6533b7d5fe1ef96bd1265163

RESEARCH PRODUCT

p16INK4A (CDKN2A) gene deletion is a frequent genetic event in synovial sarcomas.

subject

description

We assessed the frequency of genomic deletion of p16 INK4A (CDKN2A) in synovial sarcomas (SSs) and its possible association with immunoexpression of p16 and cyclin D1 and the Ki-67 proliferation index using dualcolor fluorescence in situ hybridization (FISH) on tissue microarray sections of 41 histologically and molecularly confirmed SSs. A heterozygous p16 INK4A gene deletion was identified in 28 (74%) of 38 cases, with 25 (89%) of them showing abnormal p16 protein expression (20 negative and 5 heterogeneous). Of 25 cases, 19 (76%) exhibiting increased cyclin D1 expression also demonstrated heterozygous p16 INK4A deletion. No significant association was observed between p16 INK4A deletion and Ki-67 proliferation index, tumor grade, or histologic subtype. Our results demonstrate that p16 INK4A (CDKN2A) gene deletion is a frequent genetic event in SS. Alterations involving cell-cycle regulators acting at the G 1 -S checkpoint, besides being the most frequent molecular targets in tumorigenesis of many human neoplasms, have also been implicated in the pathogenesis and tumor progression of sarcomas, especially those lacking specific genetic alterations. 1 Moreover, primary genetic alterations of cell-cycle regulatory proteins are postulated to be less common in translocation-associated sarcomas, in which they are considered as secondary events. 2