Differential expression of MYC in H. pylori-related intestinal and diffuse gastric tumors.

Autor: de Lima Silva-Fernandes, Isabelle Joyce, Santos Alves, Markênia Kélia, Lima, Valeska Portela, Pereira de Lima, Marcos Antônio, Pessoa Barros, Marcos Aurélio, Pitombeira Ferreira, Márcia Valéria, Barem Rabenhorst, Silvia Helena, Silva-Fernandes, Isabelle Joyce de Lima, Alves, Markênia Kélia Santos, de Lima, Marcos Antônio Pereira, Barros, Marcos Aurélio Pessoa, Ferreira, Márcia Valéria Pitombeira, Rabenhorst, Silvia Helena Barem
Zdroj: Virchows Archiv: European Journal of Pathology; Jun2011, Vol. 458 Issue 6, p725-731, 7p, 3 Charts, 3 Graphs
Abstrakt: Evidence suggests that the carcinogenic process guided by Helicobacter pylori is related to the expression of cell cycle and apoptosis proteins as BCL-2, BAX, and MYC. However, the literature is conflicting regarding the expression frequency in the histological subtypes and did not consider cagA gene presence. To investigate the expression of these proteins considering the histological subtypes of gastric cancer associated with H. pylori (cagA), a total of 89 cases were used. H. pylori infection and cagA status were determined by PCR. Immunodetection was performed for MYC, BCL-2, and BAX proteins. H. pylori was found in 95.5% of the patients, among them, 65.8% were cagA(+). Nuclear MYC was detected in 36.4%, BAX in 55.7%, while BCl-2 in just 5%. Nuclear MYC staining was significantly lower in the intestinal than diffuse subtype (p = 0.008) and was related with the presence of H. pylori cagA(+). Additionally, most of the few cases cytoplasmic MYC positive were in the intestinal subtype. In diffuse tumors, although most nuclear MYC positive cases were cagA(+), it was not significant. No difference was observed between BCL-2 or BAX expression considering the presence of cagA gene in the histological subtypes. It seems that MYC could be relevant for the diffuse tumorigenic pathway associated with H. pylori and possibly influenced by the presence of cagA gene, while in intestinal tumors, the tumorigenic pathway does not occur through the MYC expression. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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