stilbenes and Melanoma

Melanoma is one of the deadliest forms of skin cancer, having a high metastatic potential and afflicting all age groups. The need for successful preventative measures is particularly urgent as metastatic melanoma is largely incurable. The beneficial role of nutrition and other natural compounds in the prevention and treatment of melanoma has been clearly demonstrated in the past, and is an exciting source for potential therapies in the future.. We sought to review updates in the current literature regarding new developments in the relationship between nutrition and melanoma risk and treatment.. Articles in the public domain regarding the impact of diet, grape seed proanthocyanidins, selenium, vitamin D, vitamin E, epigallocatechin-3-gallate, resveratrol, rosmarinic acid, lycopene, and fig latex on melanoma were included.. Grape seed proanthocyanidins, epigallocatechin-3-gallate, resveratrol, rosmarinic acid, lycopene, and fig latex have demonstrated clear anticancer effects toward melanoma. The roles of selenium, vitamin D, and vitamin E, however, have been more controversial.. None.. The role of natural compounds in the future of melanoma prevention and treatment is promising and one that is worthy of further exploration.

Topics: Antioxidants; Carotenoids; Catechin; Diet; Grape Seed Extract; Humans; Lycopene; Melanoma; Nutrition Policy; Proanthocyanidins; Resveratrol; Selenium; Skin Neoplasms; Stilbenes; Vitamin D; Vitamin E

Melanoma is the most dangerous type of skin cancer. Despite the rise of public awareness, the incidence rate among the white population has been rising constantly for several decades. Systematic improvement in knowledge about the biology of pigment cells and molecular mechanisms of their neoplastic transformation has enhanced the possibility of melanoma chemoprevention. Hence, chemopreventive agents that prevent, inhibit, or reverse melanoma development are being investigated intensively. Among synthetic compounds, especially well studied are lipid-lowering drugs and cyclooxygenase inhibitors. Substances found in everyday diet, such as genistein, apigenin, quercetin, resveratrol, and curcumin may also have potential chemopreventive qualities. However, studies examining the chemopreventive activity of these compounds have shown widely varying results. Early reports on the possible chemopreventive activity of statins and fibrates were not proved by the results of randomized clinical trials. Similarly, case-control studies examining the influence of NSAIDs on the risk of melanoma do not confirm the antitumor activity of cyclooxygenase inhibitors. Further clinical trials involving carefully selected target populations as well as the identification of specific biomarkers of prognostic and predictive value seem to be essential for the evaluation of the chemopreventive activity of the studied substances.

Topics: Aminoquinolines; Anti-Inflammatory Agents, Non-Steroidal; Anticarcinogenic Agents; Cell Line, Tumor; Cell Transformation, Neoplastic; Chemoprevention; Curcumin; Flavonoids; Humans; Imiquimod; Melanoma; Melanoma, Cutaneous Malignant; Pigmentation; Randomized Controlled Trials as Topic; Resveratrol; Retinoids; Risk; Skin; Skin Neoplasms; Stilbenes; Tea; Treatment Outcome; Vitamin D

The vascular disrupting agent combretastatin A4 phosphate (CA4P) causes major regression of animal tumours when given as combination therapy.. Patients with advanced cancer refractory to standard therapy were treated with CA4P as a 10-min infusion, 20 h before carboplatin, paclitaxel, or paclitaxel, followed by carboplatin.. Combretastatin A4 phosphate was escalated from 36 to 54 mg m(-2) with the carboplatin area under the concentration curve (AUC) 4-5, from 27 to 54 mg m(-2) with paclitaxel 135-175 mg m(-2), and from 54 to 72 mg m(-2) with carboplatin AUC 5 and paclitaxel 175 mg m(-2). Grade 3 or 4 neutropenia was seen in 17%, and thrombocytopenia only in 4% of 46 patients. Grade 1-3 hypertension (26% of patients) and grade 1-3 tumour pain (65% of patients) were the most typical non-haematological toxicities. Dose-limiting toxicity of grade 3 hypertension or grade 3 ataxia was seen in two patients at 72 mg m(-2). Responses were seen in 10 of 46 (22%) patients with ovarian, oesophageal, small-cell lung cancer, and melanoma.. The combination of CA4P with carboplatin and paclitaxel was well tolerated in the majority of patients with adequate premedication and had antitumour activity in patients who were heavily pretreated.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Ataxia; Carboplatin; Carcinoma, Small Cell; Dose-Response Relationship, Drug; Esophageal Neoplasms; Female; Humans; Infusions, Intravenous; Life Expectancy; Lung Neoplasms; Male; Melanoma; Middle Aged; Neoplasms; Ovarian Neoplasms; Paclitaxel; Patient Selection; Stilbenes

Vascular disrupting agents (VDA) cause acute shutdown of abnormal established tumor vasculature, followed by massive intratumoral hypoxia and necrosis. However, a viable rim of tumor tissue invariably remains from which tumor regrowth rapidly resumes. We have recently shown that an acute systemic mobilization and homing of bone marrow-derived circulating endothelial precursor (CEP) cells could promote tumor regrowth following treatment with either a VDA or certain chemotherapy drugs. The molecular mediators of this systemic reactive host process are unknown. Here, we show that following treatment of mice with OXi-4503, a second-generation potent prodrug derivative of combretastatin-A4 phosphate, rapid increases in circulating plasma vascular endothelial growth factor, stromal derived factor-1 (SDF-1), and granulocyte colony-stimulating factor (G-CSF) levels are detected. With the aim of determining whether G-CSF is involved in VDA-induced CEP mobilization, mutant G-CSF-R(-/-) mice were treated with OXi-4503. We found that as opposed to wild-type controls, G-CSF-R(-/-) mice failed to mobilize CEPs or show induction of SDF-1 plasma levels. Furthermore, Lewis lung carcinomas grown in such mice treated with OXi-4503 showed greater levels of necrosis compared with tumors treated in wild-type mice. Evidence for rapid elevations in circulating plasma G-CSF, vascular endothelial growth factor, and SDF-1 were also observed in patients with VDA (combretastatin-A4 phosphate)-treated cancer. These results highlight the possible effect of drug-induced G-CSF on tumor regrowth following certain cytotoxic drug therapies, in this case using a VDA, and hence G-CSF as a possible therapeutic target.

Topics: Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Bevacizumab; Chemokine CXCL12; Diphosphates; Endothelial Cells; Granulocyte Colony-Stimulating Factor; Hematopoietic Stem Cell Mobilization; Humans; Melanoma; Mice; Mice, Inbred C57BL; Mice, Nude; Mice, Transgenic; Neoplasms; Prodrugs; Stem Cells; Stilbenes; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

Melanoma is the most life-threatening and aggressive class of skin malignancies. The incidence of melanoma has steadily increased. Metastatic melanoma is greatly resistant to standard antimelanoma treatments such as chemotherapy, and the 5-year survival rate of cases with melanoma who have a metastatic form of the disease is less than 10%. The contributing role of apoptosis, angiogenesis and autophagy in the pathophysiology of melanoma has been previously demonstrated. Thus, it is extremely urgent to search for complementary therapeutic approaches that could enhance the quality of life of subjects and reduce treatment resistance and adverse effects. Resveratrol, known as a polyphenol component present in grapes and some plants, has anti-cancer properties due to its function as an apoptosis inducer in tumor cells, and anti-angiogenic agent to prevent metastasis. However, more clinical trials should be conducted to prove resveratrol efficacy. Herein, for the first time, we summarize the current knowledge of anti-cancerous activities of resveratrol in melanoma.

Topics: Apoptosis; Humans; Melanoma; Quality of Life; Resveratrol; Skin Neoplasms; Stilbenes

For therapy of skin cancer, transdermal administration has been a potential way to enhance chemotherapy. However, the drug delivery efficacy remained unsatisfactory because of the physiological barriers from the skin to the tumor, which hindered the effect of 3,5,4'-trimethoxy-trans-stilbene (BTM), a drug that has toxicity to cancer. Herein, we prepared an oil-in-water (O/W) microemulsion to load BTM (BTM-ME) for transdermal therapy of melanoma. BTM-ME was characterized by size, zeta potential, and polymer disperse index (PDI). B16F10 melanoma cell line was used for cell experiments and animal models. And cell uptake, viability assay, and flow cytometry were to test the cell internalization and the ability of BTM-ME to induce cancer cell apoptosis. Skin penetration testing was to detect its penetration efficiency to the skin. And tumor-bearing mice were used to prove the improvement of anti-cancer efficacy of BTM-ME with the combination of Taxol. BTM was successfully loaded in O/W microemulsion, with a drug loading capacity of 24.82 mg/mL. BTM-ME can penetrate the skin and increase the retention of BTM in the epidermis. And the combination of Taxol and BTM-ME effectively suppressed tumor growth and has lower toxicity to normal organs. BTM-ME provides adjuvant therapy to cutaneous melanoma and the combination of Taxol and BTM-ME has the clinical potential for skin cancer therapy. Graphical abstract.

Topics: Administration, Cutaneous; Animals; Emulsions; Melanoma; Mice; Skin Neoplasms; Stilbenes

To study the antitumor effect of piceatannol (PIC) on malignant melanoma. B16F10 cells were cultured. The cell viability of B16F10 decreased with increasing PIC concentration. The results of the Transwell assay showed that invasion ability decreased with increasing PIC concentration, and healing time was prolonged at increased PIC concentration in the wound healing assay. Western blot results showed that PIC mainly inhibited the phosphorylation of Syk and inhibited the expression of MMP-2, MMP-9, and VEGF. RNA interference pointed out that blocking the expression of Syk can reveal the same inhibition effect on B16F10 cells as PIC.. PIC might block the progression of malignant melanoma by inhibiting spleen tyrosine kinase.

Topics: Animals; Cell Line, Tumor; Cell Movement; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Melanoma; Mice; Neoplasm Invasiveness; Stilbenes; Syk Kinase; Vascular Endothelial Growth Factor A

Melanin protects our skin from harmful ultraviolet (UV) radiation. However, when produced in excess, it can cause hyperpigmentation disorders, such as melanoma, freckles, lentigo, and blotches. In this study, we investigated the effects of pinostilbene hydrate (PH) on melanogenesis. We also examined the underlying mechanisms of PH on melanin production in B16F10 cells. Our findings indicated that PH significantly inhibits melanin content and cellular tyrosinase activity in cells without causing cytotoxicity. In addition, Western blot analysis showed that PH downregulated the protein levels of microphthalmia-associated transcription factor (MITF), tyrosinase, and other melanogenic enzymes, such as tyrosinase-related protein-1 (TRP-1) and tyrosinase-related protein-2 (TRP-2). Although PH activated the phosphorylation of extracellular signal-regulated kinase (ERK), it inhibited p38 mitogen-activated protein kinases (p38). Furthermore, the inhibition of tyrosinase activity by PH was attenuated by treatment with PD98059 (a specific ERK inhibitor). Additionally, p-AKT was upregulated by PH treatment. Finally, the inhibitory effects of PH on melanin content and tyrosinase activity were confirmed in normal human melanocytes. These results suggest PH downregulates melanogenesis via the inhibition of MITF expression, followed by the MAPKase signaling pathways. Thus, PH may be used to treat or prevent hyperpigmentation disorders and in functional cosmetic agents for skin whitening.

