Concurrent overexpression of serum p53 mutation related with Helicobacter pylori infection.

Background & Aims: In the province of Cadiz (Spain), the adjusted mortality rate for gastric cancer in the coastal town of Barbate is 10/100.000 inhabitants, whereas in the inland town of Ubrique, the rate is twice as high. The rate of Helicobacter pylori (H. pylori) infection (H. pylori antibodies) in the normal population was 54% in Ubrique, but only 32% in Barbate. In the two decades since its original discovery, p53 has found a singularly prominent place in our understanding of human gastric cancer and H. pylori cause accumulation of reactive oxygen species in the mucosa compartment. This study was designed to compare serum levels of p53 in a population characterized by high mortality due to stomach cancer and a high prevalence of H. pylori infection and another population in which mortality from this cause and the prevalence of H. pylori infection are low.

Materials And Methods: 319 subjects from the low mortality population and 308 from the high mortality population were studied, as were 71 patients with stomach cancer. We measured serum immunoglobulin G antibody to H. pylori and serum mutant p53 protein and ceruloplasmin.

Results: The difference between the two populations in the prevalence of H. pylori infection was significant (p < 0.001). Of the seropositive, 81% had elevated values of mutant p53, in comparison with 11% of the seronegative (p < 0.0001). Serum concentration of ceruloplasmin was significantly higher in seropositive with elevated mutant p53 protein than in seronegative with normal levels of p53 (p < 0.05).

Conclusions: There is a significant association between infection with H. pylori, elevated titers of H. pylori antibodies, and positivity for serum mutant p53 protein. Such information can significantly increase our basic knowledge in molecular pathology of gastric cancer and protection against H. pylori infection.