肾透明细胞癌组织SMO表达与肾癌细胞增殖和凋亡的相关性

Expression of smoothened in clear cell renal cell carcinoma and its influence on renal cell proliferation and apoptosis

目的 Hedgehog信号通路参与了肿瘤的发生发展,本研究探讨该通路关键信号分子Smoothened(SMO)在肾透明细胞癌中的表达及对肾癌细胞增殖和凋亡的影响。方法选取2012-01-01-2013-06-30青岛大学附属医院泌尿外科,行手术治疗的80例肾透明细胞癌患者的临床及病理资料,采用免疫组织化学方法检测SMO在肾透明细胞癌组织中的表达并分析其与临床病理特征间的关系。采用小干扰RNA下调SMO在人肾癌细胞786-O中的表达,分别应用CCK-8法、流式细胞术及蛋白质印迹法检测下调SMO表达对细胞增殖、凋亡及Gli1和Gli2表达的影响。结果 SMO在73例(91.25%)肾透明细胞癌组织中有表达,其在高级别肾癌中表达(80.49%)较低级别(56.41%)显著升高,χ2=5.39,P=0.02。RT-PCR检测结果显示,SMO在人肾癌细胞系786-O中表达量为0.704±0.059;蛋白质印迹结果显示,SMO在786-O中表达量为0.651±0.074。在786-O细胞中应用小干扰RNA沉默SMO表达后,实验组细胞相较于对照组其活力百分比在48、72和96h分别为92.7%、80.9%和79.9%,3个时间点差异有统计学意义(P=0.003),细胞凋亡显著增加,t=-29.2,P<0.001;与空白对照组和阴性对照组相比,其下游分子Gli1和Gli2蛋白表达明显减少(Gli1:3.2 vs 2.9 vs 1;Gli2:2.5 vs 2.1vs 1)。结论 SMO可能通过调控细胞增殖和凋亡,以及调节Gli蛋白表达参与了肾癌的发生发展。

OBJECTIVE The Hedgehog signaling pathway is involved in carcinogenesis. This study aimed to inves- tigate the expression of smoothened （SMO） in clear cell renal cell carcinoma （ccRCC） and its influence on RCC cell prolif- eration and apoptosis. METHODS The expression levels of SMO in 80 cases of ccRCC tissues were detected using immunohistochemistry, and their clinicopathological significance was analyzed. SMO expression was down-regulated in human RCC cell lines 786-0 by small interfering RNA （siRNA）. CCK-8 assay and flow cytometry were performed to evaluate cell proliferation and apoptosis. Expression levels of Glil and Gli2 were detected using western blot. RESULTS SMO expression was observed in 91. 25% of ceRCC tissues. The expression levels were significantly higher in high grade ccRCC （80.49%） compared with low grade ccRCC （56.41%）（x2=5.39,P=0.02）. The expression levels of SMO mR- NA and protein in human renal cell carcinoma cells 786-0 were 0. 704±0. 059 by RT-PCR and 0. 651±0. 074 by western blot, respectively. After down-regulation of SMO expression in 786-0 cells by siRNA, the percentages of viable cells were 92.70/oo, 80. 9% and 79.9% at 48 h, 72 h and 96 h respectively. Cell proliferation was notably inhibited （P = 0. 003）, and number of apoptosis cells was greatly increased （t=- 29.2,P〈0. 001）. In addition, the expression levels of Glil and Gli2 were significantly reduced compared with the control group （Glil：3.2 vs 2.9 vs 1;Gli2：2.5 vs 2.1 vs 1）. CONCLUSION SMO may participate in RCC carcinogenesis through regulating cell proliferation and apoptosis, as well as Gli2 and Gli2 expression.