OBJECTIVE: To investigate the effect of tumor necrosis factor death receptor (DR) 4 demethylation to the proliferation and apoptosis of myeloid leukemia K562 cells. METHODS: The logarithmic phase of K562 cells were treated by desitabine (DCA) at 0, 0.8, 1.6 and 3.2 μmol/L, and the cells were divided into control group, DCA low dose group, DCA medium dose group and DCA high dose group respectively. The cells in control group were treated by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) 0.5 μg/ml for 24 h, and the cells were divided into TRAIL group. The cells in DCA high dose group were treated by TRAIL 0.5 μg/ml for 24 h, and were divided into DCA high dose + TRAIL group. Methylation-specific polymerase chain reaction (MS-PCR) was used to measure the methylation status of the DR4 gene promoter in the control group and DCA low, medium and high dose groups. Real-time fluorescent quantitative polymerase chain reaction (qRT-PCR) and Western blot were used to determine the relative expression of DR4 mRNA and protein in the control group and DCA low, medium and high dose groups. Dime- thylthiazole (MTT) method was used to determine the inhibition rate of cell proliferation of the cells in control group, DCA high dose group, TRAIL group, DCA high dose + TRAIL group. Flow cytometry was used to determine the apoptotic rate of the cells in control group, DCA high dose group, TRAIL group, DCA high dose + TRAIL group. RESULTS: The cells in the control group were methylation-positive, the brightness of the methylation bands of the cells in the DCA low, medium, and high dose groups was gradually decreased to disappear, and the DCA high dose group showed negative for methylation. The relative expression of DR4 mRNA and protein in the control group, DCA low, medium and high dose groups was increased sequentially (r=0.624, 0.704). The inhibition rate of cell proliferation of the cells in the control group, DCA high dose group, TRAIL group, DCA high dose + TRAIL group was increased sequentially (r=0.653, 0.754, 0.709, 0.725) at 24, 48 and 72 h. CONCLUSION DCA can reverse the methylation level of DR4 gene promoter in ML K562 cells and up-regulate the expression of DR4, which may enhance the proliferation inhibition and apoptosis promotion effects of TRAIL on K562 cells.
Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Demethylation ; Humans ; K562 Cells ; Leukemia, Myeloid ; Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism* ; TNF-Related Apoptosis-Inducing Ligand/metabolism*

OBJECTIVE: To investigate the effect of lycium barbarum polysaccharide (LBP) alone or combined with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on the apoptosis of leukemia cell lines with MLL gene-rearrangement, and to explore the cell apoptotic pathway after the combined action. METHODS: MLL-ALL cell line KOCL44 and KOCL45 were selected as the research object, then the control and experimental groups were set up. The cell survival rate was measured by the trypan blue dye exclusion method, the cell early apoptosis and expression of death receptors on the cell surface were detected by flow cytometry with Annexin-V/PI double staining. The protein level of caspase-8, BID, caspase-3, caspase-9, BAD, BCL-2, as well as mitochondrial and cytosol Cyto-C were detected by Western blot. RESULTS: LBF combined with TRAIL inhibited the growth of KOCL44 and KOCL-45 cells and showed the synergistic effect, the results of flow cytometry with Amnexiu V/PI double staining were consistent with above-mentioned results. After treatment of KOCL44 and KOCL45 cells with LBF plus TRAIL, the significant expression of DR4 on cell surface was not found, while the expression of DR4 receptor was enhanced significantly, the pro-apoptotic proteins including caspase-8, BID, caspase-3, caspase-9 and BAD were activated significantly and BCL-2 was suppressed significantly with time-dependent manner. The expression of mitochondria cyto-C in KOCL44 and KOCL45 decreased along with prolonging of treatment time (r=-0.95, r=-0.866), while the expression of cytosol cyto-C in KOCL44 and KOCL45 increased along with prolonging of treatment time (r=0.883, r=0.903). CONCLUSION The combination of LBP and TRAIL significantly increases the apoptosis of KOCL44 and KOCL45, and the LBP and TRAIL can up-regulate the expression of TRAIL death receptor-DR5 on the cell surface, activate the pathway of caspase and mito-chrondia mitachondria, thus enhance the sensitivity of KOCL44 and KOCL45 to TRAIL induced apoptosis through both mitochondrial and apoptotic pathway.
Apoptosis ; Caspase 8 ; Drugs, Chinese Herbal ; Leukemia, Myeloid, Acute ; Receptors, TNF-Related Apoptosis-Inducing Ligand ; TNF-Related Apoptosis-Inducing Ligand ; Tumor Necrosis Factor-alpha

