Zhang Haichen, Chu Tong, Zheng Jin, Teng Yun, Ma Ruilan, Zou Lijuan, Zhao Haidong
Second Hospital of Dalian Medical University, 467 Zhongshan Road, Shahekou District, Dalian City, Liaoning Province, China.
Med Oncol. 2022 Dec 31;40(2):68. doi: 10.1007/s12032-022-01890-x.
Dinaciclib is a selective cyclin-dependent kinase inhibitor, but its radiosensitizing effect remains unclear. The aim of this study is to investigate the radiosensitizing effect of Dinaciclib on cervical cancer cells. Two cervical cancer cell lines, Hela and Siha, were selected, and the IC50 was determined by CCK8. The radiosensitizing effect of Dinaciclib was verified by plate cloning assay, and the G2/M phase arrest and apoptosis of IR cells were verified by flow cytometry. Immunofluorescence assay was used to verify the formation of γH2AX foci following DNA damage. Western blot was performed to detect cell cycle, apoptosis, autophagy, and DNA damage-related pathways. Dinaciclib increased the cell sensitivity to IR. IR induced G2/M phase arrest and apoptosis, and Dinaciclib enhanced this effect. Further, Dinaciclib delayed DNA repair, including non-homologous end joining repair and homologous recombination repair, and reduced the expression of DNA repair proteins Ku80 (SiHa cells), Ku70, and RAD51, as well as the expression of apoptotic marker Bcl-2. The expression of autophagy marker Beclin1 induced tumor cell death and increased the formation of DNA damage marker γH2AX foci. Dinaciclib improves the sensitivity of cervical cancer cells to IR by inducing cell cycle arrest, delaying DNA repair, and increasing apoptosis. However, further research is needed to unravel the complexity of DNA repair pathways.
地西他滨是一种选择性细胞周期蛋白依赖性激酶抑制剂，但其放射增敏作用尚不清楚。本研究旨在探讨地西他滨对宫颈癌细胞的放射增敏作用。选取两种宫颈癌细胞系Hela和Siha，采用CCK8法测定IC50。通过平板克隆实验验证地西他滨的放射增敏作用，采用流式细胞术验证IR细胞的G2/M期阻滞和凋亡。采用免疫荧光实验验证DNA损伤后γH2AX焦点的形成。进行蛋白质免疫印迹法检测细胞周期、凋亡、自噬和DNA损伤相关通路。地西他滨增加了细胞对IR的敏感性。IR诱导G2/M期阻滞和凋亡，地西他滨增强了这种作用。此外，地西他滨延迟了DNA修复，包括非同源末端连接修复和同源重组修复，并降低了DNA修复蛋白Ku80（SiHa细胞）、Ku70和RAD51的表达，以及凋亡标志物Bcl-2的表达。自噬标志物Beclin1的表达诱导肿瘤细胞死亡并增加DNA损伤标志物γH2AX焦点的形成。地西他滨通过诱导细胞周期阻滞、延迟DNA修复和增加凋亡来提高宫颈癌细胞对IR的敏感性。然而，需要进一步研究来阐明DNA修复途径的复杂性。
