ABSTRACT
@# Objective: To investigate the reverse effect and mechanism of IL-12 on chemotherapeutic medicine suppressing the immune function of NK cells. Methods: Purified NK cells were stimulated with PMAplus Ionomycin in the presence or absent of Cisplatin (DDP) and IL-12. The levels of IFN-γ and TNF-α in culture supernatants were detected by enzyme-linked immunosorbent assay (ELISA); The content of IFN-γ and TNF-α, TRAIL (TNF-related apoptosis inducing ligand) and transcription factors including T-bet and p-STAT-4 in NK cells were analyzed by Flow cytometry. The cytotoxicity of purified NK cells (pretreated with/without chemotherapeutics and IL-12 for 48 h) to Jurkat cells was measured by Flow cytometry. Results: Chemotherapeutics significantly inhibited the production of IFN-γ, TNF-α and the expression of TRAILin NK cells, which were significantly reversed by IL-12 (P<0.05 or P<0.01). Further study revealed that chemotherapeutics down-regulated while IL-12 reversed the expression of p-STAT4 to restore cytokine production. In addition, DDP also inhibited but IL-12 recovered the cytotoxicity of NK cells against tumor cells by inducing the expression of TRAIL (P<0.05 or P<0.01). Conclusion: Chemotherapeutics inhibited the cytotoxicity of NK cells and its secretion of cytokines (IFNγ and TNF-α), which were reversed by IL-12 via up-regulating TRAIL and p-STAT-4; this might provide experimental evidence for the clinical application of IL-12 for rebuild the immune function of tumor patients receiving chemotherapy.
ABSTRACT
Objective To investigate the effects of ionizing radiation on the expression of P21 protein in Jurkat cell line and p21 gene in thymocytes and splenocytes of mice.Methods Flow cytometry (FCM)was used to analyze the expression of P21 protein in Jurkat cells at 12 and 24 h after irradiation to 0,0.5,1.0,2.0,4.0,and 6.0 Gy.Real-time PCR was used to detect the expression of p21 gene in thymocytes and splenocytes of mice at4 and 24 h after irradiation to 0,0.5,1.0,2.0,4.0,and 6.0 Gy.Multi-staining was used to analyze the micronucleus rates of Rct in bone marrow.Results The expressions of P21 protein were increased in a dose-dependent manner during 0.5-4.0 Gy(t=-24.23--3.96,P<0.05),but decreased at 6.0 Gy at 12 and 24 h post-irradiation(t=-11.19,-14.50,P<0.05).The expressions of p2 1 gene in both thymocytes and splenocytes of mice were increased in dose-dependent manner in the range of 0-6.0 Gy(including 6.0 Gy)(t=-29.96-8.80,P<0.05),and reached to the peak at 6.0 Gy at 4 and 24 h post-irradiation(t=-11.84--3.42,P<0.05),except thymocytes at 4 h and 1.0 Gy post-irradiation(t=-3.42,P>0.05).Conclusions The expressions of P21 protein and p21 gene could be increased by X-ray irradiation.which shows good dosedependent manners in certain range of dose.
ABSTRACT
In this study, we examined the effects of aspirin on the growth rates, subcellar distribution of β-catenin protein, the expression of β-catenin/TCF signaling pathway target gene cyclinD1 mRNA,and cell cycle of Jurkat cell line (Human T-acute lymphoblastic leukemia). Our results showed that the treatment with aspirin inhibited the growth of Jurkat cell line. Jurkat cells treated with 3 mmol/L of aspirin could significantly decrease nuclear localization of β-catenin, and at 5 mmol/L of aspirin,the nuclear localization of β-catenin was undetectable. QRT-PCR showed that the target gene cyclinD1 mRNA expression was gradually decreased with the dosage of aspirin. Aspirin induced G0/G1cell cycle arrest in Jurkat cells. We are led to conclude that aspirin acts through β-catenin-independent mechanisms. The effects of aspirin include down-regulation of β-catenin nuclear localization and G0/G1 cell cycle arrest, which might serve as a means of growth inhibition in aspirin-treated human Jurkat cell line.