Integrin Alpha-V Beta-3-Matrix Metalloproteinase-2 (MMP-2), Cross-Talk

Abstract

The present study aimed to detect comparative expression of integrin α V β 3 and its involvement in expression and activation of matrix metalloproteinase-2 (MMP-2) in 25 malignant human breast tumor and adjacent normal breast tissues from different clinical TNM stages (DCIS to T4) of the disease and possible involvement of known regulating parameters of MMP-2 like TIMP-2, MT1-MMP and EMPRIN. Integrin α V β 3 was highly expressed in tumors than adjacent normal breast tissues. Pro-MMP-2(72-KD) was mainly expressed in adjacent normal tissues compared to tumors. The mature forms of MMP-2 (68 KD and 64 KD) were found only in tumors. Appreciable expression of TIMP-2 and induction of MT1-MMP and EMPRIN in T2-T4 stages suggested their possible role in MMP-2 activation. Over expression Integrin α V β 3 in tumors than adjacent normal breast tissues was an indication of cancer progression with involvement of integrin signaling. We conclude that, the co-precipitation of MMP-2 with α v β 3 by anti- α v antibody is a strong indication that integrin α v β 3 is a surface receptor for MMP-2 and α v β 3 -MMP-2 complex on the surface of tumor cells may play a very important role in determining the invasive property and malignant behavior of tumor tissues. The positive expression of endogenous inhibitor of MMP-2, TIMP-2 may have an appreciable role in activation of this protease and risk of malignancy in advanced stage of the disease. The enhanced expression of MT1-MMP and EMPRIN suggested a role for these factors in gelatinase regulation. However the exact mechanism(s) remains to be investigated. Finally, evaluation of integrin α V β 3 associated MMP-2 expression and activity may add valuable information and can possibly be therapeutic target. The clinical exploitation of integrins will provide oncologists with novel therapeutic strategies for the treatment of malignancy in breast cancer.