naphthoquinones and Melanoma

β-Lapachone is an ortho-naphthoquinone originally isolated from the heartwood of Handroanthus impetiginosus and can be obtained through synthesis from lapachol, naphthoquinones, and other aromatic compounds. β-Lapachone is well known to inhibit topoisomerase I and to induce NAD(P)H: quinone oxidoreductase 1. Currently, phase II clinical trials are being conducted for the treatment of pancreatic cancer. In view of ever-increasing scientific interest in this naphthoquinone, herein, the authors present a review of the synthesis, physicochemical properties, biological activities, and toxicity of β-lapachone. This natural compound has shown activity against several types of malignant tumors, such as lung and pancreatic cancers and melanoma. Furthermore, this ortho-naphthoquinone has antifungal and antibacterial activities, underscoring its action against resistant microorganisms and providing anti-inflammatory, antiobesity, antioxidant, neuroprotective, nephroprotective, and wound-healing properties. β-Lapachone presents low toxicity, with no signs of toxicity against alveolar macrophages, dermal fibroblast cells, hepatocytes, or kidney cells.

Topics: Anti-Infective Agents; Humans; Melanoma; Naphthoquinones; Wound Healing

The cyclotron-produced radiohalogen, 211At, is eminently suitable as a possible therapeutic radionuclide. It decays by the emission of 6.8 MeV mean energy alpha-particles, which from a radiobiological viewpoint are of near optimal therapeutic LET. This paper reviews developments in the possible application of [211At]astato-labelled molecules as potential anti-tumour agents. Additionally, radio-dosimetric evidence is presented, and its implications for human cancer therapy are discussed.

Topics: Animals; Antibodies, Monoclonal; Astatine; Humans; Melanoma; Naphthoquinones; Neoplasms; Nucleic Acid Precursors; Radiotherapy Dosage

Some pharmacologic properties of nine antitumor agents from higher plants are described. The agents are vincristine, vinblastine the epiodophyllotoxin derivatives VM-26 and VP-16-213, maytansine, bruceantin, thalicarpine, camptothecin, and lapachol. When sufficient information is available, the agents are discussed with regard to their antitumor activity, mechanism of action, pharmacologic disposition, structure-activity relationships, and toxicity.

Topics: Animals; Antineoplastic Agents, Phytogenic; Aporphines; Camptothecin; Carcinoma, Squamous Cell; Chemical Phenomena; Chemistry; Etoposide; Humans; Leukemia L1210; Leukemia, Experimental; Leukemia, Lymphoid; Maytansine; Melanoma; Naphthoquinones; Nasopharyngeal Neoplasms; Neoplasms; Neoplasms, Experimental; Phenanthrenes; Structure-Activity Relationship; Teniposide; Vinblastine; Vincristine

Survivin is a microtubule-associated protein believed to be involved in preserving cell viability and regulating tumor cell mitosis, and it is overexpressed in many primary tumor types, including melanoma. YM155 is a first-in-class survivin suppressant. The purpose of this Phase 2 study was to evaluate the 6-month progression-free survival (PFS) rate in patients with unresectable Stage III or IV melanoma receiving a combination of YM155 plus docetaxel. The study had two parts: Part 1 established the dose of docetaxel that was tolerable in combination with YM155, and Part 2 evaluated the tolerable docetaxel dose (75 mg/m(2) ) in combination with YM155 (5 mg/m(2) per day continuous infusion over 168 h every 3 weeks). The primary endpoint was 6-month PFS rate. Secondary endpoints were objective response rate (ORR), 1-year overall survival (OS) rate, time from first response to progression, clinical benefit rate (CBR), and safety. Sixty-four patients with metastatic melanoma were treated with docetaxel and YM155. Eight patients received an initial docetaxel dose of 100 mg/m(2) and 56 patients received 75 mg/m(2) of docetaxel. Six-month PFS rate per Independent Review Committee (IRC) was 34.8% (n = 64; 95% CI, 21.3-48.6%), and per Investigator was 31.3% (n = 64; 95% CI, 19.5-43.9%). The best ORR (complete response [CR] + partial response [PR]) per IRC was 12.5% (8/64). The stable disease (SD) rate was 51.6% (33/64), leading to a CBR (CR + PR + SD) of 64.1% (41/64). Estimated probability of 1-year survival was 56.3%. YM155 is a novel agent showing modest activity when combined with docetaxel for treating patients with melanoma. YM155 was generally well tolerated, but the predetermined primary efficacy endpoint (i.e., 6-month PFS rate ≥20%) was not achieved.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Biomarkers; Docetaxel; Drug Resistance, Neoplasm; Female; Humans; Imidazoles; Kaplan-Meier Estimate; Male; Melanoma; Middle Aged; Naphthoquinones; Neoplasm Metastasis; Neoplasm Staging; Taxoids; Treatment Outcome

Purpose Population pharmacokinetics (PK) of sepantronium bromide (YM155) was characterized in patients with non-small cell lung cancer, hormone refractory prostate cancer, or unresectable stage III or IV melanoma and enrolled in one of three phase 2 studies conducted in Europe or the U.S. Method Sepantronium was administered as a continuous intravenous infusion (CIVI) at 4.8 mg/m(2)/day over 7 days every 21 days. Population PK analysis was performed using a linear one-compartment model involving total body clearance (CL) and volume of distribution with an inter-individual random effect on CL and a proportional residual errors to describe 578 plasma sepantronium concentrations obtained from a total of 96 patients by NONMEM Version VI. The first-order conditional estimation method with interaction was applied. Results The one-compartment model with one random effect on CL and two different proportional error models provided an adequate description of the data. Creatinine clearance (CLCR), cancer type, and alanine aminotransferase (ALT) were recognized as significant covariates of CL. CLCR was the most influential covariate on sepantronium exposure and predicted to contribute to a 25 % decrease in CL for patients with moderately impaired renal function (CLCR = 40 mL/min) compared to patients with normal CLCR. Cancer type and ALT had a smaller but nonetheless significant contribution. Other patient characteristics such as age, gender, and race were not considered as significant covariates of CL. Conclusions The results provide the important information for optimizing the therapeutic efficacy and minimizing the toxicity for sepantronium in cancer therapy.

Topics: Adult; Aged; Aged, 80 and over; Carcinoma, Non-Small-Cell Lung; Dose-Response Relationship, Drug; Ethnicity; Female; Follow-Up Studies; Humans; Imidazoles; Infusions, Intravenous; Inhibitor of Apoptosis Proteins; Japan; Lung Neoplasms; Male; Maximum Tolerated Dose; Melanoma; Middle Aged; Models, Biological; Naphthoquinones; Neoplasm Staging; Neoplasms, Hormone-Dependent; Prognosis; Prostatic Neoplasms; Survivin; Tissue Distribution

Melanoma continues to be a major health problem with no effective therapy. Melanocytes, both benign and malignant, express many anti-apoptotic factors. Survivin is a member of the family of inhibitors of apoptosis proteins (IAP) and is preferentially expressed in tumor cells, including melanoma. YM155 is a small molecule suppressant of survivin that has been shown in preclinical cell lines, xenograft models and phase I studies to have anti-tumor activity.. This was an open-label, multi-center, study of YM155 monotherapy in subjects with unresectable stage III or IV melanoma. Thirty-four chemotherapy naïve subjects were treated with YM155 at a dose of 4.8 mg/m(2)/day administered by continuous infusion for 168-hours (7 days) followed by a 14-day rest period, for up to 6 cycles or until disease progression.. One subject had a partial response to treatment seen at cycle two and lasting through cycle eight. Median progression-free survival was 1.3 months (95% CI; 1.3-2.7). Median overall survival was 9.9 months (95% CI; 7.0-14.5). Overall, YM155 was well tolerated with the most common (>20%) adverse events reported as fatigue, nausea, pyrexia, headache, arthralgia and back pain. Only four subjects required dose reductions.. YM155 was well tolerated in subjects with advanced melanoma; however, the pre-specified primary end-point for efficacy which required two responders in 29 evaluable subjects was not achieved.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Disease-Free Survival; Female; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Male; Melanoma; Microtubule-Associated Proteins; Middle Aged; Naphthoquinones; Neoplasm Staging; Skin Neoplasms; Survivin; Treatment Outcome

Melanoma treatment is highly resistant to current chemotherapeutic agents. Due to its resistance towards apoptotic cell death, non-apoptotic cell death pathways are sought after.. We investigated a Chinese herbal medicine, shikonin, and its effect on B16F10 melanoma cells in vitro.. Cell growth of B16F10 melanoma cells treated with shikonin was analyzed using an MTT assay. Shikonin was combined with necrostatin, an inhibitor of necroptosis; caspase inhibitor; 3-methyladenine, an inhibitor of autophagy; or N-acetyl cysteine, an inhibitor of reactive oxygen species. Flow cytometry was used to assess types of cell death resulting from treatment with shikonin. Cell proliferation was also analyzed utilizing a BrdU labeling assay. Monodansylcadaverine staining was performed on live cells to gauge levels of autophagy. Western blot analysis was conducted to identify specific protein markers of necroptosis including CHOP, RIP1, and pRIP1. MitoTracker staining was utilized to identify differences in mitochondrial density in cells treated with shikonin.. Analysis of MTT assays revealed a large decrease in cellular growth with increasing shikonin concentrations. The MTT assays with necrostatin, 3-methyladenine, and N-acetyl cysteine involvement, suggested that necroptosis, autophagy, and reactive oxygen species are a part of shikonin's mechanism of action. Cellular proliferation with shikonin treatment was also decreased. Western blotting confirmed that shikonin-treated melanoma cells increase levels of stress-related proteins, e.g., CHOP, RIP, pRIP.. Our findings suggest that mainly necroptosis is induced by the shikonin treatment of B16F10 melanoma cells. Induction of ROS production and autophagy are also involved.

