微小RNA-23a调节前列腺癌细胞骨架蛋白的分子机制

Mechanism of miR-23a on the regulation of the cytoskeleton proteins of prostate cancer cells

目的探讨微小RNA-23a（miR-23a）影响前列腺癌细胞骨架迁移及侵袭行为的分子机制。方法PC-3前列腺癌细胞转染siPAK6、miR-23a模拟物，48h后以共聚焦显微镜观察细胞骨架的改变；Westernblot法检测LIMK1、磷酸化LIMK1（p-LIMKl）、丝切蛋白（cofilin）和磷酸化丝切蛋白（p-cofilin）蛋白的表达。结果转染siPAK6组及miRNA一23a组PC-3细胞骨架的应力纤维均明显减少，肌动蛋白形态皱缩。Westernblot检测显示转染siPAK6组的p-LIMKl、p-cofilin的表达分别下降75％、80％（P〈0．01），而LIMKl、cofilin表达量无明显变化（P〉0．05）；转染miRNA-23a组的p-LIMKl、p-cofilin的表达分别下降60％、70％（P〈0．01），LIMKl、cofilin的表达量无明显变化（P〉0．05）。结论miR-23a可通过p21活化激酶6（PAK6）-LIMK1-cofilin信号通路，影响前列腺癌细胞骨架的重构，抑制癌细胞迁移及侵袭能力。

Objective To investigate the mechanism of the miR-23a-activation of p21 activated kinase 6 （PAK6） signaling on the cytoskeleton, the inhibiting migration and invasion abilities of prostate cancer cells. Methods The expression of LIMK1, p-LIMK1, cofilin and p-cofilin was detected by using Western blotting in PC-3 prostate cancer cells transfected with siPAK6 and miR-23a mimics for 48 h. The cytoskeleton changes were stained and observed under the confocal microscopy. Results The cytoskeletal actin remodeling and reduction of stress fibers were observed in the cells transfected with siPAK6 and miR- 23a mimics respectively under the confocal microscopy. The p-LIMK1 and p-cofilin expression was remark- ably decreased by 75% and 80% respectively in the group of PC-3 cells transfected with siPAK6 （P 〈 0. 01 ） , and decreased by 60% and 70% respectively in the group of PC-3 cells transfected with miR-23a mimics （ P 〈 0. O1 ）. Both the LIMK1 expression and the cofilin expression had no changes in PC-3 cells. Conclusion MiR-23a pathway inhibits the migration and invasion activities of prostate cancer cells by suppressing PAK6-LIMKI-eofilin signaling pathway and the cytoskeletal actin remodeling.