Loss of heterozygosity on chromosome 9q21 (p16 gene) uncommon in soft-tissue sarcomas.

Chromosome region 9p21 contains a tumor suppressor locus (p16) that may be involved in the genesis of several kinds of malignant tumors. To characterize the role of this gene in the development of soft-tissue tumors (STTs), we investigated the frequency of loss of heterozygosity (LOH) at this locus. DNA was obtained from 77 tumors and the peripheral blood of 23 of the patients with the tumors. Using one microsatellite 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 were 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 hypothesize that the p16 gene is not essential for STT oncogenesis.