Xiang Jun, Bian Cuidong, Wang Hao, Huang Shengsong, Wu Denglong
Department of Urology, Tongji Hospital, Tongji University School of Medicine, NO 389 Xinchun road, Shanghai, 200065, China.
The Experimental Center of Basic Medical, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
J Exp Clin Cancer Res. 2015 Jan 31;34(1):8. doi: 10.1186/s13046-015-0125-x.
Evidence supports an important role for miR-203 in the regulation of the proliferation, migration and invasion of prostate cancer (PCa) cells. However, the exact mechanisms of miR-203 in PCa are not entirely clear.
We examined the expression of miR-203 in prostate cancer tissues, adjacent normal tissues, PCa cell lines and normal prostate epithelial cells by qRT-PCR. Then, the effects of miR-203 or Rap1A on proliferation, adhesion and invasion of PCa cells were assayed using CKK-8, adhesion analysis, and transwell invasion assays. Luciferase reporter assay was performed to assess miR-203 binding to Rap1A mRNA. Tumor growth was assessed by subcutaneous inoculation of cells into BALB/c nude mice.
Here, we confirmed that the expression of miR-203 was significantly downregulated in prostate cancer specimens compared with matched adjacent normal prostate specimens. Mechanistic dissection revealed that miR-203 mediated cell proliferation, adhesion and invasion in vitro, and tumor growth in vivo, as evidenced by reduced RAC1, p-PAK1, and p-MEK1 expression. In addition, we identified Rap1A as a direct target suppressed by miR-203, and there was an inverse relationship between the expression of miR-203 and Rap1A in PCa. Knockdown of Rap1A phenocopied the effects of miR-203 on PCa cell growth and invasion. Furthermore, Rap1A over-expression in PCa cells partially reversed the effects of miR-203-expression on cell adhesion and invasion.
These findings provide further evidence that a crucial role for miR-203 in inhibiting metastasis of PCa through the suppression of Rap1A expression.
有证据表明miR - 203在前列腺癌细胞的增殖、迁移和侵袭调控中起重要作用。然而，miR - 203在前列腺癌中的具体机制尚不完全清楚。
我们通过qRT - PCR检测了miR - 203在前列腺癌组织、癌旁正常组织、前列腺癌细胞系和正常前列腺上皮细胞中的表达。然后，使用CCK - 8、黏附分析和transwell侵袭试验检测miR - 203或Rap1A对前列腺癌细胞增殖、黏附和侵袭的影响。进行荧光素酶报告基因试验以评估miR - 203与Rap1A mRNA的结合。通过将细胞皮下接种到BALB/c裸鼠中来评估肿瘤生长。
在此，我们证实与匹配的癌旁正常前列腺标本相比，miR - 203在前列腺癌标本中的表达显著下调。机制剖析显示，miR - 203在体外介导细胞增殖、黏附和侵袭，在体内介导肿瘤生长，RAC1、p - PAK1和p - MEK1表达降低证明了这一点。此外，我们确定Rap1A是miR - 203抑制的直接靶点，在前列腺癌中miR - 203与Rap1A的表达呈负相关。敲低Rap1A模拟了miR - 203对前列腺癌细胞生长和侵袭的影响。此外，前列腺癌细胞中Rap1A的过表达部分逆转了miR - 203表达对细胞黏附和侵袭的影响。
这些发现进一步证明了miR - 203通过抑制Rap1A表达在抑制前列腺癌转移中起关键作用。
