Upregulation of microRNA-23a regulates proliferation and apoptosis by targeting APAF-1 in laryngeal carcinoma

Abstract

MicroRNA-23a (miR-23a) is a potential biomarker for laryngeal cancer. Apoptotic protease activating factor 1 (APAF-1) was recently demonstrated to be a target of miR-23a. However, whether miR-23a exerts its effects via APAF-1 in laryngeal cancer, remains unknown. In the present study, miR-23a expression was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). APAF-1 mRNA and protein expression levels were assayed by RT-qPCR and western blotting, respectively. Binding of miR-23a to APAF-1 was monitored by a luciferase reporter assay. Gain-of-function and loss-of-function studies were performed in order to investigate the roles of miR-23a and APAF-1 in Hep2 cell proliferation and apoptosis. miR-23a and APAF-1 were found to be significantly upregulated and downregulated, respectively, in laryngeal cancer tissues, and there was a significant negative correlation between APAF-1 and miR-23a expression. The results of the luciferase reporter assay demonstrated that miR-23a bound directly to the APAF-1 mRNA 3'-untranslated region. Ectopic expression of miR-23a and knockdown of APAF-1 significantly promoted cell proliferation and colony formation, and inhibited early apoptosis in Hep2 cells. In conclusion, miR-23a acts as an oncogenic regulator in laryngeal carcinoma by directly targeting APAF-1, and may be a useful biomarker in the diagnosis and treatment of laryngeal carcinoma.