B16F10 Murine Melanoma Cell Line Research Articles

Green does not always mean go: A sulfated galactan from Codium isthmocladum green seaweed reduces melanoma metastasis through direct regulation of malignancy features

Melanoma is the most lethal form of skin cancer, with a worldwide increase in incidence. Despite the increased overall survival of metastatic melanoma patients given recent advances in targeted and immunotherapy, it still has a poor prognosis and available treatment options carry diverse severe side effects. Polysaccharides from seaweed have been shown to exert antitumor activities. Here we show in vitro and in vivo antitumor activities of a sulfated homogalactan (named 3G4S) from Codium isthmocladum seaweed in the B16-F10 murine melanoma cell line. 3G4S did not induce cytotoxicity or proliferation changes; however, it was able to reduce solid tumor growth and metastasis, while not inducing side effects in mice. B16-F10 cells traits related to the metastatic cascade were also impaired by 3G4S, reducing cell invasion, colony-forming capacity and membrane glycoconjugates. Therefore, 3G4S shows promising antitumor activities without the commonly associated drawbacks of cancer treatments and can be further explored.

Planar and tomographic imaging dosimetry comparing to develop a new radiopharmaceutical for melanoma therapy

This work aims to compare SPECT (Single Photon Emission Tomography Computed) and planar modalities as the most efficient methodology to perform dosimetry by molecular imaging. Twenty-one male C57BL6 mice induced with murine melanoma cell line B16-F10, administered 131I-Ixolaris were used for melanoma therapy. The procedures applied to them followed the standards described for the use of experimental animals, duly approved by the National Council for Animal Experimentation Control (CONCEA from Federal University of Rio de Janeiro. The accumulated activities were obtained in order to estimate the absorbed doses in each organ. Mass and metabolic differences between mice and humans were considered and used to extrapolate data acquired at different scales. From the dose factors provided by the MIRDOSE software, the absorbed doses in the target organs irradiated by the source organs were calculated and, finally, the effective dose was estimated. From the Student's t-hypothesis test performed in the accumulated activity, absorbed dose and S-factor quantities, there is no statistically significant difference between performing the image dosimetry from SPECT and planar acquired images.

Inhibitory Effects of Polyphenol-Rich Plant Extracts on Melanogenesis in B16F10 Murine Melanoma Cell Line

Abstract Objectives Polyphenol compounds have been demonstrated to exhibit melanin inhibitory activities in previous studies. We studied 4 extracts of polyphenol-rich plants—rose petal (Rosa centifolia), pomegranate (Punica granatum L.), red orange (Citrus sinensis (L.) Osbeck), and acai berry (Euterpe oleracea Mart.)—for their inhibitory effects on melanogenesis as potential skin whitening agents. Methods Four plant extracts were supplemented into the culture of B16F10 murine melanoma cell line respectively to study their influences on the cell viability using CCK-8 assay and optimal concentrations were determined for the following melanogenesis inhibitory experiments. Thereafter, melanin concentration in the co-cultured B16F10 cells was measured by the NaOH lysis method. Arbutin and kojic acid were used as positive controls. Results Plant extracts showed different effects on cell viability. To achieve cell viability higher than 80%, the concentration of rose and pomegranate extracts should be lower than 1.56 and 3.12 μg/mL, respectively; whereas acai and red orange extracts should be within 50 and 100 μg/mL, respectively. In the range of concentrations adopted in this study, 1.56 μg/mL rose petal extract, 25 μg/mL red orange fruit extract and 25 μg/mL acai berry polyphenol extract showed a melanogenesis inhibitory effect of 33.29%, 29.13%, and 24.09%, respectively, which were greater than that of 50 μg/mL arbutin (10.27%, P < 0.05), but had no difference with 50 μg/mL kojic acid (29.96%). Pomegranate juice powder exhibited a similar inhibitory effect with arbutin, but weaker than kojic acid (P < 0.05). Conclusions Four polyphenol-rich plant extracts were studied for their melanin inhibitory activity in B16F10 melanoma cells in the current study. Red orange fruit extract and acai berry polyphenol extract exhibited stronger inhibitory activity on melanogenesis but milder influence on cell viability compared to the extracts of rose petal and pomegranate, therefore they could be used as potential candidates for developing new skin whitening agents. Funding Sources As a joint project, this research was cofounded by Heilongjiang Feihe Co., Ltd. and Beijing Technology and Business University.

