cyclin G2在乳腺病变组织中表达及其对MCF-7细胞的作用

Expression of cyclin G2 in breast diseases and its effect on breast cancer cell line MCF-7

目的研究细胞周期蛋白G2(cyclin G2)在乳腺病变中的表达及意义,探讨cyclin G2对乳腺癌MCF-7细胞凋亡的影响。方法用免疫组化SP法检测cyclin G2在人乳腺不同病变中的蛋白表达,并进行显微图像分析;利用阳离子介导的脂质体法转染pDsRed2-cyclin G2融合基因至人乳腺癌细胞系MCF-7细胞中,流式细胞术检测MCF-7细胞的凋亡率。结果 (1)cyclinG2在乳腺增生症中的阳性表达率及表达强度与正常乳腺组织相当,而在导管原位癌(ductal carcinoma in situ,DCIS)以及浸润性导管癌(invasive ductal carcinoma,IDC)中表达逐渐下降,差异有统计学意义(P<0.05)。(2)转染了重组质粒pDsRed2-cyc-lin G2的MCF-7细胞凋亡率明显增高(P<0.01)。结论 cyclin G2蛋白表达随着乳腺疾病恶性程度增加而降低,外源性转染cyclin G2至MCF-7细胞中可促进其凋亡,抑制细胞增殖。

Purpose To study the expression of cyclin G2 in breast diseases,and its influence on breast cancer cell line MCF-7 cell in vitro.Methods Different breast diseases were examined by immunohistochemical technique to observe cyclin G2 expression and analyze the positive rates and the change of average gray value by micro-image analysis system.The pDsRed2-cyclin G2 fusion protein expression vector was transferred into MCF-7 cell through cation lipofectamine reagent.The apoptosis was analyzed by FCM after 48 hours.Results The positive expression ratio and intensity of cyclin G2 had no significant difference between normal breast tissues and hyperplastic breast tissue（P0.05）,but the expression of cyclin G2 in normal breast tissues and hyperplastic breast tissue was significantly decreased as compared with that in DCIS（P0.05） and IDC（P0.01）.After transfected pDsRed2-cyclin G2 fusion protein expression vector,MCF-7 cells showed partly apoptosis（54.23%）,which was higher than the common MCF-7 cells（0.21%） and the cells transfected with pDsRed2-N1 vector（27.16%）（P0.01） after 48 hours by FCM.Conclusions The expression level of cyclin G2 is associated with the differentiation degree of breast diseases.The pDsRed2-cyclin G2 fusion protein can promote the apoptosis of MCF-7 cells,and inhibit the proliferation of the cells.