OBJECTIVETo explore the effects of bufalin on inhibiting proliferation, up-regulating methylation of Wilm' tumor 1 gene (WT1) as well as its possible mechanisms in human erythroid leukemic (HEL) cells.

METHODSThe HEL cells were treated with bufalin at various concentrations to observe cellular morphology, proliferation assay and cell cycle. The mRNA and protein expression levels of WT1 were detected by reverse transcription polymerase chain reaction (RT-PCR), Western blot and immunocytochemistry, DNA methylation of WT1 and protein expression levels of DNA methyltransferase 3a (DNMT3a) and DNMT3b were analyzed by methylation-specific PCR, and Western blot respectively.

RESULTSThe bufalin was effective to inhibit proliferation of HEL cells in a dose-dependent manner, their suppression rates were from 23.4%±2.1% to 87.2%±5.4% with an half maximal inhibit concentration (IC) of 0.046 μmol/L. Typical apoptosis morphology was observed in bufalin-treated HEL cells. The proliferation index of cell cycle decreased from 76.4%±1.9% to 49.7%±1.3%. The expression levels of WT1 mRNA and its protein reduced gradually with increasing doses of bufalin, meanwhile, the methylation status of WT1 gene changed from unmethylated into partially or totally methylated. While, the expression levels of DNMT3a and DNMT3b protein gradually increased by bufalin treatment in a dose-dependent manner.

CONCLUSIONSBufalin can not only significantly inhibit the proliferation of HEL cells and arrest cell cycle at G/Gphase, but also induce cellular apoptosis and down-regulate the expression level of WT1. Our results provide the evidence of bufalin for anti-leukemia, its mechanism may involve in increasing WT1 methylation status which is related to the up-regulation of DNMT3a and DNMT3b proteins in erythroid leukemic HEL cells.

Apoptosis ; drug effects ; genetics ; Bufanolides ; pharmacology ; Cell Cycle Checkpoints ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Shape ; drug effects ; DNA (Cytosine-5-)-Methyltransferases ; metabolism ; DNA Methylation ; drug effects ; genetics ; Gene Expression Regulation, Leukemic ; drug effects ; Humans ; Leukemia, Erythroblastic, Acute ; enzymology ; genetics ; pathology ; RNA, Messenger ; genetics ; metabolism ; Up-Regulation ; drug effects ; genetics ; WT1 Proteins ; genetics ; metabolism

The aim of the study was to investigate the anti-proliferation and apoptosis-inducing effects of S1, a novel tetrandrine derivative, in human gastric cancer BGC-823 cells and explore the possible mechanism of action. The anti-proliferative activity was determined by MTT assay; the induction of cell cycle arrest and apoptosis were detected by flow cytometry. Quantitative real time RT-PCR and Western blotting were used to evaluate the mRNA and protein expression levels in mitochondrial pathway. S1 significantly reduced cell viability and induced a G2/M phase arrest and apoptosis in dose- and time-dependent manner. Further studies showed that S1 increased mRNA and protein expression of Bax and the Bax/Bcl-2 ratio. Moreover, S1 decreased the protein expression of procaspase-9 and procaspase-3, suggesting that the induction of apoptosis may be related to the alteration of the ratio of Bax/Bcl-2 and the activation of caspases. These findings suggested that S1 merits further investigation as a novel therapeutic agent for the treatment of human gastric cancer.
Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Benzylisoquinolines ; chemistry ; pharmacology ; Caspase 3 ; genetics ; metabolism ; Caspase 9 ; genetics ; metabolism ; Cell Cycle Checkpoints ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Humans ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Stomach Neoplasms ; drug therapy ; enzymology ; genetics ; physiopathology ; bcl-2-Associated X Protein ; genetics ; metabolism

