Peripheral position of CCND1 and HER-2/neu oncogenes within chromosome territories in esophageal and gastric cancers non-related to amplification and overexpression

Autor(es)

Bizari, Lucimari ^[1] ; Tajara, Eloiza Helena ^[2] ; Silva, Ana Elizabete ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Dept Biol, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

^[2] Fac Med, Dept Biol Mol, Sao Jose Do Rio Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: GENETICS AND MOLECULAR BIOLOGY; v. 32, n. 2, p. 242-250, 2009.
• Citações Web of Science: 0
• Assunto(s): Neoplasias gástricas Neoplasias esofágicas

Resumo

Interphase chromosomes have been shown to occupy discrete regions of the nucleus denominated chromosome territories (CTs), their active genes being preferentially positioned on the surfaces of these CTs, where they are accessible to transcriptional machinery. By means of FISH (Fluorescence in situ Hybridization), we analyzed the CCND1 and HER-2/neu gene positions within the CTs and their relationship with gene amplification and protein over-expression in esophageal and gastric cancers. The CCND1 and HER-2/Neu genes were more often positioned at the periphery (mean frequency of 60%-83%) of the CTs in tumor tissues of the esophagus and stomach. Moreover, this positioning revealed no association with either gene amplification or the protein over-expression status of these genes, although, in esophageal carcinoma, Kappa statistics showed a moderate agreement between amplification of the CCND1 gene (Kappa = 0.400) and its location within the CT, as well as with over-expression of the corresponding protein (Kappa = 0.444). Thus, our results suggest that gene positioning in interphase chromosomes does not follow a definitive pattern neither does it depend only on gene transcriptional activity. Apparently, this positioning could be both gene- and tissue-specific, and depends on other factors acting together, such as dense-gene, chromosome size, chromatin structure, and the level and stability of its expression. (AU)

• Processo FAPESP: 03/07772-7 - Estudo da amplificacao, expressao e localizacao dos oncogenes ciclina d1 e c-erbb-2 nos dominios interfasicos cromossomicos em tumores de bexiga, esofago e estomago pela tecnica fish.
• Beneficiário: Ana Elizabete Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular