“…Using carcinogenic agents to induce the transformation of normal cells has been a routine method for the study of tumors in vitro (Male et al, 1987;Narayan et al, 2004). The isolation of normal, primary gastric epithelial cells, however, is not suitable for the study of carcinogenesis mechanisms as these cells rapidly enter into a senescence phase (Terano et al, 1983;Rutten et al, 1996;Smoot et al, 2000). In our previous study (Zhu et al, 2004a), we utilized telomerase reverse transcriptase (hTERT) and simian virus 40 (SV40) large T antigen to establish successfully a conditionally immortalized, normal human gastric epithelial cell line (NEC), which also expressed c-src/ Lyn kinase.…”