LOSS OF CONSTITUTIONAL HETEROZYGOSITY ON CHROMOSOME-5 AND CHROMOSOME-17 IN CHOLANGIOCARCINOMA

It has been established that loss of tumour suppressor genes is crucia l in carcinogenesis. There has been no reported study on searching for tumour suppressor genes in cholangiocarcinomas as yet. In order to in vestigate the loss of heterozygosity (LOH), which may represent such g ene loss, in cholangiocarcinoma, we studied 14 patients with this tumo ur using restriction fragment length polymorphism analysis. Twenty-two probes assigned to chromosomes 1, 5, 7, 9, 11, 12, 13, 14, 16, 17 and 18 were used. Allelic losses were found in chromosomal regions 5q35-q ter and 17p13. Loss of genetic material in these regions in cholangioc arcinoma was shared with hepatocellular carcinoma. Probes for other ch romosomes have as yet shown no consistent LOH. In conclusion, this stu dy for the first time showed LOH on chromosomes 5 and 17 in cholangioc arcinoma.