Cloning of a new member of the human kallikrein gene family, KLK14, which is down-regulated in different malignancies

Kallikreins (KLKs) belong to the serine protease family of proteolytic enzy mes. Human pancreatic/renal KLK (KLK1) encodes for an enzyme that is involv ed in posttranslational processing of polypeptide precursors. The function of the other members of this gene family is currently unknown, but growing evidence suggests that many KLKs are implicated in carcinogenesis. By using the positional candidate approach, we were able to identify a new human KL K-Iike gene, KLK14 (also known as KLK-L6), This new gene maps to chromosome 19q13.3-q13.4 and is formed of seven exons (two untranslated and five codi ng exons) and six intervening introns, KLK14 was defined as a KLK gene base d on structural and mapping criteria, in relation to other known KLK genes. KLK14 is expressed in a variety of tissues, but the highest levels of KLK1 4 are found in the central nervous system, including brain, cerebellum and spinal cord. Our preliminary results show that KLK14 is down-regulated, at the mRNA level, in breast, testicular, prostatic, and ovarian cancer.