The Correlation between OCT4B1 and Apoptosis in Human Cancer Cell Lines

ABSTRACT BACKGROUND AND OBJECTIVE: OCT4B1, as one of the variants of OCT4 gene, is expressed at higher levels in cancer tissues and cancer cell lines, compared to other OCT4 variants. Recent studies have revealed the anti-apoptotic role of OCT4B1. The aim of this study was to evaluate the effect of OCT4B1 suppression on the expression profile of anti-apoptotic genes in three human tumor cell lines. METHODS: In this in-vitro study, three human tumor cell lines including AGS (stomach adenocarcinoma), 5637 (bladder cancer), and U87MG (brain tumor) were purchased from the National Cell Bank of Iran (Pasteur Institute) and cultured in test and control groups. In order to suppress OCT4B1 expression, the cultures were transfected, using siRNA technology and lipofection method. After confirming the suppression process, total RNA was extracted and cDNA was synthesized. Finally, the expression rates of anti-apoptotic genes were determined, using specific primers and real-time PCR technique. FINDINGS: Our data revealed an almost similar pattern of alteration in the expression profile of anti-apoptotic genes in all three cell lines. Also, BCL2, BRAF, and BFAR genes exhibited the most significant down-regulation by 20.87, 18.33, and 15.11 folds, respectively. The expression of at least 20 genes (out of 26 genes) decreased, while the expression rates of CASP2, IGF1R, TNF, and MCL1 were up-regulated or remained unchanged. Also, the expression of CFLAR gene was up-regulated in U87MG and down-regulated in other cell lines (5637 and AGS). CONCLUSION: Based on our findings, OCT4B1 suppression by blocking the expression of anti-apoptotic genes may result in the induction of apoptosis in cancer cell lines