16 Kallikrein 15 (KLK15) in prostate cancer: in silico analysis and single nucleotide polymorphism verification

Abstract

Introduction: Prostate cancer is the most common cancer in Caucasian men and there is strong evidence that kallikreins are part of an enzymatic cascade pathway activated in this disease. Altered KLK15 expression has been associated with cancer progression and grade and we postulate that single nucleotide polymorphisms (SNPs) in the KLK15 gene, will alter gene expression and will be associated with prostate cancer susceptibility and prognosis.Materials and Methods: We have used in silico prediction of function of wildtype and variant promoter sequences through assessment of hormone receptor elements and transcription factor binding sites; as well as prediction of likely splice variants through genomic, splicing and EST databases and web sites, and multiple sequence alignment packages. We have also used PCR and sequence analysis to further characterise the promoter region of the gene.Results: In silico analysis of the KLK15 gene has identified the following: two putative promoter regions, two putative androgen response elements (AREs) and four putative estrogen response elements (EREs); two clusters of cis elements; and 109 SNPs. Forty‐seven SNPs alter transcription factor sites (22 gain sites), 20 gain/increase probability of an ERE and three alter nuclear hormone receptor binding sites. Three new EST clones have been identified by analysis of gene expression in CGAP databases and suggest a new KLK15 splice variant, with a different start site.Conclusion: We have identified a number of new SNPs in the KLK15 gene, which may be functionally important and, in collaboration with the Queensland Cancer Fund (ProsCan Study), we will further investigate the association of these SNPs with prostate cancer risk and prognosis.