Topics: Animals; Cell Line, Tumor; Extracellular Signal-Regulated MAP Kinases; Flavonoids; MAP Kinase Signaling System; Melanins; Melanocytes; Melanoma; Mice; Microphthalmia-Associated Transcription Factor; Monophenol Monooxygenase; Phosphorylation; Proto-Oncogene Proteins c-akt; Signal Transduction; Stilbenes

We extracted and purified oxyresveratrol (OXY) from Artocarpus heterophyllus Lam. and identified its structure. The kinetics and mechanisms of OXY-induced mushroom tyrosinase inhibition were studied using fluorescence spectroscopy, copper ion chelation, and circular dichroism (CD). We found that OXY significantly inhibited tyrosinase with a half maximal inhibitory concentration (IC

Topics: Agaricales; Animals; Apoptosis; Artocarpus; Caenorhabditis elegans; Melanins; Melanoma; Melanoma, Experimental; Mice; Monophenol Monooxygenase; Oxidative Stress; Plant Extracts; Protein Conformation; Skin Pigmentation; Stilbenes; Time Factors

Very recently, we have produced new resveratrol derived compounds, especially labruscol by culture of elicited grapevine cell suspensions (Vitis labrusca L.). This new polyphenolic oligomer could function as cancer chemopreventive agent in similar manner of resveratrol. In this study, we have determined the efficiency of resveratrol, ε-viniferin and the labruscol on human melanoma cell with or without metastatic phenotype. Our results show a differential activity of the three compounds where the resveratrol remains the polyphenolic compound with the most effective action compared to other oligomers. These three compounds block cell cycle of melanoma cells in S phase by modulating key regulators of cell cycle i.e. cyclins A, E, D1 and their cyclin-dependent kinases 1 and 2. These effects are associated with an increase of cell death while these compounds have no cytotoxic action on normal human dermal fibroblasts.

Topics: Anticarcinogenic Agents; Benzofurans; CDC2 Protein Kinase; Cell Line, Tumor; Cell Proliferation; Cyclin A; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase 2; Fibroblasts; Humans; Melanoma; Resveratrol; S Phase; Skin; Stilbenes; Vitis

Resveratrol, a dietary product present in grapes, vegetables and berries, regulates several signaling pathways that control cell division, cell growth, apoptosis and metastasis. Malignant melanoma proliferates more readily in comparison with any other types of skin cancer. In the present study, the anti‑cancer effect of resveratrol on melanoma cell proliferation was evaluated. Treating A375SM cells with resveratrol resulted in a decrease in cell growth. The alteration in the levels of cell cycle‑associated proteins was also examined by western blot analysis. Treatment with resveratrol was observed to increase the gene expression levels of p21 and p27, as well as decrease the gene expression of cyclin B. In addition, the generation of reactive oxygen species (ROS) and endoplasmic reticulum (ER) stress were confirmed at the cellular and protein levels using a 2',7'‑dichlorofluorescein diacetate assay, TUNEL assay and western blot analysis. Resveratrol induced the ROS‑p38‑p53 pathway by increasing the gene expression of phosphorylated p38 mitogen‑activated protein kinase, while it induced the p53 and ER stress pathway by increasing the gene expression levels of phosphorylated eukaryotic initiation factor 2α and C/EBP homologous protein. The enhanced ROS‑p38‑p53 and ER stress pathways promoted apoptosis by downregulating B‑cell lymphoma‑2 (Bcl‑2) expression and upregulating Bcl‑2‑associated X protein expression. In conclusion, resveratrol appears to be an inducer of ROS generation and ER stress, and may be responsible for growth inhibition and cell cycle arrest of A375SM melanoma cells.

Topics: Apoptosis; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; Endoplasmic Reticulum Stress; Humans; Melanoma; Melanoma, Cutaneous Malignant; Models, Biological; Reactive Oxygen Species; Resveratrol; Skin Neoplasms; Stilbenes

Malignant melanoma is developed from pigment-containing cells, melanocytes, and primarily found on the skin. Malignant melanoma still has a high mortality rate, which may imply a lack of therapeutic agents. Lakoochin A, a compound isolated from

Topics: Antineoplastic Agents, Phytogenic; Caspases; Cell Line, Tumor; Cell Proliferation; Cell Survival; Gene Expression Regulation, Neoplastic; Humans; MAP Kinase Signaling System; Melanoma; Mitochondria; Reactive Oxygen Species; Stilbenes

The prevalence of melanoma and the lack of effective therapy for metastatic melanoma warrant extensive and systematic evaluations of small molecules in cellular and pre-clinical models. We investigated, herein, the antitumor and anti-metastatic effects of trans-4,4'-dihydroxystilbene (DHS), a natural product present in bark of Yucca periculosa, using in vitro and in vivo melanoma murine models. DHS showed potent melanoma cytotoxicity, as determined by MTT and clonogenic assay. Further, DHS induced cytotoxicity was mediated through apoptosis, which was assessed by annexin V-FITC/PI, sub-G1 and caspase activation assays. In addition, DHS inhibited cell proliferation by inducing robust cell cycle arrest in G1-phase. Imperatively, these inhibitory effects led to a significant reduction of melanoma tumor in pre-clinical murine model. DHS also inhibited cell migration and invasion of melanoma cells, which were examined using wound healing and Transwell migration/invasion assays. Mechanistically, DHS modulated the expressions of several key metastasis regulating proteins e.g., MMP-2/9, N-cadherin, E-cadherin and survivin. We also showed the anti-metastatic effect of DHS in a melanoma mediated lung metastasis model in vivo. DHS significantly reduced large melanoma nodule formation in the parenchyma of lungs. Therefore, DHS may represent a promising natural drug in the repertoire of treatment against melanoma tumor growth and metastasis.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Male; Melanoma; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Neoplasm Invasiveness; Neoplasm Metastasis; Skin Neoplasms; Stilbenes

Cellular senescence is related to organismal aging and is observed after DNA damaging cancer therapies, that induce tumor-suppressive modifications, but it is characterized by a strong increase in secreted factors, termed the "senescence-associated secretory phenotype" (SASP). Particularly, SASP from stroma senescent fibroblasts creates a cancer-favoring microenvironment, providing targets for anti-cancer interventions. In the present article, chronic treatment (5 weeks) with 5 µM resveratrol has been used to modulate senescence-related protumoral features of MRC5 fibroblasts, reducing SASP-related interleukins IL1α, IL1β, IL6, and IL8; transforming-growth-factor-β (TGFβ); matrix metallo-proteinases MMP3 and MMP2; urokinase plasminogen activator (uPA); receptor proteins uPAR, IL6R, insulin growth factor receptor-1 (IGF-1R), TGFβ-R2, and CXCR4. The cellular nuclear-factor-kB (NF-kB) protein level was also reduced, confirming its role in the induction of SASP. Resveratrol pretreated MRC5 fibroblasts were resistant to activation by TGFβ. Resveratrol treatment of senescent MRC5 induced the production of conditioned media (CM) which counteracted the protumoral effect of senescent CM on A375 and A375-M6 melanoma cell proliferation and invasiveness, and reduced the expression of epithelial-to-mesenchymal transition markers related to malignant features. This experimental approach proposes a treatment that targets the senescent stromal cell phenotype to induce an anti-tumor hosting microenvironment, which is suitable for both preventive and therapeutic purposes.

Topics: Animals; Biomarkers, Tumor; Blotting, Western; Cell Line, Tumor; Cell Proliferation; Cellular Senescence; Culture Media, Conditioned; Fibroblasts; Humans; Interleukins; Melanoma; Mice; Phenotype; Real-Time Polymerase Chain Reaction; Resveratrol; Stilbenes; Tumor Cells, Cultured; Tumor Microenvironment

trans-Resveratrol (tRES) is a polyphenolic stilbene found in plant products which has attracted great attention because of its antioxidant, anti-inflammatory and anticancer properties.. The possible correlation between tRES-induced suppression of melanoma cell growth and its influence on telomerase expression has been investigated by biological assays. Moreover, in order to gain new knowledge about possible mechanisms of action of tRES as antineoplastic agent, its interaction with biologically relevant secondary structure-forming DNA sequences, its aggregation properties and copper-binding activity have been studied by CD, UV and fluorescence spectroscopies.. Biological assays have confirmed that growth inhibitory properties of tRES well correlate with the reduction of telomerase activity and hTERT gene transcript levels in human melanoma cells. Biophysical studies in solution have proved that tRES binds all the studied DNA model systems with low affinity, however showing high ability to discriminate G-quadruplex vs. duplex DNA. In addition, tRES has shown no propensity to form aggregates in the explored concentration range and has been found able to bind Cu. From these biological and biophysical analyses it has emerged that tRES produces cytotoxic effects on human melanoma cells and, at a molecular level, is able to bind Cu. Expanding the knowledge on the putative mechanisms of action of tRES as antitumour agent can help to develop novel, effective tRES-based anticancer drugs.

Topics: Antineoplastic Agents; Biophysical Phenomena; Cell Line, Tumor; Cell Proliferation; Circular Dichroism; Copper; G-Quadruplexes; Humans; Melanoma; Nucleic Acid Conformation; Resveratrol; Spectrometry, Fluorescence; Spectrum Analysis; Stilbenes; Telomerase

The present study was aimed to investigate the effect of resveratrol on the viability of HT-144 melanoma cells and formation of melanin. MTT assay was used for analysis of cell viability and western blot for determination of phospho-Mek 1/2, phospho-Erk 1/2 (Tyr-204), Mitf, PBG-D and p-CREB-1 expression. MTT assay results showed that treatment of HT-144 cells with various doses of resveratrol led to a concentration dependent inhibition of proliferation. The antiproliferative activity was significant at 15 μM concentration of resveratrol after 24 h. Western blot analysis revealed that resveratrol caused significant reduction in the expression of phospho-extracellular signal related kinase (p-ERK) and p-MEK 1/2. Additionally, tyrosinase activity was increased by 1.5-6.8-fold on increasing the concentration of resveratrol from 1 to 15 μM. Resveratrol treatment also enhanced the expression of cAMP-response element-binding proteins (CREB) after 24 h. Furthermore resveratrol treatment up-regulated porphobilinogen deaminase (PBG-D) expression in HT-144 cells. Taken together, the study demonstrates that resveratrol treatment inhibits proliferation and promotes melanogenesis of HT-144 cells through inhibition of MEK/ERK pathway. Therefore, resveratrol has a scope for further evaluation against melanogenesis.

Topics: Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cyclic AMP Response Element-Binding Protein; Humans; MAP Kinase Signaling System; Melanins; Melanoma; Mitogen-Activated Protein Kinase 3; Resveratrol; Stilbenes

Resveratrol (Res) is a natural compound with anti-cancer effects. The goal of this study is to evaluate the suppression of Res in melanoma and investigate its relationship with miRNAs during this process. The in vitro and in vivo anti-cancer abilities of Res were evaluated using cellular assays and animal model. Two melanoma cell lines (A375 and MV3) were used for both in vitro assay and in vivo experiments. qRT-PCR and Western blot were used to detect the changes in gene expressions and protein levels. Dual-luciferase reporter assay and bioinformatic tools were used to further confirm the protein binding and activation of targeted genes. In vitro experiments showed Res significantly decreased the expression of miR-221, an oncogenic microRNA, which was confirmed by the overexpression of miR-221 with or without Res treatment. Mechanistically, we showed that the inhibition of miR-221 by Res was achieved by regulating NF-κB (RELA) activity. In the meantime, we also identified that TFG, a tumor suppressor gene, was a target of miR-221. Finally, using in vivo melanoma model, we confirmed the tumor suppressive effects of Res and our in vitro regulatory network. Res displayed a significant anti-tumor effect on melanoma cells both in vitro and in vivo. The cellular mechanism under this effect involves miRNA regulation.

Topics: Animals; Antineoplastic Agents, Phytogenic; Carcinogenesis; Cell Line, Tumor; Down-Regulation; Gene Expression Regulation, Neoplastic; Humans; Melanoma; Mice; Mice, SCID; MicroRNAs; Proteins; Resveratrol; Signal Transduction; Stilbenes; Transcription Factor RelA; Xenograft Model Antitumor Assays

Melanoma took top position among the lethal cancers and, despite there have been some great attempts made to increase the natural life of patients with metastatic disease, long-lasting and complete remissions are few. Piceatannol, owns the similar function as resveratrol, has been defined as an anti-cancer agent playing important role in inhibition of proliferation, migration and metastasis in various cancer. Thus, we aim to investigate the anti-cancer effect and mechanisms of piceatannol in melanoma cells.. Melanoma cell lines WM266-4 and A2058 were treated either with or without piceatannol. Cell viability and cell apoptosis were assessed by using MTT and Annexin V/PI assay, respectively. Cells were transfected with specific miRNA using Lipfectamine 2000. miRNA bingding ability to 3'-UTR region within specific gene was assed by firefly luciferase analysis. Gene and protein expression was eveluated by qRT-PCR and western blot analysis, respectively.. Our study showed that piceatannol inhibited WM266-4 and A2058 cells growth and induced apoptosis. Totally, 16 differentially expressed miRNAs were screened out including 8 up-regulated and 8 down-regulated miRNAs. Expression level of miR-181a is significantly higher in piceatannol-treated cells than normal control and is lower in melanoma cancer tissues than its adjacent normal tissues. Bcl-2 is a target gene of miR-181a. Moreover, silencing of miR-181a reverses the decrease of cell viability induced by piceatannol in WM266-4 and A2058 cells. Taken together, present study uncovered the ability of piceatannol to repress melanoma cell growth and clarified the contribution of miR-181a in the anticancer role of piceatannol.. The present study proposes that piceatannol can be taken into account to be a hopeful anticancer agent for melanoma.

