stilbenes and Leukemia

Resveratrol (RSV) is a well known chemopreventive molecule featuring anti-cancer properties. Our paper describes the main molecular targets of RSV linked to its antiproliferative activity on lymphoma and leukemia experimental models. It discusses further the most recent and most promising among these molecular targets for a translational application.

Topics: Anticarcinogenic Agents; Humans; Leukemia; Lymphoma; Resveratrol; Stilbenes

Lymphoma and leukemia represent a serious threat to human health and life expectancy. Resveratrol is, among the natural-derived chemopreventive molecules, one of the most effective and better studied. In this paper the main mechanisms of cell death triggered by- or linked to- resveratrol are reviewed and discussed. The main focus is on lymphoma and leukemia experimental models where resveratrol has been tested and investigated at the cellular, molecular or physiological levels. The most relevant in vivo challenges involving resveratrol are also reported and analyzed in order to define the key features of this polyphenol and the potential for the treatment of hematologic tumors.

Topics: Angiogenesis Inhibitors; Animals; Apoptosis; Biomarkers, Tumor; Cell Line, Tumor; Humans; Leukemia; Lymphoma; Models, Biological; Resveratrol; Stilbenes

The abnormal BCR-ABL oncoprotein is a constitutively active tyrosine kinase driving aberrant proliferation of transformed hematopoietic cells. BCR-ABL regulates activation of many mitogenic and pro-survival pathways, including the PI 3'K/AKT/mTOR pathway that controls various effectors and regulates initiation of mRNA translation in mammalian cells. Although tyrosine kinase inhibitors (TKIs) that target the ABL kinase domain have remarkable clinical activity and have dramatically changed the natural history of Ph+ leukemias, resistance to these agents also develops via a wide range of mechanisms. Efforts to target the PI3'K/AKT/mTOR signaling pathway using kinase inhibitors have been the focus of extensive ongoing investigations by several research groups. Here we review the effects of activation of the AMPK kinase, which regulates downstream targeting and inhibition of mTOR. The potential for future clinical-translational applications of AMPK activators such as AICAR, metformin and resveratrol for the treatment of chronic myelogenous leukemia (CML) and Ph+ acute lymphoblastic leukemia (ALL) are discussed.

Topics: AMP-Activated Protein Kinase Kinases; Genes, abl; Hematologic Neoplasms; Humans; Leukemia; Metformin; Phosphatidylinositol 3-Kinase; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Protein Kinases; Proto-Oncogene Proteins c-akt; Resveratrol; Stilbenes; TOR Serine-Threonine Kinases

Plant-derived polyphenolic compounds, such as the stilbene resveratrol (trans-3,4',5-trihydroxystilbene), have been identified as potent anti-cancer agents. Extensive in vitro studies revealed multiple intracellular targets of resveratrol, which affect cell growth, inflammation, apoptosis, angiogenesis, and invasion and metastasis. These include tumor suppressors p53 and Rb; cell cycle regulators, cyclins, CDKs, p21WAF1, p27KIP and INK and the checkpoint kinases ATM/ATR; transcription factors NF-kappaB, AP-1, c-Jun, and c-Fos; angiogenic and metastatic factors, VEGF and matrix metalloprotease 2/9; cyclooxygenases for inflammation; and apoptotic and survival regulators, Bax, Bak, PUMA, Noxa, TRAIL, APAF, survivin, Akt, Bcl2 and Bcl-X(L). In addition to its well-documented anti-oxidant properties, there is increasing evidence that resveratrol exhibits pro-oxidant activity under certain experimental conditions, causing oxidative DNA damage that may lead to cell cycle arrest or apoptosis. This review summarizes in vitro mechanistic data available for resveratrol and discusses new potential anti-cancer targets and the antiproliferative mechanisms of resveratrol.

Topics: Anticarcinogenic Agents; Breast Neoplasms; Cathepsins; Cell Cycle; Cell Division; Female; Humans; Inflammation; Leukemia; Lymphoma; Male; Neoplasms; Prostatic Neoplasms; Resveratrol; Safety; Stilbenes; Transcription Factors

Resveratrol is a phytoalexin naturally present in fruits, medicinal plants and wines. It has a diversity of biological activities. While its role in the protection against coronary heart disease (CHD) in people with moderate wine consumption, remains unclear, resveratrol preferentially inhibits the growth of leukemia cells in culture. Potential mechanisms for its anti-leukemia effect include induction of leukemia cell differentiation, apoptosis, and cell cycle arrest at S-phase; and inhibition of DNA synthesis by inhibiting ribonucleotide reductase or DNA polymerase. Preliminary results suggest that resveratrol also inhibits the viability of freshly isolated leukemia cells, especially promyelocytic leukemia cells. Because of its low in vivo toxicity, resveratrol deserves further investigation as an anti-leukemia agent.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Cycle; Hematopoietic Stem Cells; Humans; Leukemia; Resveratrol; Stilbenes

The biological activities of shancigusin C (

Topics: Antineoplastic Agents; Biological Products; Cell Line, Tumor; Chemistry Techniques, Synthetic; Chemistry, Pharmaceutical; Dihydrostilbenoids; Drug Design; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Humans; Leukemia; Magnetic Resonance Spectroscopy; Models, Chemical; Molecular Conformation; Molecular Structure; Orchidaceae; Plant Extracts; Stereoisomerism; Stilbenes

Piceatannol, a polyphenolic compound present in grapes and wine, has been reported to exhibit anticancer properties. Recently, it has been demonstrated to exert antiproliferative and proapoptotic effects in various human cancer types. The aim of our study was to investigate whether piceatannol induces autophagy and apoptosis in MOLT-4 human leukemia cells. Our results revealed that piceatannol activated autophagy in MOLT-4 cells, as evidenced by the detection of an increased level of LC3-II protein and a concomitant decrease in p62/SQSTM1 protein level. Moreover, piceatannol induced apoptosis in MOLT-4 cells which was accompanied by phosphatidylserine externalization, caspase-3 activation, disruption of mitochondrial membrane potential, internucleosomal DNA fragmentation, PARP1 cleavage, chromatin condensation, and fragmentation of cell nuclei. However, the toxic effects exerted by piceatannol in MOLT4 cells diminished after longer periods of exposure to the compound. Our findings imply that MOLT-4 cells may acquire resistance to piceatannol toxicity, which may result from the induction of efflux transporters such as P-glycoprotein. The present study provides new data showing that the use of piceatannol as a potential chemotherapeutic agent in the treatment of leukemia may be associated with the risk of multidrug resistance.

