Loss of heterozygosity on chromosome 9 and p16 (MTS1, CDKN2) gene mutations in esophageal cancers.
Loss of heterozygosity on chromosome 9 has been reported in a variety of human cancers. The cyclin-dependent kinase inhibitor p16 gene, mapped on chromosome 9p21, is presumed to be the tumor-suppressor gene localized in this chromosome. The aim of our study was to determine, in 26 Barrett's adenocarcinomas and 20 squamous-cell carcinomas of the esophagus, the prevalence of loss of heterozygosity on chromosome 9 by typing of microsatellite loci and mutation of p16 by direct sequencing of exons 1 and 2. Allelic losses were found in 69% of adenocarcinomas, but only a microdeletion in exon 1 of p16 occurred in 1 tumor. Among squamous-cell carcinomas, 65% had allelic losses and 5 tumors were mutated on the p16 gene (1 deletion, 3 nucleotide substitutions and 1 insertion). The relatively low rate of p16 mutation observed here coupled with the high frequency of loss of heterozygosity on chromosome 9 suggests that one or several tumor-suppressor gene(s) distinct from p16 may be the target(s) of allelic deletion in most esophageal cancers or that p16 is inactivated in another way.
Muzeau
F
F
INSERM U410, Faculté Xavier Bichat, Paris, France.
Fléjou
J F
JF
Thomas
G
G
Hamelin
R
R
D000230:Adenocarcinoma / Q000235:genetics; D000328:Adult; D000368:Aged; D001471:Barrett Esophagus / Q000150:complications; D002294:Carcinoma, Squamous Cell / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics*; D002872:Chromosome Deletion; D002899:Chromosomes, Human, Pair 9; D019941:Cyclin-Dependent Kinase Inhibitor p16; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D004938:Esophageal Neoplasms / Q000235:genetics*; D005260:Female; D016147:Genes, Tumor Suppressor; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged
D002352:Carrier Proteins; D019941:Cyclin-Dependent Kinase Inhibitor p16; D018844:Cyclin-Dependent Kinases