Inhibition of NF-κB by mutant IκBα enhances TNF-α-induced apoptosis in HL-60 cells by controlling bcl-xL expression

Backgound The aim of this study was to explore whether the inhibition of nuclear factor-κB (NF-κB)activation by mutant IκBα (S32,36→A) can enhance TNF-α-induced apoptosis of leukemia cells and to investigate the possible mechanism. Methods The mutant IκBα gene was transfected into HL-60 cells by liposome-mediated techniques. G418 resistant clones stably expressing mutant IκBα were obtained by the limiting dilution method. TNF-α-induced NF-κB activation was measured by electrophoretic mobility shift assay (EMSA). The expression of bcl-xL was detected by RT-PCR and Western blot after 4 hours exposure of parental HL-60 and transfected HL-60 cells to a variety of concentrations of TNF-α. The percentage of apoptotic leukemia cells was evaluated by flow cytometry (FCM). Results Mutant IκBα protein was confirmed to exist by Western blot. The results of EMSA showed that NF-κB activation by TNF-α in HL-60 cells was induced in a dose-dependent manner, but was almost completely inhibited by mutant IκBα repressor in transfected cells. The levels of bcl-xL mRNA and protein in HL-60 cells increased after exposure to TNF-α, but changed very little in transfected HL-60 cells. The inhibition of NF-κB activation by mutant IκBα enhanced TNF-α-induced apoptosis. Thecytotoxic effects of TNF-α were amplified in a time- and dose-dependent manner. Conclusions NF-κB activation plays an important role in the resistance to TNF-α-induced apoptosis. The inhibition of NF-κB by mutant IκBα could provide a new approach that may enhance the antileukemia effects of TNF-α or even of other cytotoxic agents.     

The Role of IκBα in TNF-α-induced Apoptosis in Hepatic Stellate Cell Line HSC-T6

To investigate the role of NF-κB in TNF-α induced apoptosis in HSC-T6, a mutant IκBα was transfected into HSC-T6 cells by lipofectin transfection technique and its transient effect was examined 48 h after the transfection. The activation of NF-κB was detected by immune fluorescence cytochemistry and Western blotting with anti-p65 antibody. The apoptosis and the rate of inhibition by TNF-α in both transfected and untransfected HSC-T6 cells were measured respectively by FAC-Scan side scatter analysis and MTF methods. Our results showed that TNF-α could activate NF-κB in untransfected cells but not in transfected HSC-T6 cells. The percentage of apoptosis in transfected cells were significantly higher than that in the untransfected ones （P〈0.01） and it was also true of the inhibition rate （P〈0.01）. It is concluded that the resistance of HSC-T6 towards apoptosis induced by TNF-α can be mediated by NF-κB activation. The inhibition of NF-κB activation by mutant IκBα can attenuate the resistance of HSC-T6 cells and increase its sensitivity to TNF-α.     

Triptolide-induced apoptosis by inactivating nuclear factor-kappa B apoptotic pathway in multiple myeloma <Emphasis Type="Italic">in vitro</Emphasis>

The effect of triptolide on proliferation and apoptosis of human multiple myeloma RPMI-8226 cells in vitro,as well as the roles of nuclear factor-kappa B(NF-κB) and IκBα was investigated.The effect of tritptolide on the growth of RPMI-8226 cells was studied by MTT assay.Apoptosis was detected by Hoechest 33258 staining and Annexin V/PI double staining assay.The expression of NF-κB and IκBα was observed by Western blot and confocal microscopy.The results showed that triptolide inactivated NF-κB apoptotic pathway in human multiple myeloma RPMI-8226 cells.Triptolide at nM range induced proliferation inhibition in a dose-and time-dependent manner and apoptosis in a dose-dependent fashion in RPMI-8226 cells.Besides,we observed the inhibition of NF-κB /p65 in the nuclear fraction was correlated with the increase in the protein expression of IκBα in the cytosol.These results suggested that triptolide might exhibit its strong anti-tumor effects via inactivation of NF-κB/p65 and IκBα.     