Topics: Antineoplastic Agents; Apoptosis; ATP Binding Cassette Transporter, Subfamily B, Member 1; ATP Binding Cassette Transporter, Subfamily G, Member 2; Autophagy; Cell Line, Tumor; Drug Resistance, Neoplasm; Humans; Leukemia; Multidrug Resistance-Associated Proteins; Neoplasm Proteins; Stilbenes

Resveratrol at high concentrations (50-100 μmol/L) is known to induce cell death in leukemia cells. Here, we investigated whether pinosylvin, a resveratrol analogue, induced cell death in leukemia cells. Cell death was found to be markedly elevated by 50- to 100-μmol/L pinosylvin in THP-1 and U937 cells. It was also shown that pinosylvin induced caspase-3 activation, flip-flop of phosphatidylserine, LC3-II accumulation, LC3 puncta, and p62 degradation in both THP-1 and U937 cells. These data indicate that pinosylvin-induced cell death may occur through apoptosis and autophagy. In addition, we showed that pinosylvin down-regulates AMP-activated protein kinase α1 (AMPKα1) in leukemia cells. Therefore, we correlated AMPKα1 down-regulation and leukemia cell death. AMPKα1 inhibition appeared to decrease pinosylvin-induced apoptosis and autophagy in leukemia cells, implying that AMPK is a key regulator of leukemia cell death. Moreover, we found that both pinosylvin-induced autophagy and apoptotic progress were reduced in AMPKα1-overexpressed leukemia cells, when compared with vector-transfected cells. Cell death was elevated by AMPKα1 overexpression, whereas pinosylvin-induced cell death was markedly decreased by caspase-3 inhibitors or autophagy inhibitors. These results suggest that pinosylvin-induced depletion of AMPKα1 enhances cell death via apoptosis and autophagy in leukemia cells.

Topics: AMP-Activated Protein Kinases; Apoptosis; Autophagy; Caspase 3; Down-Regulation; Gene Expression Regulation, Leukemic; Humans; Leukemia; Resveratrol; Stilbenes; THP-1 Cells; U937 Cells

Piceatannol, a naturally occurring stilbene derivative mainly found in grapes, possesses apoptotic activity in various cancer cell lines, in addition to potent antioxidant activity. In the current study, we showed that piceatannol exhibits potent cytotoxic effects in all tested leukemia cell lines (THP-1, HL-60, U937, and K562). These effects were accompanied by induction of DNA damage, an increase in the proportion of cells in the sub-G

Topics: Acetylcysteine; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Down-Regulation; Humans; Leukemia; Stilbenes; X-Linked Inhibitor of Apoptosis Protein

The aim of the present study was to investigate the anticancer effects of resveratrol‑4‑O‑D-(2'‑galloyl)-glucopyranoside (REG) on leukemia and the mechanism underlying its effects. Three leukemia cell lines (HL‑60, Jurkat and U937) were used in this study. A Cell Counting kit‑8 assay was performed to evaluate the anti‑proliferative activity of REG on leukemia cell lines, and flow cytometric analysis was used to detect REG‑induced apoptosis. In addition, western blot analysis was conducted to detect the levels of apoptosis‑related proteins including, cytochrome c, cleaved (c)‑caspases‑3 and ‑9, B‑cell lymphoma 2 (Bcl‑2) and Bcl‑2‑associated protein x (Bax). Finally, a HL‑60 cell xenograft model in nude mice was used to evaluate the antitumor effect of REG on leukemia in vivo. The present results indicated that REG can significantly inhibit the proliferation of HL‑60, Jurkat and U937 cell lines in a concentration‑ and time‑dependent manner. The half maximal inhibitory concentration values were 38.4, 49.1 and 48.2 µg/ml for HL‑60, Jurkat and U937 cells, respectively. Furthermore, flow cytometric analysis demonstrated that REG can induce the apoptosis of HL‑60 cells, as well as increase the levels of cytochrome c, c‑caspases‑3 and ‑9, and Bax, as well as downregulate the expression of Bcl‑2. In vivo, REG was found to possess a marked anticancer effect on leukemia. In combination, the present results indicated that REG exerts significant anticancer effects on leukemia in vivo and in vitro through the induction of apoptosis.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Caspase 9; Cell Line, Tumor; Cell Proliferation; Cytochromes c; Flow Cytometry; Glucosides; Leukemia; Mice, Nude; Proto-Oncogene Proteins c-bcl-2; Resveratrol; Stilbenes; Xenograft Model Antitumor Assays

Polydatin (PD), a natural precursor of resveratrol, has a variety of biological activities, including anti‑tumor effects. However, the underlying molecular mechanisms of the anti-cancer activity of PD has not been fully elucidated. The present study demonstrated that PD significantly inhibited the proliferation of the MOLT-4 leukemia cell line in a dose‑ and time-dependent manner by using Cell Counting Kit‑8 assay. PD also dose-dependently increased the apoptotic rate and caused cell cycle arrest in S phase in MOLT‑4 cells, as revealed by flow cytometry. In addition, PD dose-dependently decreased the mitochondrial membrane potential and led to the generation of reactive oxygen species in MOLT-4 cells. Western blot analysis revealed that the expression of anti‑apoptotic protein B-cell lymphoma 2 (Bcl-2) was decreased, whereas that of pro‑apoptotic protein Bcl‑2‑associated X was increased by PD. Furthermore, the expression of two cell cycle regulatory proteins, cyclin D1 and cyclin B1, was suppressed by PD. Of note, the pro‑apoptotic and cell cycle‑inhibitory effects of PD were potentiated by Janus kinase 2 (JAK2) inhibition. In conclusion, the results of the present study strongly suggested that PD is a promising therapeutic compound for the treatment of leukemia, particularly in combination with JAK inhibitors.

Topics: Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; Blotting, Western; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cyclin B1; Cyclin D1; Glucosides; Humans; Janus Kinase 2; Leukemia; Membrane Potential, Mitochondrial; Mitochondria; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; STAT3 Transcription Factor; Stilbenes

To explore the enhanced sensitivity of leukemia cell line KG-1a to activated immune cell-mediated cytolysis after treated with resveratrol.. The value of 50% inhibition concentration (IC₅₀) for KG-1a by resveratrol was analyzed using trypan blue staining. Peripheral blood mononuclear cells were separated, and then activated by interleukin (IL)-2 and IL-15. The sensitivity of KG-1a treated with and without resveratrol to activated immune cell-mediated cytolysis was assayed by lactate dehydrogenase (LDH) -releasing assay. The expression of tumor necrosis factor related apoptosis inducing ligand (TRAIL) on the surface of activated immune cells and its receptors (DR4/5 and DcR1/2) on the surface of KG-1a were detected by flow cytometry.. Resveratrol could inhibit the proliferation of KG-1a and IC50 at 24 h was 25 mmol/L. At a ratio of 10:1 or 20:1 between effect and target, the cytolytic rates of treated KG-1a by activated immune cells were (55.80 ± 10.88)% and (72.31 ± 13.06)%, significantly higher than (24.96 ± 9.25)% and (37.93 ± 5.21)% of untreated KG-1a (P<0.05). The expression of DR5 on the surface of KG-1a treated with resveratrol was (9.05 ± 3.57)%, significantly higher than (3.11 ± 0.54)% of untreated KG-1a (P<0.05). Conversely, the expression of DcR1 on the surface of treated KG-1a was (13.23 ± 3.56)%, lower than (53.75 ± 10.51)% of KG-1a (P<0.05). When TRAIL pathway on the surface of activated immune cells was blocked, the cytolytic rates of treated KG-1a were (35.97 ± 6.36)% and (49.80 ± 10.68)%, significantly lower than (52.92 ± 6.98)% and (70.73 ± 9.79)% of untreated KG-1a (P<0.05) at the same ratio of effector and target.. Resveratrol could enhance cytolytic sensitivity of KG-1a by activated immune cells through TRAIL pathway.

