中文摘要：

目的：研究转染蛋白酶体激活因子REGγ基因的乳腺癌MDA-MB-231细胞在裸鼠体内的成瘤作用及其机制。方法：以脂质体转染法将构建的重组质粒pcDNA3.1-REGγ导入MDA-MB-231细胞,以G418（600mg/L）筛选获得稳定高表达该基因的细胞株（实验组）。以转染空载体及未施加处理因素的细胞作为对照组。将此3组细胞接种于裸鼠皮下,观察移植瘤的生长情况并计算抑瘤率。RT-PCR检测REGγ基因在移植瘤中的表达,FCM检测移植瘤的肿瘤浸润淋巴细胞（tumor-infiltra-tinglymphocyte,TIL）中CD16的表达以及肿瘤细胞周期和细胞凋亡,免疫组织化学法检测移植瘤中p^21的表达。结果：与对照组相比,实验组的移植瘤生长速度较快、体积较大,瘤体质量明显增加（P〈0.05）;REGγ基因在移植瘤中的表达增加（P〈0.01）;FCM检测提示CD16阳性率明显降低（P〈0.05）;G0/G1和G2/M期细胞减少,S期细胞明显增多,肿瘤细胞的凋亡率明显降低（P〈0.05）;p^21的表达明显降低（P〈0.05）。结论：REGγ基因在体内具有促进乳腺癌发生、发展的作用,其机制可能与加速细胞周期、抑制细胞凋亡、抑制自然杀伤细胞活化以及对p^21的特异性降解有关。

英文摘要：

Objiective：To study the tumorigenesis of human breast cancer MDA-MB-231 cells in nude mice after transfection with REGy gene （ a kind of proteasome activating factor） and the related mechanism. Methods：REC,.y gene was transfeeted into MDAMB-231 cells in peDNA3.1 vector via lipofectin mediation. The stable clones were selected by G418 600 mg/L. The cells without transfection and transfected with empty vector were regarded as control groups. Three groups of cells were inoculated subcutaneously into nude mice. The growth of transplanted tumors was observed and the tumor inhibition ratio was calculated. The expression of REGy gene in tumor tissues was detected by RT-PCR. The expression of CD16 in tumor-infiltrating lympbocytes （TIL） and the cell cycle and apoptosis were determined by flow cytometry. The expression of p^21 in transplanted tumors was examined by immunohistoehemisty. Results： As compared with control groups, xenografted tumor in REGy gene transfection group showed faster growth speed, larger tumor volume, and increased tumor weight （P 〈 0.05 ）. The expression of REGy gene in tumors was markedly increased （ P 〈 0.01 ）. The expression of CD16 in TIL was greatly decreased （P 〈 0.05 ） and the cell proportion in Go/G1 phase and G2/M phase decreased significantly but the cell percentage in S phase was obviously increased. The apoptotic ratio and the expression of p^21 were obviously reduced （ P 〈 0.05 ）. Conclusion ：REGy gene promotes the tumorigenesis and progress of breast cancer cells in nude mice. The mechanism may be explained by its effects of accelerating cell cycle, inhibiting apoptosis, suppressing the activation of NK cells, and specifically degrading p^21.