Phosphoinositide 3-Kinase/Akt and Nuclear Factor-KB Are Involved in Staphylococcus Aureus-induced Apoptosis in U937 Cells

Objective To explore the mechanisms involved in Staphylococcus aureus （S. aureus） invading human monocytic U937 cells. Methods S. aureus were added to U937 cells at multiplicity of infections （MOI） of 20：1 for 0, 15, 30, 60, and 90 minutes, respectively. Cell apoptosis was analyzed with Hoechst 33258 staining and Annexin V-fluorescein isothiocyanate （FITC）/propidium iodide （PI） flow cytometry analysis. Akt and nuclear factor-κB （NF-κB） activities were detected by Western blotting. Results Infection of U937 cells with S. aureus induced rapid cell death in a time-dependent manner, and the cells displayed characteristic features of apoptosis. S. aureus-induced apoptosis was associated with a prominent downregulation of activated （phosphorylated） Akt and NF-κB. The inhibition of phosphorylated Akt by LY294002 led to the inhibition of NF-κB in a dose-dependent manner. Inhibition of Akt with LY294002 caused further increase in apoptosis of U937 cells. Conclusions S. aureus can stimulate the apoptosis of U937 ceils. S. aureus induces apoptosis of U937 cells by inhibiting Akt-regulated NF-κB.     

Pyrrolidine dithiocarbamate Inhibits NF- κB Activation and Enhance TNFα- Induced Apoptosis in Human Breast Cancer Cells

Objective: Tumor necrosis factor α(TNFα) induced apoptosis is limited by its coactivation of nuclear factor kappa B(NF- κB) -dependent antiapoptosis genes. We examined whether pyrrolidine dithiocarbamate (PDTC) enhance TNFα - induced apoptosis in cultured breast cancer cells and explored the role of NF - κB in TNFα - induced apoptosis. Methods: Human breast cancer cell lines MCF-7 and MDA - MB -435s were treated with TNFα、 PDTC and combination therapy . Induction of apoptosis was detected by TUNEL staining and flow cytometry. NF- κB DNA binding activity was detected using electrophoresis mobility shift assay(EMSA) . Western blots of cytoplasmic lysates were performed to demonstrate IκBα (Inhibitor protein of nuclear factor κB) phosphorylation and degradation. Results:TNFα-induced IκBo phosphorylation and degradation, which was inhibited by PDTC in both cell lines. TNFα-induced apoptosis (TUNEL) increased significantly when both cells were pretreated with PDTC. Flow cytometry also confirmed this. EMSA showed that PDTC continuously inhibited TNFo-induced NF- κB DNA binding activity . Conclusions:PDTC enhances TNFo-induced apoptosis whileinhibiting IκBα phosphorylation and degradation in human breast cancer cells. NF - κB has a protective role on TNFα-induced apoptosis.     

Increased expression and activity of MMP-9 in C-reactive protein- induced human THP-1 mononuclear cells is related to activation of nuclear factor kappa-B

The relation between the expression and activity of MMP-9 in C-reactive protein （CRP）-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B （NF-κB） was studied to investigate the possible role of CRP in plaque destabilization. Human THP-1 cells were incubated in the presence of CRP at 0 （control group）, 25, 50 and 100 μg/mL （CRP groups） for 24 h. In PDTC （a specific NF-κB inhibitor） group, the cells were pre-treated with PDTC at 10 μmol/L and then with 100 μg/mL CRP. The conditioned media （CM） and human THP-1 cells in different groups were harvested. MMP-9 expression in CM and human THP-1 cells was measured by ELISA and Western blotting. MMP-9 activity was assessed by fluorogenic substrates. The expression of NF-κB inhibitor α （IκB-α） and NF-κB p65 was detected by Western blotting and ELISA respectively. The results showed that CRP increased the expression and activity of MMP-9 in a dose-dependent manner in the human THP-1 cells. Western blotting revealed that IiB-α expression was decreased in the cells with the concentrations of CRP and ELISA demonstrated that NF-κB p65 expression in the CRP-induced cells was increased. After pre-treatment of the cells with PDTC at 10 μmol/L, the decrease in IκB-α expression and the increase in NF-κB p65 expression in the CRP-induced cells were inhibited, and the expression and activity of MMP-9 were lowered too. It is concluded that increased expression and activity of MMP-9 in CRP-induced human THP-1 cells may be associated with activation of NF-κB. Down-regulation of the expression and activity of MMP-9 may be a new treatment alternative for plaque stabilization by inhibiting the NF-κB activation.     

