SMC4对人乳腺癌细胞增殖、迁移及侵袭能力的影响及其机制研究

目的 探讨敲低染色体结构维持蛋白4(SMC4)基因的表达对人乳腺癌细胞MDA-MB-231增殖、迁移和侵袭能力的影响及其可能的机制.方法 用定量PCR(qPCR)法检测20例乳腺癌患者乳腺癌组织及对应癌旁组织中SMC4的表达情况,并用qPCR及蛋白质印迹法(Western blot)检测人乳腺上皮细胞(MCF10A)及人乳腺癌细胞(MDA-MB-231、T47D、SK-BR-3、MCF7、MDA-MB-468)中SMC4的表达情况.用小分子干扰RNA(siRNA)特异性干扰MDA-MB-231中SMC4的表达后,用qPCR及Western blot检测干扰效果,用CCK8及平板克隆实验检测其增殖与克隆形成能力,Transwell小室检测其迁移及侵袭能力,用Western blot检测可能影响的通路蛋白表达情况.结果 SMC4在乳腺癌组织中的表达明显高于癌旁组织(t=3.265,P＜0.05).SMC4在乳腺癌细胞系中的表达明显高于MCF10A.在成功用siRNA干扰SMC4表达后,MDA-MB-231细胞的增殖、迁移及侵袭能力均明显下降(P＜0.05),且磷酸化蛋白激酶B (p-AKT)及磷酸化磷脂酰肌醇-3-激酶(p-PI3K)的表达同样明显降低(P＜0.05),而AKT及PI3K的表达则无明显影响.结论 干扰SMC4基因的表达可抑制MDA-MB-231的增殖、迁移及侵袭能力,其机制可能与PI3K/AKT信号通路的激活相关.

The effect and underline mechanism of SMC4 on the proliferation,migration and invasion of human breast cancer cell MDA-MB-231

Objective To explore the effect of down-regulation of structural maintenance of chromosome 4 (SMC4) on proliferation,migration and invasion capability of human breast cancer cell line MDA-MB-231 and its possible mechanism.Methods The expressions of SMC4 in breast cancer tissues and the corresponding adjacent tissues from 20 patients with breast cancer were detected by qPCR.The expressions of SMC4 in human mammary epithelial cell line (MCF10A) and breast cancer cell lines (MDA-MB-231,T47D,SK-BR-3,MCF7 and MDA-MB-468) were detected by qPCR and western blot.After down-regulated the expression of SMC4 in MDA-MB-231 by small interfering RNA (siRNA),qPCR and western blot were used to determine the effect of transfection,CCK8 and clone formation assay were used to detect the proliferation and clonogenicity,Transwell chamber assay was used to detect the migration and invasion,and the possible pathway associated proteins were detected by western blot.Results The expression level of SMC4 in breast cancer tissues was higher than that in corresponding adjacent tissues (P＜0.05).The expression levels of SMC4 in breast cancer cell lines (MDA-MB-231,T47D,SK-BR-3,MCF7 and MDA-MB-468) were higher than that in MCF10A (P＜0.05).After successfully down-regulated SMC4 expression by siRNA,the proliferation,migration and invasion capability of MDA-MB-231 were significantly decreased (P＜0.05),and the expressions of pAKT and p-PI3K were significantly decreased (P＜0.05),whereas theexpressions of AKT and PI3K were not significantly affected.Conclusion Down-regulating the expression of SMCA can inhibit proliferation,migration and invasion capability of MDA-MP-231,which may be related to the activation of PI3K/AKT signaling pathway.