Published online Oct 15, 1998. doi: 10.3748/wjg.v4.iSuppl2.97
Revised: August 1, 1998
Accepted: August 23, 1998
Published online: October 15, 1998
AIM: To observe the expression of bcl-2 and c-myc protein in gastric carcinoma and precancerous lesions.
METHODS: Ninety-three specimens of biopsy were collected, 5 cases with gastric epithelial dysplasia (GED) from 21 chronic superfical gastritis (CSG), 23 cases with GED and intestinal metaplasis (IM) from 34 chronic atrophi c gastritis (CAG) and 22 mucosa tissues adjacent to the primary cancer (MA) with GED and IM from 38 gastric carcinomas (GC). Bcl-2 and c-myc were determined with streptavidin peroxidase immunohistochemical method.
RESULTS: Immunostaining was found in cytoplasms in all the bcl-2 positive cells and most c-myc positive cells, while in a few c-myc positive cells, brown-yellow granules could be found in cytoplasm and in nuclei. The positive rates of bcl-2 and c-myc oncoprotein were 100%, 60.8% in CSG with GED, whereas in CSG without GED, were zero and 75.0% respectively. The positive expression rates of bcl-2 and c-myc were 34.8% and 73.9%, in CAG with GED and IM and zero and 63.9% in CAG without GED and IM. In gastritis, the positive rates of bcl-2 in with GED and IM were significantly higher than that in CAG without GED and IM (P < 0.05-P < 0.001), but the significant difference of c-myc expression in both was not found (P > 0.05). The positive express ion rates of bcl-2 and c-myc were 47.4% and 76.3% in GC, 54.5%, 81.8% in MA with GED and IM and zero, 25% in MA without GED and IM, respectively. The po sitive rates of bcl-2 and c-myc in GC and MA with GED and IM were significantly higher than that in MA without GED and IM (P < 0.001). In this study, the coexpression rates of bcl-2 and c-myc oncoproteins were 60%, 34.8%, 54. 5%, respectively, in with GED and IM of CSG, CAG and MA. No positive staining wa s found in without GED and IM (P < 0.001). However, expression of bcl-2 and c-myc was independent of age and sex of the patients (P > 0.05).
CONCLUSION: The mutation of bcl-2 and c-myc genes may be an early molecular marker of gastric carcinogenesis, more biological characteristics and feature of gene expression of cancer cells were found in gastric epithelial dysplasia and intestinal metaplasia. Therefore, co-detection of bcl-2 and c-myc expression may be of special importance to early recognize the occurrence of gastric carcinoma and judge prognosis.