Study on the association between Helicobacter pylori infection and the pathogenesis of gastric cancer by using...

Recent epidemiological observations have indicated that the role of Helicobacter pylori (HP) infection in the pathogenesis of gastric cancer is an important but unresolved issue. We used the polymerase chain reaction, a sensitive and specific assay, to detect the HP infection in gastric biopsy specimens and examined the correlations between HP infection and point mutation at 12 codon of H-ras oncogene, overexpression of ras p21 and DNA content. The results showed that the mutation rate of H-ras oncogene is higher in the group with HP infection than in those without HP infection. Furthermore, there is strong evidence that HP infection is associated with the increased expression of ras p21 protein, which suggested that HP infection increased the risk of ras oncogene activation. It is also noted that a significant relationship between infection with HP and the increase of DNA content and s% phase cells, indicated that rapid turnover of cells resulting from infection injury increases the risk of DNA damage.