Serpin family E member 1 (SERPINE1) is a serine proteinase inhibitor (serpin) upregulated in diverse types of cancer, including oral squamous cell carcinoma (OSCC), and it functions in an oncogenic role. Hence, exploring pathological mechanism underlying high expression of SERPINE1 is crucial to the targeted therapy of OSCC. Bioinformatics analysis was performed to identify the microRNA (miRNA) and the candidate gene contributing to OSCC progression. The viability, proliferation, and apoptosis of the OSCC cell were evaluated using Cell Counting Kit-8 (CCK-8) assay, BrdU assay, and cell apoptosis assay, respectively. The RNA pulldown assay and luciferase reporter assay were conducted to verify the relationship between SERPINE1 and miRNA 617 (miR-617). SERPINE1 was aberrantly upregulated in OSCC tissues and cell lines. Genetically inhibiting SERPINE1 led to reduction of OSCC cell viability and proliferation and elevation of OSCC cell apoptosis. According to bioinformatics analysis, miR-617 contained a response element for SERPINE1 overexpression, which is validated by the RNA pulldown and luciferase reporter assays. Furthermore, miR-617 was detected to be downregulated in OSCC tissues and cell lines, and it displayed a negative correlation with advanced stages. Besides, miR-617 mimic or inhibitor transfection could suppress or boost the SERPINE1 expression. More importantly, miR-617 mimic could block the effect of SERPINE1 overexpression on OSCC cell proliferation, viability, and apoptosis. SERPINE1 acted as a proproliferative oncogenic factor that is partly regulated by miR-167 downregulation in OSCC cells. Therefore, the miR-617/SERPINE1 axis is a potential therapeutic target against OSCC.
Keywords: SERPINE1; apoptosis; cancer; miR-617; oral squamous cell carcinoma; proliferation.