Mcl-1 and Bcl-xL, key anti-apoptotic proteins of the Bcl-2 family, have attracted attention as important molecules in the cell survival and drug resistance. In this study, we investigated whether inhibition of Bcl-xL influences cell growth and apoptosis against simultaneous treatment of resveratrol and clofarabine in the human malignant mesothelioma H-2452 cells. Resveratrol and clofarabine decreased Mcl-1 protein levels but had little effect on Bcl-xL levels. In the presence of two compounds, any detectable change in the Mcl-1 mRNA levels was not observed in RT-PCR analysis, whereas pretreatment with the proteasome inhibitor MG132 led to its accumulation to levels far above basal levels. The knockdown of Bcl-xL inhibited cell proliferation with cell accumulation at G2/M phase and the appearance of sub-G0/G1 peak in DNA flow cytometric assay. The suppression of cell growth was accompanied by an increase in the caspase-3/7 activity with the resultant cleavages of procaspase-3 and its substrate poly (ADP-ribose) polymerase, and increased percentage of apoptotic propensities in annexin V binding assay. Collectively, our data represent that the efficacy of resveratrol and clofarabine for apoptosis induction was substantially enhanced by Bcl-xL-lowering strategy in which the simultaneous targeting of Mcl-1 and Bcl-xL could be a more effective strategy for treating malignant mesothelioma.
Adenine Nucleotides/*pharmacology ; Antimetabolites, Antineoplastic/*pharmacology ; Apoptosis/*drug effects ; Arabinonucleosides/*pharmacology ; Caspase 3/metabolism ; Caspase 7/metabolism ; Cell Line, Tumor ; Cell Proliferation/drug effects ; G2 Phase Cell Cycle Checkpoints/drug effects ; Gene Knockdown Techniques ; Humans ; Leupeptins/pharmacology ; Lung Neoplasms/metabolism/pathology ; M Phase Cell Cycle Checkpoints/drug effects ; Mesothelioma/metabolism/pathology ; Myeloid Cell Leukemia Sequence 1 Protein/antagonists & inhibitors/genetics/metabolism ; RNA Interference ; RNA, Messenger/metabolism ; RNA, Small Interfering/metabolism ; Stilbenes/*pharmacology ; bcl-X Protein/antagonists & inhibitors/*genetics/*metabolism

BACKGROUND/AIMS: Most pesticide formulations contain both chief and additive ingredients. But, the additives may not have been tested as thoroughly as the chief ingredients. The surfactant, nonyl phenoxypolyethoxylethanol (NP40), is an additive frequently present in pesticide formulations. We investigated the effects of NP40 and other constituents of a validamycin pesticide formulation on cell viability and on the expression of genes involved in cell damage pathways. METHODS: The effects of validamycin pesticide ingredients on cell viability and of NP40 on the mRNA expression of 80 genes involved in nine key cellular pathways were examined in the human neuroblastoma SK-N-SH cell line. RESULTS: The chemicals present in the validamycin pesticide formulation were cytotoxic to SK-N-SH cells and NP40 showed the greatest cytotoxicity. A range of gene expression changes were identified, with both up- and down-regulation of genes within the same pathway. However, all genes tested in the necrosis signaling pathway were down-regulated and all genes tested in the cell cycle checkpoint/arrest pathway were up-regulated. The median fold-change in gene expression was significantly higher in the cell cycle checkpoint/arrest pathway than in the hypoxia pathway category (p = 0.0064). The 70 kDa heat shock protein 4 gene, within the heat shock protein/unfolded protein response category, showed the highest individual increase in expression (26.1-fold). CONCLUSIONS: NP40 appeared to be particularly harmful, inducing gene expression changes that indicated genotoxicity, activation of the cell death (necrosis signaling) pathway, and induction of the 70 kDa heat shock protein 4 gene.
Aged ; Cell Cycle Checkpoints/drug effects/genetics ; Cell Line, Tumor ; Cell Survival/drug effects ; Dose-Response Relationship, Drug ; Female ; Gene Expression Regulation/drug effects ; Genes, cdc ; HSP110 Heat-Shock Proteins/genetics/metabolism ; Humans ; Inositol/*analogs & derivatives/chemistry/poisoning ; Necrosis ; Neurons/*drug effects/metabolism/pathology ; Nonoxynol/chemistry/*toxicity ; Pesticides/chemistry/*poisoning ; RNA, Messenger/metabolism ; Signal Transduction/drug effects ; Surface-Active Agents/chemistry/*toxicity

