The WFDC1 gene encoding ps20 localizes to 16q24, a region of LOH in multiple cancers

We previously identified ps20 protein as a secreted growth inhibitor and pu rified the protein from fetal rat prostate urogenital sinus mesenchymal cel l conditioned medium. The rat cDNA was subsequently cloned, and ps20 was fo und to contain a WAP-type four-disulfide core motif, indicating it may func tion as a protease inhibitor. We now report cloning and characterization of the mouse ps20 gene (designated Wfdc1), the human homolog cDNA, and the hu man gene (designated WFDC1), Both the mouse and human WFDC1 genes consist o f seven exons and encode respective ps20 proteins sharing 79.1% identity an d nearly identical WAP motifs in exon 2. The WFDC1 gene was mapped by FISH analysis to human Chromosome (Chr) 16q24, an area of frequent loss of heter ozygosity (LOH) previously identified in multiple cancers including prostat e, breast, hepatocellular, and Wilms' turner. identification and characteri zation of the WFDC1 gene may aid in better understanding the potential role of this gene and ps20 in prostate biology and carcinogenesis.