title: Differential expression of MYC in H. pylori-related intestinal and diffuse gastric tumors.
abstract: 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.
authors.affiliation: Department of Pathology and Forensic Medicine, Microbiology and Pathologic Section, Federal University of Ceará State, Fortaleza, CE, Brazil. isabellejoyce@gmail.com
authors.forename: Isabelle Joyce de Lima
authors.initials: IJ
authors.lastname: Silva-Fernandes
authors.forename: Markênia Kélia Santos
authors.initials: MK
authors.lastname: Alves
authors.forename: Valeska Portela
authors.initials: VP
authors.lastname: Lima
authors.forename: Marcos Antônio Pereira
authors.initials: MA
authors.lastname: de Lima
authors.forename: Marcos Aurélio Pessoa
authors.initials: MA
authors.lastname: Barros
authors.forename: Márcia Valéria Pitombeira
authors.initials: MV
authors.lastname: Ferreira
authors.forename: Silvia Helena Barem
authors.initials: SH
authors.lastname: Rabenhorst
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D005260:Female; D005838:Genotype; D016480:Helicobacter pylori / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007414:Intestinal Neoplasms / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism*; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D019253:Proto-Oncogene Proteins c-bcl-2; D016271:Proto-Oncogene Proteins c-myc; D051028:bcl-2-Associated X Protein