Enhanced Therapeutic Efficacy Against Melanoma through Exosomal Delivery of Hesperidin

Melanoma, characterized as the most aggressive and metastatic form of skin cancer, currently has limited treatment options, predominantly chemotherapy and radiation therapy. However, the drawbacks associated with parenterally administered chemotherapy underscore the urgent need for alternative compounds to combat melanoma effectively. Hesperidin (HES), a flavonoid present in various citrus fruits, exhibits promising anticancer activity. Nevertheless, the clinical utility of HES is hindered by challenges such as poor water solubility, a short half-life, and low oral bioavailability. In response to these limitations, we introduced a novel approach by formulating HES-loaded exosomes (Exo-HES). Isolation of exosomes was achieved through the ultracentrifugation method, and HES was efficiently loaded using the sonication method. The resulting formulations displayed a desirable particle size (∼106 nm) and exhibited a spherical morphology, as confirmed by scanning electron and atomic force microscopy. In vitro studies conducted on B16F10 cell lines demonstrated higher cytotoxicity of Exo-HES compared to free HES, supported by enhanced cellular uptake validated through coumarin-6-loaded exosomes. This superior cytotoxicity was further evidenced by DNA fragmentation, increased generation of free radicals (ROS), loss of mitochondrial membrane potential, and effective inhibition of colony formation. The antimetastatic properties of Exo-HES were confirmed through wound healing and transwell migration assays. Oral pharmacokinetics studies revealed a remarkable increase of approximately 2.5 times in oral bioavailability and half-life of HES when loaded into exosomes. Subsequent in vivo experiments utilizing a B16F10-induced melanoma model in Swiss mice established that Exo-HES exhibited superior anticancer activity compared to HES after oral administration. Importantly, no biochemical, hematological, or histological toxicities were observed in tumor-bearing mice treated with Exo-HES. These findings suggest that exosomes loaded with HES represent a promising nanocarrier strategy to enhance the therapeutic effectiveness of hesperidin in melanoma treatment.

Melanogrit potentiates melanogenesis by escalating cellular tyrosinase activity and MITF levels via pERK inhibition

Vitiligo is characterized by the development of white patches on the skin either due to the loss of functional melanocytes or perturbations in the melanogenesis pathway. In the present study, we investigated the therapeutic potential of herbo-mineral formulation, Melanogrit in neutralizing the white patches in the skin. The study utilized UPLC/MS-QToF technique to determine the diversified phytochemical profile in Melanogrit. The murine B16F10 cells when treated with Melanogrit underwent morphological changes, including increased angularity, enlarged cell size, and greater dendritic protrusions. To establish an equivalent model to study melanogenesis, we carefully optimized the dosage of α-melanocyte stimulating hormone (αMSH) in B16F10 cells as an alternative to using melanocyte-keratinocyte cocultures. The study determined a sub-optimal dose of αMSH (0.2 nM) in B16F10 cells that does not manifest any measurable effects on melanogenesis. In contrast, Melanogrit when used in conjunction with 0.2 nM αMSH, induced a dose-dependent increase in extracellular and intracellular melanin levels. Melanogrit transcriptionally up-regulated the decisive genes of the melanogenesis pathway, MITF, TYR, and TRP1, which was evident from the increased cellular tyrosine activity. Our findings also demonstrated that Melanogrit ameliorated the MITF protein levels by inhibiting pERK; notably without involving GSK3β in the process. Taken together, our findings strongly suggest that Melanogrit has the potential to stimulate melanogenesis, making it a promising candidate for clinical applications in the treatment of white skin patches that develop in vitiligo patients.

Anti-Melanogenic Effects of Lilium lancifolium Root Extract via Downregulation of PKA/CREB and MAPK/CREB Signaling Pathways in B16F10 Cells

Hyperpigmentation disorders causing emotional distress require the topical use of depigmenting agents of natural origin. In this study, the anti-melanogenic effects of the Lilium lancifolium root extract (LRE) were investigated in B16F10 cells. Consequently, a non-cytotoxic concentration of the extract reduced intracellular melanin content and tyrosinase activity in a dose-dependent manner, correlating with the diminished expression of core melanogenic enzymes within cells. LRE treatment also inhibited cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB)/microphthalmia-associated transcription factor signaling, which regulates the expression of tyrosinase-related genes. Upon examining these findings from a molecular mechanism perspective, LRE treatment suppressed the phosphorylation of protein kinase A (PKA), p38, and extracellular signal-related kinase (ERK), which are upstream regulators of CREB. In addition, L-phenylalanine and regaloside A, specifically identified within the LRE using liquid chromatography-mass spectrometry, exhibited inhibitory effects on melanin production. Collectively, these results imply that LRE potentially suppresses cAMP-mediated melanogenesis by downregulating PKA/CREB and mitogen-activated protein kinase (MAPK)/CREB signaling pathways. Therefore, it can be employed as a novel therapeutic ingredient of natural origin to ameliorate hyperpigmentation disorders.

