AIM:To investigate the inhibitory effect of in vivoexpressionof expressing plasmid pCH510 of recombinant fibronectinpolypeptide(CH50)on hepatocellular carcinoma and theimproved therapeutic effect of pCH510 in combination withchemotherapeutic agents and Hsp70-H22 hepatocarcinomaantigen peptide on tumor.METHODS:Mice were inoculated with H22 hepatocarcinomacells.The chemotactic effect of the expression of plasmidpCH510 on immunocytes was observed after in vivotransfection,tissue slicing and HE staining.Inhibitory effectof transfection with pCH510 on murine tumor originatedfrom different inoculative doses was observed.Theinhibitory effect of immediate transfection with pCH510after chemotherapy on tumor was compared with that oftransfection 5 days after chemotherapy.The change offunction and amount of mouse peritoneal macrophagesand the peripheral blood immunocytes resulted fromadministration of chemotherapeutic agents weredetected.The peptides mixture was prepared from H22hepatocarcinoma cells,pCH510+Hsp70-H22 antigen peptideswere injected into tumor-bearing mice with or withoutchemotherapy,to observe the inhibitory effects on tumor.RESULTS:At the tumor tissue site injected with pCH510,there were a great number of immunocytes which mainlywere macrophages,lymphocytes and neutrophils.Transfection of plasmid pCH510 inhibited significantly themurine tumor induced by different inoculative doses.Theinhibitory effect was negatively correlated with the inoculativedose.The therapeutic effect was not improved by immediatetransfection with pCH510 after chemotherapy,but wassignificantly improved by transfection with pCH510 5 daysafter chemotherapy.Chemotherapeutic agent decreased thenumber of immunocytes and suppressed their activation invivo.After injection of drug,the amount of immunocyteswas the lowest from d i to d 3 and returned to normal levelon the 10~(th)day.Transfection with plasmid pCH510 alonecould inhibit tumor induced by the inoculation with 10~4 H22cells.The tumor originated from the inoculation with 10~5 H22 cells was inhibited by pCH510+Hsp70-H22 antigenpeptides and that from the inoculation with 10~6 H22 cellswas inhibited by pCH510+Hsp70-H22 antigen peptides incombination with chemotherapeutic agents.CONCLUSION:In vivo expression of pCH510 recruitsimmune cells,inhibits tumor growth,and enhances theefficacy of chemotherapy.But the proper timing of combiningchemotherapy with pCH510 must be taken into greataccount.The synergism of pCH510 and Hsp70-H22 peptidescan improve the efficacy,which could be further enhancedif they are used following chemotherapy.Chemotherapeuticagent+pCH510+Hsp70-H22 peptides is a promisingtherapeutic approach of combination treatment of tumor. AIM: To investigate the inhibitory effect of in vivoexpression of plasmid pCH510 of recombinant fibronectin polynypeptide (CH50) on hepatocellular carcinoma and the implanted therapeutic effect of pCH510 in combination with chemotherapeutic agents and Hsp70-H22 hepatocarcinomaantigen peptide on tumor. METHODS: Mice were inoculated with H22 hepatocarcinoma cells. The chemotactic effect of the expression of plasmid pCH510 on immunocytes was observed after in vivotransfection, tissue slicing and HE staining. Inhibitory effect of transfection with pCH510 on murine tumor originated from different inoculative doses was observed. Inhibitory effect of of immediate transfection with pCH510 after chemotherapy on tumor was compared with that of transfection 5 days after chemotherapy. change ofunction and amount of mouse peritoneal macrophagesand the peripheral blood immunocytescreated fromadministration of chemotherapeutic agents weredetected.The peptides mixture was prepared from H22 hepatocarcinoma c ells, pCH510 + Hsp70-H22 antigen peptideswere injected into tumor-bearing mice with or without chemotherapy, to observe the inhibitory effects on tumor .RESULTS: At the tumor tissue site injected with pCH510, there were a great number of immunocytes which mainlywere macrophages, lymphocytes and neutrophils. Transfection of plasmid pCH510 inhibitor significantly reduced theirurological tumor induced by different inoculation doses. The inhibitory effect was negatively correlated with the inoculativedose. The therapeutic effect was not improved by immediatetransfection with pCH510 after chemotherapy, but wassignificantly improved by transfection with pCH510 5 days later chemotherapy. Chemotherapeutic agent decreased then of immunocytes and suppressed their activation invivo. After injection of drug, the amount of immunocytes was the lowest from di to d 3 and returned to normal level on the 10 ~ (th) day. Transfection with plasmid pCH510 alonecould inhibit tumor induced by the inoculation with 10 ~ 4 H22 cells. The tumor originated from the inoculation with 10-5 H22 cells was inhibited by pCH510 + Hsp70-H22 antigenpeptides and that from the inoculation with 10-6 H22 cellswas inhibited by pCH510 + Hsp70-H22 antigen peptides incombination with chemotherapeutic agents. CONCLUSION: In vivo expression of pCH510 recruitsimmune cells, inhibits tumor growth, and enhances the efficacy of chemotherapy.But the proper timing of combiningchemotherapy with pCH510 must be taken into greataccount. synergism of pCH510 and Hsp70-H22 peptidescan improve the efficacy, which could be further enhancedif they are used following chemotherapy. Chemotherapeutic agent + pCH510 + Hsp70-H22 peptides is a promising therapeutic approach of combination treatment of tumor.