Paclitaxel-Loaded Macrophage Membrane Camouflaged Albumin Nanoparticles for Targeted Cancer Therapy.

BackgroundMelanoma is the most common symptom of aggressive skin cancer, and it has become a serious health concern worldwide in recent years. The metastasis rate of malignant melanoma remains high, and it is highly difficult to cure with the currently available treatment options. Effective yet safe therapeutic options are still lacking. Alternative treatment options are in great demand to improve the therapeutic outcome against advanced melanoma. This study aimed to develop albumin nanoparticles (ANPs) coated with macrophage plasma membranes (RANPs) loaded with paclitaxel (PTX) to achieve targeted therapy against malignant melanoma.MethodsMembrane derivations were achieved by using a combination of hypotonic lysis, mechanical membrane fragmentation, and differential centrifugation to empty the harvested cells of their intracellular contents. The collected membrane was then physically extruded through a 400 nm porous polycarbonate membrane to form macrophage cell membrane vesicles. Albumin nanoparticles were prepared through a well-studied nanoprecipitation process. At last, the two components were then coextruded through a 200 nm porous polycarbonate membrane.ResultsUsing paclitaxel as the model drug, PTX-loaded RANPs displayed significantly enhanced cytotoxicity and apoptosis rates compared to albumin nanoparticles without membrane coating in the murine melanoma cell line B16F10. RANPs also exhibited significantly higher internalization efficiency in B16F10 cells than albumin nanoparticles without a membrane coating. Next, a B16F10 tumor xenograft mouse model was established to explore the biodistribution profiles of RANPs, which showed prolonged blood circulation and selective accumulation at the tumor site. PTX-loaded RANPs also demonstrated greatly improved antitumor efficacy in B16F10 tumor-bearing mouse xenografts.ConclusionAlbumin-based nanoscale delivery systems coated with macrophage plasma membranes offer a highly promising approach to achieve tumor-targeted therapy following systemic administration.

Non-Cytotoxic Sulfated Heterorhamnan from Gayralia brasiliensis Green Seaweed Reduces Driver Features of Melanoma Metastatic Progression.

Melanoma is a form of skin cancer with high mortality owing to its fast progression and metastatic capacity. The treatments available nowadays are only palliative in advanced stages of the disease. Thus, alternative therapies for cancer treatment are in demand, and molecules from natural sources, such as polysaccharides, could represent new possible therapeutic approaches. Polysaccharides of freshwater and marine algae with biological activities, such as antitumor properties, are greatly reported in the scientific literature. In the present study, a sulfated heterorhamnan obtained from the green seaweed Gayralia brasiliensis (Gb1 fraction) was chemically characterized and its biological activities in the B16-F10 murine melanoma cell line were evaluated. The Gb1 polysaccharidic fraction tested concentrations presented low or absence of cytotoxicity to B16-F10 cells and neither cell proliferation nor cell cycle were altered. Interestingly, Gb1 treatment decreased B16-F10 cells migration and invasion capabilities and CD44 labeling, showing to be a promising compound for further in vitro and in vivo antitumor studies.

Acremonidin E produced by Penicillium sp. SNF123, a fungal endophyte of Panax ginseng, has antimelanogenic activities

BackgroundGinseng extracts and ginseng-fermented products are widely used as functional cosmetic ingredients for their whitening and antiwrinkle effects. Recently, increasing attention has been given to bioactive metabolites isolated from endophytic fungi. However, little is known about the bioactive metabolites of the fungi associated with Panax ginseng Meyer. MethodsAn endophytic fungus, Penicillium sp. SNF123 was isolated from the root of P. ginseng, from which acremonidin E was purified. Acremonidin E was tested on melanin synthesis in the murine melanoma cell line B16F10, in the human melanoma cell line MNT-1, and in a pigmented 3D-human skin model, Melanoderm. ResultsAcremonidin E reduced melanogenesis in α-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 cells with minimal cytotoxicity. qRT–PCR analysis demonstrated that acremonidin E downregulated melanogenic genes, including tyrosinase and tyrosinase-related protein 1 (TRP-1), while their enzymatic activities were unaffected. The antimelanogenic effects of acremonidin E were further confirmed in MNT-1 and a pigmented 3D human epidermal skin model, Melanoderm. Immunohistological examination of the Melanoderm further confirmed the regression of both melanin synthesis and melanocyte activation in the treated tissue. ConclusionThis study demonstrates that acremonidin E, a bioactive metabolite derived from a fungal endophyte of P. ginseng, can inhibit melanin synthesis by downregulating tyrosinase, illuminating the potential utility of microorganisms associated with P. ginseng for cosmetic ingredients.

