stilbenes and Leukemia--Promyelocytic--Acute

Arsenic trioxide (As2O3) has been verified as a breakthrough in the management of acute promyelocytic leukemia in recent decades. However, cardiotoxicity, especially long QT syndrome (LQTS) has become the most important issue during As2O3 treatment. The characterized mechanisms behind this adverse effect are inhibition of cardiac hERG channel trafficking and increase of cardiac calcium currents. In our study, we found a new pathway underlying As2O3-induced cardiotoxicity that As2O3 accelerates lysosomal degradation of hERG on plasma membrane after using brefeldin A (BFA) to block protein trafficking. Then we explored pharmacological rescue strategies on As2O3-induced LQTS, and found that 4 therapeutic agents exert rescue efficacy via 3 different pathways: fexofenadine and astemizole facilitate hERG trafficking via promotion of channel-chaperone formation after As2O3 incubation; ranolazine slows hERG degradation in the presence of As2O3; and resveratrol shows significant attenuation on calcium current increase triggered by As2O3. Moreover, we used human-induced pluripotent stem cell derived cardiomyocytes (hiPS-CMs) to evaluate the rescue effects of the above agents on As2O3-induced prolongation of action potential duration (APD) and demonstrated that fexofenadine and resveratrol significantly ameliorate the prolonged APD. These observations suggested that pharmacological chaperone like fexofenadine and resveratrol might have the potential to protect against the cardiotoxicity of As2O3.

Topics: Action Potentials; Antineoplastic Agents; Arsenic Trioxide; Arsenicals; ERG1 Potassium Channel; HEK293 Cells; Humans; Induced Pluripotent Stem Cells; Leukemia, Promyelocytic, Acute; Long QT Syndrome; Lysosomes; Myocytes, Cardiac; Oxides; Patch-Clamp Techniques; Proteolysis; Resveratrol; Stilbenes; Terfenadine

Cardiotoxicity is an aggravating side effect of many clinical antineoplastic agents such as arsenic trioxide (As2O3), which is the first-line treatment for acute promyelocytic leukemia (APL). Clinically, drug combination strategies are widely applied for complex disease management. Here, an optimized, cardiac-friendly therapeutic strategy for APL was investigated using a combination of As2O3 and genistein or resveratrol. Potential combinations were explored with respect to their effects on mitochondrial membrane potential, reactive oxygen species, superoxide dismutase activity, autophagy, and apoptosis in both NB4 cells and neonatal rat left ventricular myocytes. All experiments consistently suggested that 5 µM resveratrol remarkably alleviates As2O3-induced cardiotoxicity. To achieve an equivalent effect, a 10-fold dosage of genistein was required, thus highlighting the dose advantage of resveratrol, as poor bioavailability is a common concern for its clinical application. Co-administration of resveratrol substantially amplified the anticancer effect of As2O3 in NB4 cells. Furthermore, resveratrol exacerbated oxidative stress, mitochondrial damage, and apoptosis, thereby reflecting its full range of synergism with As2O3. Addition of 5 µM resveratrol to the single drug formula of As2O3 also further increased the expression of LC3, a marker of cellular autophagy activity, indicating an involvement of autophagy-mediated tumor cell death in the synergistic action. Our results suggest a possible application of an As2O3 and resveratrol combination to treat APL in order to achieve superior therapeutics effects and prevent cardiotoxicity.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Arsenic Trioxide; Arsenicals; Cell Line, Tumor; Drug Screening Assays, Antitumor; Enzyme Inhibitors; Humans; Leukemia, Promyelocytic, Acute; Myocytes, Cardiac; Neoplasm Proteins; Oxides; Rats; Reactive Oxygen Species; Resveratrol; Stilbenes; Superoxide Dismutase

