H pylori (CagA) and Epstein-Barr virus infection in gastric carcinomas: correlation with p53 mutation and c-Myc, Bcl-2 and Bax expression.
OBJECTIVE
To investigate the interrelationship between H pylori and Epstein-Barr virus (EBV) infection in the gastric carcinogenesis having in focus the p53 mutation and the c-Myc, Bcl-2 and Bax expression.


METHODS
seventy-one gastric carcinoma tissues were assessed by polymerase chain reaction (PCR) for H pylori and in situ hybridization for EBV. c-Myc, Bcl-2 and Bax expression were detected by immunohistochemistry and single-stranded conformational polymorphism (SSCP) for p53 mutation.


RESULTS
The positivity rates for H pylori and EBV were 94.4% and 8.45%, respectively. The majority of the cases displayed only the H pylori presence. All EBV positive cases were also H pylori positive. None infectious agent was observed in 5.55% of the cases. The intestinal type tumor was more frequent in the co-infected and non-infected groups. The female predominated in the non-infected group showing statistical significance (70.4% vs 29.6%, P = 0.039). The Bcl-2 was only detected in the group exclusively infected by H pylori. However, c-Myc and Bax were detected in the three groups but with a low frequency in the co-infected group. Mutation of p53 was present in all groups, with the highest frequencies in the H pylori positive groups.


CONCLUSIONS
The frequency of H pylori infection in gastric carcinomas was high. The presented data indicated that gastric carcinogenesis has different pathways depending of the presence of the two investigated infectious agents, suggesting a possible involvement of H pylori with apoptotic process. The low expression of c-Myc and Bax in the EBV-positive groups suggests that EBV may inhibit the expression of these proteins. Nevertheless, p53 mutation shows to be a relevant alteration, independent of both infectious agents.
Lima
Valeska Portela
VP
Department of Pathology and Forensic Medicine, Federal University of Ceará State, Porangabussu campus, Fortaleza, Ceará State, 60183-630, Brazil. valeskacb@yahoo.com.br
de Lima
Marcos Antonio Pereira
MA
André
Angela Rosa
AR
Ferreira
Márcia Valéria Pitombeira
MV
Barros
Marcos Aurélio Pessoa
MA
Rabenhorst
Sílvia Helena Barem
SH
D000293:Adolescent; D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D020031:Epstein-Barr Virus Infections; D005260:Female; D016158:Genes, p53; D016481:Helicobacter Infections / Q000378:metabolism; D016480:Helicobacter pylori / Q000235:genetics / Q000378:metabolism; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009154:Mutation; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000235:genetics / Q000382:microbiology / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism*
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D014408:Biomarkers, Tumor; D019253:Proto-Oncogene Proteins c-bcl-2; D016271:Proto-Oncogene Proteins c-myc; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; C080866:cagA protein, Helicobacter pylori