Topics: Anticarcinogenic Agents; Apoptosis; Cell Line, Tumor; Cell Survival; Gene Expression Regulation, Neoplastic; Humans; Melanoma; MicroRNAs; Stilbenes; Up-Regulation

A new resveratrol dimer (

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Bioreactors; Cell Line, Tumor; Cell Survival; Dimerization; Humans; Magnetic Resonance Spectroscopy; Melanoma; Melanoma, Cutaneous Malignant; Molecular Structure; Plant Cells; Resveratrol; Skin Neoplasms; Stilbenes; Vitis

Polyphenolic phytochemicals have anticancer properties. However, in mechanistic studies, lack of correlation with the bioavailable concentrations is a critical issue. Some reports had suggested that these molecules downregulate the stress response, which may affect growth and the antioxidant protection of malignant cells. Initially, we studied this potential underlying mechanism using different human melanomas (with genetic backgrounds correlating with most melanomas), growing in nude mice as xenografts, and pterostilbene (Pter, a natural dimethoxylated analog of resveratrol).. Intravenous administration of Pter decreased human melanoma growth in vivo. However, Pter, at levels measured within the tumors, did not affect melanoma growth in vitro. Pter inhibited pituitary production of the adrenocorticotropin hormone (ACTH), decreased plasma levels of corticosterone, and thereby downregulated the glucocorticoid receptor- and nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-dependent antioxidant defense system in growing melanomas. Exogenous corticosterone or genetically induced Nrf2 overexpression in melanoma cells prevented the inhibition of tumor growth and decreased antioxidant defenses in these malignant cells. These effects and mechanisms were also found in mice bearing different human pancreatic cancers. Glutathione depletion (selected as an antimelanoma strategy) facilitated the complete elimination by chemotherapy of melanoma cells isolated from mice treated with Pter.. Although bioavailability-related limitations may preclude direct anticancer effects in vivo, natural polyphenols may also interfere with the growth and defense of cancer cells by downregulating the pituitary gland-dependent ACTH synthesis.. Pter downregulates glucocorticoid production, thus decreasing the glucocorticoid receptor and Nrf2-dependent signaling/transcription and the antioxidant protection of melanoma and pancreatic cancer cells. Antioxid. Redox Signal. 24, 974-990.

Topics: Adrenocorticotropic Hormone; Animals; Antineoplastic Agents; Antioxidants; Cell Line, Tumor; Female; Gene Expression Regulation, Neoplastic; Glucocorticoids; Humans; Melanoma; Mice, Nude; NF-E2-Related Factor 2; Oxidation-Reduction; Stilbenes; Xenograft Model Antitumor Assays

Mutation in B-Raf leads to gain of function in melanoma and causes aggressive behavior for proliferation. Most of the therapeutics are ineffective in this scenario. However, regulation of this aggressive behavior by targeting the key molecules would be viable strategy to develop novel and effective therapeutics. In this report we provide evidences that the resveratrol is potent to regulate melanoma cell growth than other inducers of apoptosis. Resveratrol inhibits pronounced cell proliferation in melanoma than other tumor cell types. Cell cycle analysis using flow cytometry shows that the treatment with resveratrol results in S phase arrest. Resveratrol inhibits microphthalmia-associated transcription factor (MITF) and its dependent genes without interfering the MITF DNA binding in vitro. Resveratrol-mediated cell death is protected in MITF overexpressed cells and it is aggravated in MITF knocked down cells. These suggest the resveratrol-mediated decrease in MITF is the possible cause of melanoma cell death. Though resveratrol-mediated downregulation of NF-κB is responsible for cell apoptosis, but the downregulation of MITF is the main reason for melanoma-specific cell death. Thus, resveratrol can be effective chemotherapeutic agent against rapid proliferative melanoma cells.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Cycle Checkpoints; Cell Death; Cell Line, Tumor; Cell Proliferation; Down-Regulation; HT29 Cells; Humans; Melanoma; Microphthalmia-Associated Transcription Factor; NF-kappa B; Resveratrol; S Phase; Stilbenes

The serine/threonine-protein kinase B-Raf (BRAF) V600E mutant (BRAF(V600E)) inhibitor vemurafenib, has improved clinical outcomes for patients with BRAF(V600E) melanoma, but acquired cellular resistance mediated by AKT serine/threonine kinase 1 (AKT) phosphorylation limits its efficacy. We examined the effect of resveratrol on vemurafenib-resistant melanoma cells.. A vemurafenib-resistant human metastatic melanoma cell line positive for the BRAF V600E mutation was established. The anti-tumorigenic effects of vemurafenib and resveratrol, both alone and in combination, were examined through analysis of cell proliferation and protein expression.. The level of phosphorylated AKT (p-AKT) was increased in the primary melanoma cells after treatment with vemurafenib, and the basal level of p-AKT was increased in vemurafenib-resistant melanoma cells. Notably, resveratrol both alone and in combination with vemurafenib effectively suppressed cell proliferation and AKT phosphorylation in both parental and vemurafenib-resistant melanoma cells.. Vemurafenib resistance can be reversed by addition of resveratrol in patients undergoing treatment with BRAF inhibitors.

Topics: Antineoplastic Agents; Drug Resistance, Neoplasm; Drug Synergism; Humans; Indoles; Inhibitory Concentration 50; Melanoma; Mutation, Missense; Phosphorylation; Protein Processing, Post-Translational; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-akt; Resveratrol; Stilbenes; Sulfonamides; Tumor Cells, Cultured; Vemurafenib

Resveratrol is a natural dietary product that has demonstrated multifaceted anticancer activity. Several analogues of resveratrol have been synthesized in an effort to enhance the pharmacological potency and improve the pharmacokinetic properties of the compound. 3,4,5,4'‑trans‑tetramethoxystilbene (3,4,5,4'‑TMS) is a methoxylated analogue of resveratrol that has demonstrated anti-proliferative activity in vitro (in cancer cell lines) and in vivo (in xenograft models). In the present study, the anticancer effects of 3,4,5,4'‑TMS in A375 human melanoma cells were examined. 3,4,5,4'‑TMS markedly inhibited the proliferation of A375 cells (IC50=0.7 µM), via a mechanism involving mitotic arrest at the prometaphase stage of cell division. This effect was accompanied by the upregulation of the expression of the mitogen activated protein kinases, JNK and p38, and the concomitant activation of p38, that was verified by the nuclear translocation of the phoshorylated form of the protein. The pharmacological inhibition of p38 by SB203580 (4 µM) attenuated the effects of 3,4,5,4'‑TMS, as demonstrated by decreased cell cycle progression at the mitotic phase. Furthermore, 3,4,5,4'‑TMS increased the total levels of Aurora A, while it inhibited the localization of the protein to the spindle poles. Finally, 3,4,5,4'‑TMS exhibited anti-metastatic activity, inhibiting A375 cell migration and the attachment of the cells to a collagen type IV-coated surface. Collectively, the data suggest that 3,4,5,4'‑TMS is an effective chemotherapeutic drug for the treatment of human melanoma and that it exerts its effects through multiple anticancer modes of action.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Movement; Cell Proliferation; Drug Screening Assays, Antitumor; Gene Expression Regulation, Neoplastic; Humans; MAP Kinase Signaling System; Melanoma; Prometaphase; Stilbenes

Resveratrol (Res), a natural plant extract, is an effective inducer of cell apoptosis and cell cycle arrest in multiple carcinoma cell types, which has been demonstrated by its ability to inhibit the proliferation of multiple human tumor cells in vitro. Although Res possesses chemopreventive properties against several types of cancer, the molecular mechanism underlying its anticancer activity remains to be fully elucidated. The present study demonstrated that Res induced cell cycle arrest and inhibited the proliferation of human melanoma A375 (IC50=23 µM after 48 h; P<0.05) and SK-MEL-31 (IC50=15 µM after 48 h; P<0.05) cells. Western blot analysis demonstrated that Res induced the apoptosis of human melanoma A375 and SK-MEL-31 cells by upregulating the expression of Bcl-2-associated X protein and B-cell lymphoma 2, possibly via the p53 pathway and activation of caspase-9 and caspase-3.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Cell Proliferation; G1 Phase Cell Cycle Checkpoints; Humans; Melanoma; Resveratrol; Stilbenes

Topics: Antineoplastic Agents; Cell Line, Tumor; Drug Screening Assays, Antitumor; Enzyme Activation; G2 Phase Cell Cycle Checkpoints; Humans; MAP Kinase Signaling System; Melanoma; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Neoplasm Proteins; Phosphorylation; Protein Processing, Post-Translational; Protein Transport; Stilbenes

Melanin is a natural pigment that plays an important role in the protection of skin, however, hyperpigmentation cause by excessive levels of melatonin is associated with several problems. Therefore, melanogenesis inhibitory natural products have been developed by the cosmetic industry as skin medications. The leaves of Morus alba (Moraceae) have been reported to inhibit melanogenesis, therefore, characterization of the melanogenesis inhibitory constituents of M. alba leaves was attempted in this study. Twenty compounds including eight benzofurans, 10 flavonoids, one stilbenoid and one chalcone were isolated from M. alba leaves and these phenolic constituents were shown to significantly inhibit tyrosinase activity and melanin content in B6F10 melanoma cells. To maximize the melanogenesis inhibitory activity and active phenolic contents, optimized M. alba leave extraction conditions were predicted using response surface methodology as a methanol concentration of 85.2%; an extraction temperature of 53.2 °C and an extraction time of 2 h. The tyrosinase inhibition and total phenolic content under optimal conditions were found to be 74.8% inhibition and 24.8 μg GAE/mg extract, which were well-matched with the predicted values of 75.0% inhibition and 23.8 μg GAE/mg extract. These results shall provide useful information about melanogenesis inhibitory constituents and optimized extracts from M. alba leaves as cosmetic therapeutics to reduce skin hyperpigmentation.

Topics: Benzofurans; Cell Line, Tumor; Chalcone; Flavonoids; Humans; Hyperpigmentation; Melanins; Melanoma; Monophenol Monooxygenase; Morus; Phenols; Plant Extracts; Plant Leaves; Stilbenes

Astragalus, a commonly used traditional Chinese medicine, has exhibited antitumor actions in patients. In this study, in vitro and in vivo antitumor effects of astragalus and synergistic antitumor efficacy in combination with pterostilbene were investigated. Melanoma cells were treated with pterostilbene (Pt), graduated doses of astragalus injection (AI), or these in combination. Cell viability was measured using a MTT assay. Released nucleosomes and caspase activity were measured using enzyme-linked immunosorbent assay. Growth inhibition in vitro and in vivo was also assessed. Analysis of variance and t tests were used for statistical analysis. Significant reduction (p<0.05) in cellular proliferation were observed with AI and AI-Pt in a time- and concentration-dependent manner. Apoptosis and caspase-3/7 activity were significantly increased by AI and AI-Pt treatment (p<0.05). In vivo, AI inhibited melanoma tumor growth, with inhibition rates ranging from 36.5 to 62.3%, by inducing apoptosis via up-regulation Bax expression and the Bax/Bcl-2 ratio and down-regulating Bcl-2 expression. AI significantly inhibits the growth of melanoma in vitro and in vivo by inducing apoptosis. These data suggest that combined treatment of astragalus with pterostilbene enhances antitumor efficacy.

