We examined the susceptibility of six human gastric carcinoma cell lines to infection with recombinant p53 adenovirus vector (AxCA-p53). AxCA-p53 infection at a muliplicity of infection (MOI) of 50 resulted in apoptotic cell death (MKN-1 cells), growth arrest (MKN-45, MKN-74 and KATO-III cells), or non-effectiveness (TMK-1 and OCUM-2M cells). Western blot analysis revealed increasing expression levels of p21/WAF1 protein after infection with AxCA-p53 in all the cell lines. After infection with AxCA-p53, the expression levels of bax or bcl-XL protein changed in MKN-1, but not in the other cell lines. These results suggest that the apoptotic pathway (dependence on the expressions of bcl-2 family proteins) dominates the growth arrest pathway (dependence on the expressions of p21/WAF1 protein) after infection with AxCA-p53. Thus, the bcl-2 family might play a crucial role in p53-mediated growth arrest and apoptosis in human gastric carcinoma cells.