Comparative genomic hybridization defines frequent loss on 16p in human anaplastic thyroid carcinoma

Anaplastic thyroid cancer (ATC) is one of the malignant tumors with the poo r prognosis that is thought to arise from well-differentiated thyroid cance r (DTC). To investigate the molecular mechanism of ATC, we studied genomic alterations of eight ATC cell lines and three DTC cell lines by means of th e comparative genomic hybridization (CGH) method. Loss of 16p was observed in five of eight ATC cell lines (62.5%), but none of the three DTC cell lin es showed loss of this chromosome arm. It is notable that loss of 18q [7/8 of ATC (87.5%), 2/3 of DTC (67%)] and gain of 20q [5/8 of ATC (62.5%), 3/3 of DTC (100%)] were frequently seen in both histologic types. Our results s uggest that there is a gene in 16p that is closely associated with transfor mation from well-differentiated thyroid cancer to anaplastic cancer.