Molecular cloning of the human kallikrein 15 gene (KLK15) - Up-regulation in prostate cancer

Kallikreins are a subgroup of serine proteases with diverse physiological f unctions. Growing evidence suggests that many kallikreins are implicated in carcinogenesis. By using molecular cloning techniques, we identified a new human kallikrein gene, tentatively named KLK15 (for Kallikrein 15 gene). T his new gene maps to chromosome 19q13.4 and is located between the KLK1 and KLK3 genes. KLK15 is formed of five coding exons and four introns, and sho ws structural similarity to other kallikreins and kallikrein-like genes. KL K15 has three alternatively spliced forms and is primarily expressed in the thyroid gland and to a lower extent in the prostate, salivary, and adrenal glands and in the colon testis and kidney. Our preliminary results indicat e that the expression of KLK15 is up-regulated by steroid hormones in the L NCaP prostate cancer cell line. The KLK15 gene is also up-regulated, at the mRNA level, in prostate cancer in comparison to normal prostatic tissue. K LK15 up-regulation was found to be associated with more aggressive forms of prostate cancer. This newly discovered gene has the potential of being use d as a diagnostic and/or prognostic marker for prostate cancer.