Interrelationship between chromosome 8 aneuploidy, C-MYC amplification and increased expression in individuals from northern Brazil with gastric adenocarcinoma

AIM: To investigate chromosome 8 numerical aberrations, C-MYC oncogene alterations and its expression in gastric cancer and to correlate these findings with histopathological characteristics of gastric tumors.METHODS: Specimens were collected surgically from seven patients with gastric adenocarcinomas. Immunostaining for C-MYC and dual-color fluorescence in situ hybridization (FISH) for C-MYC gene and chromosome 8 centromere were performed.RESULTS: All the cases showed chromosome 8 aneuploidy and C-MYC amplification, in both the diffuse and intestinal histopathological types of Lauren. No significant difference (P < 0.05) was observed between the level of chromosome 8 ploidy and the site, stage or histological type of the adenocarcinomas. C-MYC high amplification, like homogeneously stained regions (HSRs) and double minutes (DMs), was observed only in the intestinal-type. Structural rearrangement of C-MYC, like translocation, was observed only in the diffuse type. Regarding C-MYC gene, a significant difference (P < 0.05) was observed between the two histological types. The C-MYC protein was expressed in all the studied cases. In the intestinal-type the C-MYC immunoreactivity was localized only in the nucleus and in the diffuse type in the nucleus and cytoplasm.CONCLUSION: Distinct patterns of alterations between intestinal and diffuse types of gastric tumors support the hypothesis that these types follow different genetic pathways. (C) 2006 The WJG Press. All rights reserved.Fed Univ Para, Ctr Ciencias Biol, Dept Biol, Lab Citogenet Humana & Genet Toxicol, BR-66075900 Belem, Para, BrazilUniv Fed Sao Paulo, Dept Morphol, Div Genet, Sao Paulo, BrazilFed Univ Para, Dept Pathol, BR-66059 Belem, Para, BrazilFed Univ Para, Surg Serv, BR-66059 Belem, Para, BrazilFed Univ Para, Joao de Barros Barreto Univ Hosp, BR-66059 Belem, Para, BrazilFed Univ Ceara, Sch Med, Dept Pathol, Genet Mol Lab, Fortaleza, Ceara, BrazilUniv Fed Sao Paulo, Dept Morphol, Div Genet, Sao Paulo, BrazilWeb of Scienc