RNA干扰沉默信息调节因子2同源蛋白1阻滞前列腺癌PC3细胞周期

摘要

Objective:To observe the effects of double-stranded small interfering RNA (siRNA) of the silent mating-type infor-mation regulation 2 homolog 1 (SIRT1) on the cell proliferation, cell cycle progression, and expression levels of the cell cycle negative regulators. These regulators include P21, P27, and phosphorylated retinoblastoma (PRb) proteins present in prostate cancer PC3 cells. This work further aims to explore the possible underlying mechanism for such effects. Methods:PC3 cells were cultured in vitro and then randomly divided into the mock group, scramble siRNA transfected group, and SIRT1 siRNA-transfected group. SIRT1 siRNA ef-ficiency was examined through reverse transcription polymerase chain reaction and Western blot analysis. The inhibitory rate of PC3 cell growth was determined through a methyl thiazolyl tetrazolium assay, and the cell cycle was investigated with the use of flow cytom-etry. The P21 and P27 protein expression levels and PRb status were determined by Western blot assay. Results:Compared with those of the mock and scramble siRNA groups, the expression levels of SIRT1 mRNA and protein significantly decreased in SIRT1 siR-NA-transfected cells. In addition, the inhibitory rate of PC3 cell growth was markedly increased, and the cell cycle of the PC3 cells was arrested at the G1 stage. The expression levels of negative cell cycle regulators, including P21 and P27 protein levels increased, whereas Rb protein phosphorylation was inhibited in SIRT1 siRNA-transfected PC3 cells. Conclusion: SIRT1 RNA interference inhibits PC3 cell growth and arrests cell cycle progression through the upregulation of the P21 and P27 proteins and the inhibition of Rb protein phosphorylation.%目的：观察沉默信息调节因子2同源蛋白1（SIRT1）小干扰RNA（siRNA）对前列腺癌PC3细胞生长增殖、细胞周期和P21、P27细胞周期调节蛋白及视网膜母细胞瘤（retinoblastoma，Rb）蛋白表达变化影响，探讨SIRT1在前列腺癌发生中的可能作用机制。方法：体外培养PC3细胞，分空白对照（Mock）组、发夹siRNA对照（scramble siRNA）组和SIRT1 siRNA转染组。RT-PCR和Western blot方法检测SIRT1 siRNA的转染效率；MTT方法测定细胞生长抑制率；流式细胞术检测细胞周期；Western blot方法检测P21、P27蛋白表达和Rb蛋白的磷酸化状态。结果：与Mock组和scramble siRNA组比较，SIRT1 siRNA组SIRT1 mRNA和蛋白表达降低，明显抑制PC3细胞增殖，阻滞在G1期。P21和P27蛋白表达增加，Rb蛋白磷酸化受到抑制。结论：SIRT1 siRNA可抑制前列腺癌PC3细胞增殖、阻滞细胞周期，其机制可能与改变P21、P27细胞周期蛋白表达和Rb蛋白的磷酸化状态相关。