Human promyeloblastic leukemia KG-1a cells exhibit many characteristics similar to leukemia stem cells, which are resistant to chemotherapeutic drugs and hyposensitive to cytotoxic cells. Resveratrol (RES), as a member of plant polyphenols, has gained considerable attention due to its ability to prevent cancer from progressing. In this study, the potential of RES to sensitize KG-1a cells to cytolysis of cytokine-induced killer cells (CIKs) through NKG2D ligands and TNF-related apoptosis-inducing ligand (TRAIL) receptors were investigated. Twenty-five micromolars RES was found to inhibit approximately 50% of KG-1a cell growth and had the least growth-inhibition effect on peripheral blood mononuclear cells (PBMCs) after 24 h. Utilizing cytokines including interleukin-2 (IL-2) and interleukin-15 (IL-15) to activate PBMCs, we obtained substantial CD3 (+) CD56 (+) natural killer cell-like T lymphocytes that secreted cytokine interferon-γ (IFN-γ) and expressed NKG2D and TRAIL on their surfaces (i.e., cytokine-induced killer cells, CIKs). RES was shown to render KG-1a cells susceptible to CIK-mediated cytolysis estimated by LDH-release assay. This heightened sensitivity correlated with an increase in cell-surface expression of NKG2D ligands and death receptor 4 (DR4), coupled with a downregulation of cell-surface expression of decoy receptor 1 (DcR1) in KG-1a cells. Blocking NKG2D ligands or TRAIL with monoclonal antibodies could abrogate CIKs-mediated cytolysis. These results demonstrated that increased sensitivity of KG-1a cells, modulated by RES to alloreactive CIKs-mediated cytolysis is a phenomenon attributable to induced expression of NKG2D ligands and activation of TRAIL pathway. Thus, resveratrol combined with alloreactive CIKs merits clinical evaluation as a novel and effective immunotherapy strategy to eliminate residual leukemia stem cells.

Topics: Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Cell Membrane; Cell Proliferation; Cytokine-Induced Killer Cells; Cytotoxicity, Immunologic; Gene Expression Regulation, Leukemic; GPI-Linked Proteins; Humans; Intercellular Signaling Peptides and Proteins; Interleukin-15; Interleukin-2; Intracellular Signaling Peptides and Proteins; Leukemia, Promyelocytic, Acute; Leukocytes, Mononuclear; Ligands; NK Cell Lectin-Like Receptor Subfamily K; Receptors, TNF-Related Apoptosis-Inducing Ligand; Receptors, Tumor Necrosis Factor, Member 10c; Resveratrol; Stilbenes; Tumor Necrosis Factor Decoy Receptors

Resveratrol (3,4',5-trihydroxy-trans-stilbene), one of secondary metabolites of low molecular weight present in plant, has various important biological effects. It can induce apoptosis in human leukemia cell types in vitro, although the mechanism is not fully understood. In the present study, we demonstrated reduced viability and DNA synthesis, as well as increased proportion of the subdiploid cell population, in HL-60 cells as determined by cell cycle analysis with resveratrol. Resveratrol treatment resulted in a gradual time-dependent decrease in the expression of anti-apoptotic Bcl-2 and increase in that of Bax, annexin A1, growth arrest- and DNA damage-induced gene 45α (GADD45α), and cleaved caspase-3. In addition, resveratrol markedly increased caspase-3 activity in cells. Our results suggest that resveratrol could inhibit the proliferation and induce apoptosis of HL-60 cells through a GADD45α and annexin A1/caspase-3 pathway.

Topics: Annexin A1; Antineoplastic Agents, Phytogenic; Apoptosis; Caspase 3; Cell Cycle Proteins; Cell Growth Processes; Cell Survival; DNA Damage; G1 Phase; HL-60 Cells; Humans; Leukemia, Promyelocytic, Acute; Nuclear Proteins; Nucleic Acid Synthesis Inhibitors; Resting Phase, Cell Cycle; Resveratrol; Stilbenes

