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Background: We evaluated microRNAs and extracellular matrix component profiles in squamous cell carcinoma of the oral cavity (OSCC) in comparison to healthy mucosa., Methods: Retrospective study investigating 64 microRNAs related to oncogenic process and to constituents of the extracellular matrix. We also performed immunohistochemical assays for molecules involved in the same biological processes., Results: High expression of miR-21-5p (p < 0.001) and miR-106-5p (p < 0.001) and low expression of miR-320a (p = 0.001) and miR-222-3p (p = 0.001) were predictors of malignancy. Individually, miR-21-5p exhibited the best statistical performance (area under the curve = 0.972; 95% confidence interval: 0.911-1.000) in the differentiation between tumor tissue and healthy mucosa. Moreover, tumor sample showed increased expression of MMP-2, MMP-9, α-laminin, and β-laminin in tumor-related fibroblasts and lower continuity of type IV collagen in the basement membrane., Conclusion: The present study demonstrates the biological effects of microRNAs on the carcinogenesis of OSCC as well as the intense modification of the tumor microenvironment., (© 2021 Wiley Periodicals LLC.)

Background: Nuclear factor erythroid 2-like 2 (NFE2L2) encodes Nrf2, transcription factor of antioxidative genes. In the presence of reactive oxygen species, Keap1 (Kelch-ECH-associating protein-1) inhibitor complex undergoes conformational changes disrupting Keap1-Nrf2 binding and Nrf2 translocates into nucleus. We evaluated the presence of mutations in NFE2L2 and KEAP1 in papillary thyroid carcinomas (PTCs) and correlated them with clinical presentation., Methods: Coding regions of NFE2L2 and KEAP1 were sequenced in 131 patients with PTC. Clinical and histopathological features were analyzed. Immunohistochemical analysis of Nrf2 expression was performed in mutated carcinomas., Results: Although no mutations were found in NFE2L2, missense mutations in KEAP1 were observed in 6 patients with PTC (4.6%). Immunohistochemistry showed increased Nrf2 expression in nuclei of all mutated carcinomas, which presented poor prognostic features in histopathology., Conclusion: We identified mutations in KEAP1 associated with Nrf2 overexpression in PTC. Mutations favored disruption of inhibitory interaction Nrf2-Keap1 to enable increased antioxidant Nrf2 activity, possibly with prognostic consequences., (© 2018 Wiley Periodicals, Inc.)