Topics: Animals; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Astragalus Plant; bcl-2-Associated X Protein; Caspase 3; Caspase 7; Cell Line, Tumor; Cell Proliferation; Cell Survival; Humans; Male; Medicine, Chinese Traditional; Melanoma; Mice; Mice, Inbred BALB C; Nucleosomes; Plant Extracts; Proto-Oncogene Proteins c-bcl-2; Stilbenes

Although many chemotherapies have been developed for melanomas, successful therapy would be aided by the identification of intrinsic mechanisms that are crucial for melanoma survival. Here, we used resveratrol, a phytoalexin, as an anti-melanoma reagent. Applying resveratrol to various human and murine melanoma cell lines, we show that survivin is essential for melanoma survival in vitro and in vivo and is targeted by resveratrol. Furthermore, we identify the down regulation of survivin transcription by resveratrol through the suppression of β-catenin and STAT3. In addition, over expression of survivin protects melanoma cells from resveratrol-induced apoptosis. Collectively, these studies establish that targeting survivin could provide an opportunity to treat melanoma patients.

Topics: Animals; Antineoplastic Agents; Antioxidants; Apoptosis; beta Catenin; Blotting, Western; Cell Line, Tumor; Chromatin Immunoprecipitation; Humans; Inhibitor of Apoptosis Proteins; Melanoma; Mice; Mice, Inbred C57BL; Real-Time Polymerase Chain Reaction; Resveratrol; Signal Transduction; Skin Neoplasms; STAT3 Transcription Factor; Stilbenes; Survivin; Xenograft Model Antitumor Assays

Radiotherapy (XRT) is used to improve local control of melanoma and for palliation of metastatic disease. Clinical use of XRT for melanoma is often limited by extent of disease and the relative radioresistance of melanoma may limit the effectiveness of XRT. Our group and others have previously shown that resveratrol (RSV) enhances radiation sensitivity in radioresistant prostate cancer cell lines.. In this study, the effects of XRT in combination with RSV on radioresistant melanoma lines, SK-Mel-5 and HTB-65, were evaluated by assessment of proliferation and apoptosis. Clonogenic assay, comparison of proliferating cell nuclear antigen staining, Quick Cell Proliferation assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining and caspase-3 activity assay were used to assess proliferation and apoptosis, as appropriate.. We found that the percentage of colonies, proliferating cell nuclear antigen + cells and the optical density value of melanoma cells were decreased after addition of RSV to XRT (XRT/RSV). TUNEL + cells and the relative caspase-3 activity in melanoma cells were increased after addition of RSV to XRT (XRT/RSV). We investigated the possible molecular mechanisms of decreased proliferation and increased apoptosis by using reverse transcriptase-polymerase chain reaction and immunohistochemical staining. The anti-proliferative effect of XRT/RSV correlated with decreased expression of pro-proliferative molecule cyclin B, cyclin D, cdk2 and cdk4. The pro-apoptotic effect of XRT/RSV correlated with decreased expression of the anti-apoptotic molecule FLIP, Bcl-2, and survivin.. These data suggest that RSV enhances radiation sensitivity of melanoma cells by inhibiting proliferation and promoting apoptosis. Resveratrol may have a potential role as a radiation sensitizer for melanoma treatment.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Caspase 3; Cell Line, Tumor; Cell Proliferation; Combined Modality Therapy; Cyclin D; Drug Therapy; Humans; Inhibitor of Apoptosis Proteins; Melanoma; Proto-Oncogene Proteins c-bcl-2; Radiation-Sensitizing Agents; Radiotherapy; Resveratrol; Skin Neoplasms; Stilbenes; Survivin

The stilbene derivative, cis-3,4',5-trimethoxy-3'-aminostilbene (stilbene 5c), is a potentially potent antitumor agent that acts via binding to the colchicine-binding site in tubulin. The current studies were designed to investigate the effectiveness of stilbene 5c against the HCT-116 human colon cancer cell line and B16/F10 melanoma cells as well as human endothelial cell tube formation and tumor perfusion. Stilbene 5c produced a time-dependent decrease in cell viability in both cell lines and the capacity of the cells to proliferate was not restored upon removal of the drug. Treatment with stilbene 5c also promoted both senescence and autophagy in both cell lines. TUNEL and annexin 5 staining indicated that apoptosis also occurs in stilbene 5c-treated HCT-116 cells, but not in B16/F10 melanoma cells. DAPI staining revealed morphological changes in the cell nuclei (binucleated and micronucleated cells) indicative of mitotic catastrophe in HCT-116 cells but not in the B16/F10 melanoma cells. p53-null HCT-116 cells demonstrated a similar growth arrest/cell death response to stilbene as p53-wild type HCT-116 cells. Stilbene 5c also completely inhibited human endothelial cell tube formation on Matrigel, consistent with potential anti-angiogenic actions. Using a new method developed for monitoring the pharmacodynamic effects of stilbene 5c in vivo, we found that a single injection of stilbene 5c reduced tumor perfusion by 65% at 4h, returning to baseline by 24h, while subsequent daily injections of stilbene 5c produced progressively larger reductions and smaller rebounds. This work indicates that stilbene 5c could potentially be effective against melanoma and colon cancer through the promotion of multiple modes of growth arrest and cell death coupled with anti-angiogenic and antivascular actions.

Topics: Apoptosis; Cell Division; Cell Line, Tumor; Colorectal Neoplasms; Humans; Melanoma; Microtubules; Stilbenes

Resveratrol (RESV) is a naturally occurring compound that may possess anticancer capabilities in both prostate carcinoma and melanoma.. The in vitro and in vivo cytotoxic activity of RESV and 3,5-dihydroxy-4'-acetoxy-trans-stilbene (4-ACE) was tested using cellular assays and a xenograft model. Five prostate carcinoma cell lines were used for in vitro evaluation. A melanoma cell line (Duke melanoma 738 [DM738]) and the prostate carcinoma line CWR22 were used for in vivo experiments. Mice were randomized to osmotic mini pumps with 200 μL of RESV (250 mg/mL), 4-ACE (335 mg/mL), or vehicle (50% dimethyl sulfoxide, 50% polyethylene glycol). Serum drug and metabolite levels were calculated by high-performance liquid chromatography with diode-array detection. Western blots were performed on treated tumors. Results were analyzed using a student's t-test, analysis of variance, and the Mann-Whitney rank sum test.. RESV and 4-ACE were cytotoxic in a time- and dose-dependent manner in all prostate carcinoma cell lines tested. Enhanced growth compared with controls was seen at the 24 h time point in four lines treated with RESV and two lines treated with 4-ACE (Ps < 0.048). In vivo, no difference in either tumor growth or postmortem tumor weight was detected in either DM738 (P = 0.555, P = 0.562) or CWR22 (P = 0.166, P = 0.811) xenografts treated with either drug. Serum drug levels did not correlate with tumor growth rates for any treatment group (all Ps > 0.11). Treated tumors demonstrated protein changes by western blot.. Although in vitro data were promising, RESV and 4-ACE have limited potential as single agents in the treatment of prostate carcinoma and melanoma.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Dose-Response Relationship, Drug; Humans; In Vitro Techniques; Male; Melanoma; Mice; Mice, Nude; Prostatic Neoplasms; Resveratrol; Skin Neoplasms; Stilbenes; Time Factors; Treatment Outcome; Xenograft Model Antitumor Assays

Resveratrol (RESV) is a naturally occurring compound that possesses anti-cancer capabilities. The goal of this study was to evaluate the potential of RESV as an adjunct to chemotherapy in melanoma treatment.. The in vitro and in vivo cytotoxic activity of RESV with or without chemotherapy was tested using cellular assays and a xenograft model. Two Duke melanoma cell lines (DM738, DM443) were used for both in vivo and in vitro experiments, and two nonmalignant human fibroblast lines (NHDF, HS68) were used for in vitro cellular assays. Xenografts were randomized to treatment arms and tumors measured to evaluate response. Results were analyzed using a Student's t-test and ANOVA. Western blots were performed on in vivo tissue.. In vitro RESV significantly decreased melanoma cell viability in all lines tested (all P < 0.0001). Treatment of fibroblast cell lines revealed that RESV selectively spared NHDF and HS68 cells compared with its cytotoxic effects on melanoma cells (P < 0.0001). Treatment of malignant cells with 50 μM RESV and temozolomide (TMZ) for 72 h significantly enhanced cytotoxicity compared with treatment with TMZ alone (P < 0.0001). In vivo, however, there was no significant difference between any treatment arms (P = 0.65).. RESV shows promise as a novel therapeutic in the management of melanoma for its selective anti-tumor activity in vitro. Translating in vitro results to in vivo models has proven difficult. Barriers thought to prevent such translation are identified, and a rationale for overcoming them is discussed.

Topics: Animals; Antineoplastic Agents; Cell Line; Cell Line, Tumor; Chemotherapy, Adjuvant; Dacarbazine; Disease Models, Animal; Drug Therapy, Combination; Humans; In Vitro Techniques; Melanoma; Melphalan; Mice; Mice, Nude; Mice, SCID; Resveratrol; Skin Neoplasms; Stilbenes; Temozolomide; Treatment Outcome; Xenograft Model Antitumor Assays

Capsaicin and resveratrol are strong chemopreventive agents with promising human consumption safety records and anticarcinogenic activities. However, the mechanism by which they induce apoptosis in tumor cells remains to be defined. In this study, we examined the role of nitric oxide (NO•) during apoptosis induced by these agents in A375 human melanoma cells. Capsaicin and resveratrol, alone or in combination, inhibited cell growth and promoted apoptosis by the elevation of NO• in A375 cells. Increased NO• production following treatment stimulated p53 and triggered mitochondrial apoptotic events by inducing conformational changes in Bax and Bcl-2 with subsequent release of cytochrome c and activation of caspase 9 and 3. Caspase 8 activation concurrently appeared to be mediated by death receptor processing and downstream caspases. Collectively, our data suggest that capsaicin and resveratrol activate the mitochondrial and death receptor pathways, working together to induce apoptosis in A375 cells, and indicate that NO• could be considered a potential target for improvement of the effectiveness of melanoma treatment.

Topics: Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; Capsaicin; Caspase 3; Caspase 8; Caspase 9; Cell Line, Tumor; Cytochromes c; Humans; Melanoma; Mitochondria; Nitric Oxide; Proto-Oncogene Proteins c-bcl-2; Resveratrol; Signal Transduction; Stilbenes; Tumor Suppressor Protein p53

Epithelial to mesenchymal transition (EMT) has been linked to metastasis. Resveratrol exhibits potential antitumor activities; however, the inhibitory effects of resveratrol on the EMT of melanoma have not been demonstrated. Here, a new role for LPS in promoting EMT is described. LPS-induced EMT was identified by examining the markers of EMT. To assess the activation of NF-κB signal transduction pathway, we performed a reporter assay by using tumor cells transfected with the luciferase gene under the control of NF-κB response elements. The antitumor effects of resveratrol were evaluated in an experimental mouse metastasis tumor model. LPS increased N-cadherin and Snail expression and decreased zonula occludens-1 expression in a dose- and time-dependent manner. Meanwhile, LPS stimulated cell migration through activation of TLR4/NF-κB signal pathway. LPS-induced EMT is critical for inflammation-initiated metastasis. Nuclear translocation and transcriptional activity of p65 NF-κB, an important inducer of EMT, were inhibited by resveratrol. Resveratrol inhibited LPS-induced tumor migration and markers of EMT, significantly prolonged animal survival and reduced the tumor size. Thus, resveratrol plays an important role in the inhibition of LPS-induced EMT in mouse melanoma through the down-regulation of NF-κB activity. The data provide an insight into the mechanisms on the function of resveratrol during the processes of EMT.