Medical Gas Plasma Technology Combines with Antimelanoma Therapies and Promotes Immune-Checkpoint Therapy Responses

Strategies to improve activity and selectivity are major goals in oncological drug development. Medical gas plasma therapy has been subject to intense research in dermatooncology recently. Based on partial gas ionization, this approach is exceptional in generating a variety of reactive oxygen species simultaneously that can be applied locally at the tumor side. It is hypothesized that combined gas plasma treatment can potentiate drug responses in the treatment of melanoma. Using a plasma jet approved as medical device in Europe, a systematic screening of 46 mitochondria-targeted drugs identifies five agents synergizing in vitro and in vivo. Increased intratumoral leucocyte infiltration points to immunomodulatory aspects of the treatment, motivating to investigate responses to immune checkpoint blockade in combination with plasma. Tumor growth is monitored based on bioluminescent imaging, and single-cell suspensions are retrieved from each tumor to characterize tumor-infiltrating leucocytes using multicolor flow cytometry. Gene expression profiling is done using a validated NanoString panel targeting 770 genes specifically designed for immuno-oncological research. Cell type abundancies are characterized from bulk RNA samples using the CIBERSORT computational framework. Collectively, the results indicate that local application of medical gas plasma technology synergizes with mitochondria-targeted drugs and anti-PD1 checkpoint therapy in treating melanoma.

Expression of GFP and DsRed fluorescent proteins after gene electrotransfer of tumour cells in vitro

Fluorescent reporter genes are widely used to study the transfection of various types of primary cells and cell lines. The aim of our research was to investigate the expression dynamics of GFP and DsRed reporter genes individually and combined after gene electrotransfer of plasmids with two different electroporation protocols in B16F10 and CT26 cells in vitro. The cytotoxicity after gene electrotransfer of both plasmids was first determined. Second, the intensity of fluorescence and the percentage of cells transfected with both plasmids individually and in combination were monitored in real time. The results show that the percentage of viability after gene electrotransfer of plasmids using the EP2 pulses was significantly higher compared to the EP1 pulses. In contrast, the percentage of transfected cells and fluorescence intensity were higher after gene electrotransfer with the EP1 pulse protocol. Moreover, the percentage of transfected cells was higher and started earlier in the B16F10 cell line than in the CT26 cell line. However, fluorescence intensity was higher in CT26 cells. Co-expression of fluorescent proteins was achieved only in a small number of cells. In conclusion, this study elucidated some of the dynamics of reporter gene expression in cancer cell lines after gene electrotransfer.

Anti-tumor antibody isotype response can be modified with locally administered immunoadjuvants

In situ vaccination with immunostimulatory compounds is a demonstrated means to treat tumors preclinically. While these therapeutic effects have been attributed to the actions of T cells or innate immune activation, characterisation of the humoral immune response is seldom performed. This study aims to identify whether the injection of immunoadjuvants, Addavax (Adda) and cytosine-phosphorothioate-guanine oligodeoxynucleotide (CpG), intratumorally can influence the antibody response. Specifically, whether intratumoral injection of immunoadjuvants can alter the tumor-specific antibody target, titre and isotype. Following this, the study aimed to investigate whether serum obtained from in situ vaccinated mice could neutralise circulating tumor cells. Serum was obtained from mice bearing B16F10-OVA-Luc-GFP tumors treated with immunoadjuvants. Antibody targets' titre and isotype were assessed by indirect ELISA. The ability of serum to neutralise circulating cancer cells was evaluated in a B16F10 pseudo-metastatic model. It was observed that tumor-bearing mice mount a specific anti-tumor antibody response. Antibody titre and target were unaffected by in situ vaccination with immunoadjuvants; however, a higher amount of IgG2c was produced in mice receiving Adda plus CpG. Serum from in situ vaccinated mice was unable to neutralise circulating B16F10 cells. Thus, this study has demonstrated that anti-tumor antibody isotype may be modified using in situ vaccination; however, this alone is not sufficient to neutralise circulating cancer cells.

