ABSTRACT
We used retrovial vector LXSN to construct recombinant retroviral vector with mutant membrane bound TNF - ? gene. The vectors were introduced into packaging cell line, CRIP cells. The G418-resistant colonies were selected and the supernatants of the colonies were used to determine the virus titers. The titer of virus was 1? 104CFU/ml and the retroviral vectors were used to tranduced the human gastric cancer cell line, MGC-803 cells. The results of southern blot assay showed thai the targel gene had integrated into the genomic DNA of MGC-803T. MGC - 803Tcells were ablc to kill L929 cell line, but the parent cell line showed no cytotoxicily to the cells at all. There was no any variance in the morphological appearance and growlh rate in vilro of MGC-803N and MGC-803T cells. The results of inoculation in nude mice with these cells indicated that MGC-803T cells showed a considerable decrease in size of tumor. These results suggested that the retroviral vectors expressing mulant TNF -? gene were successfully construed. MGC - 803T cells showed cytotoxicily slrongly lo L929 cell line in vilro and lumorigenicity .