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Objective To explore the signaling pathway of apoptosis induced by Paclitaxel (PTX) in leukemia cells and the chemosensitizing effect of adding short hairpin RNA(shRNA) on PTX,which targets the silencer of death domains(SODD).Methods After being treated with PTX,the expressions of SODD,B-cell lymphoma/leukemia-2 (Bcl-2),nuclear factor kappa B (NF-κB) and Caspase-3 proteins in Jurkat cells were determined by Western blot ;the shRNA-SODD vectors were constructed and transfected into Jurkat cells by electroporation,and then G418 was used to select the stable tranfected cell line expressing the shRNA-SODD recombinant plasmids.The incidence of cell apoptosis induced by PTX was determined by flow cytometry labeled with propidium iodide.Results During the process of inducing apoptosis of Jurkat cells,PTX could significantly down-regulate the expressions of SODD and Bcl-2 proteins,degrade Caspase-3 and activate NF-κB.The apoptotic sensibility of Jurkat cells transfected with shRNA-SODD to PTX was significantly increased compared with the control group,and the difference was statistically significant (F =10.35,P ＜ 0.05).Conclusions PTX can effectively induce apoptosis of Jurkat cells.Perhaps,SODD/Bcl-2 represents a specific apoptotic signaling pathway of PTX in leukemia cells and this apoptotic signaling pathway is Caspase-3-dependent,in which the function of NF-κB is to modulate the correlative apoptotic factors.Inhibiting the expression of SODD through transfecting shRNA-SODD vectors can significantly increase the apoptotic sensibility of leukemia cells to PTX.
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In order to investigate the inhibitory effects of all trans-retinoitc acid (ATRA) on differentiation and apoptosis of Walker-256 hepatocellular carcinoma cells and the therapeutic effects of ATRA combined with transarterial chemoembolization (TACE) on rat Walker-256 transplanted hepatocarcinoma, Walker-256 hepatocarcinoma cell lines were treated with ATRA at different concentrations. After culture for 48 h, the inhibitory rate of cell proliferation was determined by MTT assay; the changes of Fas and Bcl-2 mRNA expression were determined by RT-PCR, and the expression levels of Caspase3 and Caspase8 proteins were detected by Western blot. Twenty-seven Wistar rat models of hepatocarcinoma were set up successfully by implanting Walker-256 cell lines. The tumor volume at the 11th day after implantation (V(preoperation)) was measured by magnetic resonance imaging (MRI). The 27 rats were randomly and equally divided into three groups, and the therapy scheme was performed as follows: group A (ATRA 0.1 mg+mitomycin 0.05 mL+lipiodol 0.05 mL+gelfoam powder 0.025 mg); group B (mitomycin 0.05 mg+lipiodol 0.05 ml+gelfoam 0.025 mg; group C (0.9% NaCl 0.2 mL). After another 11 days, MRI was performed once again to measure the tumor volume (V(postoperation)). The expression of factor and Ki VIII -67 in the tumor tissues was detected by immunohistochemistry. The results showed that ATRA could suppress proliferation of Walker-256 cell lines. After treatment of Walker-256 cell lines with ATRA, the expression of Fas mRNA was significantly up-regulated and the Bcl-2 mRNA was significantly down-regulated by ATRA at the concentration of 10 mumol/L as compared with the control group (P<0.05). After treatment with 10 mumol/L ATRA for 48 h, the Caspase3 and Caspase8 were significantly activated as compared with the control group (P<0.05). Significant difference existed in growth rate among the three groups (P<0.01) and between either two groups (P<0.05). The expression rate of factor VIII and Ki-67 was gradually increased from group A, group B to group C. The study suggests that ATRA could inhibit the proliferation of Walker-256 cells and the effectiveness of the combined therapy (ATRA+TACE) for treating transplanted hepatoma of rats is superior to that of TACE alone.
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The expression of silience of death domains (SODD) and its clinical significance and relationship with phospho-NF-κB-p65 proteins in bone marrow cells of childhood acute lymphoblastic leukaemia (ALL) were explored, and the expression of SODD and phospho-NF-κB-p65 in Jurkat cells treated with chemotherapeutic drugs was detected in order to find a new chemotherapeutic target. The expression of SODD and phospho-NF-κB-p65 proteins in bone marrow cells was detected by immunohistochemistry in 25 children with ALL. The apoptosis rate was measured by Annexin-V-Fluorescence/PI double-labeling flow cytometry and the expression of SODD and phospho-NF-κB-p65 proteins determined by Western blotting in the Jurkat cells. It was found that the expression of SODD and active P65 in ALL was significantly higher than that in normal control group (P＜0.05). The expression of the SODD and phospho-NF-κB-p65 proteins in the high-risk (HR) group was significantly higher than that in the standard-risk (SR) group (P＜0.05). The Pearson rank correlation analysis revealed that there was a positive correlation between SODD and phospho-NF-κB-p65 expression (P＜0.01, r=0.69). VCR could effectively induce the apoptosis of Jurkat cells, and down-regulate the expression of SODD and phospho-NF-κB-p65 proteins in a time-dependent manner, but DNR could not down-regulate the expression of SODD effectively. It was concluded that SODD may be closely related to the clinical classification and prognosis of ALL in children. The expression of SODD and phospho-NF-κB-p65 had a definite synergistic relationship with the onset and development of ALL. VCR could down-regulate the expression of SODD and inhibit the NF-κB activation, which could recover the sensibility of apoptosis in leukemic cells.
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The expression of silence of death domains (SODD) and its clinical significance and relationship with phospho-NF-kappaB-p65 proteins in bone marrow cells of childhood acute lymphoblastic leukaemia (ALL) were explored, and the expression of SODD and phospho-NF-kappaB-p65 in Jurkat cells treated with chemotherapeutic drugs was detected in order to find a new chemotherapeutic target. The expression of SODD and phospho-NF-kappaB-p65 proteins in bone marrow cells was detected by immunohistochemistry in 25 children with ALL. The apoptosis rate was measured by Annexin-V-Fluorescence/PI double-labeling flow cytometry and the expression of SODD and phospho-NF-kappaB-p65 proteins determined by Western blotting in the Jurkat cells. It was found that the expression of SODD and active P65 in ALL was significantly higher than that in normal control group (P<0.05). The expression of the SODD and phospho-NF-kappaB-p65 proteins in the high-risk (HR) group was significantly higher than that in the standard-risk (SR) group (P<0.05). The Pearson rank correlation analysis revealed that there was a positive correlation between SODD and phospho-NF-kappaB-p65 expression (P<0.01, r=0.69). VCR could effectively induce the apoptosis of Jurkat cells, and down-regulate the expression of SODD and phospho-NF-kappaB-p65 proteins in a time-dependent manner, but DNR could not down-regulate the expression of SODD effectively. It was concluded that SODD may be closely related to the clinical classification and prognosis of ALL in children. The expression of SODD and phospho-NF-kappaB-p65 had a definite synergistic relationship with the onset and development of ALL. VCR could down-regulate the expression of SODD and inhibit the NF-kappaB activation, which could recover the sensibility of apoptosis in leukemic cells.