: RAC showed significantly higher colony forming efficiency (p < 0.05), sphere forming ability, greater migration ability (p < 0.05), exhibited longer G2 phase and displayed higher expression of integrin b1 and other stem-cell related molecules as compared to MAC and LAC. RAC induced tongue tumours in NOD-SCID mice with the highest incidence. These tumours were also bigger and metastasised more frequently in loco-regional lymph nodes than MAC and LAC. Conclusions: These findings prove for the first time that OSCC cells with tumour initiating properties can be enriched based on their rapid adhesiveness to collagen IV. This separation procedure provides a potentially useful tool for isolating TICs in OSCC for further studies on understanding their characteristics and drug-resistant behaviour.

• Sapkota, Dipak; Costea, Daniela Elena; Ibrahim, Salah Osman; Johannessen, Anne Chr. & Bruland, Ove (2013). S100A14 interacts with S100A16 and regulates its expression in human cancer cells. PLOS ONE. 8(9). doi: 10.1371/journal.pone.0076058. Full text in Research Archive
• Sapkota, Dipak; Costea, Daniela Elena; Blø, Magnus; Bruland, Ove; Lorens, James B. & Vasstrand, Endre N. [Show all 7 contributors for this article] (2012). S100A14 inhibits proliferation of oral carcinoma derived cells through G1-arrest. Oral Oncology. ISSN 1368-8375. 48(3), p. 219–225. doi: 10.1016/j.oraloncology.2011.10.001. Full text in Research Archive
• Dabija-Wolter, Gabriela; Sapkota, Dipak; Cimpan, Mihaela Roxana; Neppelberg, Evelyn; Bakken, Vidar & Costea, Daniela Elena (2012). Limited in-depth invasion of Fusobacterium nucleatum into in vitro reconstructed human gingiva. Archives of Oral Biology. ISSN 0003-9969. 57(4), p. 344–351. doi: 10.1016/j.archoralbio.2011.09.015. Full text in Research Archive
• Sand, Lars; Jalouli, Miranda M; Jalouli, Jamshid; Sapkota, Dipak & Ibrahim, Salah Osman (2012). p53 Codon 72 polymorphism in oral exfoliated cells in a Sudanese population. In Vivo. ISSN 0258-851X. 26(1), p. 59–62. Full text in Research Archive
• Jalouli, Jamshid; Jalouli, Miranda M; Sapkota, Dipak; Ibrahim, Salah Osman; Larsson, Per-Anders & Sand, Lars (2012). Human papilloma virus, herpes simplex virus and epstein barr virus in oral squamous cell carcinoma from eight different countries. Anticancer Research. ISSN 0250-7005. 32(2), p. 571–580. Full text in Research Archive
• Fluge, Øystein; Bruland, Ove; Risa, Kristin; Storstein, Anette; Kristoffersen, Einar Klæboe & Sapkota, Dipak [Show all 10 contributors for this article] (2011). Benefit from B-lymphocyte depletion using the anti-CD20 antibody rituximab in chronic fatigue syndrome. A double-blind and placebo-controlled study. PLOS ONE. 6(10). doi: 10.1371/journal.pone.0026358. Full text in Research Archive Show summary

  Background: Chronic fatigue syndrome (CFS) is a disease of unknown aetiology. Major CFS symptom relief during cancer chemotherapy in a patient with synchronous CFS and lymphoma spurred a pilot study of B-lymphocyte depletion using the anti-CD20 antibody Rituximab, which demonstrated significant clinical response in three CFS patients. Methods and Findings: In this double-blind, placebo-controlled phase II study (NCT00848692), 30 CFS patients were randomised to either Rituximab 500 mg/m2 or saline, given twice two weeks apart, with follow-up for 12 months. Xenotropic murine leukemia virus-related virus (XMRV) was not detected in any of the patients. The responses generally affected all CFS symptoms. Major or moderate overall response, defined as lasting improvements in self-reported Fatigue score during follow-up, was seen in 10 out of 15 patients (67%) in the Rituximab group and in two out of 15 patients (13%) in the Placebo group (p = 0.003). Mean response duration within the follow-up period for the 10 responders to Rituximab was 25 weeks (range 8–44). Four Rituximab patients had clinical response durations past the study period. General linear models for repeated measures of Fatigue scores during follow-up showed a significant interaction between time and intervention group (p = 0.018 for self-reported, and p = 0.024 for physician-assessed), with differences between the Rituximab and Placebo groups between 6–10 months after intervention. The primary end-point, defined as effect on selfreported Fatigue score 3 months after intervention, was negative. There were no serious adverse events. Two patients in the Rituximab group with pre-existing psoriasis experienced moderate psoriasis worsening. Conclusion: The delayed responses starting from 2–7 months after Rituximab treatment, in spite of rapid B-cell depletion, suggests that CFS is an autoimmune disease and may be consistent with the gradual elimination of autoantibodies preceding clinical responses. The present findings will impact future research efforts in CFS.

• Sapkota, Dipak; Bruland, Ove; Costea, Daniela Elena; Haugen, Hallvard; Vasstrand, Endre N. & Ibrahim, Salah Osman (2011). S100A14 regulates the invasive potential of oral squamous cell carcinoma derived cell-lines in vitro by modulating expression of matrix metalloproteinases, MMP1 and MMP9. European Journal of Cancer. ISSN 0959-8049. 47(4), p. 600–610. doi: 10.1016/j.ejca.2010.10.012. Full text in Research Archive
• Jalouli, Miranda; Jalouli, Jamshid; Sapkota, Dipak; Ibrahim, Salah Osman; Sand, Lars & Hirsch, Jan-M (2011). Differential expression of apoptosis, cell cycle regulation and intermediate filament genes in oral squamous cell carcinomas associated with toombak use in Sudan. Anticancer Research. ISSN 0250-7005. 31(10), p. 3345–3351. Full text in Research Archive
• Jalouli, Jamshid; Ibrahim, Salah Osman; Sapkota, Dipak; Jalouli, Miranda M; Vasstrand, Endre N. & Hirsch, Jan M [Show all 7 contributors for this article] (2010). Presence of human papilloma virus, herpes simplex virus and Epstein-Barr virus DNA in oral biopsies from Sudanese patients with regard to toombak use. Journal of Oral Pathology & Medicine. ISSN 0904-2512. 39(8), p. 599–604. doi: 10.1111/j.1600-0714.2010.00910.x. Full text in Research Archive Show summary

  Larsson har oppgitt Helsingborg Hospital i artikkel/AA

• Jalouli, Jamshid; Ibrahim, Salah Osman; Mehrotra, Ravi; Jalouli, Miranda M; Sapkota, Dipak & Larsson, Per Anders [Show all 7 contributors for this article] (2010). Prevalence of viral (HPV, EBV, HSV) infections in oral submucous fibrosis and oral cancer from India. Acta Oto-Laryngologica. ISSN 0001-6489. 130(11), p. 1306–1311. doi: 10.3109/00016481003782041. Full text in Research Archive
• Sapkota, Dipak; Bruland, Ove; Bøe, Olav Egil; Bakeer, Hala; Elgindi, O. A-Aziz & Vasstrand, Endre N. [Show all 7 contributors for this article] (2008). Expression profile of the S100 gene family members in oral squamous cell carcinomas. Journal of Oral Pathology & Medicine. ISSN 0904-2512. 37(10), p. 607–615. doi: 10.1111/j.1600-0714.2008.00683.x. Full text in Research Archive

