BACKGROUND: The expression of the inhibitor of apoptosis proteins (IAPs) family has not been fully investigated in colorectal carcinomas. This study investigated IAP expression in colorectal carcinomas and assessed their prognostic significance. METHODS: Livin, XIAP, and SMAC/DIABLO expression was assessed by immunohistochemistry in 159 colorectal carcinomas. Correlations between protein expression and clinicopathological features were evaluated. The survival data analysis was estimated according to the Kaplan-Meier method. RESULTS: Increased expression of IAPs in cancer tissues compared to surrounding nonneoplastic counterparts was observed in 67 cases (42.1%) for Livin, 50 cases (31.4%) for XIAP, and 68 cases (42.8%) for SMAC. A significant correlation was found between Livin expression and tumor differentiation, and SMAC expression and tumor location. The recurrence-free and overall survival of patients with low Livin expression were inferior to those of patients with high Livin expression (p=0.054 and 0.095, respectively). High XIAP expression was significantly associated with shorter progression-free survival (p= 0.041). CONCLUSIONS: Our study demonstrated that altered expression of IAP family members, including Livin, XIAP, and SMAC, is frequent in colorectal carcinoma. This result suggests that high Livin expression and low XIAP expression may be a favorable prognostic implication related to patient survival.
Apoptosis ; Colorectal Neoplasms ; Disease-Free Survival ; Humans ; Immunohistochemistry ; Inhibitor of Apoptosis Proteins ; Intracellular Signaling Peptides and Proteins ; Mitochondrial Proteins ; Prognosis ; Proteins ; Statistics as Topic ; X-Linked Inhibitor of Apoptosis Protein

BACKGROUND: Dysregulation of apoptosis plays an important role in carcinogenesis, tumor progression, and resistance to chemotherapy. X-linked inhibitor of apoptosis (XIAP) is considered to be the most potent caspase inhibitor of all known IAP (inhibitor of apoptosis) family members. This study was designed to assess the pattern of expression and the prognostic value of XIAP in radically resected non-small cell lung carcinoma (NSCLC) patients. METHOD: The expression of XIAP and its relationship with clinicopathologic parameters (patient age, TNM stage, TNM-pT, TNM-pN, histologic type, VEGF expression, microvessel density, PCNA index) and overall survival were analysed with formalin-fixed, paraffin-embedded blocks from eighty cases of NSCLC. In addition, the apoptotic index (AI) was also assessed. RESULTS: In a regard to histologic type, squamous cell carcinoma (SCC) showed XIAP expression in 91.3%(42/46) and adenocarcinoma (AC) in 61.8%(21/34). The difference was significant(p=0.001). There was no correlation between XIAP expression and other parameters. In the group of AC, XIAP expression showed the signifcant correlation with older age group > or = 58 years and VEGF expression(p=0.028, p=0.014, respectively). The AI in the group with or without XIAP expression were 2.5+/-4.9% and 18.5+/-28.9%, respectively(p=0.001). Both groups just aforementioned showed no significant difference in median survival time (42.5 months, 29.8 months, respectively). CONCLUSION: This study suggests that the XIAP expression in NSCLCs could have relation to inhibition of apoptosis, and show differential expression according to histologic type. However, its prognostic role during the progression of NSCLC needs to be further defined.
Adenocarcinoma ; Apoptosis* ; Carcinogenesis ; Carcinoma, Squamous Cell ; Drug Therapy ; Humans ; Inhibitor of Apoptosis Proteins ; Lung ; Microvessels ; Prognosis* ; Proliferating Cell Nuclear Antigen ; Small Cell Lung Carcinoma* ; Vascular Endothelial Growth Factor A ; X-Linked Inhibitor of Apoptosis Protein*

OBJECTIVETo investigate the expression of apoptotic protein inhibitors, survivin and XIAP, in patients with myelodysplastic syndromes (MDS) and in the cell line MUTZ-1, as well as to explore the possible mechanisms of homoharringtonine (HHT) in the treatment of MDS.

