The Mechanism Of High Mobility Group Protein B1Inducing Apoptosis Of Dendritic Cells Which Was Released From Prostate Cancer After Cryoablation

Objective:To investigate the expression level of HMGB1(high mobility group protein B1, HMGB1) in prostate cancer cells undergone cryoablation, and the mechanism of it inducing apoptosis on allogeneic peripheral blood dendritic cells.Materials and Methods:Culture cells of PC-3, DU-145, which received cryoablation (using a1.7mm freezer in diamete from Endocare Argon-Helium cryosurgery system), collecting the supernatant fluid. Then, enzyme-linked immunosorbent assay (ELISA) was performed to measure the serum levels of HMGB1in the supernatant. Peripheral blood from Prostate cancer patients were collected, using lymphocyte separation medium (Ficoll) to get adherent mononuclear cells (PBMC), after using recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) and recombinant human interleukin4(rhIL-4) which stimulating the cells,we obtained immature DC (imDC). Liquid of the necrotic cells after cryoablation directly or by adding sufficient TLR-2/TLR-4neutralizing antibodies were mixed with imDC and cultured under suitable culture conditions. DC surface receptors were analyzed by flow cytometry. Further to observe the apoptosis rate of DC in every intervention groups by flow cytometry.Result:1. The PC-3cells and DU-145cells after cryoablation, most were necrosis (P <0.05).2. The expression of HMGB1of prostate cells undergo cryoablation was significantly increased (P<0.05).3. The expression of DC surface receptors (TLR-2/4) were higher after the stimulating of the necrotic cells liquid.4. The apoptosis rate of DC was significantly decreased after the TLR-2/TLR-4antibodies neutralized when it was cultured with the necrotic cells liquid. Conclusion:1. Most of the prostate cancer cells were destroyed after cryoablation.2. The prostate cancer cells PC-3, DU-145which undergo cryoablation could release amount of HMGB1.3. HMGB1in necrotic tumor cells liquid could promote the expression of Toll-like receptors of DC surface, which probable mediated the apoptosis pathway.4. The toll like receptors-2,4mediate the apoptosis pathway of HMGB1interact with dendritic cells.