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• Sapkota, Dipak (2026). Oral Epithelial Dysplasia: Old and New. Full text in Research Archive
• Sapkota, Dipak (2026). Fibroblast functional status is crucial in regulating the phenotype of dysplastic oral keratinocytes in 3D organotypic models. doi: https:/interceptoralcancer.com/news/5th-opmday. Full text in Research Archive
• Sapkota, Dipak (2025). Medikamentrelatert osteonekrose i kjevene: Et økende problem som krever mer oppmerksomhet. Full text in Research Archive
• Sapkota, Dipak (2025). Allergiske reaksjoner mot odontologiske biomaterialer. Full text in Research Archive
• Sapkota, Dipak (2025). Allergiske reaksjoner mot odontologiske biomaterialer. Den norske tannlegeforenings Tidende. ISSN 0029-2303. Full text in Research Archive
• Sapkota, Dipak (2025). Why Should care about oral leukoplakia? Full text in Research Archive
• Sapkota, Dipak (2025). Can we predict the malignant potential of oral leukoplakia? Full text in Research Archive
• Bhattarai, Bishwa Prakash; Singh, Ashutosh Kumar; Singh, Rabindra; Chaulagain, Rajib; Søland, Tine Merete & Hasséus, Bengt [Show all 7 contributors for this article] (2025). Kombinasjon av lasereksisjon og fordamping kan redusere forekomsten av residiv ved oral leukoplaki. Den norske tannlegeforenings Tidende. ISSN 0029-2303. doi: 10.56373/6836e846c55bc. Full text in Research Archive
• Bhattarai, Bishwa Prakash; Søland, Tine Merete; Schreurs, Olaf Joseph Franciscus; Hasséus, Bengt & Sapkota, Dipak (2024). Expression of Cell Cycle Regulating Proteins in Oral Leukoplakia. Full text in Research Archive
• Bhattarai, Bishwa Prakash; Singh, Ashutosh Kumar; Singh, Rabindra; Chaulagain, Rajib; Søland, Tine Merete & Hasséus, Bengt [Show all 7 contributors for this article] (2024). Can we predict the recurrence of oral leukoplakia? Full text in Research Archive
• Pokpong, Amornvit; Rokaya, Dinesh; Sapkota, Dipak & Sasiwimol, Sanohkan (2022). Oral and Craniofacial Anomalies of Fraser Syndrome: Prosthetic Management. Kathmandu University Medical Journal. ISSN 1812-2027. Full text in Research Archive
• Rogala, Agnieszka; Kristoffersen, Anne Karin; Enersen, Morten; Sapkota, Dipak & Küntziger, Thomas M. (2021). Defining the role of Porphyromonas gingivalis’ peptidyl arginine deiminase (PPAD) in oral carcinoma. Full text in Research Archive
• Pandey, Sushma; Søland, Tine Merete; Bjerkli, Inger-Heidi; Sand, Lars Peter; Costea, Daniela Elena & Senguven, Brucu [Show all 7 contributors for this article] (2020). Low involucrin expression correlates to poor prognosis in oral squamous cell carcinoma of mobile tongue. Full text in Research Archive
• Kafle, Dashrath & Sapkota, Dipak (2020). Saliva as a Biological Sample for COVID-19 Diagnosis? Kathmandu University Medical Journal. ISSN 1812-2027. 18(2), p. 107–110. doi: 10.3126/kumj.v18i2.33069. Full text in Research Archive
• Sapkota, Dipak; Thapa, Suraj Bahadur; Hasseus, Bengt & Jensen, Janicke Liaaen (2020). Saliva testing for COVID-19? British Dental Journal. ISSN 0007-0610. doi: 10.1038/s41415-020-1594-7. Full text in Research Archive
• Pandey, Sushma; Follin-Arbelet, Benoit; Pun, Chin Babadur; Gautam, Dej K.; Johannessen, Anne C. & Petersen, Fernanda Cristina [Show all 8 contributors for this article] (2019). Helicobacter pylori is not present in oral squamous cell carcinomas from cohorts of Norwegian and Nepalese patients. Full text in Research Archive
