STC2基因在乳腺癌中的表达及抑制其表达对癌细胞生物学特性的影响研究

Expression of STC2 gene in breast cancer and influence of its expression on biological characteristics of cancer cells

目的:探讨斯钙素-2(STC2)基因在乳腺癌中的表达及抑制其表达对癌细胞增殖、周期及凋亡的影响。方法:RT-PCR及Western blot分别检测乳腺癌组织中STC2基因的mRNA及蛋白表达,并分析其与病理特征的关系;将STC2-siRNA转染人乳腺癌MCF-7细胞,另设空白对照组(Control)和阴性对照组(NC-siRNA),转染48 h后,Western blot检测各组细胞中STC2、ki67、细胞周期素(cyclin D1)、活化的含半胱氨酸的天冬氨酸蛋白水解酶3(Cleaved caspase3)、Notch1、Hes1蛋白表达;CCK8检测细胞增殖;流式细胞仪检测细胞周期及凋亡。结果:STC2基因在乳腺癌中的mRNA及蛋白表达均显著高于癌旁组织(P<0.05);STC2基因表达与乳腺癌患者年龄、组织学分级及是否发生转移无关(P>0.05),与病理分期、肿瘤大小相关(P<0.05);NC-siRNA组STC2的蛋白表达与Control组差异无统计学意义(P>0.05),STC2-siRNA组STC2的蛋白表达显著低于Control组(P<0.05);STC2-siRNA组细胞存活率、S期和G2/M细胞及ki67、cyclin D1、Notch1、Hes1蛋白表达显著低于Control组,细胞凋亡率、G0/G1期细胞及Cleaved caspase3蛋白表达显著高于Control组(P<0.05)。结论:STC2基因在乳腺癌中高表达,其表达与病理分期和肿瘤大小相关,抑制其表达可降低癌细胞的增殖,阻滞细胞于G1期,并诱导细胞凋亡,其机制与下调ki67、cyclin D1和上调Cleaved caspase3表达及下调Notch1信号通路有关。

Objective： To investigate the expression of STC2 gene in breast cancer and the influence of its expression on the proliferation,cycle and apoptosis of cancer cells. Methods： RT-PCR and Western blot were used to detect mRNA and protein expression of STC2 gene in breast cancer,and to analyze the relationship with pathological features; STC2-siRNA transfected human breast cancer cell line MCF-7,a blank control group（ control） and negative control group（ NC-siRNA） were set,expression of STC2,ki67,cyclin D1,Cleaved caspase3,Notch1,Hes1 protein after transfected for 48 h were detected Western blot; cell proliferation was detected by CCK8 assay; cell cycle and apoptosis were detected by flow cytometry. Results： The mRNA and protein expression of STC2 gene in breast cancer were significantly higher than adjacent tissues（ P〈0. 05）; the expression of STC2 gene was not correlated with age,histological grade and metastasis of breast cancer patients（ P〉0. 05）,was correlated with pathological stage and tumor size（ P〈0. 05）; STC2 expression had no significant difference between NC-siRNA group and control group（ P 〉0. 05）,expression of STC2 protein in STC2-siRNA group was significantly lower than control group（ P〈0. 05）; the cell survival rate,S cell and G2/M cell and the expression of ki67,cyclin D1,Notch1 and Hes1 protein in STC2-siRNA group were significantly lower than control group,the apoptosis rate,G0/G1 cells and Cleaved caspase3 protein expression was significantly higher than Control group（ P〈0. 05）. Conclusion： The expression of STC2 gene in breast cancer was higher,the expression was correlated with pathological stage and tumor size,the inhibition of its expression can reduce the proliferation of cancer cells,block cells in G1 stage,and induce cell apoptosis,the mechanism is related to down regulation of ki67,cyclin D1 expression and up regulation of Cleaved caspase3 expression and down regulation of Notch1 signaling pathway.