RESUMO
<p><b>OBJECTIVE</b>To study the effect of polyamine biosynthesis inhibition on growth characteristics of human lung carcinoma cells and its correlation with the expression of human lung carcinoma associated antigen ALT-04ag gene.</p><p><b>METHODS</b>The gene expression was detected by RT-PCR and immunocytochemical tests. The cell growth characteristics were studied by cell growth curves, morphological observation, FCM analysis and DNA electrophoresis.</p><p><b>RESULTS</b>Human lung squamous carcinoma cells L78 treated with 5 mmol/L alpha-difluoromethylornithine (DFMO) for 5 days showed significant growth inhibition and apoptosis induction. The mRNA and protein expressions of ALT-04ag gene in the cells were downregulated, while these changes resulted from DFMO treatment were prevented by provision of DFMO along with exogenous putrescine.</p><p><b>CONCLUSION</b>The effect of polyamine biosynthesis inhibition induced by DFMO restrains the growth characteristics and promotes apoptosis of human lung carcinoma L78 cells, which is associated with down regulation of ALT-04ag gene expression.</p>