Many studies have investigated the expression of c-met and c-erbB2 protein in human gastric adenocarcinomas, but the expression of gastrin protein in human gastric cancer and the relationship between gastrin and c-met are unknown. We have constructed a tissue microarray containing 408 formalin-fixed and paraffin-embedded human tissue blocks, including tissues containing intestinal metaplasia (IM, n=72) and primary tumors (n=232), as well as normal gastric mucosa (n=104) from patients with gastric cancer. Immunohistochemistry (IHC) was used for detecting gastrin, c-met and c-erbB2 proteins. Gastrin was detected in 13.5% (7/52) and c-met in 15.3% (11/72) of IM cases. In gastric carcinomas, 48.4% (103/213) of cases expressed gastrin, 68.8% (148/215) expressed c-met, and 5.5% (11/200) expressed c-erbB2. Gastrin and c-met protein expression were significantly higher in gastric tumor tissue than in IM (P<0.0001). Overexpression of c-erbB2 protein was detected in gastric carcinomas but not in normal gastric mucosa (P<0.05). Expression of gastrin and c-met protein was associated (P<0.01), but no significant difference was found on the changes of gastrin, c-met and c-erbB2 expression in gastric cancer with tumor stage, grade of differentiation or tumor type. These results indicate that gastrin and c-met play a role in the early process during malignant transformation of the gastric mucosa.

OBJECTIVE:To clarify the frequency of mtDNA 4 977 bp deletion in tumor cell lines, solid tumors, patient's serum of gastric tumor and to find a easy and exact method to diagnose gastric tumor.METHODS:Primer-shift PCR method was used in 13 gastric tumor cell lines, 52 cases of gastric fresh tumor tissues matched the adjacent normal tissues, 40 cases of patient's serum of gastric tumor and 40 cases of normal serums for analysis of mtDNA deletion.RESULTS:Frequency of 4 977 bp mtDNA deletion was detected in 12 of 13 (92.3%) tumor cell lines, 38 of 52 (73.1%) cases of solid tumor tissues, 27 of 52 (52%) adjacent normal tissues, 17 of 40 (42.5%) patient's serum and 8 of 40 (20%) normal serums. Further more, in 2 of 10 pairs microdissected specimens, we found this deletion occurred not only in primary tumor but also in intestinal metaplasia comparing with no deletion was found in normal tissues. The frequency of this deletion was statistically significantly higher in the gastric tumor tissues and serums than in the adjacent normal tissues and serums. A good correlation between the deletion and young age of patients was representative in our data.CONCLUSION:mtDNA 4 977 bp deletion maybe play an important role in the carcinogenesis of human gastric mucous and maybe has happened in the tumor cell malignant transformation. To detect this deletion in patient's serum is a easy and exact method and maybe become a potential tumor marker.