OBJECTIVE: To investigate the effects of tectochrysin on prostate cancer cell line 22Rv.1 and reveal its molecular mechanism. METHODS: Tectochrysin at the concentrations of 0～20 μg/ml was applied to 22Rv.1 cells and normal prostate cell RWPE-1. The proliferation activity of the cells was detected by MTS assay. Flow cytometry and hoechst 33342 staining were used to analyze the effects of drugs on cell apoptosis, death, cell cycle and nuclear type changes. LDH release test was used to analyze the cytotoxicity of the drug to 22Rv.1 cells. QPCR and Western blot were used to analyze the effects of the drug on the expressions of genes in 22Rv.1 cells. Finally, the tumor inhibited effect of the drug on the bearing tumor BALB/c mice were confirmed though anti-tumor experiment. RESULTS: Tectochrysin could significantly inhibit the proliferation activity of 22Rv.1 cells and induced their apoptosis, and promoted the expressions of genes dr4, dr5, trail, p53, caspase-3, caspase-8, caspase-9, bid, bax and foxo3, inhibited the expressions of anti-apoptotic genes akt, pi3k and bcl-2. CONCLUSION Tectochrysin can induce prostate cancer cells apoptosis through affecting TRAIL and PI3K/AKT signaling pathways, and has anti-prostate cancer effect.
Animals ; Apoptosis ; Cell Line, Tumor ; Flavonoids ; pharmacology ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Prostatic Neoplasms ; drug therapy ; pathology ; Signal Transduction ; TNF-Related Apoptosis-Inducing Ligand ; metabolism

Inflammation is the crucial biological process of immune system which acts as body's defense and protective response against the injuries or infection. However, the systemic inflammation devotes the adverse effects such as multiple inflammation associated diseases. One of the best ways to treat this entity is by blocking the tumor necrosis factor alpha (TNF-α) and TNF-related apoptosis-inducing ligand (TRAIL) to avoid the proinflammation cytokines production. Thus, this study aims to evaluate the potency of Sambucus bioactive compounds as anti-inflammation through in silico approach. In order to assess that, molecular docking was performed to evaluate the interaction properties between the TNF-α or TRAIL with the ligands. The 2D structure of ligands were retrieved online via PubChem and the 3D protein modeling was done by using SWISS Model. The prediction results of the study showed that caffeic acid (−6.4 kcal/mol) and homovanillic acid (−6.6 kcal/mol) have the greatest binding affinity against the TNF-α and TRAIL respectively. This evidence suggests that caffeic acid and homovanillic acid may potent as anti-inflammatory agent against the inflammation associated diseases. Finally, this study needs further examination and evaluation to validate the potency of Sambucus bioactive compounds.
Biological Processes ; Computational Biology ; Computer Simulation ; Cytokines ; Homovanillic Acid ; Immune System ; Inflammation ; Ligands ; Plants ; Sambucus ; TNF-Related Apoptosis-Inducing Ligand ; Tumor Necrosis Factor-alpha

Psoriasis is a chronic, recurrent, heterogeneous, cutaneous inflammatory skin disease for which there is no cure. It affects approximately 7.5 million people in the United States. Currently, several biologic agents that target different molecules implicated in the pathogenic processes of psoriasis are being assessed in diverse clinical studies. However, relapse usually occurs within weeks or months, meaning there is currently no cure for psoriasis. Therefore, recent studies have discovered diverse new potential treatments for psoriasis: inhibitors of bacteria such as Staphylococcus aureus, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and neuropilin 1 (NRP1). A promising approach that has recently been described involves modifying antimicrobial peptides to develop new cutaneous anti-bacterial agents that target inflammatory skin disease induced by Staphylococcus. Increased expression of TRAIL and its death receptors DR4 and DR5 has been implicated in the pathogenesis of plaque psoriasis. In addition, TRAIL has the ability to inhibit angiogenesis by inducing endothelial cell death and by negative regulation of VEGF-induced angiogenesis via caspase-8-mediated enzymatic and non-enzymatic functions. Since NRP1 regulates angiogenesis induced by multiple signals, including VEGF, ECM and semaphorins, and also initiates proliferation of keratinocytes through NF-κB signaling pathway in involved psoriatic skin, targeting NRP1 pathways may offer numerous windows for intervention in psoriasis. In this review, we will focus on the current knowledge about the emerging role of synthetic antimicrobial peptides, TRAIL and NRP1 blocking peptides in the pathogenesis and treatment of psoriasis.
Anti-Bacterial Agents ; Bacteria ; Biological Factors ; Endothelial Cells ; Keratinocytes ; Necrosis ; Neuropilin-1 ; Peptides ; Psoriasis ; Receptors, Death Domain ; Recurrence ; Semaphorins ; Skin ; Skin Diseases ; Staphylococcus ; Staphylococcus aureus ; Therapeutic Uses ; TNF-Related Apoptosis-Inducing Ligand ; United States ; Vascular Endothelial Growth Factor A

