AIM To observe the tumor inhibitory effects bytransfecting IL-6 cDNA into colon cancer cell lineHT-29 with retroviral vector pZIP cDNA.METHODS Human IL-6 gene was reconstructedin retrovirus vector and transfected into incasingcells PA317 by lipofectamine mediated method,the clones of the cells transferred with hlL-6were selected by G418,and targeted HT-29 cellswere infected with the virus granules secretedfrom PA317 and also selected by G418.Test genetranscription and expression level byhybridization,ELISA and MTT assay,etc.Analyze tumor inhibitory effects according to thecell growth curve,plating forming rate andtumorigenicity in nude mice.RESULT Successfully constructed andtransfected recombinant expressing vectorspZIPIL-6 cDNA and got positive transfected celllines.The colon cancer cell line(HT-29 IL-5)transfected with the hlL-5 gene by retroviralvector was established.The log proliferationperiod and the doubling time of this cell line wasbetween 4 to 7 days and 2.5 days according tothe direct cell count,the cell proliferation wasobviously inhibited with MTT assay,the platinginhibitory rate was 50% by plating efficiencytest.When HT-29 IL-6 cells were inoculated intothe nude mice subcutaneously,carcinogenicactivity of the solid tumor was found superior tothe control group and the size of tumor was notsignificantly enlarged.Injection of combinationvirus fluid containing 11.-6 gene intotransplantation tumors could inhibit the growthand development of the tumor.CONCLUSION IL-6 could inhibit the growth andproliferation of colon cancer cells by retroviralvector-mediated transduction. AIM To observe the tumor inhibitory effects bytransfecting IL-6 cDNA into colon cancer cell lineHT-29 with retroviral vector pZIP cDNA.METHODS Human IL-6 gene was reconstructedin retrovirus vector and transfected into incasingcells PA317 by lipofectamine mediated method,the clones of the cells Transferred with hlL-6were selected by G418,and targeted HT-29 cellswere infected with the virus granules secretedfrom PA317 and also selected by G418.Test genetranscription and expression level byhybridization,ELISA and MTT assay,etc.Analyze tumor inhibitory effects according to thecell growth The curve,plating forming rate and tumorigenicity in nude mice.RESULT Successfully constructed and transfected recombinant expressing vector spZIPIL-6 cDNA and got positive transfected cell lines.The colon cancer cell line (HT-29 IL-5)transfected with the hlL-5 gene by retroviral vector was established .The log proliferation period and the doubling time of this cell line wasbetween 4 to 7 days and 2.5 days according t Othe direct cell count, the cell proliferation wasobviously inhibited with MTT assay, the platinginhibitory rate was 50% by plating efficiencytest.When HT-29 IL-6 cells were inoculated intothe nude mice subcutaneously,carcinogenicactivity of the solid tumor was found superior to the control group And the size of tumor was notsignificantly enlarged.Injection of combinationvirus fluid containing 11.-6 gene intotransplantation tumors could inhibit the growthand development of the tumor.CONCLUSION IL-6 could inhibit the growth andproliferation of colon cancer cells by retroviral vector-mediated transduction.