Topics: Apoptosis; Cell Line, Tumor; Cysteine; Humans; Melanoma; Naphthoquinones; Necrosis; Reactive Oxygen Species

To verrify the anti-tumor efficacy and toxicity between juglone (Jug) and Jug-loaded PLGA nanoparticles (Jug-PLGA-NPs).. Jug-PLGA-NPs were prepared by ultrasonic emulsification. The anti-tumor activity of Jug (2, 3, 4 µg/mL) and Jug-PLGA-NPs (Jug: 2, 3, 4 µg/mL) in vitro was measured by MTT assay and cell apoptosis analysis. The distribution, anti-tumor effect and biological safety in vivo was evaluated on A375 nude mice.. With the advantage of good penetration and targeting properties, Jug-PLGA-NPs significantly inhibited proliferation and migration of melanoma cells both in vitro and in vivo (P<0.05 or P<0.01) with acceptable biocompatibility.. Jug can inhibit the growth of melanoma but is highly toxic. With the advantage of sustained release, tumor targeting, anti-tumor activity and acceptable biological safety, Jug-PLGA-NPs provide a new pharmaceutical form for future application of Jug.

Topics: Animals; Cell Line, Tumor; Delayed-Action Preparations; Drug Carriers; Melanoma; Mice; Mice, Nude; Nanoparticles; Naphthoquinones; Particle Size; Polylactic Acid-Polyglycolic Acid Copolymer

Myeloid-derived suppressor cells (MDSCs) represent a negative prognostic factor in malignant melanoma. These cells are generated under chronic inflammatory conditions typical of cancer. The transcription factor signal transducer and activator of transcription 3 (STAT3) orchestrates MDSC accumulation and acquisition of immunosuppressive properties. Here we studied STAT3 inhibition by Napabucasin as a way to block MDSC accumulation and activity and its potential to treat malignant melanoma.. Napabucasin was able to abrogate the capacity of murine MDSC to suppress CD8. Our findings demonstrate that STAT3 inhibitor Napabucasin completely abrogated the immunosuppressive capacity of murine MDSC and human M-MDSC and improved melanoma-bearing mouse survival. Moreover, patients with malignant melanoma with high expression levels of activated STAT3 in M-MDSC displayed shorter PFS, indicating its role as a promising therapeutic target in patients with malignant melanoma and a predictive marker for their clinical outcome.

Topics: Animals; Benzofurans; Humans; Melanoma; Mice; Mice, Transgenic; Myeloid-Derived Suppressor Cells; Naphthoquinones; STAT3 Transcription Factor

Melanoma is a complex and heterogenous disease, displays the deadliest form of skin cancer, and accounts for approx. 80% of all skin cancer deaths. In this study, we reported on the synthesis and pharmacological effects of a novel shikonin derivative (SK119), which is active in a nano-molar range and exhibits several promising in vitro effects in different human melanoma cells. SK119 was synthesized from shikonin as part of our search for novel, promising shikonin derivatives. It was screened against a panel of melanoma and non-tumorigenic cell lines using XTT viability assays. Moreover, we studied its pharmacological effects using apoptosis and Western blot experiments. Finally, it was combined with current clinically used melanoma therapeutics. SK119 exhibited IC

Topics: Apoptosis; Azetidines; Cell Line; Humans; Melanoma; Naphthoquinones; Piperidines; Proto-Oncogene Proteins B-raf; Skin Neoplasms; Vemurafenib

Shikonin, a natural product isolated from the roots of Lithospermum erythrorhizon, exhibits pharmacological effects against inflammation, ulcers, infections, and tumors. In the present study, we aimed to investigate the antitumor effects of shikonin on the human melanoma cell line, A375SM, and in an in vivo mouse xenograft model. We examined the anticancer effects of shikonin by in vitro experiments (MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, 4',6-diamidino-2-phenylindole (DAPI) stain, annexin V/ propidium iodide (PI) stain, and protein analysis of apoptosis and mitogen-activated protein kinase (MAPK) pathways). Further, the anticancer effect in vivo was confirmed through a xenograft model. Our results showed that shikonin inhibited the proliferation of melanoma cells in a dose-dependent manner. In addition, shikonin significantly increased nucleus and chromatin condensation and early/late apoptosis. Shikonin also increased the pro-apoptotic proteins and decreased the anti-apoptotic proteins. Additionally, shikonin was overexpressed in MAPK pathways. Investigation of the effects of shikonin in a mouse xenograft model not only showed decreased A375SM tumor volume but also increased apoptosis as determined by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. Furthermore, pathologic changes were not observed in the liver and kidney of mice. Collectively, the study indicated that shikonin inhibited the proliferation of the human melanoma cells by inducing apoptosis, mediated by MAPK pathway and that it is a potential candidate for an anticancer drug against melanoma cancer.

Topics: Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Humans; In Situ Nick-End Labeling; MAP Kinase Signaling System; Melanoma; Mice; Naphthoquinones; Neoplasm Proteins; Xenograft Model Antitumor Assays

In previous research, a series of cytotoxic anticancer analogues related to 2-acylamino-1,4-naphthoquinone derivatives has been demonstrated. As microtubule plays an important role in many essential cellular processes such as mitosis, tubulin is an important target of anticancer drug. This study performed molecular docking simulation, pharmacophore model, comparative force field analysis model and comparative similarity indices analysis model to investigate the relationship between inhibitory activities and the properties of compounds, in order to further progress the development of cytotoxic anticancer analogues. These compounds have common H-bond interactions with key residues Lys254 and Lys352, but compounds with large R2 substituent have different docking poses than compounds with small R2 substituent. Some of derivatives such as compound 18 formed the H-bonds with residue Lys254 using the oxygen atoms in R1 substituent and formed π-cation interactions with residue Lys352 using phenyl moiety of 1,4-naphthoquinone. The R1 substituent of these compounds preferred to have disfavoured hydrophobic fields and favourable space towards the direction of residue Asn258, while the R2 substituent of these compounds preferred to have about 2-3 carbon chain length hydrophobic substituent towards the direction of residues Ala316 and Lys352. These results offer some beneficial advices for further study in anticancer drug development process.

Topics: Antineoplastic Agents; Humans; Melanoma; Molecular Docking Simulation; Molecular Dynamics Simulation; Naphthoquinones; Neoplasm Proteins; Tubulin

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cyclopropanes; Humans; Melanoma; Naphthoquinones

Topics: Animals; Antineoplastic Agents; Apoptosis; Caspases; Cell Line, Tumor; DNA; DNA Fragmentation; Female; Gene Expression Regulation, Neoplastic; Humans; MAP Kinase Kinase 4; MAP Kinase Signaling System; Melanoma; Membrane Potential, Mitochondrial; Mice, Inbred C57BL; Mitochondria; Naphthoquinones; p38 Mitogen-Activated Protein Kinases; Reactive Oxygen Species

Melanoma is a malignant cancer that affects melanocytes and is considered the most aggressive skin-type cancer. The prevalence for melanoma cancer for the last five year is about one million cases. The impact caused of this and other types of cancer, revel the importance of research into potential active compounds. The natural products are an important source of compounds with biological activity and research with natural products may enable the discovery of compounds with potential activity in tumor cells.. The Sulforhodamine B was used to determine cell density after treatment with lawsone derivatives. Apoptosis and necrosis were analyzed by flow cytometer. Morphological changes were observed by fluorescence using the Phalloidin/FITC and DAPI stains. The clonogenic and wound healing assays were used to analyze reduction of colonies formation and migratory capacity of melanoma cells, respectability.. In pharmacological screening, seven compounds derived from lawsone were considered to have high cytotoxic activity (GI > 75%). Three compounds were selected to assess the inhibitory concentration for 50% of cells (IC. The results of this study showed that the evaluated lawsone derivatives have potential activity on tumor cells. The compound 9 is capable of inducing cell death by apoptosis in melanoma cells (B16F10).

