Abstract:

Objective　To investigate the effect of fas gene transfection and monoclonal anti-fas antibody on tumorigenicity and proliferation of transplanted tumor of Tca8113 cell.Methods　Plasmid 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. Untrans- fected cell (control), fas-tansfected cell and fas-transfected cell treated with antibody were transplanted to nude mice subcuta- neously. Growth of transplanted tumorwas observed and recorded regularly. Animals were sacrificed and tumor samples were har- vested at the end of experiment. Fas expression in each neoplasm was assessed by RT-PCR. Apoptosis, proliferation and expres- sion of fas protein in tumor tissue were measured by flow cytometry (FCM).Results　Tumor occurred much later in fas-transfect- ed 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.Conclusion　Fas-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 tumorige- nesis might be associated with activation of apoptosis and repression of proliferation.

Key words: Fas, gene transfection, monoclonal anti-fas antibody, tongue squamous cell carcinoma, gene therapy