Vav1 plays an important role in the all-trans retinoic acid (ATRA)-induced completion of the differentiation program of acute promyelocytic leukemia (APL)-derived cells, in which it strengthens the drug effects and is involved in the regulation of maturation-related proteins, such as the CD11b surface antigen. In both myeloid and lymphoid cells, accumulating data attribute to the multidomain protein Vav1 a functional relevance in the control of gene expression, by direct interaction with chromatin remodeling and/or transcriptional proteins. The present study provides evidence that, in the APL-derived NB4 cell line, Vav1 and the transcription factor PU.1 cooperate in regulating the ATRA-induced CD11b expression. Both chromatin immunoprecipitation (ChIP) experiments and electrophoretic mobility shift assays (EMSA) indicate that Vav1 and PU.1 are recruited to CD11b promoter. Even if the two proteins may participate in diverse protein/DNA complexes, the amounts of complexes including PU.1 seem to be dependent on the interaction of this transcription factor with tyrosine-phosphorylated Vav1. The reported data suggest that the ATRA-induced increase of Vav1 expression and tyrosine phosphorylation may be involved in recruiting PU.1 to its consensus sequence on the CD11b promoter and, ultimately, in regulating CD11b expression during the late stages of neutrophil differentiation of APL-derived promyelocytes.

Topics: CD11b Antigen; Cell Differentiation; Cell Line, Tumor; Cell Nucleus; Chromatin Immunoprecipitation; DNA; Electrophoretic Mobility Shift Assay; Gene Expression Regulation, Neoplastic; Granulocyte Precursor Cells; Humans; Intracellular Signaling Peptides and Proteins; Leukemia, Promyelocytic, Acute; Neutrophils; Phosphorylation; Promoter Regions, Genetic; Protein Binding; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-vav; RNA, Small Interfering; Stilbenes; Syk Kinase; Trans-Activators; Tretinoin

Bcl-2 protects cancer cells from the apoptotic effects of various chemotherapeutic agents. Inhibition or downregulation of Bcl-2 represents a new therapeutic approach to bypass chemoresistance in cancer cells. Previously we designed and synthesized the resveratrol analogue HS-1793 displaying stronger antitumor efficacy than resveratrol and further demonstrated the HS-1793 resistance conferred by Bcl-2 in human leukemic U937 cells. We undertook this study to determine if HS-1793 treatment can bypass the anti-apoptotic effects of Bcl-2 in human renal cancer cells, with a specific focus on the involvement of promyelocytic leukemia nuclear bodies (PML-NBs). Experiments were conducted with Bcl-2-overexpressing human renal clear cell carcinoma Caki-1 cells. Various apoptosis assessment assays demonstrated that HS-1793 overcomes the resistance conferred by Bcl-2 in Caki-1 cells by inducing apoptosis. We elucidated that HS-1793-induced formation of mature promyelocytic leukemia (PML) nuclear bodies (NBs) correlates with overcoming the anti-apoptotic effects of Bcl-2 in Caki-1 cells. Our findings show that the resveratrol analogue HS-1793 might provide a novel promising strategy for overcoming the resistance conferred by Bcl-2 via PML protein and the formation of mature PML-NBs.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Renal Cell; Cell Line, Tumor; Drug Resistance, Neoplasm; Flow Cytometry; Fluorescent Antibody Technique; Humans; Intranuclear Inclusion Bodies; Kidney Neoplasms; Leukemia, Promyelocytic, Acute; Membrane Potential, Mitochondrial; Microscopy, Confocal; Naphthols; Nuclear Proteins; Promyelocytic Leukemia Protein; Proto-Oncogene Proteins c-bcl-2; Resorcinols; Resveratrol; Stilbenes; Transcription Factors; Tumor Suppressor Proteins

Results of a number of epidemiological and experimental studies indicate that polyphenols (e.g. resveratrol (RES), epicatechins etc.), antioxidant agents and abundant micronutrients in our food could have strong anti-mitotic as well as pro-apoptotic effects. In this study we raised the question whether roscovitine (ROSC), an inhibitor of cyclin-dependent kinases (CDKs) with increased selectivity towards CDK2, could be able to affect human leukemia HL-60 cells in which the p53 gene is inactivated and whether ROSC-induced effects could be additionally modulated by compounds of natural origin, especially by polyphenols e.g. RES. Exposure of HL-60 cells to ROSC for 24 h inhibited their proliferation. Flow cytometric analyses revealed that unlike MCF-7 cells, HL-60 cells were arrested in G(1) upon ROSC treatment. Furthermore, ROSC also induced apoptosis in HL-60 cells. After treatment with 40 microM ROSC for 24 h the frequency of hypoploid cells representing cells undergoing apoptosis reached approximately 50%. In the next step the action of RES alone or in combination with ROSC was examined. Interestingly, synergistic effects were observed after combined treatment for 24 h and sequential post-incubation for 48 h in the presence of RES. Such combined treatment resulted in a marked reduction of the frequency of the S- and G(2)/M-phase cells and simultaneously increased the G(1) cell population up to 80% at a fourfold lower ROSC dose. Further analyses revealed that the combined treatment strongly activated caspase-3. These results clearly evidence that RES strongly potentiates ROSC-induced apoptosis.