Topics: Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cell Survival; Drug Screening Assays, Antitumor; Glycosides; Humans; Melanoma; Mice; Naphthoquinones; Skin Neoplasms; Tumor Stem Cell Assay

The use of natural products as potential ligands has been explored as a strategy in the development of metal-based chemotherapy. Since ruthenium complexes are promising alternatives to traditional antitumor agents, this study evaluated the anti-melanoma potential of two ruthenium(II) complexes containing the naphthoquinone ligands lapachol (lap), [Ru(lap)(dppm)

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Coordination Complexes; Ligands; Male; Melanoma; Mice, Inbred C57BL; Naphthoquinones; Phosphines; Ruthenium

Melanoma is the most aggressive form of skin cancer, with high metastasis rates and poor prognosis. Survival rates and possible therapies depend on the state of the tumor and its mutational profile. BRAF and NRAS are the most frequent driver mutations. Currently, there is no efficient therapy for NRAS-mutated or late-stage melanoma. In this study, the therapeutic potential of β,β-dimethylacrylshikonin (DMAS) was investigated on melanoma. The influence of DMAS was determined in five different melanoma cell lines with different mutational profiles. The effects of this compound on cell viability, apoptosis, and gene and protein expression were examined. The results obtained were validated in vivo. DMAS significantly reduced the viability of several melanoma cell lines in a concentration- and time-dependent manner. Furthermore, DMAS induced caspase-3-dependent apoptosis via

Topics: Apoptosis; Caspase 3; Cell Line, Tumor; Cell Survival; Humans; Melanoma; Mitochondria; Molecular Structure; Mutation; Naphthoquinones; Signal Transduction; Up-Regulation

Melanoma is the most dangerous form of skin cancer with a very poor prognosis. Melanoma develops when unrepaired DNA damage causes to skin cells to multiply and form malignant tumors. The current therapy is limited by the highly ability of this disease to metastasize rapidly. Plumbagin is a naphthoquinone (5-hydroxy-2-methyl-1, 4-naphthoquinone), isolated from the roots of medicinal plant Plumbago zeylanica, and it is widely present in Lawsonia inermis L. It has been shown that plumbagin has an anti-proliferative and anti-invasive activities in various cancer cell lines; however, the anti-cancer and anti-metastatic effects of plumbagin are largely unknown against melanoma cells. In this study, we evaluated the effect of plumbagin on B16F10 murine melanoma cells . Plumbagin decreased B16F10 cell viability as well as the cell migration, adhesion, and invasion. The molecular mechanism was studied, and plumbagin downregulated genes relevant in MAPK pathway, matrix metalloproteinases (MMP's), and cell adhesion. Furthermore, plumbagin elevated the expression of apoptosis and tumors suppressor genes, and genes significant in reactive oxygen species (ROS) response. Taken together, our findings suggest that plumbagin has an anti-invasion and anti-metastasis effect on melanoma cancer cells by acting on MAPK pathway and its related genes.

Topics: Animals; Breast Neoplasms; Cell Adhesion; Cell Line, Tumor; Cell Proliferation; Cell Survival; Female; Gene Expression Regulation, Neoplastic; Humans; MAP Kinase Signaling System; Melanoma; Melanoma, Experimental; Mice; Naphthoquinones; Neoplasm Invasiveness; Neoplasm Metastasis; Oligonucleotide Array Sequence Analysis; Plant Extracts; Signal Transduction; Wound Healing

Accumulating evidence demonstrated that alteronol, a novel compound that has a similar structure with paclitaxel, exerts anticancer effects against diversified tumors. However, whether alteronol induces autophagy and the relationship between its anticancer effects and autophagy in melanoma remains elusive. In this study, we show that alteronol induces not only anti-proliferation activity and apoptosis but also autophagy in A375 and UACC62 cells. In addition, alteronol inhibits A375 and UACC62 cells invasion and migration by preventing the epithelial-mesenchymal transition (EMT). Blocking autophagy enhances alteronol-induced apoptosis and anti-EMT effects in vitro and in vivo. Mechanistically, we find that alteronol significantly inhibits Akt/mTOR and TGFβ/Smad3 pathways, and co-treatment with autophagy inhibitor 3-MA further potentiate these effects. Our results suggest that alteronol induces cyto-protective autophagy in melanoma cells through inhibition of Akt/mTOR pathway, thus attenuates apoptosis and promotes melanoma cell EMT through TGF-β/Smad3 pathway. Combination with alteronol and autophagy inhibitor 3-MA may be a potential treatment for melanoma as it not only significantly inhibited tumor growth but also suppressed tumor invasion and migration as anti-metastasis agent.

Topics: Animals; Autophagy; Epithelial-Mesenchymal Transition; Humans; Male; Melanoma; Mice; Naphthoquinones; Signal Transduction; Transforming Growth Factor beta

BRAF inhibitors are some of the most effective drugs against melanoma; however, their clinical application is largely limited by drug resistance. Juglone, isolated from walnut trees, has demonstrated anti‑tumour activity. In the present study, it was investigated whether juglone could enhance the responses to a BRAF inhibitor in melanoma cells (A375R and SK‑MEL‑5R) with an acquired resistance. These cells were treated with juglone alone, BRAF inhibitor (PLX4032) alone, or juglone combined with PLX4032. It was demonstrated that the combination of juglone and PLX4032 had synergistic effects on BRAF inhibitor‑resistant melanoma cells. Juglone potentiated PLX4032‑induced cytotoxicity and mitochondrial apoptosis in both A375R and SK‑MEL‑5R cells, which was accompanied by a decline in mitochondrial membrane potential and a decrease in Bcl‑2/Bax ratio. Moreover, juglone combined with PLX4032 markedly increased the intracellular level of reactive oxygen species (ROS) and activated p38 and p53, as compared with juglone alone or PLX4032 alone. Pre‑treatment with N‑acetyl‑L‑cysteine, a ROS scavenger, completely reversed the cytotoxicity induced by juglone combined with PLX4032. In conclusion, juglone potentiated BRAF inhibitor‑induced apoptosis in resistant melanoma cells, and these effects occurred partially through ROS and the p38‑p53 pathway, suggesting the potential of juglone as a sensitizer to BRAF inhibitors in the treatment of melanoma.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Humans; MAP Kinase Signaling System; Melanoma; Naphthoquinones; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Reactive Oxygen Species; Signal Transduction; Tumor Suppressor Protein p53; Vemurafenib

Shikonin, a botanical drug extracted from Lithospermum erythrorhizon, exhibits anti-cancer effects in various cancer cell lines. However, the mechanisms underlying these effects have not been completely elucidated yet. Here, we showed that Shikonin induces apoptosis and autophagy in A375 cells and inhibits their proliferation. Shikonin caused G2/M phase arrest through upregulation of p21 and downregulation of cyclin B1. Shikonin significantly triggered ER stress-mediated apoptosis by upregulating the expression of p-eIF2α, CHOP, and cleaved caspase-3. It also induced protective autophagy by activating the p38 pathway, followed by an increase in the levels of p-p38, LC3B-II, and Beclin 1. Upon suppression of autophagy by 3-methyladenine, Shikonin-induced apoptosis was enhanced in A375 cells. Moreover, after pretreatment with N-acetyl-cysteine, Shikonin increased the production of reactive oxygen species that are involved in regulating ER stress-mediated apoptosis and p38-activated autophagy, as evidenced by the reversion of cell viability and apoptosis and a decrease in p-eIF2α, CHOP, p-p38, LC3B-II, and Beclin 1 levels. Thus, we demonstrated that Shikonin induced apoptosis and autophagy in A375 cells via the activation of ROS-mediated ER stress and p38 pathways, indicating that Shikonin can serve as a potential agent for human melanoma therapy.

