Recombinant Polypeptide CH50 of Fibronectin Inhibits the Expression and Activation of Matrix Metalloproteinase 2 and 9 in Melanoma

Objective To explore the effect of a recombinant polypeptide of fibronectin, CH50, on the invasive ability of melanoma B16 cells, and examine the mechanism by which CH50 inhibits the growth and invasion of tumor. Methods B16 cells was cultured in vitro and the mouse model of melanoma was established by s.c. injection of 2×105 of B16 cells into C57BL/6 mouse. Then the expression and activity of MMP2 and MMP9 in the culture supernatant and melanoma tissue were detected by gelatin zymography. To observe the effect of CH50 on MMPs, CH50 polypeptide was added to the cultured B16 cells and CH50-expressing vector plasmid or mock plasmid was transfected to tumor site. The cultured cells and tumor tissues were analyzed by gel zymography. Results The B16 cells mainly expressed MMP2 in vitro, while both MMP2 and MMP9 were abundantly expressed in melanoma tissue. The MMP expression in tumor tissue was significantly higher than that in cultured B16 cells. After treatment with CH50, both production and activation of MMP2 and MMP9 were decreased in melanoma tissue, but no obvious change was observed in cultured B16 cells. After the treatment, the expression of B16 cells were significantly inhibited in vivo. The CH50 could also obviously inhibit the MMP expression of tumor and reduce the invasiveness of tumors. Conclusion CH50 can effectively suppress both the expression and activation of MMP2 and MMP9 in tumor microenvironment, therefore it may act as a potent inhibitor for the prevention of the invasion and metastasis of melanoma.