METHODSBone marrow samples from 47 patients with de novo MDS at diagnosis were examined and bone marrow samples from 15 normal donors were used as control. A MDS-RAEB cell line MUTZ-1 was used as in vitro model. Detection of apoptotic cells and cell cycle analysis were performed with flow cytometry (FACS). The expression of apoptotic protein inhibitor survivin and XIAP in the MDS cells were detected by RT-PCR technique. MUTZ-1 were treated with antisense oligodeoxynucleotide (AS-ODNs) of survivin and or HHT, the effects were evaluated by cell viability and cell apoptosis.

RESULTSSurvivin mRNA positive rate in MDS were significantly higher than that in normal controls (38.3% and 0, respectively, P < 0.01), and the positive rate in high risk group (RAEB, RAEBT and CMML) was significantly higher than that in RA/RAS group (53.6% and 16.7%, respectively, P < 0.05). XIAP was expressed in all untreated MDS and healthy controls. XIAP mRNA expression in high risk group was significantly higher than that in RA/RAS subtypes and healthy controls (1.55 +/- 0.34, 0.74 +/- 0.24, and 1.01 +/- 0.28, respectively, P < 0.01). However, XIAP mRNA expression was significantly lower in RA/RAS subtypes than in healthy control (0.74 +/- 0.24 and 1.01 +/- 0.28, P < 0.054). Apoptosis peak detected by FACS analysis and positive Annexin V FITC staining on cell membrane indicated that HHT could induce MUTZ-1 cell undergoing apoptosis in dose- and time-dependent manners. Treatment of MUTZ-1 cells with HHT revealed that HHT could significantly down-regulate survivinexpression but had no significant effect on XIAP expression in the cells. AS-ODNs of survivin could inhibit MUTZ-1 cells growth, induce them to apoptosis and sensitize them to HHT.

CONCLUSIONThe expression levels of survivin; Institute of Hematology, Oncology and Tumor Immunology, Robert Roessle Clinic, Humboldt University, Berlin, Germany (Wolf Dieter Ludwig, Christian Wuchter) and XIAP vary in different subtypes of MDS patients, suggesting that the proteins may play an important role in the pathogenesis of the disease. Down-regulation of survivin in MUTZ-1 cells may be one of the mechanisms that HHT induces apoptosis of MDS cells.

Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Division ; drug effects ; Harringtonines ; therapeutic use ; Humans ; Inhibitor of Apoptosis Proteins ; Microtubule-Associated Proteins ; genetics ; physiology ; Myelodysplastic Syndromes ; drug therapy ; pathology ; Neoplasm Proteins ; Oligonucleotides, Antisense ; pharmacology ; Proteins ; genetics ; physiology ; RNA, Messenger ; analysis ; X-Linked Inhibitor of Apoptosis Protein

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

OBJECTIVETo clarify expression and subcellular localization of XIAP and XAF1 protein in human normal oral keratinocytes (hNOK) and Tca8113 cells human tongue carcinoma cell line.

METHODSThe hNOKs and Tca8113 cells were cultured in vitro. Expression and subcellular localization of XIAP and XAF1 protein were examined by combination of indirect immunofluorescence and confocal laser scanning microscopy.

RESULTSXIAP expression was weak in the hNOKs and fluorescence staining localized chiefly in the cytoplasm and perinuclear areas. In the Tca8113 cells, high level of XIAP protein could be detected in both the cytoplasm and the nucleus. In the hNOKs, XAF1 distributed mostly in the nucleus. Homogeneous nuclear and cytoplasmic distribution of XAF1 could be visualized in the Tca8113 cells.

CONCLUSIONSIn cancerization of oral mucosa, XIAP protein could play an important antiapoptotic role by overexpression, while XAF1 protein does not appear to antagonize effectively the role of XIAP.

Apoptosis ; Cell Line, Tumor ; Cells, Cultured ; Humans ; Intracellular Signaling Peptides and Proteins ; Keratinocytes ; metabolism ; pathology ; Mouth Mucosa ; cytology ; metabolism ; Neoplasm Proteins ; metabolism ; Tongue Neoplasms ; metabolism ; pathology ; X-Linked Inhibitor of Apoptosis Protein ; metabolism

OBJECTIVEResistance to chemotherapy may indicate an unfavorable outcome for patients with gastric cancer. The purpose of this study was to examine whether docetaxel-resistance could be due in part to the expression of the inhibitor of apoptosis proteins (IAP).

