Increased circulating myeloid-derived suppressor cells correlate with cancer stages, interleukin-8 and -6 in prostate cancer.

Aim: Myeloid-derived suppressor cells (MDSCs) are a population of cells which negatively regulate immune response during tumor progression. In this study, we assessed the accumulation of MDSCs (CD33(+)CD11b(+)HLA-DR(-)CD14(-)) in patients with prostate cancer and its clinical relevance.

Methods: We tested the frequency of MDSCs in the peripheral blood of patients with prostate cancer or benign prostate hyperplasia and healthy donors. Serumal interleukin-8, -6 and -10 were analyzed. Effects of MDSCs on the T cell response were determined.

Results: MDSCs increased in cancer patients, and there was an association between MDSCs and cancer stages or overall survival. Elevated serumal interleukin-8 and -6 in cancer patients correlated with MDSCs. Moreover, accumulation of MDSCs was associated with defective T cell function.

Conclusion: Our study showed an increased population of MDSCs in patients with prostate cancer. Interleukin-8 and -6 in serum may play a new important role companied with MDSCs in prostate cancer.