Topics: Apoptosis; Autophagy; Cell Cycle Proteins; Cell Line, Tumor; Cell Survival; Endoplasmic Reticulum Stress; G2 Phase Cell Cycle Checkpoints; Humans; MAP Kinase Signaling System; Melanoma; Molecular Structure; Naphthoquinones; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Reactive Oxygen Species

Reliance on aerobic glycolysis is one of the hallmarks of cancer. Although pyruvate kinase M2 (PKM2) is a key mediator of glycolysis in cancer cells, lack of selective agents that target PKM2 remains a challenge in exploiting metabolic pathways for cancer therapy. We report that unlike its structural analog shikonin, a known inhibitor of PKM2, lapachol failed to induce non-apoptotic cell death ferroxitosis in hypoxia. However, melanoma cells treated with lapachol showed a dose-dependent inhibition of glycolysis and a corresponding increase in oxygen consumption. Accordingly, in silico studies revealed a high affinity-binding pocket for lapachol on PKM2 structure. Lapachol inhibited PKM2 activity of purified enzyme as well as in melanoma cell extracts. Blockade of glycolysis by lapachol in melanoma cells led to decreased ATP levels and inhibition of cell proliferation. Furthermore, perturbation of glycolysis in melanoma cells with lapachol sensitized cells to mitochondrial protonophore and promoted apoptosis. These results present lapachol as an inhibitor of PKM2 to interrogate metabolic plasticity in tumor cells.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Cell Proliferation; Enzyme Inhibitors; Glycolysis; Humans; Melanoma; Mitochondria; Models, Molecular; Naphthoquinones; Oxygen Consumption; Pyruvate Kinase

Despite much research in the last centuries, treatment of malignant melanoma is still challenging because of its mostly unnoticeable metastatic spreading and aggressive growth rate. Therefore, the discovery of novel drug leads is an important goal. In a previous study, we have isolated several shikonin derivatives from the roots of

Topics: Apoptosis; Boraginaceae; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Membrane; Cell Proliferation; DNA Breaks, Double-Stranded; Histones; Humans; Melanoma; Naphthoquinones; Phosphorylation; Plant Roots; Skin

Skin cancer is currently diagnosed as one in every three cancers. Melanoma, the most aggressive form of skin cancer, is responsible for 79% of skin cancer deaths and the incidence is rising faster than in any other solid tumor type. Previously, we have demonstrated that dimethylacrylshikonin (DMAS), isolated from the roots of

Topics: Apoptosis; Cell Line, Tumor; Cell Proliferation; Gene Expression Regulation; Humans; Melanoma; Membrane Potential, Mitochondrial; Mitochondria; Naphthoquinones; Reactive Oxygen Species; Signal Transduction

β-Lapachone is a natural quinone compound from Lapacho trees, which has various pharmacological effects such as anti-bacterial, anti-fungal, anti-viral, and anti-inflammatory activities. However, the effect of β-lapachone on metastasis of melanoma cells is unclear. In this study, β-lapachone reduced cell viability of metastatic melanoma cancer cell lines B16F10 and B16BL6 through induction of apoptosis via the mitogen-activated protein kinase (MAPK) pathway. Additionally, flow cytometry results showed that β-lapachone increased DNA content in the G0/G1 phase of the cell cycle. Analysis of the mechanisms of these events indicated that β-lapachone regulated the expression of Bcl-2, Bcl-xL, and Bax, resulting in the activation of caspase-3, -8, -9, and poly-ADP-ribose polymerase (PARP). Moreover, the β-lapachone-administered group showed significantly decreased lung metastasis in the experimental mouse model. In conclusion, our study demonstrates the inhibitory effect of β-lapachone on lung metastasis of melanoma cells and provides a new insight into the role of β-lapachone as a potential antitumor agent.

Topics: Animals; Female; Humans; Lung Neoplasms; MAP Kinase Signaling System; Melanoma; Mice; Mice, Inbred C57BL; Naphthoquinones; Neoplasm Metastasis

Tumor necrosis factor‑related apoptosis‑inducing ligand (TRAIL)‑based cancer therapy offers promise as TRAIL can kill cancer cells without apparent toxicity towards normal cells. However, intrinsic or acquired resistance to TRAIL inseveral types of cancer cell has become a major challenge in TRAIL‑based cancer therapy. Juglone is a natural compound isolated from walnut trees. In the present study, it was demonstrated that juglone sensitized melanoma cells to TRAIL‑induced cytotoxicity by MTT and crystal violet assays. Flow cytometry analysis indicated that juglone potentiated TRAIL‑induced cell death. Western blot assay demonstrated that the expressions of cleaved poly(ADP‑ribose) polymerase (PARP) and cleaved caspase 3 were markedly increased in the juglone combined with TRAIL group. Exposure to TRAIL alone did not induce the production of reactive oxygen species (ROS), activation of p38 orincrease of p53 in the TRAIL‑resistant melanoma cells, as determined by flow cytometry and western blot analysis. However, exposure to TRAIL in combination with juglone markedly increased the production of ROS, activated p38 and increased p53, compared with the cells treated with either juglone or TRAIL alone. Pretreatment with N‑acetyl cysteine, a ROS scavenger, significantly reduced the cytotoxicity of juglone in combination with TRAIL, which further supported that ROS was involved in the juglone‑induced sensitization of TRAIL. In conclusion, juglone potentiated TRAIL‑induced apoptosis in melanoma cells, and these effects were partially mediated through the ROS‑p38‑p53 pathway. These findings suggested that juglone may be a potential sensitizer for TRAIL therapy in the treatment of melanoma.

Topics: Apoptosis; Cell Line, Tumor; Cell Survival; Humans; Melanoma; Naphthoquinones; p38 Mitogen-Activated Protein Kinases; Reactive Oxygen Species; Signal Transduction; TNF-Related Apoptosis-Inducing Ligand; Tumor Suppressor Protein p53

Melanoma is a highly drug resistant cancer. To circumvent this problem, a class of synergistically acting drug combinations, which inhibit multiple key pathways in melanoma cells, could be used as one approach for long-term treatment of this deadly disease. A screen has been undertaken on cell lines to identify those that could be combined to synergistically kill melanoma cells. Plumbagin and Celecoxib are two agents that were identified to synergistically kill melanoma cells by inhibiting the COX-2 and STAT3 pathways, which are constitutively activated in up to 70% of melanomas. The combination of these two drugs was more effective at killing melanoma cells than normal cells and decreased cellular proliferation as well as induced apoptosis of cultured cells. The drug combination inhibited development of xenograft melanoma tumors by up to 63% without affecting animal weight or blood biomarkers of organ function, suggesting negligible toxicity. Mechanistically, combination of Celecoxib and Plumbagin decreased melanoma cell proliferation and retarded vascular development of tumors mediated by inhibition of COX-2 and STAT3 leading to decreased levels of key cyclins key on which melanoma cell were dependent for survival.

Topics: Animals; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Celecoxib; Cell Line, Tumor; Cell Proliferation; Cyclins; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Drug Synergism; G2 Phase Cell Cycle Checkpoints; Humans; Melanoma; Mice, Nude; Naphthoquinones; Signal Transduction; Skin Neoplasms; STAT3 Transcription Factor; Time Factors; Tumor Burden; Xenograft Model Antitumor Assays

Using multiple drugs to kill cancer cells can decrease drug resistance development. However, this approach is frequently limited by the bioavailability and toxicity of the combined agents and delivery at ratios to specific locations that synergistically kill cancer cells. Loading the individual agents into a nanoparticle that releases the drugs at synergizing ratios at a single location is one approach to resolve this concern. Celecoxib and plumbagin are two drugs that were identified from a screen to synergistically kill melanoma cells compared with normal cells. Combined use of these agents by traditional approaches was not possible due to poor bioavailability and toxicologic concerns. This study details the development of a nanoliposomal-based agent containing celecoxib and plumbagin, called CelePlum-777, which is stable and releases these drugs at an optimal ratio for maximal synergistic killing efficacy. CelePlum-777 was more effective at killing melanoma than normal cells and inhibited xenograft melanoma tumor growth by up to 72% without apparent toxicity. Mechanistically, the drug combination in CelePlum-777 led to enhanced inhibition of melanoma cell proliferation mediated by decreasing levels of key cyclins important for cancer cell proliferation and survival, which was not observed with the individual agents. Thus, a novel nanoparticle-based drug has been developed containing celecoxib and plumbagin that lacks toxicity and delivers the agents at a synergistically killing drug ratio to kill cancer cells.

Topics: Animals; Antineoplastic Agents, Phytogenic; Celecoxib; Cell Line, Tumor; Cell Survival; Cyclooxygenase 2 Inhibitors; Disease Models, Animal; Drug Compounding; Drug Stability; Drug Synergism; Female; Humans; Liposomes; Melanoma; Mice; Nanoparticles; Naphthoquinones; STAT3 Transcription Factor; Tumor Burden; Xenograft Model Antitumor Assays

β-lapachone (β-lap), a novel natural quinone derived from the bark of the Pink trumpet tree (Tabebuia avellanedae) has been demonstrated to have anticancer activity. In this study, we investigated whether β-lap exhibits anti-proliferative effects on two human malignant melanoma (HMM) cell lines, G361 and SK-MEL-28. The effects of β-lap on the HMM cell lines were investigated using 3-(4,5-dimethylthiazol-2-yl)‑5-(3-carboxymethoxyphenyl)‑2-(4-sulfophenyl-2H-tetrazolium (MTS) assay, 4',6-diamidino-2-phenylindole (DAPI) staining, Annexin V and Dead cell assay, mitochondrial membrane potential (MMP) assay and western blot analysis. We demonstrated that β-lap significantly induced apoptosis and suppressed cell viability in the HMM cells. Intriguingly, the transcription factor specificity protein 1 (Sp1) was significantly downregulated by β-lap in a dose- and time-dependent manner. Furthermore, β-lap modulated the protein expression level of the Sp1 regulatory genes including cell cycle regulatory proteins and apoptosis-associated proteins. Taken together, our findings indicated that β-lap modulates Sp1 transactivation and induces apoptotic cell death through the regulation of cell cycle- and apoptosis-associated proteins. Thus, β-lap may be used as a promising anticancer drug for cancer prevention and may improve the clinical outcome of patients with cancer.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Cycle; Cell Cycle Proteins; Cell Line, Tumor; Down-Regulation; Drug Screening Assays, Antitumor; Gene Expression Regulation, Neoplastic; Humans; Intracellular Signaling Peptides and Proteins; Melanoma; Membrane Potential, Mitochondrial; Naphthoquinones; Neoplasm Proteins; Skin Neoplasms; Sp1 Transcription Factor; Transcriptional Activation

