[Cryoablation for prostate cancer induces tumor-specific immune response].
OBJECTIVE
To assess the anti-tumor immune response to percutaneous cryoablation in patients with local prostate cancer.


METHODS
We treated 10 patients with local prostate cancer by percutaneous cryoablation, collected the blood samples before and 2 weeks after the treatment and isolated peripheral blood mononuclear cells (PBMCs). Protein lysates were made by biopsy from autologous prostate cancer or non-cancer tissues. The levels of serum TNF-alpha, IFN-gamma, IL4 and IL-10 were determined by enzyme-linked immunosorbent assay (ELISA) and the Th1/Th2 ratio was calculated by the IFN-gamma/IL-4 ratio. The number of IFN-gamma + T cells under the stimulation of different protein lysates was counted by enzyme link immunol spot (ELISPOT). And the cytolytic activity of cytotoxic T lymphocytes (CTL) was detected by LDH assay.


RESULTS
Compared with pre-treatment, the levels of TNF-alpha and IFN-gamma, the Th1/ Th2 ratio and the number of IFN-gamma + T cells induced by tumor protein lysates in PBMCs were increased significantly after cryosurgery (P < 0.01), while the levels of IL4 and IL-10 decreased slightly, and the non-tumor protein lysates induced no obvious changes in the number of IFN-gamma T cells. The cytolytic activity of cytotoxic T lymphocytes against human prostate cancer cells LNCaP was markedly increased, but not that against renal cancer cells GRC-1. One case of recurrence was found during the 3-6 months follow-up.


CONCLUSIONS
Percutaneous cryoablation for prostate cancer could induce a tumor-specific immune response.
Si
Tong-Guo
TG
Department of Interventional Therapy, Cancer Hospital, Tianjin Medical University, Tianjin 300060, China. dr.sitg@yahoo.com.cn
Guo
Zhi
Z
Wang
Hai-Tao
HT
Han
Yan-Ping
YP
Hao
Xi-Shan
XS
D000368:Aged; D003452:Cryosurgery; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D016753:Interleukin-10 / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000276:immunology* / Q000628:therapy*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma