KLK5 gene expression is severely upregulated in androgen-independent prostate cancer cells after treatment with the chemotherapeutic agents docetaxel and mitoxantrone.

Kallikrein-related peptidases (KLKs), including KLK5, have been proposed as promising biomarkers for prostate cancer diagnosis and prognosis. In the present study, we report that distinct augmentations (up to 6.4-fold) of KLK5 mRNA expressional levels, calculated via quantitative real-time PCR, occur after treatment of DU145 cells with appropriate concentrations, determined by the MTT method, of docetaxel and mitoxantrone. Our data reveal the endogenous need of prostate cancer cells for modified KLK5 expression to cope with the administration of chemotherapeutic drugs. Furthermore, it is proposed that the expression profile of KLK5 could serve as a putative biomarker for monitoring the treatment response in hormone refractory prostate cancer patients.