DMAKO-05((S)-1-((5E,8E)-5,8-bis(hydroxyimino)-1,4-dimethoxy-5,8-dihydronaphthalen-2-yl)-4-methylpent-3-enyl 3-methylbutanoate) is a novel oxime derivative of shikonin, the major component extracted from Chinese herb Lithospermun erythrorhizon. Here, we report that DMAKO-05 had an antitumor activity against mouse melanoma cell line B16F0. Our studies indicated that DMAKO-05 not only inhibited B16F0 proliferation and migration but also led to cell cycle arrest at G1 phase and cell apoptosis, in which DMAKO-05 triggered mitochondrial-mediated apoptosis signal including caspase-9/3 and PARP. In response to DMAKO-05 treatment, the Akt-mediated survival signals were remarkably attenuated in B16F0 cells. Collectively, DMAKO-05 has a strong cytotoxicity in B16F0 cells via inhibiting Akt activation, inducing G1 arrest, and promoting B16F0 cell apoptosis. DMAKO-05 might serve as a potential candidate lead compound for melanoma.

Topics: Animals; Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Cell Proliferation; Drug Screening Assays, Antitumor; Melanoma; Naphthoquinones; Proto-Oncogene Proteins c-akt; Rats; Signal Transduction

Cancer is a public health problem and the second leading cause of death worldwide. The incidence of cutaneous melanoma has been notably increasing, resulting in high aggressiveness and poor survival rates. Taking into account the antitumor activity of biflorin, a substance isolated from Capraria biflora L. roots that is cytotoxic in vitro and in vivo, this study aimed to demonstrate the action of biflorin against three established human melanoma cell lines that recapitulate the molecular landscape of the disease in terms of genetic alterations and mutations, such as the TP53, NRAS and BRAF genes. The results presented here indicate that biflorin reduces the viability of melanoma cell lines by DNA interactions. Biflorin causes single and double DNA strand breaks, consequently inhibiting cell cycle progression, replication and DNA repair and promoting apoptosis. Our data suggest that biflorin could be considered as a future therapeutic option for managing melanoma.

Topics: Cell Line, Tumor; Cell Survival; DNA; DNA Modification Methylases; DNA Repair Enzymes; GTP Phosphohydrolases; Humans; Melanoma; Membrane Proteins; Mutation; Naphthoquinones; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins B-raf; ras Proteins; Thymidylate Synthase; Tumor Suppressor Protein p53; Tumor Suppressor Proteins

The purpose of this study is to evaluate the anti-metastatic effects of alteronol on melanoma B16F10 and B16F1 cells in vitro and in vivo.. Melanoma B16F1 and B16F10 cells were cultured in vitro. Cell proliferation was analyzed via 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The cell migration and invasion were evaluated via wound healing and transwell chamber assays. The activity of matrix metalloproteinase 2 (MMP-2) in culture supernatants was assessed via gelatin zymography. The expression of MMP-2 and TIMP-2 were detected via enzyme-linked immunosorbent assay (ELISA) assay. The anti-metastatic ability in vivo was detected through experimental lung metastasis.. The data indicate that alteronol can inhibit the proliferation, invasion, and migration of B16F1 and B16F10 cells in vitro and in vivo, decrease the activity and expression of MMP-2, enhance the expression level of Tissue Inhibitor of Metalloproteinase-2 (TIMP-2), and inhibit the experimental lung metastasis of B16F1 and B16F10 cells.. Although alteronol and taxol are obtained from the same source, these substances do not destroy the rare resource; the mechanisms of them on tumor growth inhibition are different. Conversely, alteronol treatment had lesser effects on normal cells revealing for a selective property and a strong competitive advantage.

Topics: Animals; Cell Line, Tumor; Cell Movement; Cell Survival; Enzyme Activation; Lung Neoplasms; Matrix Metalloproteinase 2; Melanoma; Mice; Molecular Structure; Naphthoquinones; Neoplasm Invasiveness; Neoplasm Metastasis

Accumulating evidence supports the concept that melanoma is highly heterogeneous and sustained by a small subpopulation of melanoma stem-like cells. Those cells are considered as responsible for tumor resistance to therapies. Moreover, melanoma cells are characterized by their high phenotypic plasticity. Consequently, both melanoma stem-like cells and their more differentiated progeny must be eradicated to achieve durable cure. By reevaluating compounds in heterogeneous melanoma populations, it might be possible to select compounds with activity not only against fast-cycling cells but also against cancer stem-like cells. Natural compounds were the focus of the present study.. We analyzed 120 compounds from The Natural Products Set II to identify compounds active against melanoma populations grown in an anchorage-independent manner and enriched with cells exerting self-renewing capacity. Cell viability, cell cycle arrest, apoptosis, gene expression, clonogenic survival and label-retention were analyzed.. Several compounds efficiently eradicated cells with clonogenic capacity and nanaomycin A, streptonigrin and toyocamycin were effective at 0.1 µM. Other anti-clonogenic but not highly cytotoxic compounds such as bryostatin 1, siomycin A, illudin M, michellamine B and pentoxifylline markedly reduced the frequency of ABCB5 (ATP-binding cassette, sub-family B, member 5)-positive cells. On the contrary, treatment with maytansine and colchicine selected for cells expressing this transporter. Maytansine, streptonigrin, toyocamycin and colchicine, even if highly cytotoxic, left a small subpopulation of slow-dividing cells unaffected. Compounds selected in the present study differentially altered the expression of melanocyte/melanoma specific microphthalmia-associated transcription factor (MITF) and proto-oncogene c-MYC.. Selected anti-clonogenic compounds might be further investigated as potential adjuvants targeting melanoma stem-like cells in the combined anti-melanoma therapy, whereas selected cytotoxic but not anti-clonogenic compounds, which increased the frequency of ABCB5-positive cells and remained slow-cycling cells unaffected, might be considered as a tool to enrich cultures with cells exhibiting melanoma stem cell characteristics.

Topics: Apoptosis; Biological Products; Cell Cycle Checkpoints; Cell Survival; Colony-Forming Units Assay; Drug Discovery; Gene Expression Regulation; Humans; Melanoma; Microphthalmia-Associated Transcription Factor; Naphthoquinones; Neoplastic Stem Cells; Proto-Oncogene Mas; Streptonigrin; Toyocamycin

The down-regulation or loss of epithelial markers is often accompanied by the up-regulation of mesenchymal markers. E-cadherin generally suppresses invasiveness, whereas N-cadherin promotes invasion and metastasis in vitro. The aim of this work is to investigate the role of biflorin, a naphthoquinone with proven anticancer properties, on the expression of N-cadherin and AKT proteins in MDA-MB-435 invasive melanoma cancer cells after 12h of exposure to 1, 2.5 and 5 μM biflorin. Biflorin inhibited MDA-MB-435 invasion in a dose-dependent manner (p<0.01). Likewise, biflorin down-regulated N-cadherin and AKT-1 expression in a dose-dependent manner. Biflorin did not inhibit the adhesion of MDA-MB-435 cells to any tested substrates. Additionally, biflorin blocked the invasiveness of cells by down-regulating N-cadherin, most likely via AKT-1 signaling. As such, biflorin may be a novel anticancer agent and a new prototype for drug design.

