膜型基质金属蛋白酶=1上调人乳腺癌细胞血管内皮生长因子的表达并诱导肿瘤血管新生

MT1-MMP up-regulates VEGF expression in human breast carcinoma MCF-7 cells and induces tumor angiogenesis

目的研究膜型基质金属蛋白酶-1（MT1-MMP）在肿瘤血管新生过程中的作用，探讨其诱导肿瘤血管新生的作用途径。方法应用基因转染方法，将MT1-MMP导入人乳腺癌细胞系MCF-7细胞；应用半定量逆转录聚合酶链反应（RT—PCR）和免疫荧光染色，比较转染前后肿瘤细胞血管内皮生长因子（VEGF）表达的变化；通过裸鼠异种移植瘤模型，检测MT1-MMP对肿瘤生长速度、肿瘤组织微血管密度（MVD）和VEGF表达的影响。结果在MT1-MMP稳定转染后的MCF-7细胞中，VEGF189、VEGF165和VEGF121 mRNA表达水平显著上调（P〈0．001）。免疫荧光检测结果显示，MT1-MMP组的VEGF蛋白免疫荧光强度为93．8±10．3，明显强于MCF-7组（42．9±5．3）和pcDNA3．1组（41．04±5．4，P〈0．001）。裸鼠异种移植瘤模型结果显示，MT1-MMP能够加快肿瘤生长速度。肿瘤组织MVD检测结果显示，MT1-MMP能够显著提高肿瘤组织的MVD（P〈0．05）。免疫组织化学染色结果显示，VEGF在MT1-MMP组呈强阳性表达。结论MT1-MMP能够通过上调肿瘤细胞VEGF表达水平而有效诱导肿瘤血管新生。MT1-MMP的这一作用途径可能为临床抗肿瘤研究及抗肿瘤药物开发提供新思路。

Objective To study the function of MT1-MMP in tumor angiogenesis and elucidate the possible way of action that MT1-MMP contributes to angiogenesis. Methods MT1-MMP was transfected into human breast carcinoma cell line MCF-7 cells. Semi-quantitative RT-PCR and immunofluorescence staining were employed to detect the expression of VEGF in the transfected and non-transfected MCF-7 cells. Tumor growth, microvessel density and expression of VEGF in nude mice were detected through in vivo tumorigenicity assay. Results In MT1-MMP stable transfected MCF-7 ceils, mRNA expression of VEGF189, VEGF165, and VEGFI21 and immunofluorescence intensity were significantly elevated （P 〈 0. 001 ）. In vivo tumorigenicity assay in the nude mice showed that MT1-MMP promoted tumor growth. The MVD in the MT1-MMP-transfected cells-transplanted tumor tissue was significantly elevated （ P 〈 0.05 ）. Immunohistochemical assay showed that there was a strong immunostaining of VEGF in those tumor tissues. Conclusion MT1-MMP can induce tumor angiogenesis through up-regulation of VEGF expression. This function of MT1-MMP may open a new approach for clinical anti-tumor research and anti-tumor drug development.