From bench to counter: Discovery and validation of a peony extract as tyrosinase inhibiting cosmeceutical

The anti-melanogenic principle of peony (Paeonia officinalis subsp. officinalis) seeds was elucidated via activity-guided isolation. Resveratroloside (trans-resveratrol-4′-O-beta-d-glucopyranoside) was found to be the main metabolite of P. officinalis subsp. officinalis seeds and its tyrosinase inhibiting activity was confirmed via an enzymatic assay. Furthermore, the in vitro activity and the therapeutic window were studied employing the murine melanoma cell line B16F10. The results from the conducted stability assay and the high content of resveratroloside in the seeds (i.e. 10.4% dw) motivated us to push the extract forward to an in vivo tolerance assay. A clinical study with forty Caucasian participants proofed a good skin-tolerance with high moisture effect and reduction of pores.

Vitamin A Enhances Macrophages Activity Against B16-F10 Malignant Melanocytes: A New Player for Cancer Immunotherapy?

Background and objectives: The incidence of cutaneous melanoma has been increasing. Melanoma is an aggressive form of skin cancer irresponsive to radiation and chemotherapy, rendering this cancer a disease with poor prognosis: In order to surpass some of the limitations addressed to melanoma treatment, alternatives like vitamins have been investigated. In the present study, we address this relationship and investigate the possible role of vitamin A. Materials and Methods: We perform a co-culture assay using a macrophage cell model and RAW 264.7 from mouse, and also a murine melanoma cell line B16-F10. Macrophages were stimulated with both Escherichia coli lipopolysaccharides (LPS) as control, and also with LPS plus vitamin A. Results: Using B16-F10 and RAW 264.7 cell lines, we were able to demonstrate that low concentrations of vitamin A increase cytotoxic activity of macrophages, whereas higher concentrations have the opposite effect. Conclusion: These findings can constitute a new point of view related to immunostimulation by nutrients, which may be considered one major preventive strategy by enhancing the natural defense system of the body.

MicroRNA-92 Expression in CD133+ Melanoma Stem Cells Regulates Immunosuppression in the Tumor Microenvironment via Integrin-Dependent Activation of TGFβ.

In addition to being refractory to treatment, melanoma cancer stem cells (CSC) are known to suppress host antitumor immunity, the underlying mechanisms of which need further elucidation. In this study, we established a novel role for miR-92 and its associated gene networks in immunosuppression. CSCs were isolated from the B16-F10 murine melanoma cell line based on expression of the putative CSC marker CD133 (Prominin-1). CD133+ cells were functionally distinct from CD133- cells and showed increased proliferation in vitro and enhanced tumorigenesis in vivo. CD133+ CSCs also exhibited a greater capacity to recruit immunosuppressive cell types during tumor formation, including FoxP3+ Tregs, myeloid-derived suppressor cells (MDSC), and M2 macrophages. Using microarray technology, we identified several miRs that were significantly downregulated in CD133+ cells compared with CD133- cells, including miR-92. Decreased expression of miR-92 in CSCs led to higher expression of target molecules integrin αV and α5 subunits, which, in turn, enhanced TGFβ activation, as evidenced by increased phosphorylation of SMAD2. CD133+ cells transfected with miR-92a mimic and injected in vivo showed significantly decreased tumor burden, which was associated with reduced immunosuppressive phenotype intratumorally. Using The Cancer Genome Atlas database of patients with melanoma, we also noted a positive correlation between integrin α5 and TGFβ1 expression levels and an inverse association between miR-92 expression and integrin alpha subunit expression. Collectively, this study suggests that a miR-92-driven signaling axis involving integrin activation of TGFβ in CSCs promotes enhanced tumorigenesis through induction of intratumoral immunosuppression. SIGNIFICANCE: CD133+ cells play an active role in suppressing melanoma antitumor immunity by modulating miR-92, which increases influx of immunosuppressive cells and TGFβ1 expression.

