CH50, A Recombinant Polypeptiide Of Fibronectin, Inhibits The Metastasis Of Melanoma B16 Cell In Vivo

Objective The aim of this study is to investigate the inhibitory effect of recombinant polypeptide of fibronectin, CH50, on the metastasis of melanoma B16 cells. Methods The cultured B16 cells were labeled with fluorescent dye CFSE, and then inoculated into spleen of mice. 24 hours later, the spleen, liver and lung were removed for observation of metastatic B16 cells. The CH50-expressing vector was efficiently transfected into liver of tumor-bearing mice using hydrodynamics-based gene delivery technique. The expression of transfected vector in the liver was determined by RT-PCR and Western-blot. And the curative effect of the expressed CH50 was evaluated according to the number, size, and distribution of the black tumor nodes. Gelatin Zymography evaluate the expression of MMP-2, MMP-9. Results 24 hours after the injection of tumor cells, the obvious fluorescence was observed in spleen. The primary tumor was formed 14 days after the injection of B16 cells into spleen, and the metastatic liver tumor nodes were formed 35 days later. So we have constructed animal model of tumor transfection through organs in vivo(from spleen to liver) successfully. After the injection of plasmid pCH510 through tail vein, the expression of mRNA in the liver could be detected 6 hours later, 24 hours later,the expression was the most extensive was weaker obviously after 72 hours. CH50 polypeptide could be detected. By macroscopic observation, after treatment of plasmid PCH510, although the quantity of tumor nodus formed on the surface of spleen was not different obvious from PCDNA3.1 and blank control group, the magnitude of spleen tumor nodus was smaller than these two groups significantly. After treatment of plasmid CH510, metastatic tumor nodus did not form on the surface of liver while formed on the surface of those two groups. In any case, no tumor nodus were formed on the surface of lung. After administration of pCH510, the expressions of MMP-2, MMP-9 in tumor were obviously decreased compared to controls. Conclusion CH50 polypeptide can inhibit the formation of B16 tumor nodes, invasion, and metastasis and the underlying mechanism possibly involves the inhibition of tumorous MMP-2 and MMP-9 by CH50.