Analysis of microsatellite alterations in gastric carcinoma using the crypt isolation technique.
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.
Jiao
Yu-Fei
YF
Division of Pathology, Central Clinical Laboratory, School of Medicine, Iwate Medical University, Morioka, Japan.
Sugai
Tamotsu
T
Habano
Wataru
W
Suzuki
Masamichi
M
Takagane
Akinori
A
Nakamura
Shin-Ichi
S
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*
D004273:DNA, Neoplasm