Liver fibrosis is an important health problem that can further progress into cirrhosis or liver cancer, and result in significant morbidity and mortality. Inhibiting proliferation and inducing apoptosis of hepatic stellate cells (HSCs) may be the key point to reverse liver fibrosis. At present, anti-fibrosis drugs are rare. Kinetin is a type of plant-derived cytokinin which has been reported to control differentiation and induce apoptosis of human cells. In this study, the HSCs were incubated with different concentrations of kinetin. The proliferation of rat HSCs was measured by MTT assay, cell cycle and apoptosis were analyzed by flow cytometry, and the apoptosis was examined by TUNEL method. The expression of Bcl-2 and Bax proteins was detected by immunocytochemistry staining. It was found that kinetin could markedly inhibit proliferation of HSCs. In a concentration range of 2 to 8 μg/mL, the inhibitory effects of kinetin on proliferation of HSCs were increased with the increased concentration and the extension of time (P < 0.01). Flow cytometry indicated that kinetin could inhibit the DNA synthesis from G0/G1 to S phase in a dose-dependent manner (P < 0.01). The apoptosis rates of the HSCs treated with 8, 4 and 2 μg/mL kinetin (25.62% ± 2.21%, 15.31% ± 1.9% and 6.18% ± 1.23%, respectively) were increased significantly compared with the control group (3.81% ± 0.93%) (P < 0.01). All the DNA frequency histogram in kinetin-treated groups showed obvious hypodiploid peak (sub-G1 peak), and with the increase of kinetin concentrations, the apoptosis rate of HSCs also showed a trend of increase. It was also found that kinetin could down-regulate the expression of Bcl-2, and up-regulate the expression of Bax, leading to the decreased ratio of Bcl-2/Bax significantly. The kinetin-induced apoptosis of HSCs was positively correlated with the expression of Bax, and negatively with the expression of Bcl-2. It was concluded that kinetin can inhibit activation and proliferation of HSCs by interrupting the cell cycle at G1/S restriction point and inducing apoptosis of HSCs via reducing the ratio of Bcl-2/Bax.
Animals ; Apoptosis ; drug effects ; Cell Line, Transformed ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; G1 Phase Cell Cycle Checkpoints ; drug effects ; genetics ; Gene Expression Regulation ; Growth Inhibitors ; pharmacology ; Hepatic Stellate Cells ; cytology ; drug effects ; metabolism ; Kinetin ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; antagonists & inhibitors ; genetics ; metabolism ; Rats ; Signal Transduction ; bcl-2-Associated X Protein ; agonists ; genetics ; metabolism

Proteasome inhibitors have shown remarkable success in the treatment of hematologic neoplasm. There has been a lot of attention to applying these drugs for solid tumor treatment. Recent preclinical study has signified the effectiveness on cell proliferation inhibition in lung adenocarcinoma treated by carfilzomib (CFZ), a second generation proteasome inhibitor. However, no insight has been gained regarding the mechanism. In this study, we have systematically investigated the CFZ functions in cell proliferation and growth, cell cycle arrest, and apoptosis in lung adenocarcinoma cells. Flow cytometry experiments showed that CFZ significantly induced G2/M cell cycle arrest and apoptosis in lung adenocarcinoma. MTS and colony formation assays revealed that CFZ substantially inhibited survival of lung adenocarcinoma cells. All results were consistently correlated to the upregulation expression of Gadd45a, which is an important gene in modulating cell cycle arrest and apoptosis in response to physiologic and environmental stresses. Here, upregulation of Gadd45a expression was observed after CFZ treatment. Knocking down Gadd45a expression suppressed G2/M arrest and apoptosis in CFZ-treated cells, and reduced cytotoxicity of this drug. The protein expression analysis has further identified that the AKT/FOXO3a pathway is involved in Gadd45a upregulation after CFZ treatment. These findings unveil a novel mechanism of proteasome inhibitor in anti-solid tumor activity, and shed light on novel preferable therapeutic strategy for lung adenocarcinoma. We believe that Gadd45a expression can be a highly promising candidate predictor in evaluating the efficacy of proteasome inhibitors in solid tumor therapy.
Adenocarcinoma of Lung/pathology* ; Apoptosis/drug effects* ; Cell Cycle Checkpoints/drug effects* ; Cell Cycle Proteins/genetics* ; Cell Line, Tumor ; Forkhead Box Protein O3/physiology* ; Gene Expression Regulation, Neoplastic/drug effects* ; Humans ; Lung Neoplasms/pathology* ; Oligopeptides/pharmacology* ; Proto-Oncogene Proteins c-akt/physiology* ; Up-Regulation