Topics: Cell Line, Tumor; Cell Proliferation; Humans; Leukemia; Leukocytes, Mononuclear; Male; Receptors, TNF-Related Apoptosis-Inducing Ligand; Receptors, Tumor Necrosis Factor, Member 10c; Resveratrol; Stilbenes; TNF-Related Apoptosis-Inducing Ligand

The powerful activating receptor NKG2D is expressed by natural killer (NK) cells and promotes cytotoxic lysis of cancer cells expressing NKG2D ligands (NKG2D-Ls). We report the effective induction of NKG2D-Ls, achieved with the naturally occurring polyphenol resveratrol, in a broad range of leukemia cells. In this study, resveratrol upregulated the NKG2D-Ls MHC class I chain-related proteins MICA and MICB, and UL16-binding proteins ULBP1, ULBP2, and ULBP3 in most of the leukemia cells analyzed. Ligand upregulation induced by resveratrol was impaired by pharmacological and genetic disruption of ataxia-telangiectasia mutated kinase, the main regulator of NKG2D-L expression. Leukemia cells treated with resveratrol were more susceptible to killing by NK cells than untreated cells, and the enhanced cytotoxicity of NK cells was blocked by treatment of NK cells with anti-NKG2D mAbs. Interestingly, resveratrol consistently upregulated the NKG2D receptor expression and enhanced NKG2D-mediated functions in resting NK cells obtained from healthy individuals. Therefore, resveratrol has attractive immunotherapeutic potential.

Topics: Anticarcinogenic Agents; Ataxia Telangiectasia Mutated Proteins; Blotting, Western; Cell Cycle Proteins; Cell Line, Tumor; DNA-Binding Proteins; Flow Cytometry; Humans; Killer Cells, Natural; Leukemia; Ligands; NK Cell Lectin-Like Receptor Subfamily K; Protein Serine-Threonine Kinases; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Stilbenes; Tumor Suppressor Proteins; Up-Regulation

Pterostilbene, a naturally occurring structural analog of resveratrol, has been reported to exert antiproliferative and proapoptotic effects in various cancer types. Recently, it has been demonstrated to induce both autophagy and apoptosis in human bladder and breast cancer cell lines. The aim of this study was to evaluate the effects of pterostilbene on HL60 human leukemia cells. Cell morphology was examined using confocal and electron microscopy. Cell viability was determined by MTT, neutral red uptake and trypan blue exclusion assays. LC3 processing was studied based on Western blotting and immunofluorescence analyses. Flow cytometry was used to study cell cycle distribution, phosphatidylserine externalization, caspase activation, disruption of mitochondrial membrane potential and intracellular production of reactive oxygen species. DNA degradation was examined by gel electrophoresis. We found that treatment of HL60 cells with pterostilbene at the IC90 concentration resulted in the G0/G1 cell cycle arrest. Pterostilbene induced conversion of cytosolic LC3-I to membrane-bound LC3-II and accumulation of large LC3-positive vacuolar structures. Pterostilbene also led to phosphatidylserine externalization, internucleosomal DNA fragmentation, caspase activation and disruption of mitochondrial membrane potential. Moreover, it did not induce oxidative stress. Our results suggest that pterostilbene induces accumulation of autophagic vacuoles followed by cell death in HL60 cells.

Topics: Antineoplastic Agents; Autophagy; Caspases; Cell Cycle; Cell Death; Cell Survival; DNA Fragmentation; HL-60 Cells; Humans; Leukemia; Membrane Potential, Mitochondrial; Microtubule-Associated Proteins; Reactive Oxygen Species; Stilbenes; Vacuoles

We studied the effect of riccardin D, a macrocyclic bisbibenzyl, which was isolated from the Chinese liverwort plant, on human leukemia cells and the underlying molecular mechanism. Riccardin D had a significant antiproliferative effect on human leukemia cell lines HL-60, K562 and its multidrug resistant (MDR) counterpart K562/A02 cells, but showed no effect on the topoisomerase-II-deficient HL-60/MX2 cells, as measured by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The pBR322 DNA relaxation assay revealed that riccardin D selectively inhibited the activity of topoisomerase II (topo II). The suppression of topo II activity by riccardin D was stronger than that of etoposide, a known topo II inhibitor. After treatment with riccardin D, nuclear extracts of leukemia K562 and K562/A02 cells left the majority of pBR322 DNA in a supercoiled form. Further examination showed that riccardin D effectively induced HL-60, K562 and K562/A02 apoptosis as evidenced by externalization of phosphatidylserine and formation of DNA ladder fragments. The activation of cytochrome c, caspase-9, caspase-3 and cleaved poly ADP-ribose polymerase (PARP) was also enhanced, as estimated by Western blot analysis. By contrast, riccardin D was unable to induce apoptosis in the topoisomerase-II-deficient HL-60/MX2 cells, indicating that the induction of apoptosis by riccardin D was due to the inhibition of topo II activity. In addition, riccardin D was able to significantly decrease P-glycoprotein (P-gp) expression in K562/A02 cells. Taken together, our data demonstrate that riccardin D is a novel DNA topo II inhibitor which can induce apoptosis of human leukemia cells and that it has therapeutic potential for both regular and MDR strains of leukemia cells.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; Caspase 3; Caspase 9; Cell Proliferation; Cytochromes c; DNA Fragmentation; DNA Topoisomerases, Type II; DNA, Superhelical; Dose-Response Relationship, Drug; Drug Resistance, Multiple; Drug Resistance, Neoplasm; HL-60 Cells; Humans; K562 Cells; Leukemia; Phenyl Ethers; Phosphatidylserines; Poly(ADP-ribose) Polymerases; Stilbenes; Time Factors; Topoisomerase II Inhibitors