Intratumoral delivery and therapeutic efficacy of nanoparticle-encapsulated anti-tumor siRNA following intrapulmonary administration for potential treatment of lung cancer

This study evaluated the delivery efficiency and antitumor effects of the intrapulmonary administration of antitumor small interfering ribonucleic acid (siRNA)-containing nanoparticles to mice with metastatic lung tumor. Fluorescence-labeled, siRNA-containing nanoparticles were administered using Liquid MicroSprayer® to mice with metastatic lung tumors induced by the murine melanoma cell line B16F10. Fluorescent signals in the whole lung and in the tumor region following the intrapulmonary administration of siRNA-containing nanoparticles were stronger than those following intravenous administration. The intrapulmonary administration of nanoparticles containing a mixture of siRNA against MDM2, c-Myc, and vascular endothelial growth factor (VEGF) significantly improved survival and prolonged the survival of mice with metastatic lung tumor. In addition, after the intrapulmonary or intravenous administration of the mixture, the activity levels of interleukin-6 and -12, markers of systemic toxicity, were similar to those of nontreatment. These results indicate that the antitumor siRNA-containing nanoparticles were delivered efficiently and specifically to tumor cells, effectively silencing the oncogenes in the lung metastasis without any significant systemic toxicity.

Bio-Mimicking Nanoparticles for Targeted Therapy of Malignant Melanoma.

Polyethylene glycol-poly(lactic-co-glycolic acid) (PEG-PLGA) nanoparticles coated with neutrophil membranes were fabricated to afford a bio-mimicking delivery system and achieve targeted delivery of chemotherapeutics towards malignant melanoma via systemic administration. Using celastrol as the model compound, celastrol-loaded PEG-PLGA nanoparticles coated with neutrophil membranes displayed significantly enhanced cytotoxicity and apoptosis rate in a murine melanoma cell line B16F10 compared to celastrol-loaded PEG-PLGA nanoparticles. Moreover, PEG-PLGA nanoparticles coated with neutrophil membranes exhibited significantly higher internalization efficiency in B16F10 cells than nanoparticles without membrane coating. Next, a B16F10 tumor xenograft mice model was established to explore the biodistribution profiles of PEG-PLGA nanoparticles coated with neutrophil membranes which showed remarkably prolonged blood circulation and more selective accumulation at the tumor site. Celastrol-loaded PEG-PLGA nanoparticles coated with neutrophil membranes also demonstrated greatly improved antitumor efficacy in B16F10 tumor bearing mice xenografts. Taken together, PEG-PLGA nanoparticles coated with neutrophil membranes represent a highly promising nanoscale delivery system to achieve tumor-targeted therapy following systemic administration.

Clinical scale synthesis of intrinsically radiolabeled and cyclic RGD peptide functionalized 198Au nanoparticles for targeted cancer therapy

