miR-27b-3p通过靶向PLK2促进乳腺癌细胞的辐射抵抗  

Elevated miR-27b-3p enhances the radioresistance by targeting PLK2 in breast cancer

作　　者：张松灵 朱长春 冯国兴 樊赛军[1] Zhang Songling;Zhu Changchun;Feng Guoxing;Fan Saijun(Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine,Institute of Radiation Medicine,Chinese Academy of Medical Sciences and Peking Union Medical College,Tianjin 300192,China)

机构地区：[1]中国医学科学院北京协和医学院放射医学研究所、天津市放射医学与分子核医学重点实验室,天津300192

出　　处：《中华放射医学与防护杂志》2023年第6期409-417,共9页Chinese Journal of Radiological Medicine and Protection

基　　金：中国医学科学院医学与健康科技创新工程重大协同创新项目(2021⁃I2M⁃1⁃042)。

摘　　要：目的研究miR-27b-3p对乳腺癌细胞辐射抵抗的影响。方法通过检索基因表达(GEO)数据库,筛选分析miR-27b-3p在正常乳腺组织和乳腺癌组织中的表达水平。利用实时荧光定量PCR技术分析其在不同乳腺癌细胞系中的表达水平。通过细胞克隆形成、免疫荧光和5-乙炔基-2'-脱氧尿苷(EDU)检测技术评价miR-27b-3p对乳腺癌细胞辐射抵抗作用。采用荧光素酶报告基因技术确定miR-27b-3p的靶基因PLK2,并在乳腺癌细胞中进一步验证miR-27b-3p的辐射抵抗作用。结果与正常乳腺组织和细胞相比,miR-27b-3p在乳腺癌组织(t=2.99,P<0.01)和乳腺癌细胞中表达水平显著上调(t=21.21、32.88,P<0.05)。尤其在抗辐射细胞MCF-7R中升高更加明显(t=25.63,P<0.05)。过表达miR-27b-3p增强了MCF-7细胞的克隆形成能力(t=10.32,P<0.05),且随着辐照剂量的增加,miR-27b-3p对MCF-7增殖能力的保护效应逐渐凸显(t=8.77、8.26、8.03,P<0.05);干扰miR-27b-3p则抑制MCF-7R细胞克隆形成数(t=40.00,P<0.05),且随着辐照剂量的增加,进一步削弱了MCF-7R细胞的增殖能力(t=8.54、8.32、8.23,P<0.05)。报告基因实验结果表明,PLK2是miR-27b-3p的直接靶标。过表达PLK2抑制了miR-27b-3p介导的乳腺癌细胞辐射抵抗(MCF-7:t=9.66,P<0.05;MCF-7R:t=6.42,P<0.05)。结论miR-27b-3p可通过靶向PLK2提高乳腺癌细胞的辐射抗性。Objective To investigate the effect of miR-27b-3p on radiation resistance of breast cancer cells.Methods The relative expression levels of miR-27b-3p in normal tissues and breast cancer tissues were analyzed through GEO database and verified by the qRT-PCR assay.Cloning formation,immunofluorescence,and EDU assay were used to assess the functions of miR-27b-3p on radioresistance of breast cancer cells.The luciferase reporter assay was used to verify whether miR-27b-3p directly targeted PLK2 mRNA.A rescue experiment was performed to identify the influence of PLK2 overexpression on miR-27b-3p regulated radioresistance.Results The expression level of miR-27b-3p in both breast cancer tissues(t=2.99,P<0.01)and breast cancer cells(t=21.21,32.88,P<0.05)was significantly higher than those in normal breast tissues and cells,especially,it was elevated in radioresistant MCF-7R cells(t=25.63,P<0.05).Overexpression of miR-27b-3p enhanced the cloning efficiency of MCF-7 cells(t=10.32,P<0.05),and had a protective effect on the proliferation of irradiated MCF-7 cells(t=8.77,8.26,8.03,P<0.05).But interference of miR-27b-3p reduced the cloning efficiency and proliferation of MCF-7R cells(t=40.00,P<0.05)after irradiation with different doses(t=8.54,8.32,8.23,P<0.05).Moreover,PLK2 was verified to be a direct target of miR-27b-3p,and overexpression of PLK2 inhibited miR-27b-3p-mediated radioresistance of breast cancer cells(MCF-7:t=9.66,P<0.05;MCF-7R:t=6.42,P<0.05).Conclusions miR-27b-3p contributes to the radioresistance of breast cancer cells by targeting PLK2.

关 键 词：miR⁃27b⁃3p PLK2 乳腺癌细胞 MCF⁃7 辐射抗性 

分 类 号：R737.9[医药卫生—肿瘤]