Quantitative analysis of hippostasin/KLK11 gene expression in cancerous and noncancerous prostatic tissues

Objectives. Hippostasin/kallikrein 11 (KLK11) is a member of the human kallikrein gene family, which includes prostate-specific antigen (PSA), human kallikrein 2 (hK2), and another 12 members, all localized on chromosome 19q 13.4. Hippostasin has two alternative splicing isoforms, known as the brain type and prostate type. We have previously reported that the prostate-type isoform is not expressed in human prostate cancer cell lines. Methods. We compared the expression of hippostasin/KLK11 isoforms in 76 matched pairs of human normal and prostate cancer tissues by quantitative reverse transcriptase-polymerase chain reaction. Results. The expression of both isoforms of KLK11 was 25% to 45% higher in cancer tissues compared with their normal counterparts. Regarding prostate-type KLK11, we identified a significant association between lower expression and higher tumor stage, Gleason score, and tumor grade. No such association was seen with the brain-type isoform. Conclusions. The expression of the prostate-type isoform of KLK11 is increased in prostate cancer. This parameter should be examined further as a new prognostic indicator of prostate cancer. (C) 2003, Elsevier Inc.