IntroductionThe emerging concept of intrinsically radiolabeled nanoparticles has the potential to transform the preclinical and clinical studies by improving the in vivo stability and demonstrating minimal alteration in the inherent pharmacokinetics of the nanoparticles. In this paper, a simple and efficient single-step method for clinical scale synthesis of intrinsically radiolabeled 198Au nanoparticles conjugated with cyclic arginine−glycine−aspartate peptide (198AuNP-RGD) is reported for potential use in targeted cancer therapy. MethodsLarge radioactive doses (>37 GBq) of 198AuNP-RGD were synthesized by reaction of 198Au-HAuCl4 with cyclic RGD peptide. The synthesized nanoparticles were characterized by various analytical techniques. In vitro cell binding studies were carried out in B16F10 (murine melanoma) cell line. Biodistribution studies were carried out in melanoma tumor bearing C57BL/6 mice to demonstrate the tumor targeting ability of 198AuNP-RGD. The therapeutic efficacy of 198AuNP-RGD was evaluated by carrying out systematic tumor regression studies in melanoma tumor bearing mice after intravenous administration of the radioactive doses. ResultsWell dispersed and biocompatible nanoparticles (~12.5 nm diameter) could be synthesized with excellent radiochemical and colloidal stability. In vitro studies exhibited the cell binding affinity and specificity of 198AuNP-RGD towards melanoma cell line. A high uptake of 8.7 ± 2.1%ID/g in the tumor was observed within 4 h post-injection (p.i.). Significant decrease in tumor uptake of 198AuNP-RGD (2.9 ± 0.8%ID/g) at 4 h p.i. on co-injection of a blocking dose of the peptide suggested that tumor localization of the intrinsically radiolabeled nanoparticles was receptor mediated. Administration of 37.0 MBq of 198AuNP-RGD resulted in significant regression of tumor growth with no apparent body weight loss over a period of 15 d. ConclusionsOverall, these promising results demonstrate the suitability of 198AuNP-RGD as an advanced functional nanoplatform for targeted cancer therapy.

Synergistic cytotoxic effect of sodium dichloroacetate combined with chemotherapeutic drugs on B16F10 murine melanoma cell line.

The incidence of skin cancer has increased dramatically in recent decades, particularly melanoma. In this study, the cytotoxic effects of sodium dichloroacetate (DCA) in combination with chemotherapeutic drugs such as doxorubicin (DOX) and cisplatin (CIS) were evaluated. In vitro, B16F10, macrophages, and murine erythrocytes were treated with DCA (ranged from 3.66 × 104 to 3.66 × 105 μmol/L), DOX (1.38 × 10-4 to 1.38 × 10-3 μmol/L) and CIS (0.16 to 1.28 μmol/L) alone or in combination and were incubated for 72 h. Cell viability and hemolysis were determined by the MTT method and released hemoglobin, respectively. The results obtained on B16F10 cells indicate that the treatment with DCA alone showed a half-maximal inhibitory concentration (IC50) of 1.49 × 105 μmol/L, DOX caused an IC50 of 1.12 × 10-4 μmol/L and CIS-induced an IC50 of 1.14 μmol/L. Combinations of treatments with IC50 of DCA+CIS or DCA+DOX resulted in significantly decreased cell viability by 60 and 95%, respectively. Finally, the treatments alone or in combination did not cause lysis of murine erythrocytes and did not affect the cell viability of macrophages. Our results suggest that DCA enhances cytotoxicity induced by CIS or DOX on B16F10 cells without affecting erythrocytes and macrophages integrity.

Preparation of Novel Homodimers Derived from Cytotoxic Isoquinolinequinones. A Twin Drug Approach.

The synthesis of five novel homodimers is reported based on the anilinoisoquinolinequinone scaffold. In these twin-drug derivatives, two units of the anilinoquinone pharmacophores are linked through a methylene spacer. The formation of dimers was achieved by reaction of isoquinolinequinones with 4, 4′-diaminodiphenylmethane via a sequence of two oxidative amination reactions. A preliminary in vitro screening of the homodimers reveals moderate to high cytotoxic activities against MDA-MB-21 breast adenocarcinoma and B16-F10 murine metastatic melanoma cell lines. The asymmetrical homodimer 15 stands out due to its cytotoxic potencies at submicromolar concentrations and high selectivity index (mean IC50 = 0.37 μM; SI = 6.97) compared to those of etoposide (mean IC50 = 3.67; SI = 0.32) and taxol (mean IC50 = 0.35; SI = 0.91) employed as reference anticancer drugs.

Cell internalization of 7-ketocholesterol-containing nanoemulsion through LDL receptor reduces melanoma growth in vitro and in vivo: a preliminary report.

