S 腺苷甲硫氨酸脱羧酶基因沉默抑制乳腺癌MCF7细胞生长的研究

目的探讨S 腺苷甲硫氨酸脱羧酶（SAMDC）基因沉默对乳腺癌MCF 7细胞增殖及侵袭能力的抑制作用。方法用特异性沉默SAMDC基因表达的RNA干扰真核表达载体SAMDC shRNA表达载体(pGPU6 SAMDC)转染乳腺癌MCF 7细胞，采用RT PCR和Western blot技术分别检测SAMDC mRNA和蛋白质表达水平；细胞增殖实验（CCK 8法）和细胞周期分析评价SAMDC基因沉默对乳腺癌MCF 7细胞增殖的影响，肿瘤侵袭实验观察SAMDC基因沉默对乳腺癌细胞MCF 7侵袭活性的影响。结果SAMDC shRNA表达载体转染后，MCF 7细胞SAMDC mRNA水平下调43.8％，蛋白表达水平下降66.5％；MCF 7细胞的增殖活性和侵袭能力均受到明显抑制，细胞增殖活性下降37%，细胞周期分析G1期细胞增加。结论SAMDC基因沉默可通过延长细胞周期的G1期而抑制乳腺癌MCF7细胞的增殖,并能降低癌细胞侵袭活性，提示SAMDC可作为乳腺癌基因治疗的靶分子。

Gene silencing of S-adenosylmethionine decarboylase inhibits growth of breast cancer MCF-7 cells

Objective To investigate the inhibitory effect of the S-adenosylmethionine decarboylase (SAMDC) gene silencing on proliferation and invasion of breast cancer MCF-7 cells. Methods Breast cancer MCF-7 cells were transfected with a short hairpin RNA eukaryotic expression vector against SAMDC (pGPU6-SAMDC). The effect of suppressing proliferation of MCF-7 cells was detected by cell proliferation assay(CCK-8) and cell cycle analysis. Semi-quantitative RT-PCR analysis of mRNA and western blot analysis of proteins were used to determine expression of the SAMDC gene. The invasive ability of breast cancer MCF-7 cells was assessed by invasion assay in vitro. Results After the shRNA expression vector was transfected into breast cancer MCF-7 cells, the growth and invasive ability of MCF-7cells were significantly inhibited, and the proliferation of cells was decreased by 37 % . Gene expression of SAMDC in MCF-7 cells was also significantly inhibited, of mRNA was inhibited by 43.8 % and of protein was inhibited by 66.5% . Moreover, the proportion of MCF-7 cells in the G_0/G_1 phase was increased. Conclusion The shRNA of the SAMDC gene can effectively inhibit the proliferation and invasion of MCF-7 cells and is a potential target in gene therapy of breast cancer.