Topics: Apoptosis; Blotting, Western; Cell Cycle; Cell Proliferation; Cyclin-Dependent Kinases; Flow Cytometry; HL-60 Cells; Humans; Leukemia, Promyelocytic, Acute; Phosphorylation; Protein Kinase Inhibitors; Purines; Resveratrol; Roscovitine; Stilbenes

Piceatannol (3,3',4,5'-tetrahydroxy-trans-stilbene; PCA) is a naturally occurring metabolite of resveratrol (3,4',5-trihydroxy-trans-stilbene; RV). In this study, we identified additional biochemical targets of PCA in human HL-60 promyelocytic leukemia cells. Incubation with PCA led to a significant proportion of apoptotic cells and caused an arrest in the G2-M phase of the cell cycle. PCA depleted intracellular dCTP and dGTP pools, and inhibited the incorporation of 14C-labeled cytidine into DNA. PCA significantly abolished all NTP pools, and sequential treatment with PCA and Ara-C yielded synergistic growth inhibitory effects because of remarkably increased Ara-CTP formation after PCA preincubation. Due to these promising results, PCA may support conventional chemotherapy of human malignancies and therefore, deserves further preclinical and in vivo testing.

Topics: Antimetabolites, Antineoplastic; Antineoplastic Agents; Cell Cycle; Cytarabine; Drug Screening Assays, Antitumor; Drug Synergism; Enzyme Inhibitors; HL-60 Cells; Humans; Leukemia, Promyelocytic, Acute; Models, Chemical; Propidium; Ribonucleotide Reductases; Stilbenes; Time Factors

To further explore the SAR of resveratrol-related trans-stilbene derivatives, here we describe the synthesis of (a) a series of 3,5-dimethoxy analogues in which a variety of substituents were introduced at positions 2', 3', 4', and 5' of the stilbene scaffold and (b) a second group of derivatives (2-phenylnaphthalenes and terphenyls) that incorporate a phenyl ring as a bioisosteric replacement of the stilbene alkenyl bridge. We thoroughly characterized all of the new compounds with respect to their apoptosis-inducing activity and their effects on the cell cycle. One of the new derivatives, 13g, behaved differently from the others, as it was able to block the cell cycle in the G(0)-G(1) phase and also to induce differentiation in acute myelogenous leukemia HL60 cells. Compared to resveratrol, the synthetic terphenyl 13g showed a more potent apoptotic and differentiating activity. Moreover, it was active on both multidrug resistance and Bcr-Abl-expressing cells that were resistant to resveratrol.

Topics: Antineoplastic Agents; Apoptosis; ATP Binding Cassette Transporter, Subfamily B, Member 1; Cell Differentiation; Cell Line, Tumor; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Fusion Proteins, bcr-abl; G1 Phase; Humans; Leukemia, Promyelocytic, Acute; Resting Phase, Cell Cycle; Resveratrol; Stilbenes; Structure-Activity Relationship; Terphenyl Compounds

