Overexpression of MicroRNA 142-5p Suppresses the Progression of Cervical Cancer through Targeting Phosphoinositol-3-Kinase Adaptor Protein 1 Expression.

The aim of current study was to explore the mechanism of microRNA 142-5p (miR-142-5p) in cervical cancer through mediating the phosphoinositol-3-kinase adaptor protein 1 (PIK3AP1)/PI3K/AKT axis. To this end, reverse transcription-quantitative PCR (RT-qPCR) and Western blot analysis results revealed that miR-142-5p was poorly expressed, whereas PIK3AP1 was highly expressed, in cervical cancer tissues and cells. Furthermore, miR-142-5p was hypermethylated in cervical cancer, as reflected by methylation-specific PCR (MS-PCR) and chromatin immunoprecipitation (ChIP) assessment of enrichment of DNMT1/DNMT3a/DNMT3b in the promoter region of miR-142-5p. A target binding relationship between miR-142-5p and PIK3AP1 was established, showing that miR-142-5p targeted and inhibited the expression of PIK3AP1. Loss- and gain-of-function assays were conducted to determine the roles of miR-142-5p and PIK3AP1 in cervical cancer cells. CCK-8, flow cytometry, and Transwell assay results revealed that overexpression of miR-142-5p in cervical cancer cells downregulated PIK3AP1 and inhibited the PI3K/AKT signaling pathway, leading to reduced proliferation, migration, and invasion capacity of cervical cancer cells but enhanced apoptosis. Collectively, epigenetic regulation of miR-142-5p targeted PIK3AP1 to inactivate the PI3K/AKT signaling pathway, thus suppressing development of cervical cancer, which presents new targets for the treatment of cervical cancer.