Serum concentration of interleukin-35 and its association with tumor stages and FOXP3 gene polymorphism in patients with prostate cancer

Abstract IL-35 is an immunosuppressive cytokine that is largely synthesized by regulatory T (Treg) cells and may inhibit antitumor immune responses. This investigation aimed to determine the serum IL-35 concentrations and a single nucleotide polymorphism (SNP) in position of rs3761548, within the promoter region of FOXP3 gene , in patients with prostate cancer (PC). The blood specimens were obtained from 150 PC patients prior to using radiation therapy, chemo- or immunotherapy and 150 age-matched healthy men as a control group. The serum IL-35 concentrations and the pattern of genetic variation at position of rs3761548 were assessed using ELISA and polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP), respectively. The mean serum IL-35 concentrations were significantly higher in PC patients when compared with healthy control group (20.01 ± 7.03 Pg/mL vs. 11.60 ± 2.49 Pg/mL, P