MiR-125b Inhibits Tumor Growth and Promotes Apoptosis of Cervical Cancer Cells by Targeting Phosphoinositide 3-Kinase Catalytic Subunit Delta

Backgroud: microRNAs (miRNAs) are involved in cancer-related processes. The miRNA-125b (miR-125b) has been identified as miRNA over-expressed in a wide variety of cancers. However, the role of miR-125b in the context of cervical carcinoma remains unknown. Methods: In this study, the effect of miR-125b on the proliferation and apoptosis of human cervical cells was analyzed by MTT assay and Flow cytometry analysis. we identified phosphoinositide 3-kinase catalytic subunit delta (PIK3CD) as a novel miR-125b target. Results: overexpression of miR-125b in HeLa cervical cancer cells decreased cell proliferation, induced apoptosis and downregulated expression of PIK3CD. To identify the mechanisms responsible, we investigated the PI3K/Akt pathway and found that PI3K, phospho-Akt, and phospho-mTOR were all downregulated, while Bid was up-regulated in miR-125b-overexpressing subclones. In vivo, over expression of miR-125b in HeLa cells markedly reduced their ability to form tumors. Conclusion: these results suggest that miR-125b suppresses tumor growth activity by targeting the PI3K/Akt/mTOR signal-ing pathway, and may provide a target for effective therapies. Copyright (C) 2012 S. Karger AG, Basel