Resveratrol (3,4',5,-trihydroxystilbene, RV), an ingredient of wine, is an inhibitor of the proliferation-linked enzyme ribonucleotide reductase (RR) and shows a broad spectrum of cytotoxic effects against human cancer cells. In order to enhance these effects, we introduced additional hydroxyl moieties into the molecule. In the present study, the activity of a novel RV analog, 3,3',4,4',5,5'-hexahydroxystilbene (M8), was investigated in HL-60 human promyelocytic leukemia cells.. Cytotoxicity of M8 alone or in combination with Ara-C was assessed employing growth inhibition assays. Effects of M8 on nucleoside triphosphates (NTPs) and deoxynucleoside triphosphates (dNTPs) were examined by HPLC. The apoptotic potential of M8 and RV was compared using a specific double-staining method and inhibition of TNF-alpha-induced activation of NF-kappaB was studied. Cell-cycle distribution was analyzed by FACS.. Addition of ascorbic acid decreased the IC(50) value of M8 from 6.25 microM to 2 microM. M8 depleted dATP and dTTP pools to 41% and 21% of control values, whereas dCTP pools increased to 199% of untreated controls. In addition, TTP, ATP, CTP, and GTP concentrations were decreased while UTP concentrations increased. M8 induced apoptosis at concentrations significantly lower than RV and could remarkably inhibit the activation of NF-kappaB. M8 arrested cells in the S phase of the cell cycle while depleting cells in the G2-M phase and exhibited synergistic combination effects when applied simultaneously with Ara-C.. Due to these promising results, this novel polyhydroxylated stilbene derivative might become an additional option for the treatment of leukemia and therefore deserves further preclinical and in vivo testing.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Cycle; Cytarabine; Deoxyribonucleotides; Drug Evaluation, Preclinical; Enzyme Inhibitors; HL-60 Cells; Humans; Leukemia, Promyelocytic, Acute; NF-kappa B; Pyrogallol; Resveratrol; Ribonucleotide Reductases; Ribonucleotides; Stilbenes; Tumor Necrosis Factor-alpha; Wine

Resveratrol (3,4',5-trihydroxystilbene, RV) exerts remarkable cytostatic and cytotoxic effects against a multitude of human cancer cell lines. Since the introduction of additional hydroxyl groups was supposed to increase the biological activity of RV, we have synthesized a number of polyhydroxylated stilbene analogues as potential antitumor agents. In this study, the activity of 3,3',4,4',5,5'-hexahydroxystilbene (M8) was investigated in HL-60 human promyelocytic leukemia cells. Employing a growth inhibition assay, incubation with M8 and RV resulted in IC50 values of 6.25 and 12 microM, respectively. Using a specific Hoechst/propidium iodide double staining method, we found that M8 was able to induce apoptosis in concentrations significantly lower than those of RV. In addition, M8 arrested cells in the S phase and totally depleted cells in the G2-M phase of the cell cycle (143% and 0% of control after treatment with 12.5 microM M8, respectively). We therefore believe that this promising agent deserves further preclinical and in vivo testing.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Bisbenzimidazole; Cell Cycle; Cytarabine; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Drug Synergism; Fluorescent Dyes; HL-60 Cells; Humans; Inhibitory Concentration 50; Leukemia, Promyelocytic, Acute; Propidium; Pyrogallol; Stilbenes

Resveratrol (RV), a naturally occurring stilbene derivative, is a potent free radical scavenger causing a number of biochemical and antineoplastic effects. It was shown to induce differentiation and apoptosis in leukemia cells and was also identified as an inhibitor of ribonucleotide reductase (RR), a key enzyme of DNA synthesis. In this study, we report about the biochemical effects of RV in HL-60 human promyelocytic leukemia cells. RV effectively inhibited in situ RR activity. Furthermore, incubation of HL-60 cells with RV significantly decreased intracellular dCTP, dTTP, dATP and dGTP concentrations. In growth inhibition and clonogenic assays, RV acted synergistically with both Ara-C and tiazofurin in HL-60 cells. We conclude that RV could become a viable candidate as one compound in the combination chemotherapy of leukemia and therefore deserves further in vitro and in vivo testing.