Werner syndrome (WS) is a premature aging disorder that mainly affects tissues derived from mesoderm. We have recently developed a novel human WS model using WRN-deficient human mesenchymal stem cells (MSCs). This model recapitulates many phenotypic features of WS. Based on a screen of a number of chemicals, here we found that Vitamin C exerts most efficient rescue for many features in premature aging as shown in WRN-deficient MSCs, including cell growth arrest, increased reactive oxygen species levels, telomere attrition, excessive secretion of inflammatory factors, as well as disorganization of nuclear lamina and heterochromatin. Moreover, Vitamin C restores in vivo viability of MSCs in a mouse model. RNA sequencing analysis indicates that Vitamin C alters the expression of a series of genes involved in chromatin condensation, cell cycle regulation, DNA replication, and DNA damage repair pathways in WRN-deficient MSCs. Our results identify Vitamin C as a rejuvenating factor for WS MSCs, which holds the potential of being applied as a novel type of treatment of WS.
Animals ; Ascorbic Acid ; pharmacology ; Cell Cycle Checkpoints ; drug effects ; Cell Line ; Cellular Senescence ; drug effects ; DNA Damage ; DNA Repair ; drug effects ; DNA Replication ; drug effects ; Disease Models, Animal ; Heterochromatin ; metabolism ; pathology ; Humans ; Mesenchymal Stem Cells ; metabolism ; pathology ; Mice ; Nuclear Lamina ; metabolism ; pathology ; Reactive Oxygen Species ; metabolism ; Telomere Homeostasis ; drug effects ; Werner Syndrome ; drug therapy ; genetics ; metabolism

The underground cane of Schizocapsa plantaginea (Hance) has long been used by Chinese ethnic minority as a constituent of anti-cancer formulae. Saponins are abundant secondary metabolic products located in the underground cane of this plant. The potential therapeutic effects of total saponins isolated from Schizocapsa plantaginea (Hance) (SSPH) on human hepatocellular carcinoma (HCC) were tested in vitro in human liver cancer cell lines, SMMC-7721 and Bel-7404. Apoptosis and cell cycle arrest were determined using flow cytometry, caspase activation was determined by ELISA, and PARP, cleaved PARP, mitogen-activated protein kinase (MAPK) expression and phosphorylation were measured using Western blotting analysis. In vivo anti-HCC effects of SSPH were verified in nude mouse xenograft model. SSPH exerted markedly inhibitory effect on HCC cell proliferation in time- and concentration-dependent manner. Moreover, SSPH significantly induced apoptosis through caspase-dependent signaling and arrested cell cycle at G/M phase. These anti-proliferation effects of SSPH were associated with up-regulated phosphorylation of extracellular signal-regulated kinase-1/2 (Erk1/2) and c-jun-NH2-kinase-1/2 (JNK1/2) and reduced phosphorylation of p38MAPK. Furthermore, inhibitors of ERK, UO126, and JNK, SP600125 inhibited the anti-proliferation effects by SSPH, suggesting that Erk and JNK were the effector molecules in SSPH induced anti-proliferative action. During in vivo experiments, SSPH was found to inhibit xenograft tumor growth in nude mice, with a similar mechanism in vitro. Our study confirmed that SSPH exerted antagonistic effects on human liver cancer cells both in vitro and in vivo. Molecular mechanisms underlying SSPH action might be closely associated with MAPK signaling pathways. These results indicated that SSPH has potential therapeutic effects on HCC.
Animals ; Antineoplastic Agents ; isolation & purification ; pharmacology ; toxicity ; Apoptosis ; drug effects ; Caspases ; genetics ; metabolism ; Cell Cycle Checkpoints ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Dioscoreaceae ; chemistry ; Heterografts ; drug effects ; growth & development ; Humans ; Inhibitory Concentration 50 ; Liver Neoplasms ; drug therapy ; metabolism ; pathology ; MAP Kinase Signaling System ; drug effects ; Mice ; Mice, Nude ; Phosphorylation ; drug effects ; Plant Tubers ; chemistry ; Poly (ADP-Ribose) Polymerase-1 ; metabolism ; Saponins ; isolation & purification ; pharmacology ; toxicity

