RESUMEN
Four of 51 primary gastric carcinomas exhibited amplification of the erbB-2 protooncogene ranging from 2- to 8-fold. In three cases gene amplification affected erbB-2 alleles of normal gene structure as determined by Southern blot analysis. In addition, one tumor displayed gene amplification of an apparently rearranged erbB-2 allele. Analysis of the rearranged allele revealed a structural alteration consistent with an internal deletion of approximately 2 kilobase pairs within the erbB-2 gene. Quantitation of erbB-2 mRNA in these tumors demonstrated that gene amplification coincided with overexpression of erbB-2 mRNA ranging from 8- to 32-fold above levels observed in stomach tumors without gene amplification. Furthermore, in one of the tumors with amplified normal size erbB-2 restriction fragments, elevated erbB-2 mRNA levels consisted of the normal size 5-kilobase transcript. Thus, overexpression of normal size erbB-2 mRNA accompanies gene amplification in primary stomach tumors. In addition, evidence for erbB-2 gene rearrangement suggests a role for such alteration in the development of certain gastric carcinomas.
Asunto(s)
Carcinoma/genética , Amplificación de Genes , Regulación Neoplásica de la Expresión Génica , Proteínas Proto-Oncogénicas/genética , Proto-Oncogenes , Neoplasias Gástricas/genética , Northern Blotting , Southern Blotting , Sondas de ADN , Reordenamiento Génico , Humanos , Receptor ErbB-2RESUMEN
The serum levels of total protein, albumin, and electrophoretic fractions from 610 Korean women, 21-50 years, were measured to determine their relation to age, and the effects of oral contraceptives (OCs) (Norinyl), and Lippes Loop IUD. In normal women, total protein and albumin concentrations significantly decreased with age. Alpha2 and gamma globulin concentrations were decreased after the age of 40, but the statistical significance was low. Significant decreases in total protein and albumin concentrations were observed in OC and IUD users, and rapid decrease in total protein was observed in OC users rather than in IUD users. Beta globulin was slightly increased in both groups, and gamma globulin was decreased in OC users. No significant changes in alpha1 and alpha2 globulin concentrations were noted in either group.
Asunto(s)
Factores de Edad , Proteínas Sanguíneas , Sangre , Anticonceptivos Orales , Dispositivos Intrauterinos , Características de la Población , Asia , Biología , Anticoncepción , Demografía , Países en Desarrollo , Servicios de Planificación Familiar , Asia Oriental , Corea (Geográfico) , Fisiología , PoblaciónRESUMEN
c-erbB-2 oncogene encodes a growth factor receptor whose amino acid sequence has extensive homology with human epidermal growth factor receptor. It is frequently overexpressed in human breast, ovary, lung, and stomach cancers, where its overexpression is related significantly to the prognosis. Tl investigate the possible role of c-erbB-2 oncogene in the oncogenesis of stomach cancer, we examined the genetic alterations of c-erbB-2 oncogene in 4 stomach cancer cell lines, SNU-1, SNU-5, SNU-16 and KATO III. There were no differences in c-erbB-2 mRNA level as well as c-erbB-2 gene copy number among them. But gp185-erbB-2, c-erbB-2 gene product, was increased from 2- to 4-fold in SNU-1 and SNU-5 cells, compared with that in SNU-16 or KATO III cells. Our results suggest that post-transcriptional regulation of gp185erbB-2 expression may underlie gp185erbB-2 overexpression in cancer cells.