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

OBJECTIVE: To investigate the effects of LCL161, a Smac mimetic, on the proliferation and apoptosis in hepatocellular carcinoma cells and the underlying mechanisms. 
 METHODS: The effect of LCL161 on the cell viability of HepG2 and SMMC7721 cells was measured by MTT assay. The effect of LCL161 at lower concentrations on the proliferation in hepatocellular carcinoma (HCC) cells was detected by colony formation assay. Apoptosis was assessed by flow cytometry with PI staining. The mitochondrial membrane potential was measured by JC-1 staining. The expression of PARP, p-Akt, cIAP1 and XIAP protein was analyzed by Western blot.
 RESULTS: LCL161 displayed notable antiproliferative activity on HCC cells at the concentrations of 1-16 μmol/L (P<0.01), with IC50 values of 4.3 and 4.9 μmol/L for HepG2 and SMMC7721 cells, respectively, after treatment for 48 h. LCL161 at lower concentrations obviously inhibited the colony formation of HCC cells. LCL161 induced significant apoptosis in HCC cells (P<0.01), and resulted in the apoptotic rate at (1.5±0.8)% or (1.8±0.6)% , (15.2±2.8)% or (12.2±2.4)%, (28.7±3.0)% or (22.4±2.7)%, (34.6±2.3)% or (30.2±2.4)% for HepG2 cells or SMMC7721 cells at the concentration of 0, 2, 4 or 8 μmol/L, respectively. The result of JC-1 staining indicated that the mitochondrial membrane potential of HCC cells was reduced by LCL161. In addition, LCL161 promoted the cleavage of PARP, down-regulated the protein expression of p-Akt, and degraded cIAP1.
 CONCLUSION LCL161 possesses significant anti-proliferative activity and pro-apoptotic action in HepG2 and SMMC7721 cells, which might be correlated with reduction in mitochondrial membrane potential, down-regulation of p-Akt and degradation of cIAP1.
Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; drug therapy ; genetics ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; Down-Regulation ; Hep G2 Cells ; Humans ; Inhibitor of Apoptosis Proteins ; metabolism ; Liver Neoplasms ; Membrane Potential, Mitochondrial ; drug effects ; Proto-Oncogene Proteins c-akt ; genetics ; Thiazoles ; pharmacology ; Ubiquitin-Protein Ligases ; metabolism ; X-Linked Inhibitor of Apoptosis Protein

OBJECTIVETo explore the effect of silence of Pin1 expression on hyperoxia-induced apoptosis in alveolar epithelial cells A549.

METHODSA549 cells were divided into four groups: control, hyperoxia, negative lentivirus and Pin1-shRNA hyperoxia. The hyperoxia group was exposed to a mixture of 95%O2 and 5%CO2 for 10 minutes. Then cells were cultured in a closed environment. After 24 hours, the changes of morphology were observed under an inverted microscope. Cell apoptosis was detected by flow cytometry (FCM). The expression of X-linked inhibitor of apoptosis protein (XIAP) and Caspase-9 were detected by immunohistochemistry. The production of reactive oxygen species (ROS) and cellular mitochondria membrane potential (△Ψm) were determined by fluorescence microscopy.

RESULTSUnder the inverted microscope, the A549 cells grew slowly and the changes in morphology of the cells were most obvious in the hyperoxia and negative lentivirus groups. The changes in morphology of A549 cells were obviously improved in the Pin1-shRNA hyperoxia group. The FCM results showed that the apoptosis rate of A549 cells increased, Caspase-9 expression increased, XIAP expression decreased, mitochondrial ROS production increased and mitochondrial membrane potential decreased in the hyperoxia and negative lentivirus groups compared with the control group (P<0.05). Compared with the hyperoxia and negative lentivirus groups, the apoptosis rate of A549 cells decreased, Caspase-9 expression decreased, XIAP expression increased, mitochondrial ROS production decreased and mitochondrial membrane potential increased in the Pin1-shRNA hyperoxia group (P<0.05), although the levels of the indexes did not reach to those of the control group.

CONCLUSIONSSilencing of Pin1 could suppress hyperoxia-induced apoptosis of A549 cells.

Apoptosis ; Caspase 9 ; genetics ; Humans ; Hyperoxia ; pathology ; Membrane Potential, Mitochondrial ; NIMA-Interacting Peptidylprolyl Isomerase ; Peptidylprolyl Isomerase ; physiology ; Reactive Oxygen Species ; metabolism ; X-Linked Inhibitor of Apoptosis Protein ; genetics

OBJECTIVETo investigate the effect of 3-bromopyruvate (3-BP) in sensitizing hepatocellular carcinoma cells to cisplatin-induced apoptosis and its possible mechanism.

METHODSThe growth inhibition of HepG2 and SMMC7721 cells following exposures to different concentrations of 3-BP and cisplatin was measured by MTT assay. The apoptosis of cells treated with 100 µmol/L 3-BP with or without 8 µmol/L cisplatin was assessed using flow cytometry with PI staining, and the activity of caspase-3 and intracellular ATP level were detected using commercial detection kits; the expression of XIAP and PARP was analyzed using Western blotting.

RESULTS3-BP produced obvious inhibitory effects on HepG2 and SMMC7721 cells at the concentrations of 50-400 µmol/L with IC50 values of 238.9∓13.9 µmol/L and 278.7∓11.7 µmol/L for a 48-h treatment, respectively. Cisplatin also inhibited the growth of HepG2 and SMMC7721 cells at the concentrations of 2-32 µmol/L, with IC50 values of 16.4∓0.9 µmol/L and 20.9∓1.8 µmol/L after a 48-h treatment, respectively. Treatment with 100 µmol/L 3-BP combined with 8 µmol/L cisplatin for 48 h resulted in a growth inhibition rate of (60.6∓2.2)% in HepG2 cells and (56.8∓2.3)% in SMMC7721 cells, which were significantly higher than those in cells treated with 3-BP or cisplatin alone. The combined treatment for 48 h induced an apoptotic rate of (51.1∓4.3)% in HepG2 cells and (46.5∓3.9)% in SMMC7721 cells, which were also markedly higher than those in cells with 3-BP or cisplatin treatment alone.

CONCLUSION3-BP can sensitize HepG2 and SMMC7721 cells to cisplatin-induced apoptosis possibly by causing intracellular ATP deficiency, down-regulating XIAP, and increasing caspase-3 activity.

Adenosine Triphosphate ; metabolism ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Caspase 3 ; metabolism ; Cisplatin ; pharmacology ; Hep G2 Cells ; Humans ; Liver Neoplasms ; pathology ; Pyruvates ; pharmacology ; X-Linked Inhibitor of Apoptosis Protein ; metabolism

Adenocarcinoma ; metabolism ; pathology ; Apoptosis ; drug effects ; Baculoviral IAP Repeat-Containing 3 Protein ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Chromones ; pharmacology ; Enzyme Inhibitors ; pharmacology ; Female ; Humans ; Inhibitor of Apoptosis Proteins ; genetics ; metabolism ; Morpholines ; pharmacology ; Ovarian Neoplasms ; metabolism ; pathology ; Phosphatidylinositol 3-Kinases ; genetics ; metabolism ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Signal Transduction ; Ubiquitin-Protein Ligases ; X-Linked Inhibitor of Apoptosis Protein ; genetics ; metabolism