Topics: Antimetabolites, Antineoplastic; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Proliferation; Cytarabine; Drug Screening Assays, Antitumor; Drug Synergism; Free Radical Scavengers; Free Radicals; HL-60 Cells; Humans; Leukemia, Promyelocytic, Acute; Resveratrol; Ribavirin; Stilbenes

Resveratrol, a phytochemical present in grapes, has been demonstrated to inhibit tumourigenesis in animal models. However, the specific mechanism by which resveratrol exerts its anticarcinogenic effect has yet to be elucidated. In the present study, the inhibitory effects of resveratrol on cell proliferation and apoptosis were evaluated in the human leukaemia cell line HL-60 and the human hepatoma derived cell line HepG2. We found that after a 2 h incubation period, resveratrol inhibited DNA synthesis in a concentration-dependent manner. The IC50 value was 15 microm in both HL-60 and HepG2 cells. When the time of treatment was extended, an increase in IC50 value was observed; for example, at 24 h the IC50 value was 30 microm for HL-60 cells and 60 microm for HepG2 cells. Flow cytometry revealed that cells accumulated in different phases of the cell cycle depending on the resveratrol concentration. Furthermore, an increase in nuclear size and granularity was observed in the G1 and S phases of HL-60 treated and HepG2-treated cells. Apoptosis was also stimulated by resveratrol in a concentration-dependent manner in HL-60 and HepG2 cells. In conclusion, resveratrol inhibits cell proliferation in a concentration- and time-dependent manner by interfering with different stages of the cell cycle. Furthermore, resveratrol treatment causes stimulation of apoptosis as well as an increase in nuclear size and granularity.

Topics: Annexin A5; Anticarcinogenic Agents; Apoptosis; Carcinoma, Hepatocellular; Cell Cycle; Cell Nucleus Size; DNA Fragmentation; Dose-Response Relationship, Drug; Flow Cytometry; HL-60 Cells; Humans; Leukemia, Promyelocytic, Acute; Liver Neoplasms; Resveratrol; Stilbenes; Thymidine; Tritium

Resveratrol, a naturally occurring stilbene derivative, is a potent free-radical scavenger causing a number of biochemical and antineoplastic effects. It was shown to induce differentiation and apoptosis in leukemia cells. Resveratrol was also identified as an inhibitor of ribonucleotide reductase (RR), a key enzyme of DNA synthesis. We report about the biochemical effects of resveratrol on the concentration of deoxyribonucleoside triphosphates (dNTPs), the products of RR, and on the incorporation of 14C-labeled cytidine into the DNA of HL-60 human promyelocytic leukemia cells.. Incorporation of 14C-labeled cytidine into the DNA of resveratrol-treated HL-60 cells was measured. Concentration of dNTPs was determined by a HPLC method. Cytotoxic effects of resveratrol, Ara-C, and tiazofurin were analyzed using growth inhibition and clonogenic assays. Induction of apoptosis was studied using a Hoechst/propidium iodide staining method.. We found that resveratrol effectively inhibited incorporation of 14C-labeled cytidine into DNA. Furthermore, incubation of HL-60 cells with resveratrol significantly decreased intracellular dCTP, dTTP, dATP, and dGTP concentrations. Based on these results, we investigated the combination effects of resveratrol with Ara-C or tiazofurin, both antimetabolites, which are known to exhibit synergistic effects in combination with other inhibitors of RR. In growth inhibition, apoptosis, and clonogenic assays, resveratrol acted synergistically with both Ara-C and tiazofurin in HL-60 cells.. We conclude that resveratrol could become a viable candidate as one compound in the combination chemotherapy of leukemia and therefore deserves further testing.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Differentiation; Cytarabine; Deoxyribonucleotides; DNA; Drug Synergism; HL-60 Cells; Humans; Leukemia, Promyelocytic, Acute; Resveratrol; Ribavirin; Ribonucleotide Reductases; Stilbenes

