Eight cases of metastatic castration resistant prostate cancer treated with autologous natural killer cells

Abstract

Objective To evaluate the efficacy and safety of autologous natural killer (NK) transfusion to treat the patients of metastatic castration resistant prostate cancer (mCRPC). Methods Eight consecutive patients of mCRPC were enrolled from Jan 2014 to Jun 2015 and written informed consent was provided. The patients were evaluated by using laboratory tests, medical imaging and scores. Fifty milliliter blood sample was drawn and the peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll density centrifugation, then the NK population were induced to proliferate for approximately 1 000 times. The Patients received autologous NK transfusion every one week when the NK cells passed quality and functional tests. The patients were evaluated again three days following last transfusions (3-4 time in total). Results The averaged NK cells’ population were proliferated to 4.39×109 cells (range 3.36-6.44×109 cells) in (18±3) days. The purity of NK was 84.3% (range 68.8%-94.7%). No pathogens, endotoxin and mycoplasma were detected. The NK cells could lyze the K562 and PC-3 cells at cell concentration ratio of 10∶1 and above for 4 hours, 82% and78% and above, respectively. The NK population were increased in 7/8 patients; and the CD8+ T cells population were increased in 6/8 patients (P=0.078); cytokine interleukin (IL)-2, IL-12, interferon (IFN) and tumor necrosis factor (TNF) did not show significant variation (P=0.235). The quality of life (Kamofshy score) and ostealgia (numeric rating scale, NRS) were ameliorated. No adverse events were observed. Conclusion To some extent, the immune response of mCRPC patients could be evoked following autologous NK cells transfusion. Key words: Cellular immunotherapy; Prostate cancer; Natural killer cells