Oxysterols are cholesterol oxygenated derivatives which possess several biological actions. Among oxysterols, 7-ketocholesterol (7KC) is known to induce cell death. Here, we hypothesized that 7KC cytotoxicity could be applied in cancer therapeutics. 7KC was incorporated into a lipid core nanoemulsion. As a cellular model the murine melanoma cell line B16F10 was used. The nanoparticle (7KCLDE) uptake into tumor cells was displaced by increasing amounts of low-density-lipoproteins (LDL) suggesting a LDL-receptor-mediated cell internalization. 7KCLDE was mainly cytostatic, which led to an accumulation of polyploid cells. Nevertheless, a single dose of 7KCLDE killed roughly 10% of melanoma cells. In addition, it was observed dissipation of the transmembrane potential, evidenced with flow cytometry; presence of autophagic vacuoles, visualized and quantified with flow cytometry and acridine orange; and presence of myelin figures, observed with ultrastructural microscopy. 7KCLDE impaired cytokenesis was accompanied by changes in cellular morphology into a fibroblastoid shape which is supported by cytoskeletal rearrangements, as shown by the increased actin polymerization. 7KCLDE was injected into B16 melanoma tumor-bearing mice. 7KCLDE accumulated in the liver and tumor. In melanoma tumor 7KCLDE promoted a >50% size reduction, enlarged the necrotic area, and reduced intratumoral vasculature. 7KCLDE increased the survival rates of animals, without hematologic or liver toxicity. Although more pre-clinical studies should be performed, our preliminary results suggested that 7KCLDE is a promising novel preparation for cancer chemotherapy.

Plasma Elicits Immunogenic Death In Melanoma Cells

Development of non-thermal plasma for cancer immunotherapeutic applications has received growing attention, namely for induction of immunogenic cancer cell death (ICD). Cancer cells undergoing ICD emit signals known as damage-associated molecular patterns (DAMPs), that can attract and stimulate local immune cells [1]. Of these, membrane-bound calreticulin is a key DAMP signal that facilitates engulfment of cancer cells by dendritic cells, a critical process for the development of a specific, anti-tumor immune response [2]. Several studies have shown that plasma treatment of cancer cell lines increased the exposure of CRT on the cell surface [3, 4]. However, the mechanism by which plasma elicits ICD is not fully elucidated. We therefore studied the interaction of plasma with melanoma cells, at ICD-inducing regimes. The B16-F10 murine melanoma cell line and the A375 human melanoma cell line were treated with a microsecond-pulsed dielectric barrier discharge system over a range of energies and evaluated for CRT emission. We also studied changes to liquid chemistry following plasma treatment, as cells were not treated under dry conditions. Using electron paramagnetic resonance spectroscopy and colorimetric assays, we identified the reactive oxygen and nitrogen species (RONS) present in the liquid after treatment with plasma. By comparing the trends between the exposure of CRT on the cell membrane and the concentration of RONS in the liquid following increasing plasma treatment energies, we can gain insight into which species are most crucial for plasma-induction of ICD. Knowing this will facilitate the optimization of plasma systems for immunotherapy of cancers. Ongoing work includes evaluation of ICD induction of melanoma cells in an in vivo mouse model.

Enhanced protection of C57 BL/6 vs Balb/c mice to melanoma liver metastasis is mediated by NK cells

ABSTRACTThe B16F10 murine melanoma cell line displays a low expression of MHC class I molecules favoring immune evasion and metastases in immunocompetent C57 BL/6 wild-type mice. Here, we generated metastases to the liver, an organ that is skewed towards immune tolerance, by intrasplenic injection of B16F10 cells in syngeneic C57 BL/6 compared to allogeneic Balb/c mice. Surprisingly, Balb/c mice, which usually display a pronounced M2 macrophage and Th2 T cell polarization, were ∼3 times more susceptible to metastasis than C57 BL/6 mice, despite a much higher M1 and Th1 T cell immune response. The anti-metastatic advantage of C57 BL/6 mice could be attributed to a more potent NK-cell mediated cytotoxicity against B16F10 cells. Our findings highlight the role of NK cells in innate anti-tumor immunity in the context of the liver – particularly against highly aggressive MHC I-deficient cancer cells. Moreover, the B16F10 model of melanoma liver metastasis is suited for developing novel therapies targeting innate NK cell related immunity in liver metastases and liver cancer.

Synthesis, Spectral Characterization, DNA/ Protein Binding, DNA Cleavage, Cytotoxicity, Antioxidative and Molecular Docking Studies of Cu(II)Complexes Containing Schiff Base-bpy/Phen Ligands.

