title: Analysis of microsatellite alterations in gastric carcinoma using the crypt isolation technique.
abstract: The crypt isolation technique was used to analyse loss of heterozygosity (LOH) and microsatellite instability (MSI) in gastric carcinomas (36 intestinal type, 17 solid type, and 23 diffuse type) using a polymerase chain reaction assay. Increased LOH frequencies and fractional allelic losses (FAL) were observed in samples prepared using the crypt isolation technique compared with those isolated by the conventional method. A significant increase in LOH was found at several chromosomal loci, and significant differences in FAL were found in patients with intestinal- and solid-type tumours. There was no difference in the frequency of MSI using either technique. In samples prepared by the crypt isolation technique, significant allelic losses (> or =50%) were observed at most loci tested in intestinal- and solid-type tumours, but not in diffuse-type tumours. Significant losses of some of these loci are novel findings for gastric cancer. FAL values were significantly higher in intestinal- and solid-type tumours than in diffuse-type tumours. MSI-high was observed in intestinal- (17%) and solid-type (12%) tumours. The results suggest that the crypt isolation technique is useful for accurate allelic loss analysis in gastric carcinoma and that LOH and MSI are more common in intestinal- and solid-type tumours than in diffuse-type tumors.
authors.affiliation: Division of Pathology, Central Clinical Laboratory, School of Medicine, Iwate Medical University, Morioka, Japan.
authors.forename: Yu-Fei
authors.initials: YF
authors.lastname: Jiao
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Sugai
authors.forename: Wataru
authors.initials: W
authors.lastname: Habano
authors.forename: Masamichi
authors.initials: M
authors.lastname: Suzuki
authors.forename: Akinori
authors.initials: A
authors.lastname: Takagane
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Nakamura
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002877:Chromosomes, Human / Q000235:genetics; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D005821:Genetic Techniques; D042822:Genomic Instability; D006801:Humans; D019656:Loss of Heterozygosity / Q000235:genetics*; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D013274:Stomach Neoplasms / Q000235:genetics*
chemical_list: D004273:DNA, Neoplasm