Tumor suppressor gene p16 and Rb expression in gastric cardia precancerouslesions from subjects at a high incidence area in northern China

摘要

AIM: To further understand the molecular basis for gastriccardia carcinogenesis and to provide etiological clues.METHODS: Endoscopic mucosa biopsy and histopathologicalexaminations were made on 37 subjects from a high incidencearea for both esophageal and gastric cardia carcinomas innorthem China. All the biopsy samples were fixed in 850 mi. -1 Lalcohol and embedded in paraffin. Each block contained onepiece of tissue and was serially section at 5 μm.Immunohistochemistry (ABC) was carried out on these gastriccardia samples to determine the alterations of p16 and Rb.RESULTS: Based on the histopathlogical examinationtherewere 11 cases of chronic superficial gastritis, 12 cases ofchronic atrophic gastritis and 14 cases of dysplasia. Theimmunostaining demonstrated different levels of unclearimmunostaining of p16 and Rb in normal gastric cardiatissue and the tissues with different severity of lesions. Withthe lesions progressing, the positive immunostaining ratesfor pi6 protein had a decreasing tendency. In contrast, thepositive immunostaining rate for Rb protein had anincreasing tendency. There was a significant negativerelationship between the two parameters. Changes of p16wasCSG 11(100 % ), CAG 7(58 % ), DYS 4(29 % ) andchanges of Rb was CSG 2(18 %), CAG 8(67 %) and DYS 12(86 %), (p＜0.05).CONCLUSION: The alterations of p16 and Rb protein may playa role in the early stages of gastric cardia carcinogenesis.