MiR-125b inhibits tumor growth and promotes apoptosis of cervical cancer cells by targeting phosphoinositide 3-kinase catalytic subunit delta

Background: [corrected] 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 down-regulated 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 down-regulated, 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 signaling pathway, and may provide a target for effective therapies.