The Effect Of Hp Infection On The Expressions Of Some DNA Repair Genes In Gastric Carcinogenesis

Objective: Gastric carcinoma (GCa) is the most common cancer in our country, however its pathogenesis is unknown. Helicobacter pylori (Hp) is thought as one important reason of gastric carcinogenesis, which is not clear. Some researchs indicated that Hp could induce GCa by destroying the function of gene repair systems in cells. The carcinogenesis resulted from the abnormal accumulation of gene mutations, which was the result of repair system functional defect in cells. There are complete repair system in normal cells, including base excision repair system (BER) and homologous recombination repair system (HR). The function of BER is to excise and replace the DNA base damages, and any abnormal expressions of BER genes may lead to the defect of BER functions and furthermore cellular malignant transformation. HR can repair the DNA double strand breaks (DSBs) which is the most severe damage of DNA. It is not known whether Hp induce the occurrence of GCa by inhibiting the functions of BER genes and HR genes? This study is designed to answer the question by analyzing the relationship of Hp infection to expressions of BER genes (APE1, XRCC1) and HR genes (XRCC2, XRCC3) in gastric epithelia from volunteers (normal epithelium), the epithelia surrounding carcinomas (surrounding epithelium) and carcinoma cells (carcinoma), and then to explain the possible carcinogenesis induced by Hp infection.Methods: Gastric biopsy specimens of 29 gastritis and 59 GCa were got by endoscopy from 2002 to 2003 in Dalian. Guick-ureolytase method...