A novel transmembrane serine protease (TMPRSS3) overexpressed in pancreatic cancer

We report the characterization of a novel serine protease of the chymotryps in family, recently isolated by cDNA-representational difference analysis, as a gene overexpressed in pancreatic cancer, The 2.3-kb mRNA. of the gene, named TMPRSS3, is strongly expressed in a subset of pancreatic cancer and various other cancer tissues, and its expression correlates with the metast atic potential of the clonal SUIT-2 pancreatic cancer cell lines. The deduc ed polypeptide sequence consists of 437 amino acids and exhibits all of the structural features characteristic of serine proteases with trypsin-like a ctivity. TMPRSS3 is membrane bound with a NH2-terminal signal-anchor sequen ce and a glycosylated extracellular region containing the serine protease d omain. Thus, TMPRSS3 is a novel membrane-bound serine protease overexpresse d in cancer, which may be of importance for processes involved in metastasi s formation and tumor invasion.