Identification of novel human kallikrein-like genes on chromosome 19q13.3-q13.4.

The human kallikrein gene family is localized on chromosome 19q13.3-q13.4 and currently includes three members: KLK1 or pancreatic/renal kallikrein, KLK2 or human glandular kallikrein and KLK3 or prostate-specific antigen (PSA). The latter two genes are almost prostate-specific and they are used for diagnosis and monitoring of prostate cancer and more recently, in breast cancer applications. In this paper, we analyzed a 300Kb genomic DNA region around chromosome 19q13.3-q13.4 in an effort to map known kallikrein or kallikrein-like genes and identify new kallikrein-like genes. Using the known kallikrein or kallikrein-like genes PSA, KLK2, enzyme and normal epithelial cell-specific 1 gene (NES1) as landmarks, we have identified another six novel genes of which, five have protein homologies and gene structure similarities with other kallikreins or kallikrein-like genes. We conclude, contrary to the current belief, that the human kallikrein gene locus contains a large number of kallikrein-like genes (at least thirteen). In this paper, we present a detailed description of the human kallikrein gene locus, encompassing the already known and newly identified genes. These new genes, like the already known kallikreins, may have utility for diagnosis, monitoring and therapeutics of various cancers including those of the breast, prostate and testis.