Topics: Animals; Antineoplastic Agents, Phytogenic; Cadherins; Cell Adhesion; Cell Line; Cell Line, Tumor; Cell Movement; Cell Survival; Down-Regulation; Gene Expression Regulation, Neoplastic; Humans; Melanocytes; Melanoma; Mice; Naphthoquinones; Neoplasm Proteins; Proto-Oncogene Proteins c-akt; RNA, Messenger; Signal Transduction

Activity-guided fractionation of a petroleum ether-soluble extract of the roots of Onosma paniculata, which has been shown to affect the cell cycle and to induce apoptosis in melanoma cells, led to the isolation of several shikonin derivatives, namely, β-hydroxyisovalerylshikonin (1), acetylshikonin (2), dimethylacrylshikonin (3), and a mixture of α-methylbutyrylshikonin and isovalerylshikonin (4+5). All compounds exhibited strong cytotoxicity against eight cancer cell lines and MRC-5 lung fibroblasts, with 3 found to possess the most potent cytotoxicity toward four melanoma cell lines (SBcl2, WM35, WM9, and WM164). Furthermore, 3 and the mixture of 4+5 were found to interfere with cell-cycle progression in these cell lines and led to an increasing number of cells in the subG1 region as well as to caspase-3/7 activation, indicating apoptotic cell death.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Boraginaceae; Caspase 3; Caspase 7; Cell Cycle; Drug Screening Assays, Antitumor; Drugs, Chinese Herbal; Humans; Melanoma; Molecular Structure; Naphthoquinones; Plant Roots

Biflorin, an ortho-naphthoquinone, is an active compound found in the roots of Capraria biflora L. It has been reported that biflorin presents anticancer activity, inhibiting both tumor cell line growth in culture and tumor development in mice. The aim of this study was to examine the effectiveness of biflorin treatment using both in-vitro and in-vivo melanoma models. Biflorin displayed considerable cytotoxicity against all tested cell lines, with half maximal inhibitory concentration values ranging from 0.58 μg/ml in NCI H23 (human lung adenocarcinoma) to 14.61 μg/ml in MDA-MB-231 (human breast cancer) cell lines. In a second set of experiments using B16 melanoma cells as a model, biflorin reduced cell viability but did not cause significant increase in the number of nonviable cells. In addition, the DNA synthesis was significantly inhibited. Flow cytometry analysis showed that biflorin may lead to an apoptotic death in melanoma cells, inducing DNA fragmentation and mitochondria depolarization, without affecting membrane integrity. In B16 melanoma-bearing mice, administration of biflorin (25mg/day) for 10 days inhibited tumor growth, and also increased the mean survival rate from 33.3±0.9 days (control) to 44.5±3.4 days (treated). Our findings suggest that biflorin may be considered as a promising lead compound for designing new drugs to be used in the treatment of melanoma.

Topics: Animals; Apoptosis; Cell Line, Tumor; Drug Screening Assays, Antitumor; Humans; Melanoma; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Naphthoquinones; Skin Neoplasms

Aggressive cell growth and chemoresistance are notorious obstacles in melanoma therapy. Accumulating evidence suggests that survivin is preferentially expressed in cancer cells and plays a crucial role in cell division and apoptosis dysfunction. Here, we evaluated the therapeutic potential of YM155, a selective survivin suppressant, alone and in combination with docetaxel using human melanoma models.. A375 and SK-MEL-5 human malignant melanoma cells were treated with siRNA, YM155, and/or docetaxel, and cell viability, mRNA and protein expression levels, cell-cycle distribution, and immunohistochemical staining were then evaluated. Furthermore, the efficacy of YM155 combined with docetaxel was further examined in established xenograft models.. Survivin suppression was sufficient to induce spontaneous apoptosis of melanoma cells. YM155 showed nanomolar antiproliferative effects and induced tumor regression in established melanoma xenograft models. Docetaxel showed antitumor activity against melanoma cells, although it also induced survivin upregulation and G(2)/M mitotic arrest; however, cotreatment with YM155 decreased survivin expression below basal levels. Combination treatment of YM155 and docetaxel induced a greater rate of apoptosis than the sum of the single-treatment rates and promoted tumor regression without enhanced body weight loss in the melanoma xenograft models.. Survivin is responsible for the inherent low levels of spontaneous apoptosis in melanoma cells. The concomitant combination of YM155 with docetaxel diminished the accumulation of survivin in G(2)/M mitotic arrest, and induced more intense apoptosis compared with each single treatment. YM155 in combination with docetaxel is well tolerated and shows greater efficacy than either agent alone in mouse xenograft models.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Blotting, Western; Caspase 3; Caspase 7; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Docetaxel; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; Humans; Imidazoles; Immunohistochemistry; Inhibitor of Apoptosis Proteins; Male; Melanoma; Mice; Mice, Nude; Naphthoquinones; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; Survivin; Taxoids; Xenograft Model Antitumor Assays

A study of the components of the fruits of Kigelia pinnata was undertaken to identify compounds with potential growth inhibitory activity against human melanoma cells, since extracts from the fruits of this plant have been described in traditional medicine to have application in the treatment of skin cancer and other skin ailments. A bioactivity-guided fractionation process yielded a number of crude fractions, which demonstrated cytotoxicity in vitro against human melanoma cells. Compounds isolated and identified included the isocoumarins, demethylkigelin (1) and kigelin (2), fatty acids, oleic (3) and heneicosanoic acids (4), the furonaphthoquinone, 2-(1-hydroxyethyl)-naphtho[2,3-b]furan-4,9-dione (5), and ferulic acid (6). A number of structurally related synthetic compounds were also tested using the MTT assay. The most potent series of these compounds, the furonaphthoquinones, also demonstrated a cytotoxic effect in two human breast cancer cell lines tested.

Topics: Antineoplastic Agents, Phytogenic; Bignoniaceae; Breast Neoplasms; Cell Line, Tumor; Female; Fruit; Growth Inhibitors; Humans; Melanoma; Naphthoquinones; Phytotherapy; Plant Extracts; Skin Neoplasms

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising anti-cancer agent. However, emergence of drug resistance limits its potential use. Plumbagin is a natural quinonoid compound isolated from plant. In this study, induced apoptosis effect of the combined treatment with plumbagin and TRAIL on human melanoma A375 cell line was examined and possible mechanism was investigated. The cells were divided into four groups: control group, plumbagin group (plumbagin, 5 or 10 mumol/L), TRAIL group (TRAIL, 30 ng/mL) and plumbagin+TRAIL group (combined treatment group). The apoptosis, and the expression of DR4 and DR5 were detected by flow cytometry. The activities of caspase-8 and caspase-3 were determined by colorimetric assay. The results showed that the apoptosis rate was 8.3% in TRAIL group, 10.35%-16.94% in plumbagin group and 52.39%-65.39% in combined treatment group, respectively, with the difference being significant between combined treatment group and plumbagin or TRAIL group (P<0.05 for each). Moreover, plumbagin alone could markedly up-regulate DR5 mRNA and protein expression, and slightly increase DR4 mRNA and protein expression. Treatment of human melanoma A375 cells with plumbagin resulted in the activation of Caspase-3, but not Caspase-8. These results suggest that plumbagin might be useful for TRAIL-based treatment for melanoma.

Topics: Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Apoptosis; Caspase 3; Caspase 8; Cell Line, Tumor; Humans; Melanoma; Naphthoquinones; Receptors, TNF-Related Apoptosis-Inducing Ligand; Skin Neoplasms; TNF-Related Apoptosis-Inducing Ligand; Up-Regulation

Quinones have diverse pharmacological properties including antibacterial, antifungal, antiviral, anti-inflammatory, antipyretic and anticancer activity. The cytotoxic potential of 1,4-naphthoquinone (NQ14) was studied against B16F1 melanoma cells grown in vitro. NQ14 treatment resulted in a concentration-dependent cytotoxicity as indicated by MTT assay and lactate dehydrogenase leakage assay. Depletion in cellular glutathione levels after 1h incubation with NQ14 correlated with the corresponding increase in reactive oxygen species generation as determined by 2',7'-dicholorofluorescein diacetate assay suggests the role of oxidative stress in cell death. The frequency of micronucleated binucleate cells increased with increasing doses of NQ14 with a corresponding decrease in the cytokinesis block proliferation index indicating the drug induced genotoxicity and cell division delay. Further, a dose-dependent decrease in the clonogenic cell survival indicated the potential of NQ14 to inhibit cell proliferation contributing to cell death. The cell death after NQ14 treatment may be attributed to apoptosis as seen in DNA ladder pattern along with necrosis as indicated in flow cytometric analysis of Annexin V/PI stained cells. Results of the present study demonstrate the cytotoxic and genotoxic potential of NQ14 by the induction of oxidative stress mediated mechanisms leading to tumor cell kill.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Formazans; Glutathione; L-Lactate Dehydrogenase; Melanoma; Mice; Micronucleus Tests; Naphthoquinones; Necrosis; Oxidative Stress; Reactive Oxygen Species; Tetrazolium Salts

The development of vitiligo has been associated with an improved clinical response in melanoma patients.. We report a case of vitiligo associated with a novel antisurvivin drug and review the literature to determine the pathogenesis of vitiligo occurring during melanoma treatment.. A 78-year-old man with stage IV malignant melanoma developed vitiligo after the first therapeutic cycle of a novel antisurvivin drug. Although his vitiligo remained static, his melanoma continued to progress and he died in 8 months. A review of the literature demonstrates a relationship between vitiligo development and improved clinical response in many melanoma cases treated with immunotherapy; however, the relationship may depend on the type of treatment.. Understanding complex immune responses in vitiliginous skin and melanoma sites is important in order to interpret the development of vitiligo occurring during melanoma treatment.