Topics: Animals; Antineoplastic Agents, Phytogenic; Biomarkers, Tumor; Cadherins; Disease Models, Animal; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Humans; Lipopolysaccharides; Male; Melanoma; Mice; Mice, Inbred C3H; NF-kappa B; Resveratrol; Signal Transduction; Skin Neoplasms; Snail Family Transcription Factors; Stilbenes; Transcription Factors

Immunotherapy with high-dose interleukin-2 (HDIL-2) is an effective treatment for patients with metastatic melanoma and renal cell carcinoma. However, it is accompanied by severe toxicity involving endothelial cell injury and induction of vascular leak syndrome (VLS). In this study, we found that resveratrol, a plant polyphenol with anti-inflammatory and anti-cancer properties, was able to prevent the endothelial cell injury and inhibit the development of VLS while improving the efficacy of HDIL-2 therapy in the killing of metastasized melanoma. Specifically, C57BL/6 mice were injected with B16F10 cells followed by resveratrol by gavage the next day and continued treatment with resveratrol once a day. On day 9, mice received HDIL-2. On day 12, mice were evaluated for VLS and tumor metastasis. We found that resveratrol significantly inhibited the development of VLS in lung and liver by protecting endothelial cell integrity and preventing endothelial cells from undergoing apoptosis. The metastasis and growth of the tumor in lung were significantly inhibited by HDIL-2 and HDIL-2 + resveratrol treatment. Notably, HDIL-2 + resveratrol co-treatment was more effective in inhibiting tumor metastasis and growth than HDIL-2 treatment alone. We also analyzed the immune status of Gr-1(+)CD11b(+) myeloid-derived suppressor cells (MDSC) and FoxP3(+)CD4(+) regulatory T cells (Treg). We found that resveratrol induced expansion and suppressive function of MDSC which inhibited the development of VLS after adoptive transfer. However, resveratrol suppressed the HDIL-2-induced expansion of Treg cells. We also found that resveratrol enhanced the susceptibility of melanoma to the cytotoxicity of IL-2-activated killer cells, and induced the expression of the tumor suppressor gene FoxO1. Our results suggested the potential use of resveratrol in HDIL-2 treatment against melanoma. We also demonstrated, for the first time, that MDSC is the dominant suppressor cell than regulatory T cell in the development of VLS.

Topics: Animals; Antineoplastic Agents; Apoptosis; Endothelial Cells; Female; Immunotherapy; Interleukin-2; Killer Cells, Lymphokine-Activated; Lung Neoplasms; Melanoma; Mice; Neoplasm Transplantation; Resveratrol; Stilbenes; T-Lymphocytes, Regulatory

The purpose of this study was to develop a targeted combinatorial polymeric micelle system that can sequentially kill tumor vasculature and tumor cells and increase the anticancer efficacy. Toward this goal, αvβ3 integrin-targeting peptide (RGD) functionalized polymeric micelles (RFPMs) based on the use of poly(ethylene glycol)-b-poly(d,l-lactide) (PEG-PLA) was developed. Doxorubicin was conjugated to the biodegradable PEG-PLA micelle core, and combretastatin A4 was physically encapsulated into micelles (RFPMs-DOX-CA4). The RFPMs-DOX-CA4 has a particle size of 29.2 ± 2.5nm with spherical shape and high encapsulation efficiency for both drugs (> 95%). The micelles exhibited sequential release kinetics for both drugs. Treatment with RFPMs-DOX-CA4 resulted in the sequential killing of endothelial cells and tumor cells in vitro. RFPMs displayed prolonged circulation time and more drug accumulation in solid tumor than unfunctionalized polymeric micelles (UFPMs). In B16-F10 tumor-bearing mice, RFPMs-DOX-CA4 showed stronger tumor growth inhibition and significantly higher survival rate compared with the other treatment groups. Treatment with RFPMs-DOX-CA4 caused a dramatic destruction of tumor vasculature and reduction of tumor cell proliferation in vivo. These results suggested that the integrated strategy can be exploited as a potential treatment modality for cancer.

Topics: Animals; Antibiotics, Antineoplastic; Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Cell Proliferation; Doxorubicin; Humans; Melanoma; Mice; Micelles; Polyethylene Glycols; Stilbenes

Implantation and growth of metastatic cancer cells at distant organs is promoted by inflammation-dependent mechanisms. A hepatic melanoma metastasis model where a majority of metastases are generated via interleukin-18-dependent mechanisms was used to test whether anti-inflammatory properties of resveratrol can interfere with mechanisms of metastasis.. Two experimental treatment schedules were used: 1) Mice received one daily oral dose of 1 mg/kg resveratrol after cancer cell injection and the metastasis number and volume were determined on day 12. 2) Mice received one daily oral dose of 1 mg/kg resveratrol along the 5 days prior to the injection of cancer cells and both interleukin-18 (IL-18) concentration in the hepatic blood and microvascular retention of luciferase-transfected B16M cells were determined on the 18th hour. In vitro, primary cultured hepatic sinusoidal endothelial cells were treated with B16M-conditioned medium to mimic their in vivo activation by tumor-derived factors and the effect of resveratrol on IL-18 secretion, on vascular cell adhesion molecule-1 (VCAM-1) expression and on tumor cell adhesion were studied. The effect of resveratrol on melanoma cell activation by IL-18 was also studied.. Resveratrol remarkably inhibited hepatic retention and metastatic growth of melanoma cells by 50% and 75%, respectively. The mechanism involved IL-18 blockade at three levels: First, resveratrol prevented IL-18 augmentation in the blood of melanoma cell-infiltrated livers. Second, resveratrol inhibited IL-18-dependent expression of VCAM-1 by tumor-activated hepatic sinusoidal endothelium, preventing melanoma cell adhesion to the microvasculature. Third, resveratrol inhibited adhesion- and proliferation-stimulating effects of IL-18 on metastatic melanoma cells through hydrogen peroxide-dependent nuclear factor-kappaB translocation blockade on these cells.. These results demonstrate multiple sites for therapeutic intervention using resveratrol within the prometastatic microenvironment generated by tumor-induced hepatic IL-18, and suggest a remarkable effect of resveratrol in the prevention of inflammation-dependent melanoma metastasis in the liver.

Topics: Animals; Cell Adhesion; Cell Proliferation; Endothelium; Inflammation; Interleukin-18; Liver; Liver Neoplasms; Melanoma; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Microvessels; Models, Biological; Neoplasm Transplantation; Resveratrol; Stilbenes; Tumor Microenvironment; Vascular Cell Adhesion Molecule-1

Stilbenes comprise a group of polyphenolic compounds, which exert inhibitory effects on various malignancies. The aim of this study was to evaluate the antitumor effects of a previously unreported stilbene derivative-3,3',4,4',5,5'-hexahydroxystilbene, termed M8-on human melanoma cells. Cell-cycle analysis of the metastatic melanoma cell line M24met showed that M8 treatment induces G(2)/M arrest accompanied with a dose- and time-dependent upregulation of p21 and downregulation of CDK-2 and leads to apoptosis. M8 induces the expression of phosphorylated p53, proteins involved in the mismatch repair machinery (MSH6, MSH2, and MLH1) and a robust tail moment in a comet assay. In addition, M8 inhibited cell migration in Matrigel assays. Shotgun proteomics and western analysis showed the regulation among others of paxillin, integrin-linked protein kinase, p21-activated kinase, and ROCK-1 indicating that M8 inhibits mesenchymal and amoeboid cell migration. These in vitro data were confirmed in vivo in a metastatic human melanoma severe combined immunodeficient (SCID) mouse model. We showed that M8 significantly impairs tumor growth. M8 also interfered with the metastatic process, as M8 treatment prevented the metastatic spread of melanoma cells to distant lymph nodes in vivo. In summary, M8 exerts strong antitumor effects with the potential to become a new drug for the treatment of metastatic melanoma.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase Inhibitor p21; Disease Models, Animal; Disease Progression; DNA Damage; Dose-Response Relationship, Drug; Female; Humans; Melanoma; Mice; Mice, SCID; Paxillin; Pyrogallol; Skin Neoplasms; Stilbenes; Tumor Suppressor Protein p53; Xenograft Model Antitumor Assays

4'-Ester analogs of the disease preventative agent resveratrol were synthesized and evaluated for their potential as anti-melanoma and pancreatic cancer agents. A decarbonylative Heck coupling was used to assemble the protected stilbene core structure. The 4'-acetate and the palmitoate analogs demonstrated selective activity with DM443 and DM738 cells over normal NHDF cells.

Topics: Antineoplastic Agents; Cell Line, Tumor; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Esters; HL-60 Cells; Humans; Melanoma; Pancreatic Neoplasms; Resveratrol; Stilbenes; Structure-Activity Relationship

Resveratrol, a naturally occurring polyphenol, has been reported to be an anti-tumor and chemopreventive agent. Recent data show that it may also exert anti-angiogenic effects. We hypothesized that the anti-angiogenic activity of resveratrol may be caused by modulation of tumor cell release of thrombospondin-1 (TSP1) and vascular endothelial growth factor (VEGF) into the extracellular matrix, leading to vascular endothelial cell (VEC) apoptosis. We therefore evaluated the effects of resveratrol on melanoma cell lines co-cultured with vascular endothelial cells in monolayer and in three dimensional spheroids. We found that resveratrol stimulated isolated VEC proliferation, while it caused growth inhibition of VECs grown with melanoma cells in three-dimensional co-culture. This effect was associated with increased melanoma cell expression of tumor suppressor protein 53 and matrix protein TSP1, as well as decreased hypoxia-driven expression of hypoxia inducible factor-1α and inhibition of VEGF production.

Topics: Angiogenesis Inhibitors; Cell Survival; Cells, Cultured; Coculture Techniques; Drug Evaluation, Preclinical; Endothelial Cells; Gene Expression; Gene Expression Regulation, Neoplastic; Genes, p53; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Melanoma; Neovascularization, Pathologic; Protein Stability; Resveratrol; Stilbenes; Thrombospondin 1; Vascular Endothelial Growth Factor A

Pterostilbene and inositol-6-phosphate (IP6) have been shown to inhibit melanoma growth in vitro. However, pterostilbene's mechanism of action has not been clearly demonstrated. We aimed to further investigate the mechanism of action for pterostilbene and to determine whether combination treatment with IP6 produced synergistic growth inhibition.. Melanoma cells were treated with increasing doses of pterostilbene, IP6, or combinations thereof. Cell viability was measured at 24 hours, 48 hours, and 72 hours using a MTT assay. Caspase activity and vascular endothelial growth factor (VEGF) production were measured using enzyme-linked immunosorbent assay (ELISA). Analysis of variance (ANOVA) and t tests were used for statistical analysis.. Pterostilbene inhibits melanoma growth in vitro in association with increased effector caspase activity. Combination treatment with inositol hexaphosphate produces synergistic growth inhibition, greater than either treatment alone.. Pterostilbene produces caspase-dependent apoptosis in melanoma cell lines. Combination treatment with IP6 produces synergistic growth inhibition. Both compounds have significant potential for a therapeutic role in the treatment of melanoma.

Topics: Caspases; Cell Survival; Colorimetry; DNA Fragmentation; Drug Screening Assays, Antitumor; Drug Therapy, Combination; Humans; Melanoma; Phytic Acid; Phytotherapy; Pterocarpus; Stilbenes; Tumor Cells, Cultured; Vascular Endothelial Growth Factor A

Myeloid dendritic cells (mDC) activated with a B7-DC-specific cross-linking IgM Ab (B7-DC XAb) take up and retain Ag and interact with T cell compartments to affect a number of biologic changes that together cause strong antitumor responses and blockade of inflammatory airway disease in animal models. The molecular events mediating the initial responses in mDC remain unclear. In this study we show that B7-DC XAb caused rapid phosphorylation of the adaptor protein DAP12 and intracellular kinases Syk and phospholipase C-gamma1. Pretreatment of mDC with the Syk inhibitor piceatannol blocked B7-DC XAb-induced Ag uptake with a concomitant loss of tumor protection in mice. Vaccination with tumor lysate-pulsed wild-type B7-DC XAb-activated mDC, but not TREM-2 knockout XAb-activated mDC, protected mice from lethal melanoma challenge. Multimolecular caps appeared within minutes of B7-DC XAb binding to either human or mouse mDC, and FRET analysis showed that class II, CD80, CD86, and TREM-2 are recruited in tight association on the cell surface. When TREM-2 expression was reduced in wild-type mDC using short hairpin RNA or by using mDC from TREM-2 knockout mice, in vitro DC failed to take up Ag after B7-DC XAb stimulation. These results directly link TREM-2 signaling with one change in the mDC phenotype that occurs in response to this unique Ab. The parallel signaling events observed in both human and mouse mDC support the hypothesis that B7-DC cross-linking may be useful as a therapeutic immune modulator in human patients.

