EFEMP1通过下调MMP-7表达抑制肺癌细胞生长和侵袭

EFEMP1 Suppresses Growth and Invasion of Lung Cancer Cells by Downregulating Matrix Metalloproteinase-7 Expression

背景与目的 EFEMP1属于fibulin家族成员,是一种与细胞代谢密切相关的重要的细胞外基质蛋白,其在肿瘤的发生发展中的作用尚不清楚。本研究旨在探讨EFEMP1影响肺癌细胞生长和侵袭转移的生物学作用及其机制。方法 Western blot方法检测肺癌细胞中EFEMP1表达,甲基化特异性PCR(methylation-specific PCR,MSP)方法检测EFEMP1在肺癌细胞中启动子区甲基化状态。肺癌细胞中转染EFEMP1后,检测细胞克隆形成及侵袭能力变化,并用Western blot及实时定量PCR检测MMP-7表达,Luciferase实验检测EFEMP1对基质金属蛋白酶7(matrix metalloproteinase-7,MMP-7)报告质粒的影响。结果 Western blot结果显示肺癌细胞中EFEMP1表达下降,MSP分析结果说明A549和H1299中EFEMP1启动子区存在甲基化位点,5-aza-2’-deoxycytidine处理后,EFEMP1表达升高。A549和H1299转染EFEMP1后细胞克隆形成能力以及侵袭活性明显下降,MMP-7蛋白表达下调。Luciferase实验结果显示EFEMP1可以抑制MMP-7报告质粒的表达活性。结论 EFEMP1是一种肺癌生长和侵袭的抑制因子,由于表观遗传学的改变,其在肺癌细胞中表达下降,通过上调MMP-7的表达促进肺癌细胞的侵袭转移。

Background and objective EFEMP1, a member of ifbulin family proteins, is a very important extracel-lular matrix protein which is involved in cell metabolism and its role in tumor occurrence and progression is still poorly under-stood. hTe aim of this study is to investigate the functional effect and mechanism of EFEMP1 in lung cancer cell growth and invasion. Methods EFEMP1 expression in lung cancer cells was determined by Western blot. hTe promoter methylation status of EFEMP1 was detected by methylation-speciifc PCR （MSP）. Atfer transfection of control or EFEMP1 vector in lung cancer cells, the ability of colony formation and invasion was detected by colony formation experiment and matrigel invasion method. Western blot and real-time PCR were used to detect matrix metalloproteinase-7 （MMP-7） expression. Luciferase assay was used to detect expression of MMP-7 reporter construct transfected with or without EFEMP1 in lung cancer cells. Results Western blot result showed EFEMP1 expression was downregulated in lung cancer cells. hTe promoter region of EFEMP1 was methyl-ated in A549 and H1299 and atfer treatment with 5-aza-2’-deoxycytidine, the EFEMP1 expression was upregulated. hTe growth and invasion of A549 and H1299 were all signiifcantly suppressed by transfecting with EFEMP1 and the MMP-7 expression was dowanregulated by EFEMP1 as well. Expression activity of MMP-7 reporter construct was decreased by cotransfecting with EFEMP1. Conclusion Collectively, these results suggest that EFEMP1 functions as a suppressor of lung cancer growth and inva-sion. Epigenetic silencing of EFEMP1 promotes lung cancer invasion and metastasis by activating MMP-7 expression.