Investigation On The Inhibitory Effect Of Recombinant Polypeptide CH50 Of Fibronectin On Invasion And Angiogenesis Of Tumor

Objective To investigate the inhibitory effect of recombinant polypeptide CH50 of fibronectin on invasion and angiogenesis of tumor, and analyze the possible molecular mechanism of the therapeutic effect of polypeptide CH50 on tumor. Methods (1) Tumor model was established by inoculation of H22 hepatocarcinoma cells at right hind thigh of BALB/c mice. (2) Tumor gene therapy was performed by in vivo gene transfection with the method based on hydrodynamics to express polypeptide CH50. (3) Tumor weight was used to reflect the the inhibitory effect of polypeptide CH50 on tumor growth. (4) The inhibitory effect on tumor invasion and angiogenesis was observed after histotomy and HE straining of tumor tissues. (5) The protein and mRNA expression of MMP-9 in the edge tissue of tumor was evaluated by RT-PCR and Gelatin Zymography. (6) RT-PCR was used to detect the expression of the related genes in H22 cells treated with polypeptide CH50. (7) Cell adhesion assay was used to analyze the influences of polypeptide CH50 on the binding of cells to fibrinogen. Results (1) Eukaryotic expression plasmid pCH510 was expressed in vivo in a non-targeting manner which lasted at least 72h. (2) The expression of polypeptide of CH50 produced an obviously inhibitory effect on tumor growth: in comparison among groups the mean weight of treatment group was significantly different from control groups (p<0.05), no significantly difference existed between control groups (pCDN3.1 group and Saline group). The therapy with polypeptide CH50 resulted in significant necrosis of tumor cells in pCH510 group, compared with that in control groups at histological level. (3) Polypeptide CH50 could inhibit the invasion of tumor, which was limited locally in treatment group and angiogenesis of interfere with the formation of new collateral circulation of tumor. (4) The expression level of MMP-9 protein in the edge tissue of tumor was significantly decreased after therapy, especially the activation of pro-MMP-9 was inhibited significantly, whereas the expression level of MMP-9 mRNA was not influenced. (5) The expression ofαv,β3 and cdc2 mRNAs in H22 cells treated with polypeptide CH50 was down-regulated. (6) Cell adhesion assay manifested that polypeptide CH50 can reduce the activity of integrinαvβ3, which affect the adhesion ability of H22 cells to fibronogen. Conclusion Polypeptide CH50 can inhibit tumor growth and angiogenesis by suppressing the functions of MMP-9 and integrinαvβ3.