Ternary Cu(II) complexes [Cu(II)(L)(bpy)Cl] 1, [Cu(II)(L)(Phen)Cl] 2 [L=2,3-dimethyl-1-phenyl-4(2 hydroxy-5-methyl benzylideneamino)-pyrazol-5-one, bpy=2,2' bipyridine, phen =1,10 phenanthroline) were synthesized and characterized by elemental analyses, UV-Visible, FT-IR, ESR, Mass, thermogravimetric and SEM EDAX techniques. The complexes exhibit octahedral geometry. The interaction of the Cu(II) with cailf thymus DNA (CT-DNA) was explored by using absorption and fluorescence spectroscopic methods. The results revealed that the complexes have an affinity constant for DNA in the order of 104M-1 and mode of interaction is intercalative mode. The DNA cleavage study showed that the complexes cleaved DNA without any external agent. The interaction of Cu(II) complexes with bovine serum albumin (BSA) was also studied using absorption and fluorescence techniques. The cytotoxic activity of the Cu(II) complexes was probed in HeLa (human breast adenocarcinoma cell line), B16F10 (Murine melanoma cell line) and HEPA1-6 celllines, complex 1 has good cytotoxic activity which is comparable with the doxarubicin drug, with IC50 values ranging from 3 to 12.6μM. A further molecular docking technique was employed to understand the binding of the complexes towards the molecular target DNA. Investigation of the antioxidative properties showed that the metal complexes have significant radical scavenging activity potency against DPPH radical.

Yessotoxin, a Marine Toxin, Exhibits Anti-Allergic and Anti-Tumoural Activities Inhibiting Melanoma Tumour Growth in a Preclinical Model.

Yessotoxins (YTXs) are a group of marine toxins produced by the dinoflagellates Protoceratium reticulatum, Lingulodinium polyedrum and Gonyaulax spinifera. They may have medical interest due to their potential role as anti-allergic but also anti-cancer compounds. However, their biological activities remain poorly characterized. Here, we show that the small molecular compound YTX causes a slight but significant reduction of the ability of mast cells to degranulate. Strikingly, further examination revealed that YTX had a marked and selective cytotoxicity for the RBL-2H3 mast cell line inducing apoptosis, while primary bone marrow derived mast cells were highly resistant. In addition, YTX exhibited strong cytotoxicity against the human B-chronic lymphocytic leukaemia cell line MEC1 and the murine melanoma cell line B16F10. To analyse the potential role of YTX as an anti-cancer drug in vivo we used the well-established B16F10 melanoma preclinical mouse model. Our results demonstrate that a few local application of YTX around established tumours dramatically diminished tumour growth in the absence of any significant toxicity as determined by the absence of weight loss and haematological alterations. Our data support that YTX may have a minor role as an anti-allergic drug, but reveals an important potential for its use as an anti-cancer drug.

Posttranslational proteolytic processing of Leda-1/Pianp involves cleavage by MMPs, ADAM10/17 and gamma-secretase

Leda-1/Pianp is a type I transmembrane protein expressed by CNS cells, murine melanoma cell line B16F10 and rat liver sinusoidal endothelial cells. The early steps of posttranslational modifications of Leda-1/Pianp have been described to include glycosylation and processing by proprotein convertases. Here, we comprehensively characterized the subsequent steps of proteolytic processing of Leda-1/Pianp. For this purpose specific protease inhibitors and cell lines deficient in PS1, PS2, PS1/PS2 and ADAM10/17 were deployed. Leda-1/Pianp was cleaved at numerous cleavage sites within the N-terminal extracellular domain. The sheddases involved included MMPs and ADAM10/17. Ectodomain shedding yielded C-terminal fragments (CTF) of ∼15 kDa. The CTF was further processed by the γ (gamma)-secretase complex to generate the intracellular domain (ICD) of ∼10 kDa. Although PS1 was the dominant intramembrane protease, PS2 was also able to cleave Leda-1/Pianp in the absence of PS1. Thus, Leda-1/Pianp is constitutively processed by proprotein convertases, sheddases including MMPs and ADAM10/17 and intramembrane protease γ-secretase.