SNF5 cooperates with RNA helicase DDX5 to resolve R-loop and maintain genome stability in tumor cells

doi:10.3969/j.issn.1009-976X.2026.01.002

Abstract

Abstract: Objective To investigate the role and molecular mechanism of the chromatin remodeling factor SNF5 in tumor cell proliferation and genome stability maintenance. Methods An SNF5-knockout HeLa cell line was generated using CRISPR-Cas9 technology. Cell proliferation and cell cycle distribution were analyzed by EdU incorporation and flow cytometry, respectively. Colony formation assays were performed to evaluate cellular sensitivity to IR, HU, CPT, and MMC treatments. DNA fiber assays were used to assess DNA replication dynamics, and R-loop accumulation was detected by S9.6 immunofluorescence. Potential SNF5-interacting proteins under replication stress were identified by IP-MS, followed by validation of SNF5-DDX5 interaction through co-immunoprecipitation （CoIP） and GST pull-down assay. Results Loss of SNF5 impaired DNA synthesis, increased the proportion of G1-phase cells, and markedly reduced proliferation of tumor cells, accompanied by enhanced sensitivity to DNA-damaging agents. DNA fiber assay revealed slowed replication fork progression in SNF5-deficient cells, while S9.6 staining indicated increased R-loop accumulation. Protein interaction assays confirmed that SNF5 physically associates with the RNA helicase DDX5, cooperating to alleviate R-loop accumulation under replication stress. Conclusion SNF5 promotes DNA replication and tumor cell proliferation by coordinating with DDX5 to resolve R-loop and maintain genomic stability. SNF5 deficiency leads to R-loop accumulation, replication impairment, and increased sensitivity to radio- and chemotherapy, supporting SNF5 as a potential tumor therapeutic target.

Key words: SNF5, DDX5, R-loop, DNA replication stress, genome stability

摘要： 目的探讨染色质重塑因子SNF5在肿瘤细胞增殖和基因组稳定性维持中的作用及其分子机制。方法采用CRISPR-Cas9技术构建SNF5敲除的HeLa细胞株,通过EdU增殖实验和流式细胞术分析细胞增殖及周期变化;利用克隆形成实验评估细胞对IR、HU、CPT和MMC的敏感性;DNA fiber实验检测DNA复制速率;S9.6免疫荧光分析R-loop水平;IP-MS筛选复制压力下SNF5的互作蛋白;通过Co-IP和GST pull-down实验验证SNF5与RNA解旋酶DDX5的相互作用。结果 HeLa细胞中,SNF5缺失导致细胞DNA合成受阻,G1期细胞比例升高;SNF5敲除细胞的增殖能力下降,对放化疗药物的敏感性显著增加。DNA fiber实验显示SNF5敲除细胞复制速率降低,R-loop水平显著升高。蛋白互作分析证实SNF5可与DDX5结合,共同缓解复制压力下的R-loop积累。结论 SNF5通过与RNA解旋酶DDX5协同作用,减少R-loop形成,维持DNA复制速率与基因组稳定性,从而促进肿瘤细胞增殖;SNF5缺失增强了肿瘤细胞对放化疗的敏感性,提示其可能是潜在的抗肿瘤治疗靶点。

关键词: SNF5, R-loop, RNA解旋酶家族, 复制压力, 基因组稳定性

CLC Number:

R730.23

GAO Yuan, XIE Xiaojuan, HU Kaishun. SNF5 cooperates with RNA helicase DDX5 to resolve R-loop and maintain genome stability in tumor cells[J]. Lingnan Modern Clinics In Surgery, 2026, 26(01): 10-21.

高源, 谢晓娟, 胡开顺. SNF5协同RNA解旋酶DDX5缓解R-loop积累维持肿瘤细胞基因组稳定性[J]. 岭南现代临床外科, 2026, 26(01): 10-21.

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