Zeng Zhiyu, Mai Meiqing, Wang Dandan, Ouyang Jie, Chen Zhiru, Zhong Jingjing, Rao Jinjun
Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Science, Southern Medical University, Guangzhou, China.
Department of Pharmacy, Guangxi International Zhuang Medicine Hospital, Nanning, China.
Clinics (Sao Paulo). 2025 Apr 4;80:100637. doi: 10.1016/j.clinsp.2025.100637. eCollection 2025.
Retinoblastoma-Binding Protein 4 (RBBP4), belonging to the WD-40 family, is an important member of the Polycomb Repressor Complex 2 (PRC2), the Nucleosome Remodeling and Deacetylation complex (NuRD), and is involved in chromatin remodeling, histone deacetylation, and H3K27 methylation.
The effects of cisplatin treatment on cell viability were evaluated using the MTT assay. Western blotting was employed to analyze protein expression, and RNA interference-mediated knockdown of RBBP4 and cyclin D1 was conducted using Lipofectamine 2000. The formation of colonies was evaluated following a 14-day cisplatin treatment period. Cisplatin uptake was quantified by atomic absorption spectrophotometry. RNA sequencing was conducted on total RNA extracted from cells, and lentiviral vectors were employed for gene overexpression, followed by puromycin selection. Immunohistochemistry was performed on tissue microarrays of lung and cervical adenocarcinoma in order to evaluate RBBP4 expression.
In this study, cisplatin was found to induce RBBP4 expression in human lung cancer A549 cells, and RBBP4 expression in cisplatin-resistant A549/DDP cells was significantly higher than in A549 cells. Downregulating RBBP4 expression by small interfering RNA significantly increased the sensitivity of A549 and A549/DDP cells to cisplatin. Conversely, lentiviral-mediated RBBP4 overexpression reduced sensitivity to cisplatin. Mechanistic studies showed that downregulated RBBP4 increased cell sensitivity to cisplatin mainly by inhibiting cyclinD1 expression, and lentiviral-mediated cyclinD1 caused the opposite effects. These same results were verified in human HeLa cells and in cisplatin-resistant HeLa/DDP cells.
This study showed that RBBP4 regulates the sensitivity of tumor cells to cisplatin and is a potential target for reversing cisplatin resistance in tumor cells.
视网膜母细胞瘤结合蛋白4（RBBP4）属于WD-40家族，是多梳抑制复合物2（PRC2）、核小体重塑与去乙酰化复合物（NuRD）的重要成员，参与染色质重塑、组蛋白去乙酰化和H3K27甲基化。
采用MTT法评估顺铂处理对细胞活力的影响。运用蛋白质免疫印迹法分析蛋白质表达，并使用Lipofectamine 2000进行RNA干扰介导的RBBP4和细胞周期蛋白D1敲低。在14天的顺铂处理期后评估集落形成情况。通过原子吸收分光光度法定量顺铂摄取量。对从细胞中提取的总RNA进行RNA测序，并使用慢病毒载体进行基因过表达，随后进行嘌呤霉素筛选。对肺癌和宫颈腺癌组织芯片进行免疫组织化学以评估RBBP4表达。
在本研究中，发现顺铂可诱导人肺癌A549细胞中RBBP4表达，顺铂耐药的A549/DDP细胞中RBBP4表达显著高于A549细胞。通过小干扰RNA下调RBBP4表达可显著增加A549和A549/DDP细胞对顺铂的敏感性。相反，慢病毒介导的RBBP4过表达降低了对顺铂的敏感性。机制研究表明，下调RBBP4主要通过抑制细胞周期蛋白D1表达增加细胞对顺铂的敏感性，慢病毒介导的细胞周期蛋白D1则产生相反作用。在人HeLa细胞和顺铂耐药的HeLa/DDP细胞中也验证了相同结果。
本研究表明RBBP4调节肿瘤细胞对顺铂的敏感性，是逆转肿瘤细胞顺铂耐药的潜在靶点。
