Low incidence of genetic alterations of the p16CDKN2a in clear cell chondrosarcoma

Mutational inactivation of the cyclin-dependent kinase inhibitors (CDKIs) (p16 CDKN2a ) tumor suppressor gene has been found in a variety of human tumor types. To investigate the involvement of CDKI abnormality in clear cell chondrosarcoma, alterations of CDKIs were examined in clear cell chondrosarcoma tissues using a quantitative DNA/PCR, PCR-SSCP. Two of 38 specimens (5.2%) we analyzed showed abnormally low levels of p16 CDKN2a amplification, suggesting that the allelic deletion of the gene might be low frequent event in progression of this tumor. For detection of subtle sequence alterations such as point mutations, we performed SSCP analysis of the entire coding region of the p16 CDKN2a gene. No altered SSCP patterns were found in 38 clear cell chondrosarcoma specimens. This study reflects the very low incidence of genetic alterations of the p16 CDKN2a gene in clear cell chondrosarcoma. Therefore, we conclude that the alteration of the p16 CDKN2a gene is not involved significantly in the development of clear cell chondrosarcoma.