Topics: Adaptor Proteins, Signal Transducing; Animals; Antibodies; Antigens; B7-1 Antigen; B7-2 Antigen; Dendritic Cells; Gene Expression Regulation; Histocompatibility Antigens Class II; Humans; Immunologic Capping; Inflammation; Intracellular Signaling Peptides and Proteins; Melanoma; Membrane Glycoproteins; Membrane Proteins; Mice; Mice, Knockout; Myeloid Cells; Neoplasms, Experimental; Phospholipase C gamma; Phosphorylation; Protein-Tyrosine Kinases; Receptors, Immunologic; Respiration Disorders; Signal Transduction; Stilbenes; Syk Kinase; T-Lymphocytes

It is well recognized that nitric oxide (NO) is involved in tumor progression, including melanoma. Measurement of proliferative and metastatic capacity by MTS and Matrigel invasion assays, respectively, was done and showed that NO-treated melanoma cells exhibited a higher capacity compared with control, especially metastatic Lu1205 cells. Apurinic/apyrimidinic endonuclease-1/redox factor-1 (APE/Ref-1) is a multifunctional protein and its role in tumor biology has attracted considerable attention. To determine whether APE/Ref-1 plays a role in mediating NO stimulation of melanoma progression, we investigated the effect of DETA/NO on levels of APE/Ref-1 and related downstream targets [activator protein-1 (AP-1)/JunD, matrix metalloproteinase-1 (MMP-1), Bcl-2, and inducible nitric oxide synthase (iNOS)] by Western blot and reverse transcription-PCR analysis. Following DETA/NO treatment, APE/Ref-1 and other downstream molecules were induced. Knockdown of APE/Ref-1 or AP-1/JunD by specific small interfering RNA markedly reversed the induction by NO stress of target proteins. These results present evidence for the existence of a functional feedback loop contributing to progression and metastasis of melanoma cells. Resveratrol has been shown to be an APE/Ref-1 inhibitor and significant decreases in AP-1/JunD, MMP-1, Bcl-2, and iNOS protein levels occurred after exposure to resveratrol. This phenolic antioxidant may be an appropriate choice for combining with other compounds that develop resistance by up-regulation of these molecules.

Topics: Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Cell Proliferation; Disease Progression; DNA-(Apurinic or Apyrimidinic Site) Lyase; Feedback, Physiological; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Melanoma; Models, Biological; Neoplasm Metastasis; Nitric Oxide; Resveratrol; Stilbenes; Transcription Factor AP-1

Although many human melanomas express the death receptors TRAIL-R2/DR5 or TRAIL-R1/DR4 on cell surface, they often exhibit resistance to exogenous TRAIL. One of the main contributors to TRAIL-resistance of melanoma cells is upregulation of transcription factors STAT3 and NF-kappaB that control the expression of antiapoptotic genes, including cFLIP and Bcl-xL. On the other hand, the JNK-cJun pathway is involved in the negative regulation of cFLIP (a caspase-8 inhibitor) expression. Our observations indicated that resveratrol, a polyphenolic phytoalexin, decreased STAT3 and NF-kappaB activation, while activating JNK-cJun that finally suppressed expression of cFLIP and Bcl-xL proteins and increased sensitivity to exogenous TRAIL in DR5-positive melanomas. Interestingly, resveratrol did not increase surface expression of DR5 in human melanomas, while gamma-irradiation or sodium arsenite treatment substantially upregulated DR5 expression. Hence, an initial increase in DR5 surface expression (either by gamma-irradiation or arsenite), and subsequent downregulation of antiapoptotic cFLIP and Bcl-xL (by resveratrol), appear to constitute an efficient approach to reactivate apoptotic death pathways in TRAIL-resistant human melanomas. In spite of partial suppression of mitochondrial function and the mitochondrial death pathway, melanoma cells still retain the potential to undergo the DR5-mediated, caspase-8-dependent death pathway that could be accelerated by either an increase in DR5 surface expression or suppression of cFLIP. Taken together, these results suggest that resveratrol, in combination with TRAIL, may have a significant efficacy in the treatment of human melanomas.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis Regulatory Proteins; CASP8 and FADD-Like Apoptosis Regulating Protein; Cell Line, Tumor; Gene Expression Regulation; Humans; Melanoma; NF-kappa B; Receptors, TNF-Related Apoptosis-Inducing Ligand; Resveratrol; STAT3 Transcription Factor; Stilbenes; TNF-Related Apoptosis-Inducing Ligand

To test the efficacy of resveratrol, a nontoxic plant product, in the treatment of uveal melanoma.. The effect of oral administration and peritumor injection of resveratrol was tested on tumor growth in two animal models of uveal melanoma. The mechanism of resveratrol action on uveal melanoma cells was studied in vitro in a cell-viability assay: with JC-1 dye, to measure mitochondrial membrane potential; by Western blot analysis, to analyze the cellular redistribution of cytochrome c and Smac/diablo; and in a fluorescence assay with specific substrates, to measure activation of different caspases.. Resveratrol treatment inhibited tumor growth in animal models of uveal melanoma. Since oral administration resulted in relatively low bioavailability of resveratrol, the effect of increased local levels was tested by peritumor injection of the drug. This method resulted in tumor cell death and tumor regression. In vitro experiments with multiple uveal melanoma cell lines demonstrate that resveratrol causes a decrease in cell viability, resulting at least in part from an increase in apoptosis through a mitochondrial pathway. An early event in drug action is the direct targeting of mitochondria by resveratrol, which leads to a decrease in mitochondrial membrane potential and the eventual activation of caspase-3.. These data suggest that resveratrol can inhibit tumor growth and can induce apoptosis via the intrinsic mitochondrial pathway and that by further increasing bioavailability of resveratrol the potency of the drug can be increased, leading to tumor regression. The nontoxic nature of the drug at levels needed for therapy make resveratrol an attractive candidate for the treatment of uveal melanoma.

Topics: Administration, Oral; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Apoptosis Regulatory Proteins; Biological Availability; Blotting, Western; Caspase 3; Caspase 9; Cell Line, Tumor; Cell Survival; Cytochromes c; Disease Models, Animal; Dose-Response Relationship, Drug; Intracellular Signaling Peptides and Proteins; Melanoma; Membrane Potential, Mitochondrial; Mice; Mice, Nude; Mitochondria; Mitochondrial Proteins; Resveratrol; Stilbenes; Transplantation, Heterologous; Uveal Neoplasms

The incidence of melanoma continues to dramatically increase in most Western countries with predominantly Caucasian populations. However, only limited therapies for the metastatic stage of the disease are currently available. The main purpose of this study is to determine approaches that can substantially increase radiosensitivity of melanoma cells. The PI3K-AKT, NF-kappaB and COX-2 pathways, which are involved in the radioprotective response, are highly active in melanoma cells. Pharmacological suppression of COX-2 and PI3K-AKT, or RNAi-mediated knockdown of COX-2, substantially increased levels of G2/M arrest of the cell cycle and decreased clonogenic survival of gamma-irradiated melanomas, predominantly via a necrotic mechanism. On the other hand, resveratrol, a polyphenolic phytoalexin, selectively targets numerous cell signaling pathways, decreasing clonogenic survival primarily via an apoptotic mechanism. In melanoma cells, resveratrol inhibits STAT3 and NF-kappaB-dependent transcription, culminating in suppression of cFLIP and Bcl-xL expression, while activating the MAPK- and the ATM-Chk2-p53 pathways. Resveratrol also upregulates TRAIL promoter activity and induces TRAIL surface expression in some melanoma cell lines, resulting in a rapid development of apoptosis. Sequential treatment of melanoma cells, first with gamma-irradiation to upregulate TRAIL-R surface expression, and then with resveratrol to suppress antiapoptotic proteins cFLIP and Bcl-xL and induce TRAIL surface expression, had dramatic effects on upregulation of apoptosis in some melanoma lines, including SW1 and WM35. However, for melanoma lines exhibiting suppressed translocation of TRAIL to the cell surface, a necrotic mechanism of cell death was primarily involved in radiation response. Hence, surface expression of TRAIL induced by resveratrol appears to be a decisive event, one which determines an apoptotic versus a necrotic response of melanoma cells to sequential treatment.

Topics: Animals; Apoptosis; Cell Cycle; Cell Line, Tumor; Chromones; Combined Modality Therapy; Cyclooxygenase 2 Inhibitors; Gamma Rays; Humans; MAP Kinase Signaling System; Melanoma; Mice; Morpholines; Nitrobenzenes; Phosphoinositide-3 Kinase Inhibitors; Radiation-Sensitizing Agents; Resveratrol; RNA Interference; Signal Transduction; Stilbenes; Sulfonamides; TNF-Related Apoptosis-Inducing Ligand

The concept of 'vasculogenic mimicry' (VM) was introduced to describe the unique ability of highly invasive tumor cells to form capillary-like structures (CLS) and matrix-rich patterned network in three-dimensional culture that mimic embryonic vasculogenic network. Recently, we have shown that CLS formation requires apoptotic cell death through activation of caspase-3-dependent mechanism. In this study, to identify some molecular determinants driving aggressive melanoma cells to express a latent 'angiogenic program' that recapitulates the early events of CLS formation, we focused on the involvement of antioxidants (AOs) in the process of melanoma VM. We have studied the effects of resveratrol, (-)-epigallocathechin gallate, N-acetyl-cysteine (NAC) and Trolox on the ability of melanoma cells to form/destroy CLS. We observed that the formation of CLS was strongly related to reactive oxygen species level. In vivo animal experiments confirmed the involvement of reactive oxygen species level in melanoma VM. To understand the molecular mechanisms of this phenomenon, we specifically looked for induction of apoptosis and vascular endothelial growth factor (VEGF) release. Western blot analysis revealed that the level of VEGF, VEGF receptors (VEGF-Rs) and active caspase-3 dramatically decreased in cells treated with AOs. Here, we also report further experiments designed to determine whether the crosstalk between AOs and apoptosis exists in melanoma VM.

Topics: Angiogenesis Inhibitors; Animals; Antioxidants; Apoptosis; Capillaries; Caspase 3; Cell Line, Tumor; Cytochromes c; Female; Humans; Melanoma; Mice; Mice, Inbred C57BL; Neovascularization, Pathologic; Reactive Oxygen Species; Resveratrol; Stilbenes; Vascular Endothelial Growth Factor A

Resveratrol has been shown to have anticarcinogenic activity. We previously found that resveratrol inhibited growth and induced apoptosis in 2 human melanoma cell lines. In this study we determined whether resveratrol would inhibit human melanoma xenograft growth. Athymic mice received control diets or diets containing 110 micromol/L or 263 micromol/L resveratrol, 2 wk prior to subcutaneous injection of the tumor cells. Tumor growth was measured during a 3-wk period. Metabolism of resveratrol was assayed by bolus gavage of 75 mg/kg resveratrol in tumor-bearing and nontumor-bearing mice. Pellets containing 10-100 mg resveratrol were implanted into the mice, next to newly palpated tumors, and tumor growth determined. We also determined the effect of a major resveratrol metabolite, piceatannol, on experimental lung metastasis. Resveratrol, at any concentration tested, did not have a statistically significant effect on tumor growth. The higher levels of resveratrol tested (0.006% in food or 100 mg in slow-release pellets) tended to stimulate tumor growth (P = 0.08-0.09). Resveratrol and its major metabolites, resveratrol glucuronide and piceatannol, were found in serum, liver, skin, and tumor tissue. Piceatannol did not affect the in vitro growth of a murine melanoma cell line, but significantly stimulated the number of lung metastases when these melanoma cells were directly injected into the tail vein of the mouse. These results suggest that resveratrol is not likely to be useful in the treatment of melanoma and that the effects of phytochemicals on cell cultures may not translate to the whole animal system.