METHODSDocetaxel-resistant cells, BGC-823/R1, BGC-823/R2 and BGC-823/R3, were established from parent BGC-823 cells by stepwise increasing concentration of docetaxel. To characterize these cells, we examined the effects of docetaxel on cell growth and apoptosis by MTT assay and double staining with both annexin-V-FITC and PI, and analyzed the cross-resistance to various anticancer drugs. Expression of IAP compared with that in parental cells was evaluated by real-time quantitative PCR.

RESULTSThe BGC-823 resistant cells, BGC-823/R1, R2 and R3 cells, were 10.2-, 24.5-, 56.3-fold more resistant to docetaxel than parental cells, respectively, and this resistance was paralleled with reduced induction of apoptosis. BGC-823/R3 cells showed cross-resistance to paclitaxel, whereas exhibited weak or no cross-resistance against 5-fluorouracil, cisplatin and oxaliplatin. The expressions of survivin and XIAP were gradually increased with the extent of docetaxel resistance (r = 0.909, P < 0.001 and r = 0.892, P < 0.001, respectively).

CONCLUSIONIAP may make an important contribution to the resistance to the apoptotic effect of docetaxel in gastric cancer, and could be used as a potential therapeutic target.

Antineoplastic Agents ; administration & dosage ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Dose-Response Relationship, Drug ; Drug Resistance, Neoplasm ; Fluorouracil ; pharmacology ; Humans ; Inhibitor of Apoptosis Proteins ; metabolism ; Microtubule-Associated Proteins ; metabolism ; Organoplatinum Compounds ; pharmacology ; Paclitaxel ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Stomach Neoplasms ; metabolism ; pathology ; Taxoids ; administration & dosage ; pharmacology ; X-Linked Inhibitor of Apoptosis Protein ; 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

This study is to explore the inhibitory effect of methyl jasmonate on cell proliferation and expression of XIAP and survivin of human neuroblastoma cell line BE(2)-C. After cultivation of 1 - 2 mmol x L(-1) jasmonates with BE (2) -C cells for 6 - 24 h, the growth inhibiting rates of BE (2) -C cells were studied by MTT colorimetry. Cell proliferation was detected by colony formation assay. Cell cycle phases were assayed by propidium iodide staining flow cytometery. Cell apoptosis was inspected by acridine orange-ethidium bromide fluorescent staining, Hoechst 33258 fluorescent staining, and Annexin V-FITC and propidium iodide staining flow cytometry. Expressions of cyclin D1, XIAP and survivin were determined by RT-PCR and real-time RT-PCR. Methyl jasmonate inhibited the growth of BE(2)-C cells in a dose- and time-dependent manner. After addition of 1, 1.5 and 2 mmol x L(-1) of methyl jasmonate for 24 h, the inhibiting rates of cell growth reached 20.6% - 85.5% (P < 0.01), and the IC50 was 1.35 mmol x L(-1). The cell cycles were arrested at S phase. A part of cells presented the characteristic morphological changes of apoptosis. The early apoptotic rates were 13.51%, 17.32%, 24.59% (P < 0.01) and the cell death rates were 29.36% , 54.73% , 75.52% (P < 0.01), respectively. The expression of XIAP and survivin mRNA were downregulated by 18.5% - 68.9% , 22.4% - 48.7% (P < 0.05), respectively, without change in that of cyclin D1. The results indicated that methyl jasmonate could significantly inhibit the growth of BE(2) -C cells through inducing cell cycle arrest and apoptosis, downregulating the expression of XIAP and survivin might be one of its molecular mechanisms of action.
Acetates ; pharmacology ; Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclin D1 ; biosynthesis ; genetics ; Cyclopentanes ; pharmacology ; Dose-Response Relationship, Drug ; Down-Regulation ; Humans ; Inhibitor of Apoptosis Proteins ; Microtubule-Associated Proteins ; biosynthesis ; genetics ; Neuroblastoma ; metabolism ; pathology ; Oxylipins ; pharmacology ; RNA, Messenger ; metabolism ; S Phase ; X-Linked Inhibitor of Apoptosis Protein ; biosynthesis ; genetics