This study was aimed to explore the effects of proteasome inhibitor bortezomib on the drug sensitivity of imatinib-resistant primary cells in blastic phase of chronic myeloid leukemia (CML) and the expression of XIAP. MTT method was used to detect the inhibitory effect on cell growth, flow cytometry was used to assay the apoptosis and P170 expression, and RT-PCR was used to monitor the expression of XIAP mRNA. The results showed that the effect of imatinib or bortezomib alone showed an inhibitory effect on MNC in time-and dose-dependent manner; 5 and 10 nmoL/L bortezomib combined with imatinib could significantly enhance the sensitivity of mononuclear cells to imatinib. The increase of apoptosis rate, and the decrease of P170 expression could be observed by flow cytometry during treatment with bortezomib. The over-expression of XIAP could be down regulated by bortezomib. It is concluded that the bortezomib could inhibit primary cells of leukemia and enhance sensitivity of CML primary cells to imatinib.The bortezomib may increase the cell apoptosis by inhibition of XIAP expression, so as to provide the experiment evidence to spread bortezomib for the clinical treatment of chronic myeloid leukemia.
Adolescent ; Adult ; Aged ; Antineoplastic Agents ; pharmacology ; Benzamides ; pharmacology ; Boronic Acids ; pharmacology ; Bortezomib ; Drug Resistance, Neoplasm ; drug effects ; Female ; Humans ; Imatinib Mesylate ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; metabolism ; Male ; Middle Aged ; Piperazines ; pharmacology ; Proteasome Inhibitors ; pharmacology ; Pyrazines ; pharmacology ; Pyrimidines ; pharmacology ; Tumor Cells, Cultured ; X-Linked Inhibitor of Apoptosis Protein ; metabolism ; Young Adult

OBJECTIVETo investigate the expressions of the active form of glycogen synthase kinase-3(GSK-3)-pGSK-3α/β (Tyr279/216) and its downstream moleculor X-linked inhibitor of apoptosis protein (XIAP) in cholangiocarcinoma and to analyze their correlation with clinicopathological and survival significance.

METHODSImmunohistoehemistry was used to detect the expressions of the active form of GSK-3- pGSK-3α/β (Tyr279/216) and its downstream moleculor XIAP proteins in 50 cholangiocarcinoma tissues and 20 normal bile duct tissues.

RESULTSThe positive rates of pGSK-3α/β (Tyr279/216) and XIAP were 62.0% and 68.0% in cholangiocarcinoma, and 10.0% and 25.0% in normal bile duct tissues, respectively. The intensity of pGSK-3α/β (Tyr279/216) and XIAP expressions in cholangiocarcinoma were significantly higher than that in the normal bile duct tissues (P < 0.001), and there was a significant correlation between pGSK-3α/β (Tyr279/216) and XIAP expressions (r = 0.544, P < 0.001). The expression of pGSK-3α/β(Tyr279/216) protein in cholangiocarcinoma was associated with TNM stage (P = 0.042), histological grade (P = 0.031), whereas the expression of XIAP protein in cholangiocarcinoma was correlated with CEA level (P = 0.006). Patients with positive expression of pGSK-3α/β (Tyr279/216) and XIAP demonstrate a significantly worse prognosis than that of patients with negative expression of pGSK-3α/β (Tyr279/216) and XIAP for overall survival (P = 0.002, P = 0.018). Multivariate survival analysis revealed that positive pGSK-3α/β (Tyr279/216) expression provided significant independent prognostic value for overall survival (P = 0.002).

CONCLUSIONSThe expressions of pGSK-3α/β(Tyr279/216) and XIAP proteins were significantly associated with the development and progression of cholangiocarcinoma. pGSK-3α/β(Tyr279/216) may be an important prognostic factor for survival of patients with cholangiocarcinoma.

Bile Duct Neoplasms ; metabolism ; pathology ; surgery ; Bile Ducts, Intrahepatic ; Carcinoembryonic Antigen ; blood ; Cholangiocarcinoma ; metabolism ; pathology ; surgery ; Female ; Follow-Up Studies ; Glycogen Synthase Kinase 3 ; metabolism ; Glycogen Synthase Kinase 3 beta ; Humans ; Male ; Middle Aged ; Neoplasm Grading ; Neoplasm Staging ; Prognosis ; Survival Rate ; X-Linked Inhibitor of Apoptosis Protein ; metabolism

OBJECTIVETo investigate the effects of TcpC on human umbilical vascular endothelial cells (HUVECs) and its mechanisms.

METHODSHUVECs were co-cultured with TcpC secreting wild-type E. coli strain CFT073 (TcpC(wt)) or tcpc gene-deleted CFT073 mutant strain (TcpC(mut)) in transwell system,respectively. Apoptosis of HUVECs was analyzed by Annexin-V/PI double staining. Mitochondrial membrane depolarization was detected by JC-1 staining. Expression of apoptosis-related proteins in HUVECs was determined by Western blot.

