Loss of heterozygosity on chromosome 9 and p16 (MTS1, CDKN2) gene mutations in esophageal cancers

✍ Scribed by Françoise Muzeau; Jean François Fléjou; Gilles Thomas; Richard Hamelin

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: French
• Weight: 131 KB
• Volume: 72
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(19970703)72:1<27::aid-ijc3>3.0.co;2-6

✦ Synopsis

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.