Topics: Animals; Anticarcinogenic Agents; Cell Division; Cell Line, Tumor; Chromatography, High Pressure Liquid; Delayed-Action Preparations; Diet; Drug Implants; Humans; Lung Neoplasms; Male; Melanoma; Mice; Mice, Inbred C57BL; Mice, Nude; Neoplasm Metastasis; Neoplasm Transplantation; Oxidation-Reduction; Resveratrol; Stilbenes; Transplantation, Heterologous

Resveratrol has demonstrated preventive and therapeutic activities in a variety of tumors. However, the mechanistic basis of its pharmacological effects on human melanoma has not been well defined. Our results demonstrated that resveratrol significantly inhibited melanoma anchorage-independent growth, and even at high doses no distinct apoptosis or cell cycle arrest was observed. It is noteworthy that c83-2c (metastatic) and wm3211 (radial growth phase) melanoma cells became more dendritic shaped with resveratrol treatment. Major histocompatibility complex (MHC) class I antigen and Fas/CD95 constitutive surface expression levels were, respectively, increased by 2.7- and 1.6-fold of control in c83-2c cells. Resveratrol reduced both activator protein-1 (AP-1) DNA binding and transcriptional activities, and supershift assay revealed that AP-1 composition was shifted from c-Jun/JunD/Fra-1 to JunD/Fra-1/Fra-2, with markedly increased JunD, Fra-1, and Fra-2 protein expression levels in the nucleus. Furthermore, we overexpressed Fra-2 in human melanoma cells by using a Fra-2 expression construct and both AP-1 transcriptional activity and 12-O-tetradecanoylphorbol-induced transcriptional transactivation were reduced significantly, whereas MHC class I antigen and Fas/CD95 levels were elevated to 2.0 and 1.8 times of control, respectively. Addition of H(2)O(2) (10 muM) partially reversed the inhibition of colony proliferation; however, no effects on either MHC class I antigen or Fas expression was evident. Although H(2)O(2) restored participation of c-Jun in AP-1 complexes, H(2)O(2) addition did not affect the induction of Fra-1 and Fra-2 by resveratrol nor the morphological changes. We propose that alterations in AP-1 transcription signaling, mediated by changes in AP-1 dimeric composition and reduced intracellular reactive oxygen species levels, substantially contribute to the phenotypic changes induced by resveratrol.

Topics: Antioxidants; Apoptosis; Cell Cycle; Cell Line; Cell Line, Tumor; Humans; Infant, Newborn; Melanocytes; Melanoma; Phenotype; Reactive Oxygen Species; Resveratrol; Stilbenes; Tetradecanoylphorbol Acetate; Transcription Factor AP-1; Transcription, Genetic

Resveratrol (trans-3,4',5-trihydroxystilbene) is a grape-derived polyphenol under intensive study for its potential in cancer prevention. In the case of cultured human melanoma cells, no one to our knowledge has investigated whether resveratrol exerts similar anti-proliferative activities in cells with different metastatic potential. Therefore, we examined the effects of this polyphenol on the growth of weakly metastatic Line IV clone 3 and on autologous, highly metastatic Line IV clone 1 cultured melanoma cells. Comparable inhibition of growth and colony formation resulted from treatment by resveratrol in both cell lines. Flow cytometric analysis revealed that resveratrol-treated clone 1 cells had a dose-dependent increase in S phase and a concomitant reduction in the G(1) phase. No detectable change in cell cycle phase distribution was found in similarly treated clone 3 cells. Western blots demonstrated a significant increase in the expression of the tumor suppressor gene p53, without a commensurate change in p21 and several other cell cycle regulatory proteins in both cell types. Chromatography of Line IV clone 3 and clone 1 cell extracts on resveratrol affinity columns revealed that the basal expression of dihydronicotinamide riboside quinone reductase 2 (NQO2) was higher in Line IV clone 1 than clone 3 cells. Levels of NQO2 but not its structural analog NQO1 were dose-dependently increased by resveratrol in both cell lines. We propose that induction of NQO2 may relate to the observed increased expression of p53 that, in turn, contributes to the observed suppression of cell growth in both melanoma cell lines.

Topics: Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Cell Proliferation; Gene Expression Regulation, Neoplastic; Humans; Melanoma; Quinone Reductases; Resveratrol; Stilbenes; Tumor Suppressor Protein p53; Up-Regulation

Apurinic/apyrimidinic endonuclease-1/redox factor-1 (APE/Ref-1) is a multifunctional protein involved in DNA base excision repair and redox regulation of many transcription factors. In different melanoma cell lines, we found that both nucleus and cytoplasm exhibited higher levels of Ref-1 compared with normal melanocytes. Similar increases of Ref-1 expression, detected by immunohistofluorescence, were also evident in nevi and malignant melanoma biopsies compared with normal skin, which were predominantly localized in the nucleus. Using recombinant adenovirus Adref-1, encoding full-length Ref-1, we transiently overexpressed APE/Ref-1 in human melanocytes, which protected these cells from UVB-induced apoptosis and increased foci formation in culture. Ref-1 overexpression also protected melanoma cells from cisplatin- or H2O2-induced apoptosis, whereas increased apoptosis was observed with Ref-1 antisense construct infection. These observations suggested that intracellular Ref-1 levels played an important role in sensitization of melanoma cells to apoptosis. Electrophoretic mobility shift assay results showed that in both cultured primary and metastatic melanomas DNA-binding activities of activator protein-1 and nuclear factor-kappaB were significantly diminished or shifted when anti-APE/Ref-1 antibody was added to deplete APE/Ref-1 from the binding complexes. Induced nuclear factor-kappaB transcriptional activities were also evident after Ref-1 overexpression. Furthermore, using three-dimensional molecular structure modeling and virtual screening, we found that resveratrol, a natural compound found in fruits and vegetables, docks into a druggable pocket of Ref-1 protein. In vitro studies revealed that resveratrol inhibited, in a dose-dependent manner, Ref-1-activated activator protein-1 DNA-binding activities as well as Ref-1 endonuclease activities and rendered melanoma cells more sensitive to dacarbazine treatment.

Topics: DNA-(Apurinic or Apyrimidinic Site) Lyase; Electrophoretic Mobility Shift Assay; Enzyme Inhibitors; Fluorescent Antibody Technique; Humans; Melanocytes; Melanoma; Recombinant Proteins; Resveratrol; Stilbenes

Survivin is a member of the inhibitor of apoptosis proteins that is expressed at high levels in most human cancers and may facilitate evasion from apoptosis and aberrant mitotic progression. Naturally occurring dietary compounds such as resveratrol have gained considerable attention as cancer chemopreventive agents. Here, we discovered a novel function of the chemopreventive agent resveratrol: resveratrol is a potent sensitizer of tumor cells for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis through p53-independent induction of p21 and p21-mediated cell cycle arrest associated with survivin depletion. Concomitant analysis of cell cycle, survivin expression, and apoptosis revealed that resveratrol-induced G(1) arrest was associated with down-regulation of survivin expression and sensitization for TRAIL-induced apoptosis. Accordingly, G(1) arrest using the cell cycle inhibitor mimosine or induced by p21 overexpression reduced survivin expression and sensitized cells for TRAIL treatment. Likewise, resveratrol-mediated cell cycle arrest followed by survivin depletion and sensitization for TRAIL was impaired in p21- deficient cells. Also, down-regulation of survivin using survivin antisense oligonucleotides sensitized cells for TRAIL-induced apoptosis. Importantly, resveratrol sensitized various tumor cell lines, but not normal human fibroblasts, for apoptosis induced by death receptor ligation or anticancer drugs. Thus, this combined sensitizer (resveratrol)/inducer (e.g., TRAIL) strategy may be a novel approach to enhance the efficacy of TRAIL-based therapies in a variety of human cancers.

Topics: Anticarcinogenic Agents; Apoptosis; Apoptosis Regulatory Proteins; Base Sequence; Brain Neoplasms; Breast Neoplasms; Caspase Inhibitors; Caspases; Cell Cycle; Cell Division; Cell Line, Tumor; Cysteine Proteinase Inhibitors; DNA Primers; Female; Humans; Male; Melanoma; Membrane Glycoproteins; Pancreatic Neoplasms; Prostatic Neoplasms; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; Stilbenes; TNF-Related Apoptosis-Inducing Ligand; Tumor Necrosis Factor-alpha

Resveratrol, a polyphenol present in many plant species, exhibits a wide range of biological and pharmacological activities both in vitro and in vivo. It has been shown to exert a potent chemopreventive effect in carcinogenesis models and to induce cell growth inhibition and apoptosis in human tumour cells, including melanoma cells. Malignant melanoma is considered to be a chemotherapy-refractory tumour, and the commonly used anticancer drugs do not seem to modify the prognosis of metastatic disease. To further evaluate the therapeutic potential of resveratrol in the treatment of melanoma, we selected three human melanoma cell lines with different levels of resistance to temozolomide (TMZ), an antitumour triazene compound. The cell lines were subjected to resveratrol treatment and analysed for cell growth inhibition, cell cycle perturbation and apoptosis induction. We found that resveratrol markedly impaired proliferation of both the TMZ-sensitive M14 and the TMZ-resistant SK-Mel-28 and PR-Mel cell lines. The latter cell line was two-fold more resistant to the drug than M14 and SK-Mel-28 cells. The sensitivity of normal human keratinocytes to resveratrol was found to be significantly higher than that of M14 and SK-Mel-28 cells and similar to that of the PR-Mel cell line. This suggests a possible good in vivo therapeutic index for resveratrol. Our results also show that the growth-inhibitory effect of resveratrol on melanoma cells is mainly due to its ability to induce S-phase arrest and apoptosis. Taken together, our data indicate that resveratrol is an interesting candidate for the treatment of advanced melanoma.

Topics: Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Dacarbazine; Drug Resistance, Neoplasm; Humans; Inhibitory Concentration 50; Keratinocytes; Melanoma; Necrosis; Poly(ADP-ribose) Polymerases; Resveratrol; S Phase; Stilbenes; Temozolomide; Time Factors

The resveratrol analogue piceatannol (3,5,3',4'-tetrahydroxy- trans-stilbene; PICE) is a polyphenol present in grapes and wine. PICE is a protein kinase inhibitor that modifies multiple cellular targets exerting immunosuppressive, antileukemic and antitumorigenic activities in several cell lines and animal models. The present work aims to evaluate the antimelanoma effect of PICE on human melanoma cells for the first time. To this purpose, the pro-apoptotic capacity, uptake and metabolism of PICE as well as its effect on cell cycle and cyclins A, E and B1 expression will be studied.. . Human SK-Mel-28 melanoma cells were incubated with PICE (1-200 microM) for 72 hours. Cell cycle and viability were examined using flow cytometry analysis. Apoptosis was determined using the annexin V assay and also by fluorescence microscopy. Cyclins A, E and B1 were detected by Western blotting. Stability, cellular uptake and metabolism of PICE were evaluated using HPLC-DAD-MS-MS.. The lowest PICE concentration assayed (1 microM) increased about 6-fold over the control the apoptotic population of melanoma cells (10.2% at 8 hours which remained constant during 48 h). 100 microM PICE induced 13% apoptosis at 8 h increasing up to 41.5% at 48 h. The decrease in cell viability was highly correlated with the increase of apoptotic cells ( R = 0.996; P < 0.0001) revealing that significant cytotoxic, unspecific effects did not occur in melanoma cells upon incubation with PICE. Cell cycle was arrested at G(2) phase which was supported by the down-regulation of cyclins A, E and B1. Two methyl-PICE derived metabolites, 3,5,4'-trihydroxy-3'-methoxy- trans-stilbene and 3,5,3'-trihydroxy-4'-methoxy- trans-stilbene (corresponding to 36% of the initially PICE added) were excreted by cells to the medium. The same methyl-PICE derivatives were also found inside the cells (0.01% of the initially PICE added; 0.0183 picograms/cell).. The antimelanoma properties of dietary piceatannol cannot be ruled out taking into account its fast and potent pro-apoptotic capacity at low concentration (1 microM).