Vav is one of the genetic markers that correlate with the differentiation of hematopoietic cells. In T and B cells, it appears crucial for both development and functions, while, in non-lymphoid hematopoietic cells, Vav seems not involved in cell maturation, but rather in the response of mature cells to agonist-dependent proliferation and phagocytosis. We have previously demonstrated that the amount and the tyrosine phosphorylation of Vav are up-regulated in both whole cells and nuclei of tumoral promyelocytes induced to granulocytic maturation by ATRA and that tyrosine-phosphorylated Vav does not display any ATRA-induced GEF activity but contributes to the regulation of PI 3-K activity. In this study, we report that Vav accumulates in nuclei of ATRA-treated APL-derived cells and that the down-modulation of Vav prevents differentiation of tumoral promyelocytes, indicating that it is a key molecule in ATRA-dependent myeloid maturation. On the other hand, the overexpression of Vav induces an increased expression of surface markers of granulocytic differentiation without affecting the maturation-related changes of the nuclear morphology. Consistent with an effect of Vav on the transcriptional machinery, array profiling shows that the inhibition of the Syk-dependent tyrosine phosphorylation of Vav reduces the number of ATRA-induced genes. Our data support the unprecedented notion that Vav plays crucial functions in the maturation process of myeloid cells, and suggest that Vav can be regarded as a potential target for the therapeutic treatment of myeloproliferative disorders.

Topics: Cell Cycle Proteins; Cell Differentiation; Cell Line, Tumor; Enzyme Inhibitors; Gene Expression; Gene Expression Regulation, Leukemic; Granulocytes; HL-60 Cells; Humans; Leukemia, Promyelocytic, Acute; Myeloid Progenitor Cells; Phosphorylation; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-vav; RNA, Small Interfering; Stilbenes; Transfection; Tretinoin; Tumor Cells, Cultured

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a naturally occurring phytoalexin found in grapes and wine, and has been reported to exert a variety of important pharmacological effects. We have investigated the activity of resveratrol on proliferation and differentiation of the acute promyelocytic leukemia cell line NB4. The growth inhibitory properties of resveratrol appear to be due to its induction of apoptotic cell death, as determined by morphological changes, DNA fragmentation, increased proportion of the subdiploid cell population and decreased mitochondrial transmembrane potential (Deltapsi(m)). Colorimetric assay for activity of caspase-3 showed an obvious increase in caspase-3 activity in cells after treatment with resveratrol. However, the expression levels of protein Bcl-2 and Bax show no significant change in response to resveratrol treatment. These results suggest that apoptosis of NB4 cells induced by resveratrol requires caspase-3 activation and is related to the mitochondrial transmembrane potential. The combination of resveratrol and all-tran-retinoic acid (ATRA) induced 100% of the NB4 cells to become NBT-positive, whereas only a small part of cells became positive for NBT after a similar exposure to either resveratrol or ATRA alone. Thus, resveratrol may be useful in treating acute promyelocytic leukemia.

Topics: Anticarcinogenic Agents; Antineoplastic Agents; Apoptosis; Cell Differentiation; Cell Proliferation; DNA Damage; Humans; Leukemia, Promyelocytic, Acute; Resveratrol; Stilbenes; Tretinoin; Tumor Cells, Cultured

Resveratrol, a triphenolic stilbene present in grapes and other plants, has striking antioxidant and anti-inflammatory activities which have been considered to be responsible for the beneficial effects of red wine consumption on coronary heart disease. Recent studies reveal that resveratrol can inhibit each step of multistage carcinogenesis. However, the molecular mechanisms underlying anti-tumorigenic or chemopreventive activities of this phytochemical remain largely unknown. In the present work, we have found that resveratrol reduces viability and DNA synthesis capability of cultured human promyelocytic leukemia (HL-60) cells. The growth inhibitory and antiproliferative properties of resveratrol appear to be attributable to its induction of apoptotic cell death as determined by morphological and ultrastructural changes, internucleosomal DNA fragmentation, and increased proportion of the subdiploid cell population. Resveratrol treatment resulted in a gradual decrease in the expression of anti-apoptotic Bcl-2. These results, together with previous findings, suggest the cancer therapeutic as well as chemopreventive potential of resveratrol.

Topics: Anticarcinogenic Agents; Antioxidants; Apoptosis; Cell Division; Cell Nucleus; Cell Survival; DNA; DNA Fragmentation; Electrophoresis, Agar Gel; Flow Cytometry; HL-60 Cells; Humans; Leukemia, Promyelocytic, Acute; Microscopy, Electron; Proto-Oncogene Proteins c-bcl-2; Resveratrol; Stilbenes; Time Factors