Influence of human adipose stem cells on prostate cancer cell growth.

In a novel regenerative cell-based treatment developed by us for the patients with stress urinary incontinence, autologous adipose-derived stem cells (ASCs) are injected into the periurethral region and the external urethral sphincter. Since the candidates for this treatment included prostate cancer patients after radical prostatectomy, we investigated the effects of ASCs on prostate cancer cell proliferation in vitro and in vivo to confirm the feasibility of our therapeutic approach. The LNCaP (human prostate cancer cell line) cells and ASCs were co-cultured, and prostate-specific antigen (PSA) concentration in their culture medium supernatant was measured at 48 and 96 h. The PSA concentration significantly decreased in the coculture medium supernatant as compared to the culture medium with LNCaP cells alone. On the contrary, PSA concentrations in the culture medium of LNCaP cells were not affected by supplementation with ASC culture supernatant. After subcutaneous transplantation of LNCaP cells, with or without ASCs, in immunodeficient mice, tumor growth was compared. The growth of LNCaP xenograft tumor in immunodeficient mice was significantly suppressed by ASC addition. These results indicated that ASCs inhibit prostate cancer cell growth, without no proliferative effect on prostate cancer cells.