Differential Expression of the KLK2 and KLK3 Genes in Peripheral Blood and Tissues Samples of Iranian Patients with Prostate Cancer

ABSTRACT Background and Objectives: Prostate cancer is a highly prevalent malignancy with a high mortality rate in men. Many studies have investigated the diagnostic value of various genes involved in prostate cancer, but there is no data for Kallikrein 2 (KLK2) and Kallikrein 3 (KLK3) expression patterns among Iranian patients. Therefore, we aimed to evaluate the expression of these two genes in Iranian patients with prostate cancer. Methods: In this case-control study, three groups consisting of healthy individuals, patients with benign prostatic hyperplasia (BPH) and patients with prostate cancer were studied. Peripheral blood samples were collected from all subjects, mRNA was extracted after cell lysis, and cDNA was synthesized. Real-time PCR was performed to assess gene expression levels relative to a reference gene (18s rRNA gene). Results: The KLK2 gene was overexpressed in patients with prostate cancer. KLK2 expression differed significantly between the cancer patients and controls. Relative expression of the KLK3 gene in the BPH group was higher than that in the control and cancer groups. However, we observed no significant difference in the expression of KLK3 between the control and cancer subjects. Conclusion: We demonstrate that analysis of KLK2 expression is a favorable method of diagnosing prostate cancer and discriminating normal individuals from those with BPH or prostate cancer. We also found that the KLK3 gene is highly overexpressed in individuals with BPH, which might indicate that this gene is not cancer-specific. Keywords: Prostatic Neoplasm, Prostatic Hyperplasia, Kallikreins, Gene Expression