[Molecular biology in gastric cancer]

In gastric cancer, the process of carcinogenesis is thought to occur as a stepwise accumulation of genetic abnormalities. However, the mechanisms of the process of multistage carcinogenesis is still unknown for gastric cancer. Gene abnormalities seen in gastric cancer, including ras, myc, c-erbB-2, met, K-sam and cript are summarized herein. Abnormalities of cancer suppressor genes, including p53, RB and APC are also described. In our studies, the biological malignancy of patients with c-erbB-2 amplification was higher than that of patients without amplification. Moreover, the cases with amplification of c-erbB-2 were found to be highly correlated with distant organ metastasis. However, very little is currently known of the molecular abnormalities leading to gastric cancer. In order to clarify the multiple gene abnormalities in gastric cancer, we used the method of restriction landmark genomic scanning (RLGS). RLGS provides a useful method for genomic analysis of gastric cancer. In the future, new analytical methods that will permit screening of all gene abnormalities at once promise to improve our understanding of the mechanisms of gastric cancer.