MDM2/MDMX双靶点抑制蛋白在p53突变型乳腺癌中的作用及机制  

The activity and mechanism of MDM2/MDMX inhibitory protein in mt-p53 breast cancer

作　　者：耿倩倩[1] 陈南征[2] 董丹凤[3] 吴胤瑛[3] 李恩孝[3] Geng Qianqian;Chen Nanzheng;Dong Danfeng;Wu Yinying;Li Enxiao(Department of Nuclear Medicine of the First Affiliated Hospital of Xi'an Jiaotong University,Shaanxi Xi'an 710061,China;Thoracic Surgery of the First Affiliated Hospital of Xi'an Jiaotong University,Shaanxi Xi'an 710061,China;Medical Oncology of the First Affiliated Hospital of Xi'an Jiaotong University,Shaanxi Xi'an 710061,China)

机构地区：[1]西安交通大学第一附属医院核医学科,陕西西安710061 [2]西安交通大学第一附属医院胸外科,陕西西安710061 [3]西安交通大学第一附属医院肿瘤内科,陕西西安710061

出　　处：《现代肿瘤医学》2020年第5期713-719,共7页Journal of Modern Oncology

基　　金：国家自然科学基金资助项目(编号:81803015)

摘　　要：目的:明确MDM2/MDMX双靶点抑制蛋白在p53突变型乳腺癌中的抗肿瘤作用及可能机制。方法:采用MTT比色法检测细胞增殖、流式细胞仪测定细胞周期和Annexin V/FITC-PI双染法检测细胞凋亡,明确MDM2/MDMX抑制蛋白对mt-p53乳腺癌的抗肿瘤活性。应用Western Blot检测MDM2、MDMX、p53、p21、PUMA和bax蛋白在mt-p53乳腺癌细胞中的表达水平,初步探讨抑制蛋白抗mt-p53乳腺癌的可能机制。结果:MDM2/MDMX抑制蛋白抑制mt-p53乳腺癌细胞24 h、48 h细胞增殖显著优于Nutlin-3α(P均<0.05)。MDM2/MDMX抑制蛋白干预mt-p53乳腺癌细胞株24 h和48 h后G 0/G 1期的细胞比例明显高于Nutlin-3α(P<0.05)。抑制蛋白诱导mt-p53乳腺癌细胞24 h和48 h凋亡比例为(15.97±1.48)%和(17.80±2.21)%(MDA-MB-231细胞);(11.09±2.45)%和(10.44±2.90)%(BT-474细胞)。mt-p53乳腺癌细胞中,抑制蛋白干预组MDM2和MDMX蛋白表达明显降低,p53蛋白则未见明显变化;PUMA、p21和bax蛋白表达则显著增加。结论:MDM2/MDMX抑制蛋白可抑制mt-p53乳腺癌细胞增殖,阻滞周期于G0/G1期和诱导细胞凋亡。抑制蛋白可抑制MDM2和MDMX蛋白的表达,但未能激活p53蛋白表达,以p53非依赖途径上调p21,bax和PUMA蛋白表达发挥抗乳腺癌活性。Objective:To determine the anti-tumor effect and possible mechanism of MDM2/MDMX dual-target inhibitory protein in p53 mutant breast cancer.Methods:To assess the activity and mechanism of MDM2/MDMX inhibitory protein in mt-p53 breast cancer.Cell viability,cell cycle distribution and apoptosis were detected by MTT assay,flow cytometry(FCM)and Annexin V/FITC-PI staining.MDM2,MDMX,p53,PUMA,bax and p21 proteins were carried out by Western Blot assay.Results:There were significant differences between MDM2/MDMX inhibitory protein and Nutlin-3αin inhibiting cell proliferation of mt-p53 breast cancer cells for 24 h and 48 h(P<0.05).The proportions of G 0/G 1 phase cells treated with MDM2/MDMX inhibitory protein for 24 h and 48 h were significantly higher than that of Nutlin-3αtreatment(P<0.05).The early stage apoptotic cells of MDA-MB-321 treated with MDM2/MDMX inhibitory protein were(15.97±1.48)%for 24 h and(17.80±2.21)%for 48 h[BT-474 cells:(11.09±2.45)%for 24 h and(10.44±2.90)%for 48 h].In mt-p53 breast cancer cells,the expression of MDM2 and MDMX protein was significantly decreased in the inhibitory protein group,and the p53 protein was not significantly changed.The expression of PUMA,p21 and bax protein was all significantly up-regulated.Conclusion:MDM2/MDMX inhibitory protein inhibited cell proliferation,induced cell cycle arrest in G0/G1 phase and apoptosis in mt-p53 breast cancer cells.The inhibitory protein could successfully bind with MDM2 and MDMX,but cannot activate p53 in mt-p53 breast cancer cell.p21,bax and PUMA proteins were up-regulated for realization of antitumor activity by the way of p53-independent in mt-p53 breast cancer.

关 键 词：MDM2 MDMX 重组蛋白 突变型P53 乳腺癌 

分 类 号：R737.9[医药卫生—肿瘤]