Advances in the treatment of acute leukemia have resulted in significantly improved remission rates, although disease relapse poses a significant risk. By utilizing sensitive, non-invasive imaging guidance, detection of early leukemic infiltration and the extent of residual tumor burden after targeted therapy can be expedited, leading to more efficient treatment planning. We demonstrated marked survival benefit and therapeutic efficacy of a new-generation vascular disrupting agent, combretastatin-A1-diphosphate (OXi4503), using reporter gene-imaging technologies and mice systemically administered luc+ and GFP+ human leukemic cells (LCs). Before treatment, homing of double-transduced cells was serially monitored and whole-body cellular distributions were mapped using bioluminescence imaging (BLI). Imaging findings strongly correlated with quantitative GFP expression levels in solid organs/tissues, suggesting that the measured BLI signal provides a highly sensitive and reliable biomarker of tumor tissue burden in systemic leukemic models. Such optical technologies can thereby serve as robust non-invasive imaging tools for preclinical drug discovery and for rapidly screening promising therapeutic agents to establish potency, treatment efficacy and survival advantage. We further show that GFP+ HL-60 cells reside in close proximity to VE-cadherin- and CD31-expressing endothelial cells, suggesting that the perivascular niche may have a critical role in the maintenance and survival of LCs.

Topics: Animals; Antineoplastic Agents; Cell Movement; Cell Tracking; Diphosphates; Genes, Reporter; HL-60 Cells; Humans; Leukemia; Luminescent Measurements; Mice; Stilbenes; Transduction, Genetic; Tumor Burden; Xenograft Model Antitumor Assays

Cuspidan A (1), a new stilbene sestermer consisting of a resveratrol, an oxyresveratrol, and a 3,5-dihydroxyphenylmethanol constituent units and cuspidan B (2), a new tri-cyclic stilbene monomer were isolated from the bark of Gnetum cuspidatum. The structures and configurations of 1 and 2 were elucidated on the basis of 2D-NMR correlations.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Gnetum; Humans; Inhibitory Concentration 50; Leukemia; Magnetic Resonance Spectroscopy; Molecular Structure; Plant Bark; Stilbenes

To address the mechanism of piceatannol in inhibiting TNFα-mediated pathway, studies on piceatannol-treated human leukemia U937 cells were conducted. Piceatannol treatment reduced TNFα shedding and NFκB activation and decreased the release of soluble TNFα into the culture medium of U937 cells. Moreover, ADAM17 expression was down-regulated in piceatannol-treated cells. Over-expression of ADAM17 abrogated the ability of piceatannol to suppress TNFα-mediated NFκB activation. Piceatannol-evoked β-TrCP up-regulation promoted Sp1 degradation, thus reducing transcriptional level of ADAM17 gene in U937 cells. Piceatannol treatment induced p38 MAPK phosphorylation but inactivation of Akt and ERK. In contrast to p38 MAPK inhibitor or restoration of ERK activation, transfection of constitutive active Akt abolished the effect of piceatannol on β-TrCP, Sp1 and ADAM17 expression. Piceatannol-elicited down-regulation of miR-183 expression was found to cause β-TrCP up-regulation. Inactivation of Akt resulted in Foxp3 down-regulation and reduced miR-183 expression in piceatannol-treated cells. Knock-down of Foxp3 and chromatin immunoprecipitating revealed that Foxp3 genetically regulated transcription of miR-183 gene. Taken together, our data indicate that suppression of Akt/Foxp3-mediated miR-183 expression blocks Sp1-mediated ADAM17 expression in piceatannol-treated U937 cells. Consequently, piceatannol suppresses TNFα shedding, leading to inhibition of TNFα/NFκB pathway.

Topics: ADAM Proteins; ADAM17 Protein; Base Sequence; Chromatin Immunoprecipitation; DNA Primers; Down-Regulation; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Forkhead Transcription Factors; Humans; Leukemia; MicroRNAs; NF-kappa B; Proto-Oncogene Proteins c-akt; RNA Interference; Sp1 Transcription Factor; Stilbenes; Tumor Necrosis Factor-alpha; U937 Cells

Pterostilbene, a polyphenolic compound present in grapes and other fruits, has been demonstrated to inhibit growth and induce apoptosis and autophagy in some cancer cell types. We found that pterostilbene at the IC(90) concentration of 44 µM inhibited proliferation and induced apoptosis in MOLT4 human leukemia cells. Treatment with pterostilbene resulted in a transient accumulation of cells in the G(0)/G(1)-cell cycle phase followed by the S-phase arrest. Pterostilbene-induced apoptotic death of MOLT4 cells was mediated by caspase-3 activation and was accompanied by the disruption of mitochondrial membrane potential, phosphatidylserine externalization and internucleosomal DNA fragmentation. Our results suggest that pterostilbene could serve as a potential additional chemotherapeutic agent for the treatment of leukemia.

Topics: Apoptosis; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Survival; Drug Screening Assays, Antitumor; Humans; Intracellular Space; Leukemia; Reactive Oxygen Species; Stilbenes

Although piceatannol (PIC) is known to mediate anti-cancer, anti-inflammatory, and anti-oxidant activities, little is known about the mechanism of PIC in terms of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. In this study, we examined whether combined treatment with PIC and TRAIL synergistically induces apoptosis in THP-1 leukemia cells. Results indicate that PIC substantially enhances TRAIL-induced cell death including DNA fragmentation and poly(ADP-ribose) polymerase cleavage. Consistent with TRAIL-induced apoptosis, PIC significantly increased the mRNA and protein expression levels of DR5, a death receptor of TRAIL. Further, PIC enhanced DR5 promoter activity via Sp1 activation. Interestingly, the DR5 chimera antibodies significantly suppressed PIC and TRAIL-mediated apoptosis. The inhibitor of ERK also decreased PIC and TRAIL-induced apoptosis by blocking DR5 expression. In conclusion, our results suggest that PIC sensitizes TRAIL-induced-apoptosis via Sp1- and ERK-dependent DR5 up-regulation.

Topics: Antineoplastic Agents; Apoptosis; Blotting, Western; Cell Survival; Chromatin Immunoprecipitation; DNA Fragmentation; Drug Synergism; Extracellular Signal-Regulated MAP Kinases; HL-60 Cells; Humans; Leukemia; Phosphorylation; Receptors, TNF-Related Apoptosis-Inducing Ligand; Sp1 Transcription Factor; Stilbenes; TNF-Related Apoptosis-Inducing Ligand; U937 Cells; Up-Regulation

It was reported recently that resveratrol could sensitize a number of cancer cells to the antitumoral effects of some conventional chemotherapy drugs. The current study was designed to investigate whether resveratrol could sensitize leukemic cells to proteasome inhibitors.. Leukemic cells were treated with MG132 alone or in combination with resveratrol. Cell viability was investigated using MTT assay, and induction of apoptosis and cell cycle distribution was measured using flow cytometry. Western blot and real-time RT-PCR were used to investigate the expression of FOXO1 and p27Kip1. CHIP was performed to investigate the binding of FOXO1 to the p27 Kip1 promoter.. Resveratrol strongly reduced cytotoxic activities of proteasome inhibitors against leukemic cells. MG132 in combination with resveratrol caused cell cycle blockade at G1/S transition via p27Kip1 accumulation. Knockdown of p27Kip1 using siRNA dramatically attenuated the protective effects of resveratrol on cytotoxic actions of proteasome inhibitors against leukemic cells. Resveratrol induced FOXO1 expression at the transcriptional level, while MG132 increased nuclear distribution of FOXO1. MG132 in combination with resveratrol caused synergistic induction of p27Kip1 through increased recruitment of FOXO1 on the p27Kip1 promoter.. Resveratrol may have the potential to negate the cytotoxic effects of proteasome inhibitors via regulation of FOXO1 transcriptional activity and accumulation of p27Kip1.

