The human PCPH proto-oncogene: cDNA identification, primary structure, chromosomal mapping, and expression in normal...

We identified a human cDNA encoding a 47-kDa protein that shares 78% and 87% identity with the products of the Syrian hamster and mouse PCPH proto-oncogenes respectively. The human homolog was localized by radiation-hybrid mapping to chromosome band 14q24.3, a region syntenic to the Pcph location on mouse chromosome 12. Northern analyses revealed that PCPH mRNA was widely distributed in normal human adult tissues, but its expression varied significantly among human tumor cells and cell lines of several tissue types, regardless of the level of expression in the corresponding normal tissues. The highest levels of PCPH mRNA and protein were detected in kidney and liver. However, PCPH was not expressed in the majority of human neoplasms tested, including kidney tumors. These data provide suggestive evidence for a possible association of the lack of PCPH expression to the neoplastic phenotype of human tumor cells. Our results should prove instrumental in designing studies to define the cellular function of the human PCPH proto-oncogene.