Topics: Aged; Antineoplastic Agents; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Male; Melanoma; Microtubule-Associated Proteins; Naphthoquinones; Skin Neoplasms; Survivin; Vitiligo

This study demonstrates cytotoxic and genotoxic potential of juglone, a chief constituent of walnut, and its underlying mechanisms against melanoma cells. MTT assay and clonogenic assay were used to study cytotoxicity, micronucleus assay to assess genotoxicity, glutathione (GSH) assay and 2',7'-dicholorofluorescein diacetate (DCFH-DA) assay to evaluate the oxidative stress induction. Apoptosis/necrosis induction was analysed by flow cytometry. We observed a concentration-dependent decrease in cell survival with a corresponding increase in the lactate dehydrogenase levels. A dose-dependent increase in the frequency of micronucleated binucleate cells indicated the potential of juglone to induce cytogenetic damage in melanoma tumor cells. Moreover, results of the micronuclei study indicated division delay in the proliferating cell population by showing decrease in the cytokinesis blocked proliferation index. Further, juglone-induced apoptosis and necrosis could be demonstrated by oligonucleosomal ladder formation, microscopic analysis, increase in the hypodiploid fraction (sub Go peak in DNA histogram), as well as an increased percentage of AnnexinV(+)/PI(+) cells detected by flow cytometry. A significant concentration-dependent decrease in the glutathione levels and increase in dichlorofluorescein (DCF) fluorescence after juglone treatment confirmed the ability of juglone to generate intracellular reactive oxygen species. The cytotoxic effect of juglone can be attributed to mechanisms including the induction of oxidative stress, cell membrane damage, and a clastogenic action leading to cell death by both apoptosis and necrosis.

Topics: Animals; Annexin A5; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Survival; DNA Fragmentation; Glutathione; Juglans; L-Lactate Dehydrogenase; Melanoma; Melanoma, Experimental; Mice; Naphthoquinones; Reactive Oxygen Species

Topics: Antineoplastic Agents; Biomarkers, Tumor; Biopsy; Cysteine Proteinase Inhibitors; Esophageal Neoplasms; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Male; Melanoma; Microtubule-Associated Proteins; Middle Aged; Naphthoquinones; Survivin; Treatment Outcome

This study is the first to investigate the anticancer effect of plumbagin in human melanoma A375.S2 cells. Plumbagin exhibited effective cell growth inhibition by inducing cancer cells to undergo S-G2/M phase arrest and apoptosis. Further investigation revealed that plumbagin's inhibition of cell growth was also evident in a nude mice model. Blockade of cell cycle was associated with increased levels of p21, and reduced amounts of cyclin B1, cyclin A, Cdc2, and Cdc25C. Plumbagin also enhanced the levels of inactivated phosphorylated Cdc2 and Cdc25C. Plumbagin triggered the mitochondrial apoptotic pathway indicated by a change in Bax/Bcl-2 ratios, resulting in caspase-9 activation. We also found the generation of ROS is a critical mediator in plumbagin-induced cell growth inhibition. Plumbagin increased the activation of apoptosis signal-regulating kinase 1, JNK and extracellular signal-regulated kinase 1/2 (ERK1/2), but not p38. In addition, antioxidants vitamin C and catalase significantly decreased plumbagin-mediated c-Jun N-terminal kinase (JNK) activation and apoptosis. Moreover, blocking ERK and JNK by specific inhibitors suppressed plumbagin-triggered mitochondrial apoptotic pathway. Taken together, these results imply a critical role for ROS and JNK in the plumbagin's anticancer activity.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Apoptosis Regulatory Proteins; Cell Cycle; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Enzyme Activation; Glutathione; Humans; Inhibitory Concentration 50; JNK Mitogen-Activated Protein Kinases; Male; MAP Kinase Kinase Kinase 5; Melanoma; Mice; Mice, Inbred BALB C; Mice, Nude; Mitochondria; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Naphthoquinones; Neoplastic Stem Cells; Phosphorylation; Reactive Oxygen Species; Signal Transduction; Time Factors; Tumor Stem Cell Assay; Xenograft Model Antitumor Assays

2-acetyl furanonaphthoquinone (FNQ) is a naturally occurring drug with enhanced toxicity versus glucose-starved tumor cells, which frequently show topoisomerase II drug resistance. Since loss of p53 tumor suppressor function or overexpression of the anti-apoptotic bcl-2 gene can decrease susceptibility to some cancer therapies, we now investigated the effect of FNQ against genetically matched C8161 melanoma cell lines transduced to express unequal levels of Bcl-2, or engineered to harbour a functional wt p53 for comparison with dominant-negative mutant p53 R175H. Cells with differing p53 genotype showed susceptibility to FNQ. However, this response was attenuated in those overexpressing mutant p53, although a brief p53 induction was early seen in FNQ-treated wt p53 cells. Cells susceptible to FNQ showed cleavage of anti-apoptotic Mcl-1, sustained activation of the c-Jun N-terminal Kinase (p-JNK), and apoptosis-associated PARP fragmentation, all of which were counteracted in bcl-2 overexpressing cells. Suppression of JNK activation with the specific inhibitor, SP600125 also prevented FNQ-mediated cell death. Our data suggests that Bcl-2, persistent JNK phosphorylation and cleavage of anti-apoptotic Mcl-1 are key events controlling susceptibility to FNQ.

Topics: Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; Caspases; Cell Line, Tumor; Furans; Humans; Melanoma; Mitogen-Activated Protein Kinase 9; Naphthoquinones; Phosphorylation; Proto-Oncogene Proteins c-bcl-2; Tumor Suppressor Protein p53

Glycoside derivatives of diospyrin (1) were synthesized for the first time, and the cytotoxicity of the novel compounds vis-à-vis their precursors were evaluated against two human cancer cell lines, viz. malignant melanoma (A375) and laryngeal carcinoma (Hep2). The IC(50) values were in the low micromolar range for all the compounds tested, and A375 cells showed comparatively greater sensitivity than Hep2. Most of the compounds exhibited enhanced activity as compared to the plant-derived quinonoid precursor of the series (1), while the aminophenyl mannosyl (6) was found to be the most effective derivative. In A375 cells, 6 (IC(50) = 0.02 microM) showed the maximum increase in cytotoxicity (approximately 35-fold) over that of 1 (IC(50) = 0.82 microM). Again, when the glycosides were evaluated at a given concentration (0.1 microM) for their relative capacity to generate ROS from A375 cells, the compound 6 could produce the highest amount of ROS. Incidentally, this derivative also showed a comparatively lower toxicity (IC(50) approximately 41 microM) when tested against normal human peripheral blood mononuclear cells, indicating a fair prospect of its development as a novel chemotherapeutic agent for the treatment of malignant melanoma.

Topics: Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Glycoconjugates; Humans; Laryngeal Neoplasms; Melanoma; Naphthoquinones; Reactive Oxygen Species

Solid tumors are often placed under stress conditions, such as glucose starvation which may result in topoisomerase II drug resistance. In this study, we investigated whether glucose deprivation or substitution by fructose regulates tumor cell apoptosis induced by 2-acetyl furanonaphthoquinone (FNQ). We now show that FNQ exerts much greater antitumor activity than either 7-methoxy 2-ethyl FNQ or 2-ethyl FNQ. Whereas 0.8 microM FNQ induces apoptosis after 16 hours in glucose-supplemented conditions irrespective of bcl-2 overexpression in K1735 melanoma, 0.5 microM FNQ is also effective within 12 hours in low glucose or in fructose-supplemented medium. Under the latter conditions, apoptosis-associated PARP cleavage and cytosolic cytochrome C are increased, together with induction and partial translocation to mitochondria of phosphorylated Jun-N-terminal kinase and massive upregulation of mitochondrial Mn superoxide dismutase. We propose that mitochondrial colocalization of these activities is important in this synergistic anti-tumor effect of FNQ and glucose depletion. Since glucose limitation slows proliferation and decreases efficacy of some genotoxic drugs that trigger apoptosis in rapidly dividing cells, we propose evaluating FNQ as a novel therapeutic anti-cancer adjuvant against slowly proliferating tumors.