Topics: Apoptosis; Cell Line, Tumor; Cyclin-Dependent Kinase Inhibitor p27; Cytoprotection; Cytotoxins; Drug Evaluation, Preclinical; Drug Resistance, Neoplasm; Enzyme Inhibitors; Forkhead Box Protein O1; Forkhead Transcription Factors; Gene Expression Regulation, Leukemic; Humans; K562 Cells; Leukemia; Proteasome Inhibitors; Resveratrol; Stilbenes; U937 Cells

Digalloylresveratrol (DIG) is a newly synthesized agent aimed to combine the biological effects of the natural compounds, gallic acid and resveratrol, which both are free radical scavengers exhibiting anticancer activity. In this study, we investigated the effects of DIG on the growth of human HL-60 leukemia cells and on the colony formation of human BxPC-3 and PANC-1 pancreatic cancer cells. DIG was applied alone and in combination with arabinofuranosylcytosine (Ara-C) or difluorodeoxycytidine (dFdC), depending on the cell line employed. All IC(50) values observed were in the low micromolar range rendering DIG a promising antitumor compound in vitro. Considering the combination experiments, DIG yielded additive effects with Ara-C in HL-60 cells and-to a lesser extent-with dFdC in BxPC-3 and PANC-1 cells. Owing to our results, DIG may be further investigated in vitro and in animals.

Topics: Antineoplastic Combined Chemotherapy Protocols; Cell Proliferation; Cytarabine; Deoxycytidine; Gallic Acid; Gemcitabine; HL-60 Cells; Humans; Leukemia; Pancreatic Neoplasms; Stilbenes; Tumor Stem Cell Assay

The stilbenoids, arachidin-1 (Ara-1), arachidin-3, isopentadienylresveratrol, and resveratrol, have been isolated from germinating peanut kernels and characterized as antioxidant and anti-inflammatory agents. Resveratrol possesses anticancer activity, and studies have indicated that it induces programmed cell death (PCD) in human leukemia HL-60 cells. In this study, the anticancer activity of these stilbenoids was determined in HL-60 cells. Ara-1 had the highest efficacy in inducing PCD in HL-60 cells, with an approximately 4-fold lower EC50 than resveratrol. Ara-1 treatment caused mitochondrial membrane damage, activation of caspases, and nuclear translocation of apoptosis-inducing factor, resulting in chromosome degradation and cell death. Therefore, Ara-1 induces PCD in HL-60 cells through caspase-dependent and caspase-independent pathways. Ara-1 demonstrates its efficacy as an anticancer agent by inducing caspase-independent cell death, which is an alternative death pathway of cancer cells with mutations in key apoptotic genes. These findings indicate the merits of screening other peanut stilbenoids for anticancer activity.

Topics: Antineoplastic Agents; Apoptosis; Arachis; HL-60 Cells; Humans; Leukemia; Plant Extracts; Seeds; Stilbenes

Three new flavonoid glycosides (cissosides I, II, and III) and a new benzofuran-type stilbene (cissusin) were isolated from the methanolic extract of the aerial parts of Cissus sicyoides cultivated in Brazil. Their structures were elucidated on the basis of chemical and physicochemical evidence. The inhibitory effects of the isolated constituents on the release of beta-hexosaminidase as a marker of degranulation in rat basophilic leukemia (RBL-2H3) cells were examined. Cissusin, flavonols (kaempferol, quercetin), flavones (7,3',4'-trihydroxyflavone, lanceolatin B), pterocarpanes (homopterocarpin), chalcones (isoliquiritigenin, E-7-O-methylpongamol), and tryptanthrin markedly inhibited the release of beta-hexosaminidase.

Topics: Animals; Benzofurans; beta-N-Acetylhexosaminidases; Cell Degranulation; Cell Line, Tumor; Cissus; Flavonoids; Herbal Medicine; Leukemia; Molecular Conformation; Rats; Stilbenes

The crucial role of the microtubule in cell division has identified tubulin as a target for the development of therapeutics for cancer; in particular, tubulin is a target for antineoplastic agents that act by interfering with the dynamic stability of microtubules. A molecular modeling study was carried out to accurately represent the complex structure and the binding mode of a new class of stilbene-based tubulin inhibitors that bind at the alphabeta-tubulin colchicine site. Computational docking along with HINT (Hydropathic INTeractions) score analysis fitted these inhibitors into the colchicine site and revealed detailed structure-activity information useful for inhibitor design. Quantitative analysis of the results was in good agreement with the in vitro antiproliferative activity of these derivatives (ranging from 3 nM to 100 muM) such that calculated and measured free energies of binding correlate with an r(2) of 0.89 (standard error +/- 0.85 kcal mol(-1)). This correlation suggests that the activity of unknown compounds may be predicted.

Topics: Antineoplastic Agents; Binding Sites; Cell Line, Tumor; Cell Proliferation; Colchicine; Computer Simulation; Drug Evaluation, Preclinical; Humans; Leukemia; Microtubules; Stilbenes; Structure-Activity Relationship; Thermodynamics; Tubulin Modulators

There is great interest in the potential chemopreventive activity of resveratrol against human cancers. However, there are conflicting results on its growth inhibitory effect on normal cells. This project examined the differential effect of resveratrol at physiologically relevant concentrations on nonmalignant (WIL2-NS) and malignant (HL-60) cell lines and compared the underlying mechanisms via cell cycle modulation, apoptosis induction, and genotoxicity potential. Twenty-four hours of exposure to resveratrol was toxic to WIL2-NS and HL-60 cells in a dose-dependent manner. WIL2-NS cells regrew 5 times more than HL-60 cells by 120 h after the removal of 100 microM resveratrol (p < 0.05). Furthermore, significant alterations in cell cycle kinetics were induced by resveratrol in HL-60 cells, but were to a lesser extent for WIL2-NS cells. The proportion of apoptosis was also 3 times higher in HL-60 cells as compared to WIL2-NS cells for 100 microM resveratrol (p < 0.05). In conclusion, resveratrol preferentially inhibited the growth of HL-60 cells via cell cycle modulation and apoptosis induction and subsequently directed the cells to irreversible cell death, whereas the effect on WIL2-NS cells was largely reversible.