• Dhakal, Sushma Pandey; Osman, Tarig A.; Sharma, Sunita; Uhlin-Hansen, Lars; Pun, Chin Babadur & Gautam, Dej K. [Show all 10 contributors for this article] (2019). Oral squamous cell carcinomas expressing higher levels of S100A14 correlate with prognosis. Full text in Research Archive
• Jiang, Nan; Shahdafar, Aboulghassem & Sapkota, Dipak (2019). Engineering of a three dimensional biosynthetic construct equivalent to human corneal epithelium and stroma. Full text in Research Archive
• Rogala, Agnieszka; Follin-Arbelet, Benoit; Kristoffersen, Anne Karin; Enersen, Morten; Sapkota, Dipak & Küntziger, Thomas M. (2019). Defining the role of Porphyromonas gingivalis peptidyl arginine deiminase (PPAD) in oral carcinoma. Full text in Research Archive
• Rajthala, Saroj; Parajuli, Himalaya; Sapkota, Dipak; Gullberg, Donald; Johannessen, Anne Christine & Costea, Daniela Elena (2015). Expression of integrin α-11 by carcinoma associated fibroblasts modulates oral squa- mous cell carcinoma behaviour. Full text in Research Archive
• Jacobsen, Martha Rolland; Sapkota, Dipak; Johannessen, Anne Christine & Costea, Daniela Elena (2015). Oral premalignant lesions overexpress the collagen-elastin crosslinking enzyme LOXL4. Full text in Research Archive
• Parajuli, Himalaya; Sapkota, Dipak; Suliman, Salwa; McCormack, Emmet; Johannessen, Anne Christine & Gullberg, Donald [Show all 7 contributors for this article] (2015). Expression of integrin α-11 by carcinoma associated fibroblasts modulates oral squamous cell carcinoma behaviour. Full text in Research Archive
• Sapkota, Dipak; Costea, Daniela Elena; himalaya, parajuli; Osman, Tarig Al-Hadi; Bruland, Ove & Johannessen, AC (2014). Role of S100A16 in Differentiation of Oral Squamous Cell Carcinoma. Full text in Research Archive
• Osman, Amani Hamza Ali; Costea, Daniela Elena; Tsinkalovsky, Oleg; Sapkota, Dipak; Vintermyr, Olav Karsten & Johannessen, Anne Chr. (2009). Phenotypic and functional differences between oral carcinoma-associated fibroblasts and normal oral fibroblasts. Oral Oncology. ISSN 1368-8375. p. 221–221. doi: 10.1016/j.oos.2009.06.586. Full text in Research Archive
• Sapkota, Dipak; Costea, DE; Bruland, Ove; Vasstrand, Endre N. & Ibrahim, SO (2009). Expression profile of cell adhesion and matrix molecules in oral cancer. Full text in Research Archive
• Sapkota, Dipak; Bruland, Ove; Vasstrand, Endre N. & Ibrahim, Salah Osman (2009). Transcriptome signature of the extracellular matrix and adhesion molecules in oral squamous cell carcinomas from sudanese N-nitrosamine rich toombak users. Oral Oncology. ISSN 1368-8375. p. 99–100. doi: 10.1016/j.oos.2009.06.215. Full text in Research Archive
• Costea, Daniela Elena; Osman, Amani Hamza Ali; Ipatova, A; Sapkota, Dipak; Neppelberg, Evelyn & Lybak, S (2009). Enhanced self-renewal properties of transformed oral epithelial cells after interactions with stromal fibroblasts. Oral Oncology. ISSN 1368-8375. p. 92–93. doi: 10.1016/j.oos.2009.06.194. Full text in Research Archive
• Sapkota, Dipak; Bruland, Ove; Vasstrand, Endre N. & Ibrahim, Salah Osman (2008). Down-regulated expression of S100 gene family members in OSCCs. Full text in Research Archive
• Sapkota, Dipak (2011). S100 gene family members in oral squamous cell carcinomas (OSCCs): Functional characterization of S100A14 in proliferation and invasion of OSCC derived cells. Universitetet i Bergen. ISSN 9788230816783. Full text in Research Archive

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