Inhibitory Effects of Parthenolide on the Activity of NF-κB in Multiple Myeloma via Targeting TRAF6

This study examined the mechanism of the inhibitory effect of parthenolide(PTL) on the activity of NF-κB in multiple myeloma(MM). Human multiple myeloma cell line RPMI 8226 cells were treated with or without different concentrations of PTL for various time periods, and then MTT assay was used to detect cell proliferation. Cell cycle and apoptosis were flow cytometrically detected. The level of protein ubiquitination was determined by using immunoprecipitation. Western blotting was employed to measure the level of total protein ubiquitination, the expression of IκB-α in cell plasma and the content of p65 in nucleus. The content of p65 in nucleus before and after PTL treatment was also examined with immunofluorescence. Exposure of RPMI 8226 cells to PTL attenuated the level of ubiquitinated Nemo, increased the expression of IκB-α and reduced the level of p65 in nucleus, finally leading to the decrease of the activity of NF-κB. PTL inhibited cell proliferation, induced apoptosis and blocked cell cycle. Furthermore, the levels of ubiquitinated tumor necrosis factor receptor-associated factor 6(TRAF6) and total proteins were decreased after PTL treatment. By using Autodock software package, we predicted that PTL could bind to TRAF6 directly and tightly. Taken together, our findings suggest that PTL inhibits the activation of NF-κB signaling pathway via directly binding with TRAF6, thereby suppressing MM cell proliferation and inducing apoptosis.     

LMP1 activates NF- κB via degradation of IκBα in nasopharyngeal carcinoma cells

Objective To elucidate the mechanisms by which Epstein- Barr virus- encoded latent membran e protein 1 activates NF- κB in nasopharyngeal carcinoma cells. Methods A tetracycline- regulated LMP1- expressing nasopharyngeal carcinoma cell line, T et- on- LMP1- HNE2, was used as the cell model. The kinetics of the expression of proteins, including LMP1, IκBα and IκBβ, was analyzed by Western blotting . The subcellular localization of NF- κB (p65) was detected by indirect immuno fluorescence assay. The NF- κB transactivity was studied by transient transfec tion and reporter gene assay. Results IκBα was phosphorylated and degraded after the inducible expression of LMP1, a lthough the total protein levels remained stable. The steady- state level of to tal IκBβ protein may have resulted from the initiation of an autoregulation lo op after the activation of NF- κB. No change in the IκBβ level was detected . NF- κB (p65) was translocated from the cytoplasm to the nucleus following de gradation of IκBα. After the introduction of the dominant- negative mutant of IκBα (Del 71) into Tet- on- LMP1- HNE2 cells, both nuclear translocation and transactivation of NF- κB induced by LMP1 was significantly inhibited. Conclusions The results indicated that in nasopharyngeal carcinoma cells, LMP1 activated NF - κB via phosphorylation and degradation of IκBα, but not IκBβ. The do minant- negative mutant of IκBα (Del 71) could completely inhibit both the nuc lear translocation and transactivation of NF- κB induced by LMP1.     

Expression of Nuclear Factor-κB in Mouse Uterus during Peri-implantation

To investigate the expression of the subunit p65 of NF-κB and inhibitor kappa B alpha (IκBα) in mouse uterus during peri-implantation, thereby investigating whether transient activation of nuclear factor-κB (NF-κB) takes place during embryo implantation in mice. Immunohistochemical technique was used to examine the expression and localization of p65 in endometrium or deciduas, and Western blot analysis was employed to detect the levels of IκBα protein in mouse endometrium or deciduas. P65 protein was detected in stromal cells, epithelial cells of endometrium as well as in myometrium. Staining was predominately seen in the cytoplasm of the cells. Staining intensity for p65 was stronger in the epithelial compartment than the stromal compartment and myometrium. Staining intensity increased slightly during pregnancy, and it reached a high level on pregnancy day 5 and day 8. In contrast to p65, the level of IκBα protein was lowest on pregnancy day 5 in all groups. Our results suggested that NF-κB may regulate embryo implantation by its transient activation in mice.     

