Page 7 - 南京医科大学自然版

第45卷第11期 南京医科大学学报（自然科学版）
2025年11月 Journal of Nanjing Medical University（Natural Sciences） ·1537 ·

·专题研究：肿瘤·

RNA结合蛋白RBMS3通过稳定p21 mRNA抑制乳腺癌增殖

戴欣媛 ，夏 天 ，朱 磊 ，奚佩雯 ，吴 靓 ，丁 强 ，石 靓 1*
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南京医科大学第一附属医院乳腺中心，江苏 南京 210029；南京医科大学附属妇产医院乳腺科，江苏 南京 210004
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［摘 要］ 目的：探讨RNA结合基序单链作用蛋白3（RNA binding motif single stranded interacting protein 3，RBMS3）在乳腺癌
增殖中的作用及其在转录后水平调控细胞周期蛋白依赖性激酶抑制剂 1A（cyclin⁃dependent kinase inhibitor 1A，CDKN1A，又称
p21）稳定性的分子机制。方法：在体外通过集落形成和5⁃乙炔基⁃2’⁃脱氧尿苷（5⁃ethynyl⁃2’⁃deoxyuridine，EdU）掺入实验检测
细胞增殖能力；流式细胞术分析细胞周期分布和凋亡率；构建裸鼠皮下移植瘤模型，观察RBMS3对体内肿瘤生长的作用。采
用蛋白质印迹法、实时荧光定量聚合酶链式反应和免疫组化分析RBMS3与p21的表达相关性；进一步采用放线菌素D实验验
证RBMS3对p21稳定性的影响；通过RNA结合蛋白免疫沉淀实验、双荧光素酶实验和回复实验，证实RBMS3与p21的直接结
合及相互作用。结果：RBMS3过表达可抑制乳腺癌细胞增殖和裸鼠移植瘤的生长，诱导G0/G1期细胞阻滞并促进细胞凋亡；反
之，RBMS3敲降可促进乳腺癌细胞增殖。此外，RBMS3与p21呈显著正相关，且RBMS3可直接结合p21 mRNA 的3′非翻译区
（3′⁃untranslated region，3′⁃UTR）AU富集元件（AU⁃rich element，ARE），提高p21mRNA的稳定性；敲降p21可逆转RBMS3对乳腺
癌增殖的抑制作用。结论：RBMS3通过直接结合p21 3′⁃UTR的ARE并增强p21 mRNA的稳定性，上调p21的表达，进而抑制乳
腺癌细胞的增殖。上述发现提示RBMS3可能成为乳腺癌治疗的潜在靶点。
［关键词］ RBMS3；p21；mRNA稳定性；乳腺癌
［中图分类号］ R737.9 ［文献标志码］ A ［文章编号］ 1007⁃4368（2025）11⁃1537⁃10
doi：10.7655/NYDXBNSN250837

The RNA binding protein RBMS3 inhibits breast cancer proliferation by stabilizing p21
mRNA

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DAI Xinyuan ，XIA Tian ，ZHU Lei ，XI Peiwen ，WU Jing ，DING Qiang ，SHI Liang 1*
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1 Breast Center，the First Affiliated Hospital of Nanjing Medical University，Nanjing 210029；Department of Breast
Surgery，the Affiliated Obstetrics and Gynaecology Hospital of Nanjing Medical University，Nanjing 210004，China
［Abstract］ Objective：To investigate the role and molecular mechanism of RNA binding motif single stranded interacting protein 3
（RBMS3）in the proliferation of breast cancer and its molecular mechanism by regulating the stability of cyclin⁃dependent kinase
inhibitor 1A（CDKN1A，p21）at the post⁃transcriptional level. Methods：Colony formation and 5⁃ethynyl⁃ 2′⁃deoxyuridine（EdU）
incorporation assays were used to evaluate cell proliferation ability in vitro. Flow cytometry was applied to analyze cell cycle
distribution and apoptosis rate. Xenograft tumor model in nude mice was established to observe the effect of RBMS3 on tumor growth in
vivo. The correlation between RBMS3 and p21 expression was detected by Western blot，quantitative reverse transcription polymerase
chain reaction，and immunohistochemistry. Furthermore，an actinomycin D assay was performed to verify the effect of RBMS3 on p21
mRNA stability. RNA immunoprecipitation assay，dual⁃luciferase reporter assay，and rescue experiment were conducted to confirm the
direct binding and functional interaction between RBMS3 and p21. Results：Overexpression of RBMS3 inhibited the proliferation of
breast cancer cells and the growth of xenograft tumors in nude mice，induced G0/G1 phase cell cycle arrest，and promoted apoptosis.
Conversely，knockdown of RBMS3 promoted breast cancer cell proliferation. Furthermore，RBMS3 expression was significantly
positively correlated with p21. RBMS3 directly bound to AU⁃rich elements（ARE）in the 3′ untranslated region（3′⁃UTR）of p21
mRNA and enhanced the stability of p21 transcripts. Knockdown of p21 reversed the inhibition in breast cancer cell proliferation
induced by RBMS3 overexpression. Conclusion：RBMS3 upregulates p21 expression by directly binding to the ARE in the 3′⁃UTR of

［基金项目］ 国家自然科学基金（82303044）
通信作者（Corresponding author），E⁃mail：shiliang@njmu.edu.cn（ORCID：0000⁃0003⁃1177⁃7918）
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