RESULTSHUVECs showed morphological changes after co-cultured with TcpC(wt) for 24 h: the cells became detached and cell debris increased,and cell number was also decreased when compared to HUVECs co-cultured with TcpC(mut). The apoptosis of HUVEC cells co-cultured with TcpC(wt) for 24 h significantly increased,compared to that of control group and TcpC(mut) group (60.1% 9.7% compared with 9.0% 1.3% and 16.9% 0.4%,respectively, P<0.05); meanwhile the mitochondrial depolarization of HUVECs co-cultured with TcpC(wt) was significantly increased,compared to that in control and TcpC(mut) groups (64.5% 0.9% compared with 14.5% 2.1% and 15.6% 3.3%, respectively,P<0.05). Cleavage of PARP and inhibition of Mcl-1 and XIAP expression were seen in HUVECs co-cultured with TcpC(wt),but not in groups of control and TcpC(mut).

CONCLUSIONTcpC secreted from CFT073 can induce apoptosis of HUVECs through mitochondrial pathway, in which PARP is cleaved and Mcl-1 and XIAP expressions are inhibited.

Apoptosis ; drug effects ; Cells, Cultured ; Escherichia coli ; metabolism ; Escherichia coli Proteins ; pharmacology ; Human Umbilical Vein Endothelial Cells ; drug effects ; pathology ; Humans ; Membrane Potential, Mitochondrial ; Myeloid Cell Leukemia Sequence 1 Protein ; metabolism ; Poly(ADP-ribose) Polymerases ; metabolism ; Virulence Factors ; pharmacology ; X-Linked Inhibitor of Apoptosis Protein ; metabolism

Amino Acid Sequence ; Base Sequence ; Child ; Flow Cytometry ; methods ; Genes, X-Linked ; Hematopoietic Stem Cell Transplantation ; Humans ; Lymphocytes ; metabolism ; Lymphohistiocytosis, Hemophagocytic ; diagnosis ; genetics ; therapy ; Lymphoproliferative Disorders ; diagnosis ; genetics ; therapy ; Mutation ; Transplantation, Homologous ; X-Linked Inhibitor of Apoptosis Protein ; deficiency ; genetics ; metabolism

OBJECTIVE: To explore the expression and significance of second mitochondria derived activator of caspase (Smac), X-linked inhibitor of apoptosis protein (XIAP)and cysteine containing aspartate specific protease 3 (caspase-3) in the growth, development and carcinogenesis of the nonnasal inverted papilloma (NIP). METHOD: Immunohistochemical method was used to detect the expression of Smac, XIAP, caspase-3 in 10 cases of nasal cavity mucosae (NM) and 45 cases of NIP, the group of NIP including 25 cases of NIP without dysplasia, 11 cases of NIP with dysplasia, and 9 cases of NIP with malignant transformation to squamous cell carcinoma (SCC). RESULT: The intensity of the positive expression of Smac, Caspase-3 in NIP were lower than NM, the intensity of the positive expression decreased with the decreasing degree of histological differentiation. There was a significant difference between NIP without dysplasia and SCC. It was presented with a progressive tendency for the expression of XIAP in the group of NM and NIP. The lower degree of histological differentiation, the higher intensity of the positive expression. The expression between NIP without dysplasia and SCC had a significant difference. Smac negatively correlated with XIAP (r(s) = -0.323, P < 0.05), XIAP negatively correlated with caspase-3 (r(s) = -0.408, P < 0.01), Smac positively correlated with caspase 3 (r(s) = 0.424, P < 0.01). CONCLUSION Smac, XIAP, caspase 3 might be associated with the growth and carcinogenesis of NIP.
Adult ; Aged ; Caspase 3 ; metabolism ; Female ; Humans ; Intracellular Signaling Peptides and Proteins ; metabolism ; Male ; Middle Aged ; Mitochondrial Proteins ; metabolism ; Nose Neoplasms ; metabolism ; pathology ; Papilloma, Inverted ; metabolism ; pathology ; X-Linked Inhibitor of Apoptosis Protein ; metabolism