Oncology Department, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong 518100, P.R. China.
Pathology Department, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong 518100, P.R. China.
Oncol Rep. 2020 Sep;44(3):849-862. doi: 10.3892/or.2020.7659. Epub 2020 Jun 24.
Prostate cancer (PCa) remains a leading cause of mortality among men in the United States and Western Europe. The molecular mechanism of PCa pathogenesis has not been fully elucidated. In the present study, the expression profile of E2F transcription factor 7 (E2F7) in PCa was examined using immunohistochemistry and reverse transcription‑quantitative PCR, whilst cell cycle progression and apoptosis were determined using fluorescent cell activated sorting techniques. Cell viability was measured using Cell Counting Kit‑8 in loss‑ and gain‑of‑function studies. Dual‑luciferase reporter assay was used to verify if E2F7 was one of the potential targets of miR‑30c. The staining score of E2F7 of PCa tissues was found to be notably higher compared with that of adjacent normal tissues. Suppression of E2F7 expression in PCa cell lines led to significantly reduced proliferation rates, increased proportion of cells in the G1 phase of the cell cycle and higher apoptotic rates compared with those in negative control groups. Dual‑luciferase reporter assay revealed E2F7 to be one of the binding targets of microRNA (miR)‑30c. In addition, transfection of miR‑30c mimics into PCa cells resulted in reduced cell viability, increased proportion of cells in the G1 phase and higher apoptotic rates. By contrast, transfection with the miR‑30c inhibitor led to lower apoptosis rates of PCa cells compared with negative control groups, whilst E2F7 siRNA co‑transfection reversed stimulatory effects of miR‑30c inhibitors on cell viability. In addition, the expression of cyclin‑dependent kinase inhibitor p21 were found to be upregulated by transfection with either E2F7 siRNA or miR‑30c mimics into PCa cells. In conclusion, the present study suggested that E2F7 may be positively associated with PCa cell proliferation by inhibiting p21, whereas E2F7 is in turn under regulation by miR‑30c. These observations suggest the miR‑30c/E2F7/p21 axis to be a viable therapeutic target for PCa.
前列腺癌（PCa）仍然是美国和西欧男性死亡的主要原因。PCa 发病机制的分子机制尚未完全阐明。在本研究中，通过免疫组织化学和逆转录定量 PCR 检查了 E2F 转录因子 7（E2F7）在 PCa 中的表达谱，同时通过荧光细胞激活分选技术确定了细胞周期进程和细胞凋亡。在缺失和获得功能研究中使用细胞计数试剂盒-8 测量细胞活力。双荧光素酶报告基因检测用于验证 E2F7 是否是 miR-30c 的潜在靶标之一。与相邻正常组织相比，PCa 组织中 E2F7 的染色评分明显更高。与阴性对照组相比，PCa 细胞系中 E2F7 表达的抑制导致增殖率显著降低，细胞周期 G1 期的比例增加，凋亡率升高。双荧光素酶报告基因检测显示 E2F7 是 microRNA（miR）-30c 的结合靶标之一。此外，将 miR-30c 模拟物转染到 PCa 细胞中导致细胞活力降低，G1 期细胞比例增加，凋亡率升高。相反，与阴性对照组相比，转染 miR-30c 抑制剂可降低 PCa 细胞的凋亡率，而 E2F7 siRNA 共转染则逆转了 miR-30c 抑制剂对细胞活力的刺激作用。此外，发现转染 E2F7 siRNA 或 miR-30c 模拟物均可上调 PCa 细胞中细胞周期蛋白依赖性激酶抑制剂 p21 的表达。综上所述，本研究表明 E2F7 可能通过抑制 p21 与 PCa 细胞增殖呈正相关，而 E2F7 又受到 miR-30c 的调节。这些观察结果表明，miR-30c/E2F7/p21 轴可能是 PCa 的一种可行的治疗靶标。
