OBJECTIVETo investigate the effect of fas gene transfection and monoclonal anti-fas antibody on tumorigenicity and proliferation of transplanted tumor of Tca8113 cell.

METHODSPlasmid including fas gene was transfected into Tca8113 cell by lipofectamine kit. Some transfected cells were treated by monoclonal anti-fas antibody after 48 hours since transfection. Untransfected cell (control), fas-tansfected cell and fas-transfected cell treated with antibody were transplanted to nude mice subcutaneously. Growth of transplanted tumor was observed and recorded regularly. Animals were sacrificed and tumor samples were harvested at the end of experiment. Fas expression in each neoplasm was assessed by RT-PCR. Apoptosis, proliferation and expression of fas protein in tumor tissue were measured by flow cytometry (FCM).

RESULTSTumor occurred much later in fas-transfected group and fas-transfected plus antibody treated group. Growth arrest was found in them. RT-PCR and FCM suggested that fas-transfection up-regulated the expression of fas mRNA and protein, increased apoptosis index (AI). But no effect on proliferation index (PI) was observed. Monoclonal anti-fas antibody did not effect the expression of fas mRNA and protein, but increased AI and decreased PI.

CONCLUSIONFas-transfection suppressing tumorigenesis of Tca8113 cell transplanted in nude mice might be caused by up-regulation of expression of fas gene and enhancement of apoptosis. However, anti-fas antibody suppressing tumorigenesis might be associated with activation of apoptosis and repression of proliferation.