shRNA Mediated RHOXF1 Silencing Influences Expression of BCL2 but not CASP8 in MCF-7 and MDA-MB-231 Cell Lines

RHOXF1 has been shown to be expressed in embryonic stem cells, adult germline stem cells and some cancerlines. It has been proposed as a candidate gene to encode transcription factors regulating downstream genes inthe human testis with antiapoptotic effects. Its expression in cancer cell lines has implied a similar role in theprocess of tumorigenesis. The human breast cancer cell lines MDA-MB-231 and MCF-7 were cultured in DMEMmedium and transfected with a pGFP-V-RS plasmid bearing an RHOXF1 specific shRNA. Quantitative realtimeRT-PCR was performed for RHOXF1, CASP8, BCL2 and HPRT genes. Decreased RHOXF1 expressionwas confirmed in cells after transfection. shRNA knock down of RHOXF1 resulted in significantly decreasedBCL2 expression in both cell lines but no change in CASP8 expression. shRNA targeting RHOXF1 was shownto specifically mediate RHOXF1 gene silencing, so RHOXF1 can mediate transcriptional activation of the BCL2in cancers and may render tumor cells resistant to apoptotic cell death induced by anticancer therapy. shRNAmediated knock down of RHOXF1 can be effective in induction of apoptotic pathway in cancer cells via BCL2downregulation, so it can have potential therapeutic utility for human breast cancer