Topics: Apoptosis; Cell Cycle; Cell Division; Cell Survival; Dose-Response Relationship, Drug; Down-Regulation; Flow Cytometry; Humans; Melanoma; Stilbenes; Tumor Cells, Cultured; Vitis; Wine

We have developed a simple yet sensitive dual color fluorescence-based technique for dissecting the tumor-neovascularization relationship and evaluated the susceptibility of each component to therapeutic interventions. Green fluorescent protein (GFP)-expressing melanoma cells were cocultured with endothelial cells on different three-dimensional (3-D) matrices and exposed to multiple growth factors and molecules with established anti-angiogenic or anticancer activities. Cells were fixed and stained with propidium iodide, imaged using a confocal microscope, and stereologically analyzed. Three-dimensionality of the system was tested by depth-coding and pseudocolor 3-D reconstruction in the z-axis. Selective ablation of the tumor cells was affected by the anthracycline antibiotic doxorubicin. Treatment with vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) promoted the neovascular responses on matrigel and collagen-1 matrices. VEGF-induced angiogenesis was inhibited after treatment with combretastatin and thalidomide. In contrast, HGF exerted a protective effect against these anti-angiogenics in a matrigel matrix. However, this effect was lost when the matrix was substituted with collagen, suggesting that the extracellular matrix impinges on cellular function, possibly through an Akt-mediated mechanism. The VEGF-receptor antagonist PTK787 also selectively ablated the VEGF-induced angiogenic effect without inhibiting the HGF-induced response, demonstrating the sensitivity of the system to detect modulation of distinct signal cascades. The current model encompasses the possibility of studying tumor-angiogenesis-matrix interaction on the same platform, expanding the rapid screening of novel molecules in a simulated clinicopathological setting.

Topics: Angiogenesis Inhibitors; Antineoplastic Agents; Bibenzyls; Cell Line, Tumor; Coculture Techniques; Doxorubicin; Extracellular Matrix; Fluorescence; Hepatocyte Growth Factor; Humans; Melanoma; Neoplasms; Neovascularization, Pathologic; Phthalazines; Pyridines; Stilbenes; Thalidomide; Vascular Endothelial Growth Factor A

Resveratrol is a plant polyphenol found in grapes and red wine. It has been found to have beneficial effects on the cardiovascular system. Resveratrol also inhibits the growth of various tumor cell lines in vitro and inhibits carcinogenesis in vivo. In this study we examined the effect of resveratrol on growth of two human melanoma cell lines. We found that this plant polyphenol inhibited growth and induced apoptosis in both cell lines, with the amelanotic cell line A375 being more sensitive. The potential involvement of different MAP kinases in the action of resveratrol was also examined. Although resveratrol did not alter the phosphorylation of p38 or JNK MAP kinases in either cell line, it induced phosphorylation of ERK1/2 in A375, but not in SK-mel28 cells. These results suggest that in vivo studies of the effect of resveratrol on melanoma are warranted and that this plant polyphenol might have effectiveness as either a therapeutic or chemopreventive agent against melanoma.

Topics: Anticarcinogenic Agents; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Division; DNA Fragmentation; Humans; MAP Kinase Signaling System; Melanoma; Resveratrol; Stilbenes; Tumor Cells, Cultured

The effect of the naturally occurring polyphenol resveratrol (3,5,4'-trihydroxy-trans-stilbene; RES) on growth, cell cycle, and cyclins A, E, and B1 expression was investigated in the human SK-Mel-28 melanoma cell line. In addition, the structurally related compounds 4-hydroxy-trans-stilbene (4HST), piceatannol (3,5,3',4'-tetrahydroxy-trans-stilbene (PICE), and 4-trans-stilbenemethanol (4STMe) were also assayed in order to investigate the requirements of stilbenes to exert activity against melanoma cells. Both RES and 4HST inhibited cell growth in a dose- and time-dependent manner and upregulated the expression of cyclins A, E, and B1 with subsequent irreversible arrest of melanoma cells in the S-phase, concomitant with a decrease in G0/G1 and G2/M phases. In addition, potent apoptosis-mediated cell death was detected with the annexin V assay whereas no apoptosis was observed by flow cytometry, which encourages the assay of different methodologies to evaluate the effect of polyphenols on cell lines. The effect of PICE was not evaluated because of its instability in the reaction medium. No effect on cell cycle and cyclins expression was observed when 4STMe was assayed, which supported the critical requirement of the 4'-hydroxystyryl moiety to exert the above effects. In addition, this structural requirement also influenced the cellular uptake of stilbenes. The presence of two extra hydroxyl groups in RES increased its cytotoxicity whereas it diminished its efficiency to inhibit cell growth, upregulate cyclins expression, and arrest cell cycle in the S-phase with respect to 4HST. The present study suggests that the antimelanoma properties of dietary stilbenes, such as grape RES, cannot be ruled out, taking into account previous studies concerning the relationship between plasma and tissue concentrations and pharmacological activity of RES in animal models.

Topics: Apoptosis; Cell Cycle; Cell Division; Cyclin A; Cyclin B; Cyclin B1; Cyclin E; Cyclins; Fruit; Humans; Melanoma; Resveratrol; S Phase; Stilbenes; Tumor Cells, Cultured; Vitis

5,6-Dimethylxanthenone-4-acetic acid (DMXAA) and combretastatin A4 phosphate (CA-4-P) markedly inhibit tumor blood flow in mice and are both currently in clinical trial. One of the challenges in clinical evaluation of antivascular agents is the monitoring of tumor blood flow inhibition in individual patients. This study investigates, using mouse models, whether a new marker for tissue hypoxia, (99m)technetium-labeled 2,2'-(1,4-diaminobutane)bis(2-methyl-3-butanone) dioxime (99mTc-labeled HL-91; Prognox)] has potential for the scintigraphic monitoring of tumor response to antivascular agents. Determination of radioactivity in dissected tissues 3 h after DMXAA (80 micromol/kg) or CA-4-P (227 micromol/kg) was injected indicated that both drugs inhibited blood flow (86RbCl uptake; 84 and 87%, respectively) and increased 99mTc-labeled HL-91 levels (350 and 300%, respectively) selectively in murine RIF-1 tumors. Planar imaging of 99mTc-labeled HL-91 3 h after DMXAA injection showed a dose-dependent increase in tumor levels above a threshold of 50 micromol/kg; this same threshold was observed for the inhibition of tumor blood flow (determined using Hoechst 33342). DMXAA also inhibited blood flow--and increased 99mTc-labeled HL-91 uptake--in MDAH-MCa-4 mouse mammary carcinomas and in NZMN10 human melanoma xenografts. Whether 99mTc-labeled HL-91 might also be useful as a biomarker for tumor cell killing was investigated by clonogenic assay of surviving cells 15 h after imaging 99mTc-labeled HL-91 in RIF-1 tumors. Log cell kill in individual tumors showed a statistically significant linear correlation (P < 0.001) with 99mTc-labeled HL-91 uptake after 60 micromol/kg (r2 = 0.79) and 70 micromol/kg (r2 = 0.44) but not at 80 micromol/kg DMXAA. The lack of correlation at high doses presumably reflects the insensitivity of the tumor-averaged 99mTc-labeled HL-91 signal to small regions in which tumor blood flow is preserved (which will limit log cell kill). The results indicate the potential of 99mTc-labeled HL-91 for the noninvasive imaging of tumor blood flow inhibition by antivascular drugs in humans.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Biomarkers, Tumor; Cell Hypoxia; Fibrosarcoma; Humans; Mammary Neoplasms, Experimental; Melanoma; Mice; Mice, Inbred C3H; Neoplasm Transplantation; Neoplasms, Experimental; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Radiopharmaceuticals; Stilbenes; Xanthenes; Xanthones

A series of stilbenes has been prepared and tested for cytotoxicity in the five human cancer cell lines A-549 non-small cell lung, MCF-7 breast, HT-29 colon, SKMEL-5 melanoma, and MLM melanoma. The cis stilbenes 6a-f proved to be cytotoxic in all five cell lines, with potencies comparable to that of combretastatin A-4. These cytotoxic compounds were all potent inhibitors of tubulin polymerization. The corresponding trans stilbenes 7b-f were inactive as tubulin polymerization inhibitors and were significantly less cytotoxic in the five cancer cell lines. In the dihydro series, 8b, 8c, and 8f were inactive as tubulin polymerization inhibitors, while 8a, 8d, and 8e were less active than the corresponding cis compounds 6a, 6d, and 6e. The lack of tubulin polymerization inhibitory activity and cytotoxicity displayed by the phenanthrene 23b, which was synthesized as a conformationally rigid analogue of the lead compound 1, indicates that the activity of the stilbenes is not due to a totally planar conformation. Similarly, inactivity of the conformationally restricted analogue 26 suggests that the biologically active conformation of 1a resembles that of the cis alkene 1. Additional inactive compounds prepared include the benzylisoquinoline series 28-32 as well as the protoberberines 38 and 39. Shortening the two-carbon bridge of 1a to a one-carbon bridge in the diphenylmethane 20 resulted in a decrease in cytotoxicity and tubulin polymerization inhibitory activity. Although the corresponding benzophenone 18 was as active as 1a as a tubulin polymerization inhibitor, it was less cytotoxic than 1a, and the benzhydrol 19 was essentially inactive. With the exception of the amide 15c, which displayed low antitubulin activity, all of the phenylcinnamic acid derivatives 14a-c and 15a-f were inactive in the tubulin polymerization inhibition assay. The acid 14b and the ester 15a were cytotoxic in several of the cancer cell cultures in spite of their inactivity as tubulin polymerization inhibitors.

Topics: Antineoplastic Agents; Breast Neoplasms; Cell Division; Colonic Neoplasms; Humans; Lung Neoplasms; Melanoma; Stilbenes; Structure-Activity Relationship; Tubulin; Tubulin Modulators; Tumor Cells, Cultured

An array of cis-, trans-, and dihydrostilbenes and some N-arylbenzylamines were synthesized and evaluated for their cytotoxicity in the five cancer cell cultures A-549 lung carcinoma, MCF-7 breast carcinoma, HT-29 colon adenocarcinoma, SKMEL-5 melanoma, and MLM melanoma. Several cis-stilbenes, structurally similar to combretastatins, were highly cytotoxic in all five cell lines and these were also found to be active as inhibitors of tubulin polymerization. The most active compounds also inhibited the binding of colchicine to tubulin. The most potent of the new compounds, both as a tubulin polymerization inhibitor and as a cytotoxic agent, was (Z)-1-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)ethene (5a). This substance was almost as potent as combretastatin A-4 (1a), the most active of the combretastatins, as a tubulin polymerization inhibitor. Compound 5a was found to be approximately 140 times more cytotoxic against HT-29 colon adenocarcinoma cells and about 10 times more cytotoxic against MCF-7 breast carcinoma cells than combretastatin A-4. However, 5a was found to be about 20 times less cytotoxic against A-549 lung carcinoma cells, 30 times less cytotoxic against SKMEL-5 melanoma cells, and 7 times less cytotoxic against MLM melanoma cells than combretastatin A-4. The relative potencies 5a greater than 8a greater than 6a for the cis, dihydro, and trans compounds, respectively, as inhibitors of tubulin polymerization are in agreement with the relative potencies previously observed for combretastatin A-4 (1a), dihydrocombretastatin A-4 (1c), and trans-combretastatin A-4 (1b). The relative potencies 5a greater than 8a greater than 6a were also reflected in the results of the cytotoxicity assays. Structure-activity relationships of this group of compounds are also discussed.

Topics: Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Breast Neoplasms; Chemical Phenomena; Chemistry; Colchicine; Colonic Neoplasms; Humans; Lung Neoplasms; Melanoma; Molecular Structure; Polymers; Stilbenes; Structure-Activity Relationship; Tubulin; Tubulin Modulators; Tumor Cells, Cultured

Topics: Acetylesterase; Acid Phosphatase; Eosinophils; Esterases; Histocytochemistry; Humans; Lymphocytes; Macrophages; Mast Cells; Melanoma; Neutrophils; Peroxidases; Plasma Cells; Skin Neoplasms; Stilbenes; Thiocyanates