敲低SQLE基因对奶牛乳腺上皮细胞增殖及凋亡的影响

为了探讨角鲨烯环氧酶（squalene epoxidase，SQLE）基因对体外培养奶牛乳腺细胞凋亡及增殖的影响，本研究用RNAi技术敲低奶牛乳腺上皮细胞中SQLE基因；用实时荧光定量PCR方法检测奶牛乳腺上皮细胞中SQLE基因及凋亡和周期相关基因的表达；用CCK-8法检测其对细胞增殖的影响；用周期和凋亡检测试剂盒筛选细胞，用流式细胞术准确计数处于不同周期的细胞数和凋亡细胞数。结果显示，奶牛乳腺上皮细胞转染siRNA后，SQLE基因相对表达量显著下降（P<0.05），细胞增殖受到极显著抑制（P<0.01）；G1期细胞数量显著下降（P<0.05），G2期细胞数量没有显著性改变，S期细胞数量显著上升（P<0.05）；肿瘤坏死因子超家族成员6（又称Fas或CD5）的相对表达量显著上升（P<0.05），细胞周期蛋白依赖性激酶抑制剂1B（cyclin dependent kinase inhibitor 1B，P27）相对表达量显著上升（P<0.05），而细胞周期素D1（Cyclin D1）、B淋巴细胞瘤因子2（B-cell lymphoma-2，Bcl-2）、细胞周期蛋白依赖性激酶抑制剂1A（cyclin dependent kinase inhibitor 1A，P21）、Bcl-2相关X蛋白（Bcl-2 associated X，apoptosis regulator，Bax）显著下降（P<0.05）。综上所述，敲低SQLE基因通过调节相关基因的表达抑制乳腺上皮细胞的增殖。

Effects of SQLE Gene Knock-down on Proliferation and Apoptosis of Dairy Cow Mammary Epithelial Cells

In order to explore the effect of SQLE gene on the apoptosis and proliferation of dairy mammary gland cells in vitro,the relative expression of SQLE gene,apoptosis and cycle-related genes of dairy mammary epithelial cells with SQLE gene knockdown were detected by Real-time quantitative PCR.Cells were screened by cycle,apoptosis detection kits and flow cytometry.The results showed that the relative expression of SQLE gene was significantly decreased after siRNA (SQLE siRNA) transfection.The cell proliferation was significantly inhibited (P<0.05).The number of cells in G1 phase significantly decreased (P<0.05),and the proportion of cells in S phase showed an increasing trend (P<0.05).No significant difference in cells in G2 phase.The relative expression of apoptotic gene Fas and proliferation and cycle related genes P27 significantly increased (P<0.05), Cyclin D1,Bcl-2,P21 and Bax genes decreased significantly (P<0.05).In summary,knockdown of SQLE gene could inhibit the proliferation of breast epithelial cells by regulating the expression of related genes.