Inhibitory Activity of Nuclear Factor-κB Potentiates Cisplatin-induced Apoptosis in A549 Cells

Whether inhibiting the activity of nuclear factor (NF)-κB potentiates cisplatin-induced apoptosis in non-small cell lung cell line A549 cells was investigated. The recombinant plasmid pcDNA3.1( )/IκBα expressing IκBα was constructed. The in vitro cultured A549 cells were trans-fected with pcDNA3.1( )/IκBα alone, or pcDNA3.1( )/IκBα combined with cisplatin. The mitochondrial membrane potential (△ψm) was determined by rhodamine 123, the activity of caspase-3 was tested by colorimetric assay, and cell apoptosis was detected by flow cytometry with the annexin V/propidium iodide assay. The results showed that the activity of NF-κB in A549 cells was inhibited by transfecting pcDNA3.1( )/IκBα. Transfection of pcDNA3.1( )/IκBα alone did not promote apoptosis. Treatment of cisplatin alone had a little effect on cell apoptosis. Transfection of pcDNA3.1( )/IκBα combined with cisplatin treatment significantly induced apoptosis of A549 cells. It was concluded that inhibiting the activity of NF-κB potentiated cisplatin-induced apoptosis of A549 cells.     

Inhibitory Activity of Nuclear Factor-κB Potentiates Cisplatin-induced Apoptosis in A549 Cells

Whether inhibiting the activity of nuclear factor(NF)-κB potentiates cisplatin-induced apoptosis in non-small cell lung cell line A549 cells was investigated.The recombinant plasmid pcDNA3.1( )/IκBα expressing IκBα was constructed.The in vitro cultured A549 cells were transfected with pcDNA3.1( )/IκBα alone,or pcDNA3.1( )/IκBα combined with cisplatin.The mito-chondrial membrane potential(?ψm) was determined by rhodamine 123,the activity of caspase-3 was tested by colorimetric assay,and cell apoptosis was detected by flow cytometry with the annexin Ⅴ/propidium iodide assay.The results showed that the activity of NF-κΒ in A549 cells was inhibited by transfecting pcDNA3.1( )/IκΒα.Transfection of pcDNA3.1( )/IκΒα alone did not promote apoptosis.Treatment of cisplatin alone had a little effect on cell apoptosis.Transfection of pcDNA3.1( )/IκΒα combined with cisplatin treatment significantly induced apoptosis of A549 cells.It was concluded that inhibiting the activity of NF-κB potentiated cisplatin-induced apoptosis of A549 cells.     

Inhibitory activity of nuclear factor-κB potentiates cisplatin-induced apoptosis in A549 cells

Whether inhibiting the activity of nuclear factor （NF）-κB potentiates cisplatin-induced apoptosis in non-small cell lung cell line A549 cells was investigated. The recombinant plasmid pcDNA3.1（＋）/IκBα expressing IκBα was constructed. The in vitro cultured A549 cells were transfected with pcDNA3.1 （＋）/IκBα alone, or pcDNA3.1（＋）/IκBα combined with cisplatin. The mitochondrial membrane potential （△ψm） was determined by rhodamine 123, the activity of caspase-3 was tested by colorimetric assay, and cell apoptosis was detected by flow cytometry with the annexin V/propidium iodide assay. The results showed that the activity of NF-κB in A549 cells was inhibited by transfecting pcDNA3.1（＋）/IκBα. Transfection of pcDNA3.1（＋）/IκBα alone did not promote apoptosis. Treatment of cisplatin alone had a little effect on cell apoptosis. Transfection of pcDNA3.1（＋）/IκBα combined with cisplatin treatment significantly induced apoptosis of A549 ceils. It was concluded that inhibiting the activity of NF-κB potentiated cisplatin-induced apoptosis of A549 cells.     