Topics: Anticarcinogenic Agents; Apoptosis; B-Lymphocytes; Cell Cycle; Cell Division; Cell Line; HL-60 Cells; Humans; Leukemia; Micronucleus Tests; Resveratrol; Stilbenes

4-(4-Bromophenyl)-2,3-dihydro-N,3-bis(3,4,5-trimethoxyphenyl)-2-oxoidmi-dazole-1-carboxamide (MZ3) is one of the synthesized combretastatin-A-4 analogues and has been reported that it displayed a promising specific activity against leukemia cell lines. Our purpose was to investigate the mechanism of MZ3's cytotoxicity.. Cytotoxicity was measured by MTT method, apoptosis was measured by flow cytometry. DNA fragmentation was tested by agarose gel electrophoresis. Mitochondrial membrane potential (DeltaPsim) was detected by JC1 staining and flow cytometry, while intracellular reactive oxygen species (ROS) was detected by 5-(and-6)-carboxy-2'-7'-dichlorofluorescin diacetate staining and flow cytometry. Protein expression was analyzed by western blotting. In vivo activity of MZ3 was assayed through severe combined immunodeficiency (SCID) mice model of human leukemia engrafts.. MZ3 exhibited high anti-cancer activity in six leukemia cell lines, including two drug-resistant cell lines. MZ3 induced DNA fragmentation, and caused an elevation of ROS and a loss of DeltaPsim in HL60 cells. MZ3 also induced the activation of caspase-3, influenced the expression of Bcl-2 family members, MAPKs and other proteins relative to mitochondria-induced apoptosis. In addition, N-acetylcysteine cannot inhibit HL60 cell apoptosis caused by MZ3. Furthermore, a prolonged survival time was observed after treatment with MZ3 in SCID mice model of human leukemia engrafts.. MZ3 is a potent compound against leukemia cell lines both in vitro and in vivo, and the mitochondrial pathway mediated by Bcl-2 protein family and MAPKs might be involved in signaling MZ3-induced apoptosis.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Survival; DNA Fragmentation; DNA, Neoplasm; Drug Screening Assays, Antitumor; Formazans; HL-60 Cells; Humans; Imidazoles; K562 Cells; Leukemia; Longevity; Membrane Potential, Mitochondrial; Mice; Mice, SCID; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; Stilbenes; Tetrazolium Salts

trans-Resveratrol (t-RES) is one of the most relevant and extensively investigated stilbenes with a broad spectrum of biological activities. In contrast to the detailed knowledge of t-RES activities in biological systems, much less is known about the effects of higher hydroxylated stilbenes. Therefore, the aim of this study was to evaluate the protective effects (antioxidant activities) of t-RES and two analogues: the natural metabolite piceatannol (PCA) and the synthesized 3,3',4,4',5,5'-hexahydroxy-trans-stilbene (HHS) against H2O2-induced DNA damage in leukemic L1210, K562 and HL-60 cells using single-cell gel electrophoresis (SCGE). After 24 h pre-treatment of cells all compounds investigated significantly inhibited the incidence of DNA single strand breaks induced by H2O2. The protective effects of PCA and HHS in L1210 cells and of HHS in HL-60 cells were significantly higher compared to the activity of t-RES (+P < 0.05). In K562 cells the differences of the antioxidant activities of PCA and HHS, and of PCA in HL-60 cells were of much higher significance when compared to t-RES (++P < 0.01). In conclusion, we can prove that all stilbenes investigated, t-RES, PCA, and HHS, manifested potent antioxidant effects on three leukemic cell lines and the presence of ortho-dihydroxy structures enhanced the protective effect against DNA damage caused by .OH radicals.

Topics: Animals; Antineoplastic Agents, Phytogenic; Antioxidants; Cell Survival; DNA Damage; HL-60 Cells; Humans; Hydrogen Peroxide; K562 Cells; Leukemia; Mice; Oxidants; Protein-Tyrosine Kinases; Resveratrol; Ribonucleotide Reductases; Stilbenes

Naturally occurring dietary compound resveratrol (RES), possessing chemopreventive and cytostatic properties, has been shown as potent sensitizer for apoptosis induced by a variety of anticancer drugs. Cell cycle analysis in sensitive promyelocytic leukemia HL60 cell line and its multidrug-resistant variant HL60/VCR (P-gp positive) treated with RES resulted in cell cycle arrest in S-phase in both cell variants. Flow cytometry measurements showed diverse activities of RES in combination with anticancer drugs doxorubicin (DOX), cycloheximide (CHX), busulfan (BUS), gemcitabine (GEM) and paclitaxel (PTX), in some cases resulting in apoptosis induction, preferentially at the expense of S-phase. Thus, RES could become a candidate to enhance the efficacy of combination anticancer therapy in a variety of human cancer cells inclusive leukemias.

Topics: Anticarcinogenic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Busulfan; Cell Cycle; Cell Line, Tumor; Cycloheximide; Deoxycytidine; Doxorubicin; Drug Resistance, Neoplasm; Flow Cytometry; Gemcitabine; Humans; Leukemia; Paclitaxel; Resveratrol; Stilbenes

Ionizing radiation is widely used in radiotherapy, in order to promote an apoptotic response in cancerous cells. Since the need to find new substances that would enhance the radiation-induced apoptosis in cancerous cells is great, we studied the effect of epigallocatechin-gallate (EGCG, a tea component), resveratrol (a wine component) and curcuma on cell proliferation and radiation-induced apoptosis in the human leukaemic cell line, EOL-1, derived from a patient with eosinophilic leukaemia. Cells were X-irradiated with 0, 2, 4, 6 or 8 Gy and cultured in the presence of EGCG, resveratrol or curcuma (concentrations ranging from 0 to 200 microM) for 1, 2 or 3 days of culture. Cell proliferation was measured using trypan blue exclusion. Apoptosis was evaluated using light microscopy (morphology study after May-Grunwald Giemsa staining) and flow cytometry (annexin-V staining). Irradiation alone induced a dose-related reduction in cell proliferation and the appearance of polyploid cells in EOL-1 cells. Additionally, EOL-1 cells underwent a dose-related increase of apoptosis which, from the second day on, was accompanied by a dose-related increase of necrosis. When cells were exposed to EGCG, resveratrol or curcuma alone, a decrease in cell proliferation was observed, beginning from 25 microM EGCG and 50 microM resveratrol and curcuma, while an increase in the percentage of apoptotic cells was noted from 50 microM EGCG, 100 microM resveratrol and curcuma in EOL-1 cells, after only one day of culture. Simultaneous exposure to X-irradiation and, EGCG, resveratrol or curcuma resulted in a synergistic decrease of cell proliferation as well as in a synergistic increase of apoptosis and necrosis. These results suggest that, depending on the concentration, EGCG, resveratrol and curcuma enhance radiation-induced apoptosis in the leukaemic cell line, EOL-1 (EGCG >resveratrol >curcuma). In order to further characterise the radiation-induced apoptosis of this leukaemic cell line, other flow cytometrical analyses are in progress.

