Bcl-2 Regulation By Mir-429 In Human Nasopharyngeal Carcinoma In Vivo

Radioresistance and chemoresistance severely restrict the clinical treatment of nasopharyngeal carcinoma (NPC). A considerable number of evidence indicates that the abnormal expression of microRNAs (miRNAs) contributes to cancer progression and sensitivity to chemotherapy and radiation. Bcl-2 plays an important role in the pathogenesis of NPC by regulating apoptosis. This study aimed to explore Bcl-2 regulation by miR-429 in human NPC in vivo. The aberrant miR-429 expression in CNE-2 and 5-8F cells was compared with that in NPC cells, and tumor and normal tissues were screened through quantitative reverse transcription polymerase chain reaction (qRT-PCR). Bioinformatic analyses, quantitative real-time PCR assays, and Western blot were performed to explore the regulation of miR-429 targeting Bcl-2. miR-429 expression was significantly decreased in CNE-2 and 5-8F cells compared with that in NP-69 cells. Bcl-2 was predicted to be the downstream target of miR-429, which downregulated Bcl-2 expression in transfected CNE-2 and 5-8F cells according to Luciferase reporter assay. QRT-PCR identified reduced expression of Bcl-2 targeted by miR-429. Western blot analysis consistently showed that the expression level of Bcl-2 was significantly decreased in both CNE-2 and 5-8F cell lines infected with miR-429 compared with those infected with miR-NC. miR-429 contributes to the chemoresistance and radioresistance of NPC. This finding establishes Bcl-2 as a novel regulator of miR-429 and maybe a potential therapeutic target for NPC.