跨膜蛋白196对乳腺癌迁移及侵袭能力的影响

Effect of transmembrane protein 196 on migration and invasion of breast cancer

目的研究跨膜蛋白196(transmembrane protein 196,TMEM196)对乳腺癌细胞迁移及侵袭能力的影响。方法研究采用癌症基因组图谱(the cancer genome atlas,TCGA)和Oncomine数据库分析TMEM196在乳腺癌中的mRNA表达。通过实时定量-聚合酶链反应(quantitative real time-polymerase chain reaction,RT-qPCR)检测TMEM196在乳腺癌细胞中的表达,利用Kaplan-Meier数据库分析TMEM196对乳腺癌患者预后的影响;采用组织芯片分析TMEM196的蛋白水平和预后作用,该队列包含70例癌旁样本和160例浸润性乳腺癌样本,年龄(53.61±13.13)岁,在2001年1月至2004年8月接受手术切除,随访时间2~150个月;通过细胞增殖、划痕愈合和Transwell实验研究TMEM196对乳腺癌细胞增殖、迁移及侵袭能力的影响;Western blot检测TMEM196对β-连环蛋白(β-catenin)和基质金属蛋白酶7(matrix metalloproteinase 7,MMP7)表达的影响。结果TMEM196的mRNA水平和蛋白水平在乳腺癌中均显著降低(P<0.05),在三阴性乳腺癌(triple negative breast cancer,TNBC)细胞株MDA-MB-231和TNBC组织中最明显(P<0.05),低表达的TMEM196和较差的总体生存率(overall survival,OS)有关(HR=0.524,95%CI:0.293~0.936,P=0.040);过表达TMEM196之后能够显著抑制乳腺癌细胞的增殖、迁移和侵袭(P<0.05),而干扰TMEM196的表达后,能够显著增强细胞的增殖、迁移和侵袭(P<0.05);Western blot提示TMEM196能够抑制β-catenin/MMP7信号通路从而降低乳腺癌细胞的运动能力(P<0.05),加入β-catenin抑制剂后能够消除干扰TMEM196后所导致的促肿瘤作用(P<0.05)。结论TMEM196通过调节β-catenin/MMP7信号通路抑制乳腺癌细胞的迁移和侵袭。

Objective To investigate the effect of transmembrane protein 196(TMEM196)on the migration and invasion of breast cancer cells.Methods The Cancer Genome Atlas(TCGA)and Oncomine database were used to analyze the mRNA expression of TMEM196 in breast cancer.The expression of TMEM196 in breast cancer cells was detected by quantitative real time-polymerase chain reaction(RT-qPCR).Kaplan-Meier database was employed to analyze the effect of TMEM196 on the prognosis of breast cancer patients.The protein level and prognostic effect of TMEM196 were analyzed by tissue microarray.The cohort included 70 paracancerous samples and 160 invasive breast cancer samples from the patients(53.61±13.13 years old)undergoing surgical resection from January 2001 to August 2004,with a follow-up period of 2 to 150 months.Cell proliferation experiment,scratch healing test and Transwell assay were performed to determine the effect of TMEM196 on the proliferation,migration and invasion of breast cancer cells.Western blot assay was used to explore the regulation of TMEM196 on the expression ofβ-catenin and matrix metalloproteinases 7(MMP7).Results The mRNA and protein levels of TMEM196 were significantly decreased in breast cancer(P<0.05),and notably,this phenomenon was most obvious in triple negative breast cancer(TNBC)cell line MDA-MB-231 and TNBC tissues(P<0.05).Lower expression of TMEM196 was associated with poor overall survival(OS)(HR=0.524,95%CI:0.293~0.936,P=0.040).In addition,overexpression of TMEM196 could significantly inhibit the proliferation,migration and invasion of breast cancer cells(P<0.05),while its knockdown can significantly enhances the above abilities(P<0.05).The results of Western blot assay indicated that TMEM196 inhibited theβ-catenin/MMP7 signaling pathway and reduced the motility of breast cancer cells(P<0.05).On the contrary,the tumor-promoting effect which caused by knockdown of TMEM196 could be eliminated after addingβ-catenin inhibitor(P<0.05).Conclusion TMEM196 inhibits the migration and invasion of breast cancer cells by regulating theβ-catenin/MMP7 signaling pathway.