Topics: Annexin A5; Apoptosis; Catechin; Cell Line, Tumor; Cell Membrane; Cell Proliferation; Curcuma; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Eosinophils; Flow Cytometry; Humans; Leukemia; Necrosis; Plant Extracts; Radiation Tolerance; Radiation, Ionizing; Resveratrol; Signal Transduction; Stilbenes; Time Factors; X-Rays

Anticarcinogenic effects of polyphenolic compounds in fruits and vegetables are well established. Although polyphenols naturally occur as combinations, little information is available regarding possible synergistic or antagonistic biochemical interactions between compounds. Identifying potential interactions between polyphenols may provide information regarding the efficiency of polyphenol-containing foods in cancer prevention. The objective of this study was to investigate the interactions of ellagic acid and quercetin with resveratrol, polyphenols which occur in muscadine grapes, with the hypothesis that the selected polyphenols would interact synergistically in the induction of apoptosis and reduction of cell growth in human leukemia cells (MOLT-4). To test this hypothesis, alterations in cell cycle kinetics, proliferation, and apoptosis (caspase-3 activity) were examined after incubation with ellagic acid, quercetin, and resveratrol as single compounds and in combination. Results showed a more than additive interaction for the combination of ellagic acid with resveratrol and furthermore, significant alterations in cell cycle kinetics induced by single compounds and combinations were observed. An isobolographic analysis was performed to assess the apparent synergistic interaction for the combinations of ellagic acid with resveratrol and quercetin with resveratrol in the induction of caspase 3 activity, confirming a synergistic interaction with a combination index of 0.64 for the combination of ellagic acid and resveratrol and 0.68 for quercetin and resveratrol. Results indicate that the anticarcinogenic potential of foods containing polyphenols may not be based on the effects of individual compounds, but may involve a synergistic enhancement of the anticancer effects.

Topics: Anticarcinogenic Agents; Apoptosis; Caspase 3; Cell Cycle; Cell Line, Tumor; Drug Synergism; Ellagic Acid; Humans; Leukemia; Quercetin; Resveratrol; Stilbenes

Pterostilbene and 3,5-hydroxypterostilbene are the natural 3,5-dimethoxy analogs of trans-resveratrol and piceatannol, two compounds which can induce apoptosis in tumor cells. In previous studies we demonstrated the importance of a 3,5-dimethoxy motif in conferring pro-apoptotic activity to stilbene based compounds so we now wanted to evaluate the ability of pterostilbene and 3,5-hydroxypterostilbene in inducing apoptosis in sensitive and resistant leukemia cells. When tested in sensitive cell lines, HL60 and HUT78, 3'-hydroxypterostilbene was 50-97 times more potent than trans-resveratrol in inducing apoptosis, while pterostilbene appeared barely active. However, both compounds, but not trans-resveratrol and piceatannol, were able to induce apoptosis in the two Fas-ligand resistant lymphoma cell lines, HUT78B1 and HUT78B3, and the multi drug-resistant leukemia cell lines HL60-R and K562-ADR (a Bcr-Abl-expressing cell line resistant to imatinib mesylate). Of note, pterostilbene-induced apoptosis was not inhibited by the pancaspase-inhibitor Z-VAD-fmk, suggesting that this compound acts through a caspase-independent pathway. On the contrary, 3'-hydroxypterostilbene seemed to trigger apoptosis through the intrinsic apoptotic pathway: indeed, it caused a marked disruption of the mitochondrial membrane potential delta psi and its apoptotic effects were inhibited by Z-VAD-fmk and the caspase-9-inhibitor Z-LEHD-fmk. Moreover, pterostilbene and 3'-hydroxypterostilbene, when used at concentrations that elicit significant apoptotic effects in tumor cell lines, did not show any cytotoxicity in normal hemopoietic stem cells. In conclusion, our data show that pterostilbene and particularly 3'-hydroxypterostilbene are interesting antitumor natural compounds that may be useful in the treatment of resistant hematological malignancies, including imatinib, non-responsive neoplasms.

Topics: Apoptosis; Cell Line, Tumor; fas Receptor; Genes, abl; Genes, MDR; Humans; Leukemia; Phenols; Stilbenes

Efficient apoptotic signaling is a function of a permissive intracellular milieu created by a decrease in the ratio of superoxide to hydrogen peroxide and cytosolic acidification. Resveratrol (RSV) triggers apoptosis in some systems and inhibits the death signal in others. In this regard, the inhibitory effect on hydrogen peroxide-induced apoptosis is attributed to its antioxidant property. We provide evidence that exposure of human leukemia cells to low concentrations of RSV (4-8 micro M) inhibits caspase activation, DNA fragmentation, and translocation of cytochrome c induced by hydrogen peroxide or anticancer drugs C2, vincristine, and daunorubicin. Interestingly, at these concentrations, RSV induces an increase in intracellular superoxide and inhibits drug-induced acidification. Blocking the activation of NADPH oxidase complex neutralized RSV-induced inhibition of apoptosis. Furthermore, our results implicate intracellular hydrogen peroxide as a common effector mechanism in drug-induced apoptosis that is inhibited by preincubation with RSV. Interestingly, decreasing intracellular superoxide with the NADPH oxidase inhibitor diphenyliodonium reversed the inhibitory effect of RSV on drug-induced hydrogen peroxide production. These data show that low concentrations of RSV inhibit death signaling in human leukemia cells via NADPH oxidase-dependent elevation of intracellular superoxide that blocks mitochondrial hydrogen peroxide production, thereby resulting in an intracellular environment nonconducive for death execution.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Daunorubicin; HL-60 Cells; Humans; Hydrogen Peroxide; Leukemia; Mitochondria; NADPH Oxidases; Oxidation-Reduction; Resveratrol; Stilbenes; Superoxides; Vincristine

