title: Genomic instability and loh at 2 polymorphic sites in the h-ras1 gene.
abstract: Several repetitive elements have been associated with and identified in the surrounding region and within the human c-H-ras1 gene. The polymorphism exhibited by these sites provides valuable information regarding the function and structure of the H-ras gene. We have investigated two such polymorphic sites: i) a hexanucleotide microsatellite region (HRMS) within intron 1 of H-ras and ii) the VTR region at the 3' end of the gene. Comparison between normal and tumor tissues from 25 samples of bladder cancer revealed that 5 samples (20%) exhibited LOH at these polymorphic sites indicating that an allelic loss had occured at the H-ras locus. Furthermore, instability was detected in 4 cases at the hexanucleotide locus, while the VTR region was found unaffected. The two polymorphic sites are in a strong linkage disequilibrium in normal tissues, while in tumor tissues with genomic instability this linkage is altered, possibly leading to differential regulation of the H-ras. Also a previously reported allele at the HRMS locus was found to behave in a manner that preserves the linkage between the two polymorphic sites in normal tissues.
authors.affiliation: NATL HELLEN RES FDN,INST BIOL RES & BIOTECHNOL,GR-11635 ATHENS,GREECE. UNIV CRETE,SCH MED,IRAKLION,GREECE.
authors.forename: A
authors.initials: A
authors.lastname: Kotsinas
authors.forename: D
authors.initials: D
authors.lastname: Vageli
authors.forename: A
authors.initials: A
authors.lastname: Varakliotou
authors.forename: P
authors.initials: P
authors.lastname: Anezinis
authors.forename: A
authors.initials: A
authors.lastname: Cranidis
authors.forename: D
authors.initials: D
authors.lastname: Spandidos