LOSS OF HETEROZYGOSITY ON CHROMOSOME 9Q21 (P16 GENE) UNCOMMON IN SOFT-TISSUE SARCOMAS

Chromosome region 9p21 contains a tumor suppressor locus (p16) that ma y be involved in the genesis of several kinds of malignant tumors. To characterize the role of this gene in the development of soft-tissue t umors (STTs), we investigated the frequency of loss of heterozygosity (LOH) at this locus. DNA was obtained from 77 tumors and the periphera l blood of 23 of the patients with the tumors. Using one microsatellit e marker distal to p16(D9S171) and one intragenic sequence-tagged site (STS) marker (c5.1), we observed LOH in only one liposarcoma and one malignant schwannoma (2.6%). Homozygous deletions of the p16 markers w ere not found. The osteosarcoma cell line MG-63 was used as a control for loss of the p16 gene. Because of the low LOH frequency, we hypothe size that the p16 gene is not essential for STT oncogenesis. (C) 1997 Wiley-Liss, Inc.