Pro-apoptotic role of NF-κB pathway inhibition in lipopolysaccharide stimulated polymorphonuclear neutrophils

Objective To investigate the role of nuclear factor kappa B (NF-κB) pathway inhibition in lipopolysaccharide (LPS)-stimulated apoptosis of polymorphonuclear neutrophils (PMNs).Methods Rats with acute lung injury induced by LPS intratracheal instillation and cultured human venous PMNs were studied. Pyrrolidine dithiocarbamate (PDTC) and gliotoxin were used as NF-κB inhibitors. Additionally, to explore the role of extracellularly regulated protein kinase as an upstream signal in NF-κB pathway on regulating LPS-stimulated PMN apoptosis, PD098059, the specific inhibitor of extracellularly regulated protein kinase, was also applied. The lung injury was determined by protein content and PMN numbers in bronchoalveolar lavage fluid. PMN apoptosis was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) end labeling and DNA fragmentation. IκBα degradation was analyzed by Western blot. NF-κB DNA binding activity was detected by an electrophoretic mobility shift assay.Results (1) The increase of protein content and PMN numbers in bronchoalveolar lavage fluid induced by LPS (100μg per rat) intratracheal instillation were alleviated by PDTC (50, 100, or 200mg/kg, i. p. ) in a dose-dependent manner. (2) PMNs apoptosis in vivo or in vitro was delayed by LPS, and accelerated by PDTC, gliotoxin or PD098059 pretreatment. (3) IκBα degradation and increased NF-KB DNA binding activity mediated by LPS were inhibited by PDTC, gliotoxin or PD098059 pretreatment.Conclusion Inhibition of either NF-κB itself or the upstream signals in NF-κB pathway such as extracellularly regulated protein kinases has therapeutic effect on LPS-induced acute lung injury, in which the dysregulation of PMN apoptosis plays an important role.     

The role of NF-κB in hepatocellular carcinoma cell

Objective To evaluate the role of nuclear factor-kappaB (NF-κB) and IκBα in hepatocellular cacinoma (HCC) SMMC7721 cells, the consequence of NF-κB inhibition in SMMC7721 cells transfected with mutated IκBα (mIκBα) plasmid and the effect of stable inhibition of NF-κB activity in combination with Doxorubicin.Methods Western blot was used to determine the expression of NF-κB and IκBα in SMMC7721 cells and normal liver cells. Nuclear protein was used to evaluate the binding of the 32P-labeled tandem κB sequence using electrophoretic mobility shift assay and the expression of NF-κB using Western blot between SMMC7721 cells transfected with mIκBα plasmid (SMMC7721-MT) and control cells. Furthermore, cell viability was plotted between SMMC7721-MT and control cells. The binding of κB sequence and cell viability between SMMC7721-MT and control cells at different concentrations of Doxorubicin were also investigated.Results Western blot analysis for nuclear extract showed more P50 (NF-κB1) and P65 (RelA) expression in SMMC7721 cells compared with normal liver cells. The expression of cytosolic IκBα protein in SMMC7721 cells was less than that in normal cells. SMMC7721-MT cells inhibited NF-κB nuclear translocation at 0, 24, 48 and 96 hours. Furthermore, NF-κB cannot be detected in the nuclear protein of SMMC7721-MT cells by Western blot. By calculating cell viability, the proliferation of SMMC7721-MT cells was shown to be suppressed more significantly than that of control cells. NF-κB in untransfected cells was activated by Doxorubicin in a dose-dependent manner, but that in SMMC7721-MT cells was not induced at low concentrations of Doxorubicin. Compared with untransfected cells, the viability of SMMC7721-MT cells was significantly suppressed at the same concentration of Doxorubicin (P&lt;0.01）.Conclusions The present study demonstrates that upregulation of NF-κB and downregulation of inhibitory kappaB (IκBα) in SMMC7721 cells are related with the growth of hepatocellular cacinoma cells. Stable expression of mIκBα in SMMC7721-MT cells can inhibit NF-κB nuclear translocation and suppress cell growth. Furthermore, stable inhibition of NF-κB activity in combination with Doxorubicin can significantly inhibit cell proliferation in SMMC7721-MT cells. Thus, modulation of NF-κB may represent an improvement in the efficacy of HCC therapies and be worthy of further research and investigation.     

