2004•Di-san junyi daxue xuebaoRequires access
Expression of bcl-2 gene in gastric carcinoma and precancerous lesions and its regulatory role in apoptosis
Hai Liu
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Abstract
Objective To elucidate the relationship between bcl 2 gene expression and the frequency of apoptosis in different stages of malignant transformation of gastric epithelium in precancerous lesions and gastric carcinomas. Methods In situ hybridization and immunohistochemical method were used to study the frequencies of bcl 2 gene expression in 10 cases of normal gastric mucosa, 72 cases of chronic atrophic gastritis, and 53 cases of gastric carcinoma. Meanwhile, the method of in situ apoptotic cell detection was adopted to detect the apoptotic cells in these lesions. The relationship of the number of apoptotic cells with the bcl 2 gene expression in each case was observed. Results In situ hybridization revealed that the positive frequency of bcl 2 gene expression in gastric carcinoma was significantly higher than that in normal gastric mucosa, atrophic gastritis, and intestinal metaplasia ( P 0.01 and P 0.05); and that the positive frequency of bcl 2 gene expression in gastric dysplasia was significantly higher than that in normal gastric mucosa and in atrophic gastritis ( P 0.05). The expression rate of bcl 2 protein detected by immunohistochemistry was significantly higher in gastric carcinoma than that in normal gastric mucosa, atrophic gastritis, and intestinal metaplasia ( P 0.01), and remarkably higher in gastric dysplasia than that in normal gastric mucosa and atrophic gastritis ( P 0.01). There was no significant difference between the positive rates obtained by these 2 methods. Observation of the relationship of bcl 2 expression with the number of apoptotic cells in these specimens revealed that the apoptotic index in bcl 2 positive expression group was lower than that in bcl 2 negative expression group ( P 0.01). Conclusion The expression of bcl 2 gene can inhibit apoptosis in gastric carcinoma and its precancerous lesions. The abnormal regulation of apoptosis may play an important role in the pathogenesis of gastric carcinoma.