RhoB Acts as a Tumor Suppressor That Inhibits Malignancy of Clear Cell Renal Cell Carcinoma
RhoB Acts as a Tumor Suppressor That Inhibits Malignancy of Clear Cell Renal Cell Carcinoma
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DOI：
10.1371/journal.pone.0157599
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发表时间：
2016-07-06
期刊：
影响因子：
3.7
通讯作者：
Zhang, Xu
中科院分区：
文献类型：
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作者：
Chen, Weihao;Niu, Shaoxi;Zhang, Xu
本研究旨在探讨RhoB在肾透明细胞癌（ccRCC）中的生物学作用。采用免疫组化和Western blot方法检测RhoB在患者标本和细胞系中的表达。RhoB表达与临床病理变量之间的相关性也进行了分析。通过质粒转染和RNAi技术抑制RhoB在ccRCC细胞中的表达，观察RhoB对ccRCC细胞增殖、细胞周期、细胞凋亡和侵袭/迁移的影响。结果显示，与邻近正常肾组织和正常人肾近端小管上皮细胞系（HKC）相比，RhoB在ccRCC手术标本和细胞系中低表达，其蛋白表达水平与肿瘤病理参数（包括肿瘤大小）显著相关（P = 0.0157）、pT分期（P = 0.0035）、TNM分期（P = 0.0024）和Fuhrman肿瘤分级（P = 0.0008）。RhoB过表达可显著抑制癌细胞增殖、集落形成，促进癌细胞凋亡，降低癌细胞的侵袭和迁移能力。RhoB的上调可诱导细胞周期阻滞于G2/M期，并导致细胞周期调节因子CyclineB 1、CDK 1和促凋亡蛋白Casp 3、Casp 9的异常表达。此外，RhoB在HKC细胞中的敲低促进细胞增殖和迁移。总之，我们的研究表明，RhoB表达在ccRCC癌发生和进展中降低。RhoB的上调显著抑制ccRCC细胞恶性表型。这些发现表明RhoB可能在ccRCC细胞中发挥肿瘤抑制作用，提高了其作为ccRCC患者未来治疗靶点的潜在价值。
This study aims to investigate the biological role of RhoB in clear cell renal cell carcinoma (ccRCC). The expression of RhoB was examined in specimens of patients and cell lines by Western blot and Immunohistochemistry. The correlation between RhoB expression and clinicopathologic variables was also analyzed. The effects of RhoB on cell proliferation, cell cycle, cell apoptosis, and invasion/migration were detected by over-expression and knockdown of RhoB level in ccRCC cells via plasmids and RNAi. The results showed that RhoB was low-expressed in ccRCC surgical specimens and cell lines compared with adjacent normal renal tissues and normal human renal proximal tubular epithelial cell lines (HKC), and its protein expression level was significantly associated with the tumor pathologic parameter embracing tumor size(P = 0.0157), pT stage(P = 0.0035), TNM stage(P = 0.0024) and Fuhrman tumor grade(P = 0.0008). Further, over-expression of RhoB remarkably inhibited the cancer cell proliferation, colony formation and promoted cancer cell apoptosis, and aslo reduced the invasion and migration ability of ccRCC cells. Interestingly, up-regulation of RhoB could induce cell cycle arrest in G2/M phase and led to cell cycle regulators(CyclineB1, CDK1) and pro-apoptotic protein(casp3, casp9) aberrant expression. Moreover, knockdown of RhoB in HKC cells promoted cell proliferation and migration. Taken together, our study indicates that RhoB expression is decreased in ccRCC carcinogenesis and progression. Up-regulation of RhoB significantly inhibits ccRCC cell malignant phenotype. These findings show that RhoB may play a tumor suppressive role in ccRCC cells, raising its potential value in futural therapeutic target for the patients of ccRCC.