Adenovirus-mediated overexpression of novel mutated IκBα inhibits nuclear factor κB activation in endothelial cells

Nuclear factor κB （NF-κB） overactivation, requiring phosphorylation and degradation of its inhibitor IκBα, is the basis for chronicity of airway inflammation in asthma. Based on our previous plasmid pShuttle-IκBα, carrying an IκBα gene from human placenta, we optimized a novel IκBα mutant （IκBα） gene, constructed and characterized its replication-deficient recombinant adenovirus （AdIκBαM）, and tested whether AdIκBαM-mediated overexpression of IκBαM could inhibit the NF-κB activation in endothelial cells.     

Role of p38MAPK in mediating TNF-α-induced apoptosis of rat glioma cell line C6

Objective: To study the role of p38MAPK in mediating TNF-α-induced apoptosis of rat glioma cell line C6. Methods: Effect of TNF-α on the proliferation of C6 cells was determined by MTT assay. The TNF-α induced apoptosis was detected by transmission electron microscopy and flow cytometry. The expression of p38MAPK was detected by SABC method and Western-blot. The effect of SB202190, a specific inhibitor of p38MAPK, on TNF-α-induced apoptosis was observed by flow cytometry and SABC method. Results: Inhibitory rate of TNF-α(2×105 U/L) on C6 cells was 43. 75% . In the TNF-α treated group, apoptotic cells were observed by transmission electron microscopy and the apoptotic rate was 37. 5% by flow cytometry. p38MAPK positive signals were detected by SABC method and Western-blot. In the SB202190 treated group, the apoptotic rate was 7. 0% and no p38MAPK signals were found. Conclusion: Apoptosis of C6 cells and expression of p38MAPK can be induced by TNF-α. The activation of p38MAPK promotes the apoptosi     

Effects of TNF-α and curcumin on the expression of VEGF in Raji and U937 cells and on angiogenesis in ECV304 cells

Background To better understand the possibilities of antiangiogenic tumor therapy and to assess possible side effects, we investigated the effect of tumour necrosis factor （TNF）-α and curcumin on the expression of vascular endothelial growth factor （VEGF） in U937 and Raji cell lines and their effect on angiogenesis in a human umbilical vein endothelial cell （HUVECs）-derived cell line （ECV304）, and also the relationship between Notchl and VEGF. The aim of this study was to elucidate potential mechanisms controlling tumor neovascularization. Methods VEGF secreted by U937 and Raji cell lines was determined by ELISA. Angiogenesis was tested by network formation of endothelial cells on Matrigel. Levels of VEGF mRNA in U937 and Raji cells and Notchl mRNA levels in EV304 cells were determined by RT-PCR. Results Secretion of VEGF by U937 and Raji cells was increased by TNF-α treatment and suppressed by curcumin （P 〈 0. 01 ）. The mRNA expression of VEGF165 and VEGF121 （containing 165 and 121 amino acid residues, respectively） were detected in any fractions. TNF-α augmented the expression of VEGF165 and VEGF121 mRNA and curcumin reduced the expression （P 〈0. 01 ）. No networks or cords formed in control and curcumin groups. There was tube formation on matrigel in the supernatants of the Raji culture group and the supernatants groups treated by VEGF group and TNF-α in Raji cell. Notch1 mRNA was detected but there was no significant change in the VEGF group compared with control （P 〉 0. 05）. Conclusions Expressions of VEGF mRNA in U937 and Raji cells were increased by TNF-α and suppressed by curcumin. VEGF and TNF-α can induce angiogenesis, and curcumin can inhibit angiogenesis in ECV304 cells.     

Expression of SODD and P65 in ALL of Children and Its Relationship with Chemotherapeutic Drugs

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 lymphoblas- tic 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 An- nexin-V-Fluorescence/PI double-labeling flow cytometry and the expression of SODD and phos- pho-NF-κB-p65 proteins determined by Western blotting in the Jurkat cells. It was found that the ex- pression 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 correla- tion 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 man- ner, 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 ex- pression 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 ac- tivation, which could recover the sensibility of apoptosis in leukemic cells.