The in vitro effects of resveratrol (RES) on apoptotic pathway in human chronic myeloid (K562) and acute lymphoblastic (HSB-2) leukemia cells were investigated. RES treatment of both cell types significantly and irreversibly inhibited their growth, associated with extensive apoptosis and increase in hypodiploid cells. Cell cycle analysis showed accumulation in G(1) phase in HSB-2 drug exposed cells, while only K562-treated cells exhibited a marked accumulation in S phase with a concomitant decrease in G(1) and G(2)/M at 24 h. Moreover, RES caused internucleosomal DNA fragmentation, even if K562 cells were found less sensitive to the drug, as compared to HSB-2 cells, which also reacted earlier to the treatment. RES-induced apoptosis was associated with an increase of Bax expression and a marked release of cytochrome c from mitochondria. Interestingly, K562 cells exhibited a basal content of glutathione 10-fold that of HSB-2 cells, which increased after 24-48 h RES exposure, together with increment of glutathione reductase and peroxidase activities. However, the major resistance to apoptosis of K562 cells cannot be attributed to their higher pool of reducing power, since neither the inhibition of glutathione synthesis by buthionine sulphoximine nor glutathione depletion by diethylmaleate, sensitized these cells. In addition, glutathione enrichment of HSB-2 cells by N-acetylcysteine did not prevent the apoptotic effects of RES. Our data indicate that RES commitment to apoptosis in both cell lines is independent from the intracellular content of glutathione, while it is associated with either the enhanced expression of Bax and cytochrome c release.

Topics: Antioxidants; Apoptosis; bcl-2-Associated X Protein; Caspases; Cell Proliferation; Cell Survival; Cytochromes c; Enzyme Activation; Glutathione; Humans; K562 Cells; Leukemia; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; Resveratrol; Stilbenes; Tumor Cells, Cultured

Resveratrol has been shown to possess antioxidant and anticancer activities, but little is known on the effect of resveratrol derivatives. Recently we have isolated resveratrol and its dimers and trimers from peony (Paeonia lactiflora) seeds, and reported their strong antioxidant and cytotoxic activity. In the present study, we have evaluated cellular effects of resveratrol derivatives; viniferin, gnetin H, and suffruticosol B on the proliferation and apoptosis in HL-60 cells in vitro. All resveratrol and its derivatives reduced viability of HL-60 cells in a dose-dependent manner with their IC(50) values of 20-90 microM. Ascending orders of IC(50) values were suffruticosol B, gnetin H, viniferin and resveratrol respectively. HL-60 cells treated with the four stilbenes exhibited the distinct morphological changes characteristics of cell apoptosis such as chromatin condensation, apoptotic bodies, and DNA fragmentations. A time-dependent histogram of the cellular DNA analyzed by flow cytometry revealed a rapid increase in subdiploid cells and a concomitant decrease in diploid cells exposed to 100 microM resveratrol for 0-24 h. Cells treated with 25 microM of resveratrol, viniferin, gnetin H, and suffruticosol B for 24 h resulted in increment of sub-G1 population by 51, 5, 11 and 59%, respectively. Treatment of cells with 0-20 microM resveratrol for 5 h produced a concentration-dependent decrease in cytochrome P450 (CYP) 1B1 mRNA levels. Suffruticosol B also suppressed CYP1B1 gene expression. These results demonstrated that resveratrol oligomers also strongly suppressed HL-60 cell proliferation, and induced DNA damage. In addition, CYP1B1 gene supression may suggest an involvement in the resveratrol-induced apoptosis in HL-60 cells.

Topics: Apoptosis; Aryl Hydrocarbon Hydroxylases; Cell Cycle; Cytochrome P-450 CYP1B1; Cytochrome P-450 Enzyme System; Flow Cytometry; Gene Expression Regulation, Neoplastic; HL-60 Cells; Humans; Leukemia; Resveratrol; RNA, Messenger; Stilbenes

It is often postulated that trans-3,4',5-trihydroxystilbene (resveratrol, RES) exhibits cell growth regulatory and chemopreventive activities. However, mechanisms by which this polyphenol inhibits tumor cell growth, and its therapeutic potential are poorly understood. Using various human leukemia cells, we have first defined the anti-tumoral doses of this compound. RES inhibited the proliferation and induced the apoptosis of all tested lymphoid and myeloid leukemia cells with IC(50) = 5-43 microM. Prior to apoptosis, RES-induced caspase activity in a dose-dependent manner and cell cycle arrest in G(2)/M-phase, correlating with a significant accumulation of cyclins A and B. Leukemia cell death with RES required both caspase-dependent and -independent proteases, as it was significantly inhibited by simultaneous addition of Z-VAD-FMK and leupeptin to these cultures. While RES did not affect non-activated normal lymphocytes, this agent decreased the growth and induced the apoptosis of cycling normal human peripheral blood lymphocytes at lower concentrations (IC(50) <8 microM) than those required for most leukemia cells. RES also induced the apoptosis of early normal human CD34(+) cells and decreased the number of colonies generated by these precursor cells in a dose-dependent manner (IC(50) = 60 microM). Together, the data point to the complexity of RES-mediated signaling pathways and revealed the high anti-proliferative and proapoptotic activities of RES in normal cycling hemopoietic cells.

Topics: Apoptosis; Bone Marrow Cells; Cell Division; Humans; Leukemia; Resveratrol; Stilbenes

Resveratrol (trans-3,4',5-trihydroxystilbene), a polyphenol found in grapes and grape wine, has been reported to exhibit cardioprotective and chemopreventive activity against chemical carcinogenesis. It has also been shown to have growth inhibitory activity toward solid tumors in vivo. However, the antitumor activity of resveratrol against hematologic tumors in vivo has not been examined. In this study, the antileukemic activity of resveratrol in vitro and in vivo was examined using a mouse myeloid leukemia cell line (32Dp210). Treatment of 32Dp210 leukemia cells with resveratrol at micromolar concentrations (25-50 micromol/L) significantly and irreversibly inhibited their clonal growth in vitro. The clonal growth inhibition by resveratrol was associated with extensive cell death and an increase in hypodiploid (sub-G1) cells. Resveratol caused internucleosomal DNA fragmentation, suggesting apoptosis as the mode of cell death in 32Dp210 cells. DNA fragmentation was associated with activation of caspase-3, because cleavage of procaspase-3 was detected in resveratrol-treated cells. Although 32Dp210 cells treated with resveratrol in vitro did not produce leukemia in vivo, only a weak antileukemic effect of resveratrol was observed when administered orally. At doses of 8 mg or 40 mg/kg body daily, five times/wk, resveratrol did not affect the survival of mice injected with leukemia cells. Weak potential antileukemic activity of resveratrol was suggested only at a dose of 80 mg/kg body (2 survivors of 14 mice treated). Thus, despite strong antiproliferative and proapoptotic activities of resveratrol against 32Dp210 cells in vitro, a potential antileukemia effect in vivo, if present, occurs only in a small fraction of mice.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Flavonoids; In Vitro Techniques; Leukemia; Male; Mice; Mice, Inbred C3H; Neoplasm Transplantation; Phenols; Polymers; Polyphenols; Resveratrol; Stilbenes; Tumor Cells, Cultured; Vitis