MicroRNA-495 Regulates Migration and Invasion in Prostate Cancer Cells Via Targeting Akt and mTOR Signaling

Abnormal microRNA (miR) expressions were implicated in prostate cancer progression. We identified a novel miR-495, which was downregulated in prostate cancer, but not normal prostate cell lines. MiR-495 directly targeted the 3′-UTR of Akt and mTOR mRNAs. Expression of miR-495 in prostate cancer cells significantly downregulated Akt and mTOR, which further inhibited cancer cell proliferation, migration, and invasion <i>in vitro</i>. Function of miR-495 <i>in vivo</i> was examined in mouse xenograft model and was found to significantly inhibit the growth of tumors, mediated by repressing Akt and mTOR. Our report supported miR-495 as a novel tumor suppressor microRNA in prostate cancer.

异常表达的微小核糖核酸（microRNA，简称miR）与前列腺癌的进展密切相关。本研究鉴定出一种新型miR-495，该分子在前列腺癌组织中表达下调，而在正常前列腺细胞系中未出现该表达下调情况。MiR-495可直接靶向结合Akt与mTOR mRNA的3′-UTR。在前列腺癌细胞中过表达miR-495可显著下调Akt与mTOR的表达，进而在体外（in vitro）实验中抑制癌细胞的增殖、迁移与侵袭能力。针对miR-495的体内（in vivo）功能，本研究通过小鼠异种移植瘤模型开展了验证，结果显示其可通过抑制Akt与mTOR的表达，显著抑制肿瘤生长。本研究证实miR-495可作为前列腺癌中一种新型的抑癌微小核糖核酸。