Topics: Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; bcl-X Protein; Cytochromes c; Furans; Glucose; Glycolysis; Humans; MAP Kinase Kinase 4; Melanoma; Mitochondria; Naphthoquinones; Phosphorylation; Poly(ADP-ribose) Polymerases; Protein Transport; Proto-Oncogene Proteins c-bcl-2; Skin Neoplasms; Superoxide Dismutase; Transcriptional Activation; Tumor Cells, Cultured

Matrix metalloproteinases, like MMP-2 and MMP-9 gelatinases, show multiple functions as extracellular/cell-surface enzymes, and are broadly recognised for their matrix-degrading ability and involvement in cell motility. Given that adherent cells have reduced attachment during migration and also detach from their substratum during apoptosis, we now investigated whether extracellular matrix-bound gelatinases and intracellular MMP-2 and MMP-9 are modified with progression of death-inducing stimuli. This report shows that melanoma cells undergoing death in response to 2-acetyl furanonaphtoquinone (FNQ) as evidenced by greater Annexin V binding, increased cytosolic expression of pro-MMP-2 and intracellular activation of particulate MMP-9. These changes were associated with early activation of a substrate-attached 40 kDa gelatinase reciprocal with changes in extracellular matrix-bound activated MMP-2. A subsequent activation of secreted MMP-9 and induction of apoptosis-associated fragmentation of poly ADP-Ribose polymerase (PARP) correlated with cell detachment. Our data suggests that intracellularly activated gelatinases may cleave survival-associated substrates other than gelatin that share the Gly-Leu/Iso-Pro like collagen-binding acetylcholinesterase, thereby linking them to apoptosis associated with cell detachment.

Topics: Animals; Annexin A5; Apoptosis; Cell Line, Tumor; Cell Membrane; Enzyme Activation; Extracellular Matrix; Humans; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Melanoma; Mice; Naphthoquinones; Neoplasm Invasiveness; Poly(ADP-ribose) Polymerases; Proto-Oncogene Proteins c-bcl-2; Skin Neoplasms; Up-Regulation; Water

Natural products regulate cell growth in response to oncogene activation that induces cell cycle arrest and apoptosis in tumor cell lines. We investigated the mechanisms of caspase activation in human malignant melanoma, A375-S2 cells, by the natural product shikonin, which was isolated from the plant Lithospermum erythrorhizon SIEB. et ZUCC. Shikonin inhibited cell growth in a time- and dose-dependent manner, which might be mediated through up-regulation of p53 and down-regulation of cyclin-dependent protein kinase 4. Caspase activation was detected in shikonin-induced cell apoptosis, which involved in a post-mitochondrial caspase-9-dependent pathway. Decreased Bcl-2 protein levels and increased Bax protein levels were positively correlated with elevated expression of p53 protein. Apoptosis-inducing factor, another apoptotic protein of mitochondria, partially contributed to shikonin-induced release of cytochrome c. Taken together, shikonin-induced DNA damage activates p53 and caspase-9 pathways.

Topics: Apoptosis; Caspase 9; Caspases; Cell Cycle; Cell Division; Cell Line, Tumor; DNA Damage; Dose-Response Relationship, Drug; G1 Phase; Growth Inhibitors; Humans; Melanoma; Naphthoquinones; Tumor Suppressor Protein p53

The hollow fiber test has been developed for the preliminary in vivo assessment of cancer chemotherapeutic efficacy of selected natural products. Using this model, we have established growth conditions for HL-60, HUVEC, Ishikawa, KB, KB-V1, LNCaP, Lu1, MCF-7, Mel2, P-388, and SW626 cells implanted at the intraperitoneal (i.p.) and subcutaneous (s.c.) compartments of athymic mice. Five cytotoxic natural product isolates (2-6) were tested in this model, along with paclitaxel (taxol) (1). Among the compounds tested, dioscin (2) and 13-methoxy-15-oxozoapatlin (3) were found to be active, indicating their potential to function as cancer chemotherapeutic agents. On the other hand, ochraceolide A (4), alpha-lapachone (5), and 2-(1-hydroxyethyl)naphtha[2,3-b]furan-4,9-quinone (6), all of which were significantly cytotoxic to cultured mammalian cells, did not mediate significant responses with the hollow fiber model. In further xenograft studies using KB cells implanted at the subcutaneous site, compound 3 mediated a statistically significant response which was consistent with the response observed at the subcutaneous compartment in the hollow fiber tests. In sum, these studies illustrate the usefulness of the hollow fiber model in natural product drug discovery programs. Preliminary indications of potential therapeutic efficacy can be provided quickly at relatively low expense. Agents capable of mediating a response at the subcutaneous site would appear to warrant greatest attention.

Topics: Animals; Biological Factors; Colonic Neoplasms; Diosgenin; Disease Models, Animal; Diterpenes; Drug Screening Assays, Antitumor; Female; Heterocyclic Compounds, 3-Ring; HL-60 Cells; Humans; Inhibitory Concentration 50; KB Cells; Leukemia P388; Male; Melanoma; Mice; Molecular Structure; Naphthoquinones; Ovarian Neoplasms; Paclitaxel; Polymers; Prostatic Neoplasms; Triterpenes; Tumor Cells, Cultured

KILLER/DR5 is a death-domain-containing proapoptotic receptor that binds to the cytotoxic ligand TRAIL. It was originally reported that induction of KILLER/DR5 mRNA following DNA damage was p53-dependent, but some drugs that induce apoptosis can upregulate KILLER/DR5 mRNA expression in cell lines with mutated p53. We further extend those findings by classifying the capability of various apoptosis-inducing drugs to increase the expression of KILLER/DR5 mRNA in a p53-independent manner. beta-Lapachone, a topoisomerase inhibitor, increased KILLER/DR5 mRNA in colon cancer cell lines with wild-type p53 but not with mutant p53. In contrast, betulinic acid, a novel chemotherapeutic compound, induced apoptosis and KILLER/DR5 mRNA in melanoma and glioblastoma cells through a p53-independent mechanism. The synthetic glucocorticoid dexamethasone elevated KILLER/DR5 mRNA in glioblastoma, ovarian cancer, and colon cancer cell lines with mutant p53 undergoing apoptosis, and this induction was inhibited by the transcriptional inhibitor actinomycin D. Although another glucocorticoid, prednisolone, also induced apoptosis, it did not increase KILLER/DR5 mRNA. Finally, the cytokine interferon-gamma (IFN-gamma) induced apoptosis and KILLER/DR5 in cell lines with mutant p53, and the induction of KILLER/DR5 mRNA by IFN-gamma was delayed in cells lacking wild-type STAT1, a transcription factor implicated in IFN-gamma signaling. Similarly, the induction of KILLER/DR5 mRNA by the cytokine TNF-alpha was also delayed in cell lines with mutated STAT1. These findings suggest that KILLER/DR5 may play a role in p53-independent apoptosis induced by specific drugs and warrants further investigation as a novel target for chemotherapy of tumors lacking wild-type p53.

Topics: Antibiotics, Antineoplastic; Apoptosis; Betulinic Acid; Colonic Neoplasms; Dactinomycin; Dexamethasone; DNA-Binding Proteins; Female; Glioblastoma; Glucocorticoids; Humans; Interferon-gamma; Melanoma; Mutation; Naphthoquinones; Ovarian Neoplasms; Pentacyclic Triterpenes; Prednisolone; Receptors, TNF-Related Apoptosis-Inducing Ligand; Receptors, Tumor Necrosis Factor; RNA, Messenger; STAT1 Transcription Factor; Trans-Activators; Triterpenes; Tumor Cells, Cultured; Tumor Suppressor Protein p53; Up-Regulation

Serial dilutions of standardised water, ethanol, and dichloromethane extracts of the stembark and fruits of Kigelia pinnata were tested for their growth inhibitory effects against four melanoma cell lines and a renal cell carcinoma line (Caki-2) using two different (MTT and SRB) assays. Lapachol, a possible constituent of these extracts, together with known therapeutic antineoplastic agents, was also tested in the same way. The IC50 of each extract was measured after extracts were diluted to 100 micrograms/ml in 1% ethanol or water. Significant inhibitory activity was shown by the dichloromethane extract of the stembark and lapachol (continuous exposure). Moreover, activity was dose-dependent, the extract being less active after 1 h exposure. Chemosensitivity of the melanoma cell lines to the stembark was greater than that seen for the renal adenocarcinoma line. In marked contrast, sensitivity to lapachol was similar amongst the five cell lines. Lapachol was not detected in the stembark extract.

Topics: Antineoplastic Agents, Phytogenic; Carcinoma, Renal Cell; Cell Line; Humans; Kidney Neoplasms; Melanoma; Naphthoquinones; Plants, Medicinal; Tissue Extracts; Tumor Cells, Cultured; Vincristine

Furaquinocins C, D, E, F, G and H, congeners of furaquinocins A and B, were isolated from the culture broth of Streptomyces sp. KO-3988 and their structures have been determined on the basis of their spectroscopical and chemical properties. These antibiotics showed cytocidal activities against HeLa S3 and B16 melanoma cells in vitro.

Topics: Anti-Bacterial Agents; Cell Survival; Chemical Phenomena; Chemistry, Physical; HeLa Cells; Humans; Magnetic Resonance Spectroscopy; Melanoma; Molecular Structure; Naphthoquinones; Streptomyces