title: [Gene amplification in bladder tumors].
abstract: Eight patients with transitional cell bladder carcinoma were analyzed viewing the detection of ras oncogene mutations. This sample was picked out from a preliminary study of 20 cases of transitional cell tumors where complex chromosomal rearrangements were observed in tumors of grade II/III. In this first stage of the study non invasive tumors presented an almost diploid chromosome number while the most infiltrative ones displayed pseudo triploidy, triploidy or tetraploidy. A Subsequent study searched for the mutational frequency of the oncogene n-ras using the knowledge of direct DN sequencing and based on the technology of polymerase chain reaction amplification (PCR) in view to establish a relationship between the mutational frequency and the tumor stage and grade. The wild type allele was present in all the tumors examined. Point mutations were detected in 1/3 of the analyzed samples. These samples displayed a grade II-III histology as opposed to the other tumors. These data appear to indicate that n-ras mutations may be early phenomena in the development and progress of a number of human tumors of the urothelium.
authors.affiliation: Assinatura de Genética, Laboratorio de Genética, Falcultad de Medicina de Lisboa, Portugal.
authors.forename: M C
authors.initials: MC
authors.lastname: Pinto
authors.forename: A P
authors.initials: AP
authors.lastname: de Carvalho
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002295:Carcinoma, Transitional Cell / Q000235:genetics*; D002869:Chromosome Aberrations / Q000235:genetics; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D005784:Gene Amplification; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D001749:Urinary Bladder Neoplasms / Q000235:genetics*
chemical_list: D004273:DNA, Neoplasm
vernacular_title: Amplificación genética en los tumores vesicales.