Microsatellite instability in cervical and endometrial carcinomas.
Microsatellite instability has been found preferentially in tumours associated with the hereditary non-polyposis-colorectal-cancer (HNPCC) syndrome. This phenotype, manifested as new alleles at microsatellite loci, and often the result of a defective mismatch-repair gene, is seen as allelic mobility shifts during electrophoretic runs. We examined possible alterations at 8 dinucleotide loci mapping to 6 different chromosomes in endometrial cancers (n = 20) and cervical cancers (n = 82). Overall instability was found in 30% of the endometrial cancers and in 6% of the cervical cancers, including 3 (15%) and 2 (2%) tumours, respectively, unstable at more than one locus. In contrast to the endometrial cancer sub-group, the affected cervical cancers were characterized by one or two new alleles at one or few loci. By DNA ploidy measurements 5 diploid endometrial cancers were microsatellite-unstable vs. one diploid of 6 unaltered cases (p = 0.015; Fisher's exact test). Our data confirm that a sub-set of diploid sporadic endometrial cancers are characterized by a mutator phenotype similar to that found in colorectal cancer. In contrast, among cervical cancers, not characterized by the HNPCC-tumour spectrum, this mutator phenotype is seen infrequently, and positive cases appear to display only minor alterations.
Helland
A
A
Department of Genetics, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo.
Børresen-Dale
A L
AL
Peltomäki
P
P
Hektoen
M
M
Kristensen
G B
GB
Nesland
J M
JM
de la Chapelle
A
A
Lothe
R A
RA
D000230:Adenocarcinoma / Q000235:genetics*; D018196:Carcinoma, Adenosquamous / Q000235:genetics*; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D002869:Chromosome Aberrations; D016889:Endometrial Neoplasms / Q000235:genetics*; D005260:Female; D005819:Genetic Markers; D006801:Humans; D018895:Microsatellite Repeats / Q000235:genetics*; D002583:Uterine Cervical Neoplasms / Q000235:genetics*
D005819:Genetic Markers