ABSTRACT
Objective: To investigate the anticancer activity of Luteolin (Lu) and its synergism effect with bacillus calmette-guerin (BCG) on human bladder cancer cell line BIU-87. Methods: Cultured BIU-87 cells were treated with different concentrations of Lu alone or the combination of Lu with BCG. MTT assay was used to measure the cell proliferation inhibition, and IC50 was calculated. Cell cycle and apoptosis were analyzed by lfow cytometry with propidiumiodide (PI) staining and Annexin-V FITC/PI dual parameter markers to clarify the mechanism of inhibiting cell proliferation and inducing apoptosis. Caspase-3 and phosphorylated c-Jun N-terminal kinases (P-JNK) expression were measured to detect the apoptosis signal pathways of Lu in cancer cells. Results: Both Lu and BCG apparently inhibited the cell proliferation and induced the apoptosis dose-dependently, and microscope observation showed morphological changes in the apoptosis. Flow cytometry indicated that Lu arrested the cell cycle at G2 phase (P<0.05). It sensitized BCG-induced cytotoxicity and cell apoptosis, and upregulated expression of caspase-3 and activation of JNK (P<0.05). Conclusion: As an effective anticancer agent, Lu can sensitize the effect of BCG by inducing the cell cycle arrest and apoptosis. hTis synergism effect is achieved by activation of caspase-3 and JNK. Combination of Lu with BCG may be one of the potential treatment for bladder cancer.
ABSTRACT
Objective To investigate the role of OX40 in the mechanisms of memory T cells in islet transplant tolerance.Methods The expression of OX40 on native, like memory and memory CD8+T cells was detected by RT-PCR. Splenic T cells from B6 mice were injected into Rag-/- mice via the tail vein, and the Rag-/- mice were divided into three groups (n=8 each): control group, given IgG; treatment group, given anti-OX40L; and OX40 knock-out group, given T cells from OX40 knock-out B6 mice spleen. All recipients were induced into diabetes mellitus model after adoptive transfer. Islet transplantation was performed on all Rag-/- mice as recipients. The mean survival time of islet was observed.Results The expression of OX40 in native T cells, like memory T cells and memory T cells was 2.87, 111.24 and 146.15 respectively. The expression of OX40 in like memory and memory T cells was higher than in native T cells (P<0.05). Comparison with control group , The mean survival time of the DBA/2 islet allografts in treatment group (130 days) and OX40 knock-out group (125 days) was significantly longer than in control group (21 days, P<0.05).Conclusion The OX40 expression is high in memory T cells. The mean survival time of the islet allografts can be prolonged by blocking OX40/OX40L pathway. OX40/OX40L pathway may be the key point of transplant tolerance.