BACKGROUND: Hispolon has been shown to possess antitumor effects in various cancer cells. However, the underlying mechanisms are not fully understood. In this study, we evaluated the sensitizing effect of hispolon on TNF-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis in human renal carcinoma cells. METHODS: Apoptosis was analyzed by using cell-based cytometer. The mRNA levels were assessed by reverse transcription-PCR. Bax activation was determined by oligomerization and fluorescence-activated cell sorting with Bax-NT monoclonal antibody. The protein expression was measured by Western blotting. RESULTS: Hispolon induced up-regulation of Bim and death receptors expression at the post-translational level. CONCLUSIONS: Hispolon enhanced TRAIL-mediated apoptosis in renal carcinoma cells, but not in normal cells.
Apoptosis ; Blotting, Western ; Flow Cytometry ; Humans ; Receptors, Death Domain ; RNA, Messenger ; TNF-Related Apoptosis-Inducing Ligand ; Up-Regulation

OBJECTIVETo explore the effects of Osthole on apoptosis of HL-60 cells induced by tumor necrosis factor related apoptosis inducing ligand (TRAIL) and its possible mechanism.

METHODSThe proliferative inhibition of HL-60 cells treated with different concentrations of Osthole, TRAIL alone and Osthole combined with TRAIL was measured by MTT assay. The HL-60 cells were treated with Osthole, TRAIL alone and Osthole combined with TRAIL at the concentrationApoptosis and mitochondrial membrane potential (MMP) of HL-60 cells were detected by flow cytometry; the mRNA expression of BCL-2, BAX and DR5 was determined by RT-PCR; and the levels of Caspase-3,-8,-9 activity were detected by spectrophotometry.

RESULTSThe combined treatment (100µmol/L Osthole + 40 ng/ml TRAIL) of HL-60 cells for 48 h induced an apoptotic rate of (33.9±2.7) %, which was significantly higher than that of cells treated with Osthole or TRAIL alone (P<0.05); at the same time, the combined treatment promoted the decrease of MMP and the expression rate of BCL-2/BAX, and potentiated the expression of DR5 and Caspase-3,-8,-9 activity.

CONCLUSIONOsthole can sensitize HL-60 cells to TRAIL-induced apoptosis, which may be related with the activation of mitochondrial pathways and up-regulation of DR5.

Apoptosis ; Coumarins ; HL-60 Cells ; Humans ; TNF-Related Apoptosis-Inducing Ligand

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising agent for anticancer therapy. The identification of small molecules that can establish the sensitivity of prostate cancer (PCa) cells to TRAIL-induced apoptosis is crucial for the targeted treatment of PCa. PC3, DU145, JAC-1, TsuPr1, and LNCaP cells were treated with Andrographolide (Andro) and TRAIL, and the apoptosis was measured using the Annexin V/PI double staining method. Real time-polymerase chain reaction (PCR) and Western blot analysis were performed to measure the expression levels of target molecules. RNA interference technique was used to down-regulate the expression of the target protein. We established a nude mouse xenograft model of PCa, which was used to measure the caspase-3 activity in the tumor cells using flow cytometry. In this research study, our results demonstrated that Andro preferentially increased the sensitivity of PCa cells to TRAIL-induced apoptosis at subtoxic concentrations, and the regulation mechanism was related to the up-regulation of DR4. In addition, it also increased the p53 expression and led to the generation of reactive oxygen species (ROS) in the cells. Further research revealed that the DR4 inhibition, p53 expression, and ROS generation can significantly reduce the apoptosis induced by the combination of TRAIL and Andro in PCa cells. In conclusion, Andro increases the sensitivity of PCa cells to TRAIL-induced apoptosis through the generation of ROS and up-regulation of p53 and then promotes PCa cell apoptosis associated with the activation of DR4.
Animals ; Antineoplastic Agents/pharmacology* ; Apoptosis/drug effects* ; Cell Line, Tumor ; Diterpenes/pharmacology* ; Drug Synergism ; Humans ; Male ; Mice ; Mice, Nude ; Neoplasm Transplantation ; PC-3 Cells ; Prostatic Neoplasms/metabolism* ; Reactive Oxygen Species/metabolism* ; Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism* ; TNF-Related Apoptosis-Inducing Ligand/pharmacology* ; Tumor Suppressor Protein p53/metabolism* ; Xenograft Model Antitumor Assays

OBJECTIVETumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance greatly limits the clinical therapeutic efficacy of TRAIL. Elucidating the molecular mechanism underlying TRAIL resistance will be fundamental to resolving this problem.

METHODSNuclear and cytoplasmic protein extraction and immuno？uorescence (IF) assay were used to detect changes in heterogeneous nuclear ribonucleoprotein K (hnRNPK) localization in H1299 cells. The evaluation of cell apoptosis in cells transfected with GFP-hnRNPK, GFP-hnRNPK S284/353A, or GFP-hnRNPK S284/353D mutant was performed using cleaved caspase-3 antibody. The gene expression of XIAP was tested by quantitative RT-PCR.

RESULTSPreviously, we reported that hnRNPK antagonized TRAIL-induced apoptosis through inhibition of PKC-mediated GSK3β phosphorylation. In this study, we further demonstrate that TRAIL treatment induces cytoplasmic accumulation of hnRNPK in H1299 cells. The hnRNPK localized in the cytoplasm has a higher capacity to antagonize TRAIL-induced apoptosis. Both ERK1/2 signaling inhibitor U0126 and ERK-phosphoacceptor-site mutant (GFP-hnRNPK S284/353A) diminish cytoplasmic accumulation of hnRNPK induced by TRAIL. Moreover, we show that XIAP is involved in hnRNPK-mediated TRAIL resistance in H1299 cells.

CONCLUSIONTaken together, these results give new insights into the understanding of the molecular mechanism associated with TRAIL resistance in lung adenocarcinoma.

Apoptosis ; physiology ; Cell Line, Tumor ; Gene Expression Regulation ; physiology ; Heterogeneous-Nuclear Ribonucleoprotein K ; genetics ; metabolism ; Humans ; Mitogen-Activated Protein Kinase 1 ; genetics ; metabolism ; Mitogen-Activated Protein Kinase 3 ; genetics ; metabolism ; TNF-Related Apoptosis-Inducing Ligand ; genetics ; metabolism ; Up-Regulation ; physiology ; X-Linked Inhibitor of Apoptosis Protein ; genetics ; metabolism

BACKGROUND: Bile acids have anti-cancer properties in a certain types of cancers. We determined anticancer activity and its underlying molecular mechanism of ursodeoxycholic acid (UDCA) in human DU145 prostate cancer cells. METHODS: Cell viability was measured with an MTT assay. UDCA-induced apoptosis was determined with flow cytometric analysis. The expression levels of apoptosis-related signaling proteins were examined with Western blotting. RESULTS: UDCA treatment significantly inhibited cell growth of DU145 in a dose-dependent manner. It induced cellular shrinkage and cytoplasmic blebs and accumulated the cells with sub-G1 DNA contents. Moreover, UDCA activated caspase 8, suggesting that UDCA-induced apoptosis is associated with extrinsic pathway. Consistent to this finding, UDCA increased the expressions of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor, death receptor 4 (DR4) and death receptor 5 (DR5), and TRAIL augmented the UDCA-induced cell death in DU145 cells. In addition, UDCA also increased the expressions of Bax and cytochrome c and decreased the expression of Bcl-xL in DU145 cells. This finding suggests that UDCA-induced apoptosis may be involved in intrinsic pathway. CONCLUSIONS: UDCA induces apoptosis via extrinsic pathway as well as intrinsic pathway in DU145 prostate cancer cells. UDCA may be a promising anti-cancer agent against prostate cancer.
Apoptosis* ; Bile Acids and Salts ; Blister ; Blotting, Western ; Caspase 8 ; Cell Death ; Cell Survival ; Cytochromes c ; Cytoplasm ; DNA ; Humans ; Necrosis ; Prostate* ; Prostatic Neoplasms* ; Receptors, TNF-Related Apoptosis-Inducing Ligand ; Ursodeoxycholic Acid*