Department of Radiation Oncology, Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou, Henan Province 450008, China.
Radiat Res. 2021 Apr 1;195(4):378-384. doi: 10.1667/RADE-20-00180.1.
Radiotherapy plays an important role in the treatment of hepatocellular carcinoma (HCC). Cyclin G1 is a novel member of the cyclin family, and it is abnormally expressed in HCC. In this study we investigated the role of cyclin G1 in the radiotherapy of HCC cells. The expression of cyclin G1 was silenced by transfection of cyclin G1-siRNA into HepG2 cells and Huh7 cells, and the expression of cyclin G1 mRNA and protein was measured by qRT-PCR and Western blot analysis. The proliferation was analyzed using MTT assay, and the radiosensitivity of HCC cells was detected using colony formation assay and a xenograft tumor model. The expression of apoptosis-related proteins (Bcl-2 and Bax) was detected by Western blot analysis, and caspase-3 was detected using fluorimetry. The expression of cyclin G1 mRNA and protein in HepG2/Huh7-cyclin G1-siRNA cells was found to be significantly decreased compared to that in HepG2/Huh7 cells. Silencing the expression of cyclin G1 inhibited the proliferation of HCC cells and enhanced radiosensitivity in HCC cells in vitro and in vivo. Knockdown of cyclin G1 expression significantly decreased Bcl-2 expression, and increased Bax expression and caspase-3 activity in HCC cells. Silencing of cyclin G1 expression enhances the radiosensitivity of HCC cells in vitro and in vivo. The mechanism for this may be related to the regulation of apoptosis-related proteins.
放射治疗在肝细胞癌（HCC）的治疗中起着重要作用。细胞周期蛋白 G1 是细胞周期蛋白家族的一个新成员，在 HCC 中异常表达。在本研究中，我们研究了细胞周期蛋白 G1 在 HCC 细胞放射治疗中的作用。通过转染细胞周期蛋白 G1-siRNA 沉默 HepG2 细胞和 Huh7 细胞中的细胞周期蛋白 G1 表达，并用 qRT-PCR 和 Western blot 分析测量细胞周期蛋白 G1 mRNA 和蛋白的表达。用 MTT 分析检测细胞增殖，用集落形成实验和异种移植肿瘤模型检测 HCC 细胞的放射敏感性。用 Western blot 分析检测凋亡相关蛋白（Bcl-2 和 Bax）的表达，用荧光法检测 caspase-3。与 HepG2/Huh7 细胞相比，HepG2/Huh7-cyclin G1-siRNA 细胞中细胞周期蛋白 G1 mRNA 和蛋白的表达明显降低。沉默细胞周期蛋白 G1 的表达抑制 HCC 细胞的增殖，并增强 HCC 细胞在体外和体内的放射敏感性。下调细胞周期蛋白 G1 表达显著降低 HCC 细胞中 Bcl-2 的表达，增加 Bax 的表达和 caspase-3 的活性。沉默细胞周期蛋白 G1 的表达增强 HCC 细胞在体外和体内的放射敏感性。其机制可能与凋亡相关蛋白的调节有关。
