TSG101的下调对乳腺癌细胞的作用

张莹; 宋宁; 崔泽实; 王恩华; 宋敏

doi:10.3969/j.issn.1000-8179.2011.02.003

摘要: 目的：研究肿瘤易感基因101（tumor susceptibility gene 101，TSG101）的下调对人乳腺癌细胞系MCF-7细胞的作用及TSG101在乳腺癌组织中的表达。方法：应用脂质体法将靶向TSG101的小干扰RNA （small interfering RNA，siRNA）转染入乳腺癌细胞系MCF-7细胞中。分别使用MTT法、流式细胞仪、 transwell小室法检测siRNA干扰后MCF-7细胞增殖能力、细胞周期、细胞凋亡率和细胞迁移能力的变化。使用免疫组织化学方法检测TSG101在54例乳腺浸润性导管癌及癌旁正常乳腺组织中的表达。结果：MTT结果显示，TSG101 siRNA转染后的MCF-7细胞与对照组相比，增殖能力减弱。细胞周期结果显示，TSG101 siRNA转染后的MCF-7细胞周期G0/G1期及S期比例（70.51±0.23； 23.65±0.78）与对照组（59.15±0.77，34.96±0.45）、（59.21±0.68，34.89±0.30）相比，G0/G1 期比例增多， S期比例减少。细胞凋亡结果显示， TSG101 siRNA转染后的MCF-7细胞（13.71±1.31）与对照组（4.37±0.87）、（6.00±0.08）相比，细胞凋亡率增加。细胞迁移结果显示， TSG101 siRNA转染后的MCF-7细胞（4.60±0.80）与对照组（24.47±1.90）、（23.80±2.20）相比，细胞迁移能力减弱。免疫组化实验结果显示， TSG101蛋白主要定位于乳腺癌细胞质和（或）细胞核内，呈棕黄色颗粒。54例乳腺癌组织中TSG101阳性表达40例（74.07%），TSG101在癌旁正常乳腺组织中不表达或呈微弱的胞质表达， TSG101在乳腺癌组织中的表达高于癌旁正常乳腺组织。结论： TSG101的下调能够抑制乳腺癌细胞系MCF-7细胞的增殖，诱导凋亡，阻滞细胞周期于G1/S期，并且降低其迁移能力。TSG101可能参与乳腺癌的发生、发展过程。

Abstract: The Effect of Small Interfering RNATargeting TSG101 in Breast Cancer CellsYing ZHANG1, Ning SONG2, Zeshi CUI1, EnhuaWANG3, Min SONG3Correspondence to: Min SONG, E-mail: songmin6@sohu.com1The Third Division of Medical Laboratory Technology Center, China Medical University, Shenyang 110001, China2Department of Obstetrics and Gynecology, The Second Affiliated Hospital of China Medical University, Shenyang 110004, China3Department of Pathology, College of Basic Medical Sciences, China Medical University, Shenyang 110001, ChinaThis work was supported by the Fund of Scientific Project of Higher Education of Liaoning Province (No. 2008739)Abstract Objective: To investigate the effect of downregulating the tumor susceptibility gene 101 (TSG101) in the MCF-7 hu-man breast cancer cell line and the expression of TSG101 in breast cancer tissue. Methods: TSG101 siRNA was transfected into breastcancer MCF-7 cells via lipofection. The proliferation ability of transfected MCF-7 cells was tested by MTT. The cell cycle and apopto-sis of MCF-7 cells before and after transfection were examined with flow cytometry. Changes in migratory capacity of MCF-7 cells be-fore and after transfection were measured by Transwell migration assay. Immunohistochemistry was employed to detect the expressionof TSG101 proteins in cancer tissue and neighboring noncancerous tissue from 54 cases of human breast invasive ductal carcinoma. Re-sults: TSG101 siRNA transfected cells were significantly slower than the control groups in the rate of cell proliferation. The percentageof TSG101 siRNA transfected cells in stage G0/G1 was 70.51±0.23, significantly higher than that of the control groups (59.15 ± 0.77;59.21±0.68); the percentage of TSG101 siRNA transfected cells in stage S was 23.65 ± 0.78, significantly lower than that of the controlgroups (34.96 ± 0.45; 34.89 ± 0.30). The apoptosis rate of TSG101 siRNA transfected cells was 13.71±1.31, significantly higher thanthat of the control groups (4.37 ± 0.87) (6.00 ± 0.08). The migratory capacity of the TSG101 siRNA transfected cells was 4.60 ± 0.80,lower than that of the control groups (24.47 ± 1.90) (23.80±2.20). TSG101 protein expression was located in the cytoplasm and/or thenucleus. The expression rate of TSG101 protein in breast cancer tissue was 74.07% (40/54). There was no expression or only weak ex-pression of TSG101 protein in the neighboring noncancerous tissue. Conclusions: Breast cancer cells had decreased proliferation andincreased apoptosis when transfected with TSG101 siRNA. The cell cycle of TSG101 siRNA transfected breast cancer cells was arrest-ed at G1/S. Inhibition of TSG101 protein expression by TSG101 siRNA decreased the migratory capacity of breast cancer cells. TSG101may play an important role in the pathogenesis and progression of breast cancer.Keywords Breast neoplasm; Tumor susceptibility gene 101; Small interfering RNA