PDF(Pubmed)
Abstract：
Targeting CDC20 can enhance the radiosensitivity of tumor cells, but the function and mechanism of CDC20 on DNA damage repair response remains vague. To examine that issue, tumor cell lines, including KYSE200, KYSE450, and HCT116, were utilized to detect the expression, function, and underlying mechanism of CDC20 in radio-chemoresistance. Western blot and immunofluorescence staining were employed to confirm CDC20 expression and location, and radiation could upregulate the expression of CDC20 in the cell nucleus. The homologous recombination (HR) and non-homologous end joining (NHEJ) reporter gene systems were utilized to explore the impact of CDC20 on DNA damage repair, indicating that CDC20 could promote HR repair and radio/chemo-resistance. In the early stages of DNA damage, CDC20 stabilizes the RPA1 protein through protein-protein interactions, activating the ATR-mediated signaling cascade, thereby aiding in genomic repair. In the later stages, CDC20 assists in the subsequent steps of damage repair by the ubiquitin-mediated degradation of RPA1. CCK-8 and colony formation assay were used to detect the function of CDC20 in cell vitality and proliferation, and targeting CDC20 can exacerbate the increase in DNA damage levels caused by cisplatin or etoposide. A tumor xenograft model was conducted in BALB/c-nu/nu mice to confirm the function of CDC20 in vivo, confirming the in vitro results. In conclusion, this study provides further validation of the potential clinical significance of CDC20 as a strategy to overcome radio-chemoresistance via uncovering a novel role of CDC20 in regulating RPA1 during DNA damage repair.
摘要：
靶向CDC20可以增强肿瘤细胞的放射敏感性,但CDC20对DNA毁伤修复反响的感化和机制依然隐约。为了研究这个问题，肿瘤细胞系，包括KYSE200，KYSE450和HCT116，用于检测表达，函数,以及CDC20在放射性化疗耐药中的潜在机制。Westernblot和免疫荧光染色证实CDC20的表达和定位。辐射可以上调细胞核中CDC20的表达。利用同源重组（HR）和非同源末端连接（NHEJ）报告基因系统探索CDC20对DNA损伤修复的影响。表明CDC20可以促进HR修复和放射/化疗抵抗。在DNA损伤的早期阶段,CDC20通过蛋白质-蛋白质相互作用稳定RPA1蛋白，激活ATR介导的信号级联，从而帮助基因组修复。在后期阶段,CDC20通过泛素介导的RPA1降解辅助损伤修复的后续步骤。CCK-8和集落形成实验检测CDC20在细胞活力和增殖中的作用,和靶向CDC20可以加剧由顺铂或依托泊苷引起的DNA损伤水平的增加。在BALB/c-nu/nu小鼠中进行肿瘤异种移植模型以证实CDC20在体内的功能。确认体外结果。总之,本研究通过揭示CDC20在DNA损伤修复过程中调节RPA1的新作用,进一步验证了CDC20作为克服放射化疗耐药的策略的潜在临床意义.