To investigate the expression and significance of X-linked inhibitor of apoptosis protein (XIAP) and XIAP-associated factor 1 (XAF1) in acute leukemia, the expression of XIAP, XAF1, Smac, and HtrA2 mRNA in the bone marrow aspirates from 87 newly diagnosed AL patients, 23 patients in remission, 6 patients in relapse, and 17 normal controls were detected by means of reverse transcriptase polymerase chain reaction (RT-PCR), and their relationship with clinical therapeutic efficiency was analyzed. The results showed that the expression level of XIAP mRNA in newly diagnosed AL patients (0.990 +/- 0.337) was significantly higher than that in normal controls (0.395 +/- 0.148) (P < 0.01); the positive rate and expression level of XAF1 mRNA in newly diagnosed AL patients (56.32%, 0.246 +/- 0.267) were significantly lower than that in normal controls (100%, 0.964 +/- 0.387) (P < 0.01). In 69 out of 87 newly diagnosed AL patients, efficacy remained evaluable. AL patients with high level of XIAP achieved a lower complete remission (CR) rate than patients with low level of XIAP (54.55% and 86.11%, respectively) (P < 0.01). XAF1 positive patients achieved a higher CR rate than XAF1 negative patients (86.84% and 51.61%, respectively) (P < 0.01). It is concluded that the overexpression of XIAP and negativity of XAF1 may be two adverse prognostic factors in AL patients.
Acute Disease ; High-Temperature Requirement A Serine Peptidase 2 ; Humans ; Inhibitor of Apoptosis Proteins ; biosynthesis ; genetics ; Intracellular Signaling Peptides and Proteins ; genetics ; Leukemia ; metabolism ; Mitochondrial Proteins ; biosynthesis ; genetics ; Neoplasm Proteins ; biosynthesis ; genetics ; Prognosis ; RNA, Messenger ; biosynthesis ; genetics ; Serine Endopeptidases ; biosynthesis ; genetics ; X-Linked Inhibitor of Apoptosis Protein ; biosynthesis ; genetics

OBJECTIVE: To investigate the combined effects of cisplatin and the histone deacetylase (HDAC) inhibitors suberoylanilide hydroxamic acid (SAHA) or sirtinol on HeLa cells and assess the mechanism underlying HDAC inhibitor-cisplatin synergy. METHODS: The antineoplastic actions of cisplatin, SAHA and sirtinol, alone and in combination, were evaluated using the tetrazolium dye-based MTT cell proliferation assay, DAPI nuclear staining and cytotoxicity analysis. RESULTS: Exposure to cisplatin, SAHA or sirtinol alone induced a dose-dependent reduction in HeLa cell viability. Combined treatment with cisplatin and SAHA or sirtinol was significantly more cytotoxic than cisplatin alone. Individually, cisplatin, SAHA and sirtinol activated caspase-3 and induced apoptosis, but the effects of combined treatment were greater. Importantly, both HDAC inhibitors dose-dependently inhibited the expression of the antiapoptotic proteins Bcl-2 and x-linked inhibitor of apoptosis protein (XIAP). CONCLUSION: The combination of cisplatin and SAHA or sirtinol had synergistic effect on the HeLa cell viability. This potentiation of cisplatin activity was associated with HDAC inhibitor-mediated down-regulation of Bcl-2 and XIAP. These may result from the relaxation of chromatin by these HDAC inhibitors that increase cisplatin sensitivity by enhancing the accessibility of DNA to cisplatin and transcriptional regulators.
Apoptosis ; Benzamides ; Caspase 3 ; Cell Proliferation ; Chromatin ; Cisplatin ; DNA ; Down-Regulation ; HeLa Cells ; Histone Deacetylase Inhibitors ; Histone Deacetylases ; Histones ; Humans ; Hydroxamic Acids ; Indoles ; Naphthols ; Proteins ; Relaxation ; Uterine Cervical Neoplasms ; X-Linked Inhibitor of Apoptosis Protein