OBJECTIVETo explore the effect of bortezomib (BOR) on the drug sensitivity of imatinib-resistant chronic myeloid leukemia cell line K562/G01 cell and its mechanism.

METHODSMTT assay was used to detect the inhibition effect of cell growth, flow cytometry to cell cycle, and real time-PCR to the expression of COX-2 and mdr1 mRNA.

RESULTSCombination of 10 and 20 nmol/L BOR with imatinib could significantly enhance the sensitivity of K562/G01 to imatinib, the reverse factor was 1.83 and 2.72-fold respectively. Cell cycle arrested at G(2)/M phase could be observed by flow cytometry on BOR treatment. The over-expression of COX-2 and mdr1 could be down-regulated by BOR.

CONCLUSIONSBOR can enhance the imatinib sensitivity of imatinib resistant K562/G01 cell. The mechanism may be related to cell cycle phase arrested at G2/M and down-regulation of COX-2 and mdr1 expression.

ATP Binding Cassette Transporter, Sub-Family B ; ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; Antineoplastic Agents ; pharmacology ; Benzamides ; Boronic Acids ; pharmacology ; Bortezomib ; Cell Cycle ; Cell Cycle Checkpoints ; Cyclooxygenase 2 ; genetics ; Drug Resistance, Neoplasm ; drug effects ; Humans ; Imatinib Mesylate ; K562 Cells ; Piperazines ; pharmacology ; Pyrazines ; pharmacology ; Pyrimidines ; pharmacology

Various kinds of schiff base metal complexes have been proven to induce apoptosis of tumor cells. However, it remains largely unknown whether schiff base zinc complexes induce apoptosis in human cancer cells. Here, we synthesized a novel schiff base zinc coordination compound (SBZCC) and investigated its effects on the growth, proliferation and apoptosis of human osteosarcoma MG-63 cells. A novel SBZCC was synthesized by chemical processes and used to treat MG-63 cells. The cell viability was determined by CCK-8 assay. The cell cycle progression, mitochondrial membrane potential and apoptotic cells were analyzed by flow cytometry. The apoptosis-related proteins levels were determined by immunoblotting. Treatment of MG-63 cells with SBZCC resulted in inhibition of cell proliferation and cell cycle arrest at G1 phase. Moreover, SBZCC significantly reduced the mitochondrial membrane potential and induced apoptosis, accompanied with increased Bax/Bcl-2 and FlasL/Fas expression as well as caspase-3/8/9 cleavage. Our results demonstrated that the synthesized novel SBZCC could inhibit the proliferation and induce apoptosis of MG-63 cells via activating both the mitochondrial and cell death receptor apoptosis pathways, suggesting that SBZCC is a promising agent for the development as anticancer drugs.
Antineoplastic Agents ; chemical synthesis ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; genetics ; metabolism ; Caspase 8 ; genetics ; metabolism ; Caspase 9 ; genetics ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Coordination Complexes ; chemical synthesis ; pharmacology ; Fas Ligand Protein ; genetics ; metabolism ; G1 Phase Cell Cycle Checkpoints ; drug effects ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Membrane Potential, Mitochondrial ; drug effects ; Mitochondria ; drug effects ; metabolism ; pathology ; Osteoblasts ; drug effects ; metabolism ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Schiff Bases ; chemistry ; Signal Transduction ; Zinc ; chemistry ; bcl-2-Associated X Protein ; genetics ; metabolism ; fas Receptor ; genetics ; metabolism