title: Interrelationship between chromosome 8 aneuploidy, C-MYC amplification and increased expression in individuals from northern Brazil with gastric adenocarcinoma.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  Distinct patterns of alterations between intestinal and diffuse types of gastric tumors support the hypothesis that these types follow different genetic pathways.
authors.affiliation: Human Cytogenetics and Toxicological Genetics Laboratory, Department of Biology, Center of Biological Sciences, Federal University of Pará, Belém, PA, Brazil.
authors.forename: Danielle-Queiroz
authors.initials: DQ
authors.lastname: Calcagno
authors.forename: Mariana-Ferreira
authors.initials: MF
authors.lastname: Leal
authors.forename: Aline-Damaceno
authors.initials: AD
authors.lastname: Seabra
authors.forename: Andre-Salim
authors.initials: AS
authors.lastname: Khayat
authors.forename: Elizabeth Suchi
authors.initials: ES
authors.lastname: Chen
authors.forename: Samia
authors.initials: S
authors.lastname: Demachki
authors.forename: Paulo Pimentel
authors.initials: PP
authors.lastname: Assumpção
authors.forename: Mario Henrique Girão
authors.initials: MH
authors.lastname: Faria
authors.forename: Silvia Helena Barem
authors.initials: SH
authors.lastname: Rabenhorst
authors.forename: Márcia Valéria Pitombeira
authors.initials: MV
authors.lastname: Ferreira
authors.forename: Marília
authors.initials: M
authors.lastname: de Arruda Cardoso Smith
authors.forename: Rommel-Rodríguez
authors.initials: RR
authors.lastname: Burbano
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D000328:Adult; D000368:Aged; D000782:Aneuploidy; D001938:Brazil; D002898:Chromosomes, Human, Pair 8; D005784:Gene Amplification; D015972:Gene Expression Regulation, Neoplastic; D016259:Genes, myc; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000235:genetics*