The Effects of 2'-Hydroxy-3,6'-Dimethoxychalcone on Melanogenesis and Inflammation

In this study, we demonstrated that 2'-hydroxy-3,6'-dimethoxychalcone (3,6'-DMC) alleviated α-MSH-induced melanogenesis and lipopolysaccharides (LPS)-induced inflammation in mouse B16F10 and RAW 264.7 cells. In vitro analysis results showed that the melanin content and intracellular tyrosinase activity were significantly decreased by 3,6'-DMC, without cytotoxicity, via decreases in tyrosinase and the tyrosinase-related protein 1 (TRP-1) and TRP-2 melanogenic proteins, as well as the downregulation of microphthalmia-associated transcription factor (MITF) expression through the upregulation of the phosphorylation of extracellular-signal-regulated kinase (ERK), phosphoinositide 3-kinase (PI3K)/Akt, and glycogen synthase kinase-3β (GSK-3β)/catenin, and downregulation of the phosphorylation of p38, c-Jun N-terminal kinase (JNK), and protein kinase A (PKA). Furthermore, we investigated the effect of 3,6'-DMC on macrophage RAW264.7 cells with LPS stimulation. 3,6'-DMC significantly inhibited LPS-stimulated nitric oxide production. 3,6'-DMC also suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 on the protein level. In addition, 3,6'-DMC decreased the production of the tumor necrosis factor-α and interleukin-6. Successively, our mechanistic studies revealed that 3,6'-DMC also suppressed the LPS-induced phosphorylation of the inhibitor of IκBα, p38MAPK, ERK, and JNK. The Western blot assay results showed that 3,6'-DMC suppresses LPS-induced p65 translocation from cytosol to the nucleus. Finally, the topical applicability of 3,6'-DMC was tested through primary skin irritation, and it was found that 3,6'-DMC, at 5 and 10 μM concentrations, did not cause any adverse effects. Therefore, 3,6'-DMC may provide a potential candidate for preventing and treating melanogenic and inflammatory skin diseases.

Syringetin Promotes Melanogenesis in B16F10 Cells

Syringetin, an active compound present in red grapes, jambolan fruits, Lysimachia congestiflora, and Vaccinium ashei, is a dimethyl myricetin derivative which contains free hydroxyl groups at the C-2' and C-4' positions in ring B. Recent studies have revealed that syringetin possesses multiple pharmacological properties, such as antitumor, hepatoprotective, antidiabetic, antioxidative, and cytoprotective activities. To date, there has been no attempt to test the action of syringetin on melanogenesis. In addition, the molecular mechanism for the melanogenic effects of syringetin remains largely unknown. In this study, we investigated the effect of syringetin on melanogenesis in a murine melanoma cell line from a C57BL/6J mouse, B16F10. Our results showed that syringetin markedly stimulated melanin production and tyrosinase activity in a concentration-dependent manner in B16F10 cells. We also found that syringetin increased MITF, tyrosinase, TRP-1, and TRP-2 protein expression. Moreover, syringetin inhibited ERK and PI3K/Akt phosphorylation by stimulating p38, JNK, PKA phosphorylation levels, subsequently stimulating MITF and TRP upregulation, resulting in the activation of melanin synthesis. Furthermore, we observed that syringetin activated phosphorylation of GSK3β and β-catenin and reduced the protein level of β-catenin, suggesting that syringetin stimulates melanogenesis through the GSK3β/β-catenin signal pathway. Finally, a primary skin irritation test was conducted on the upper backs of 31 healthy volunteers to determine the irritation or sensitization potential of syringetin for topical application. The results of the test indicated that syringetin did not cause any adverse effects on the skin. Taken together, our findings indicated that syringetin may be an effective pigmentation stimulator for use in cosmetics and in the medical treatment of hypopigmentation disorders.

Construction of VSVΔ51M oncolytic virus expressing human interleukin-12

The use of oncolytic viruses (OVs) in combination with cytokines, such as IL-12, is a promising approach for cancer treatment that addresses the limitations of current standard treatments and traditional cancer immunotherapies. IL-12, a proinflammatory cytokine, triggers intracellular signaling pathways that lead to increased apoptosis of tumor cells and enhanced antitumor activity of immune cells via IFN-γ induction, making this cytokine a promising candidate for cancer therapy. Targeted expression of IL-12 within tumors has been shown to play a crucial role in tumor eradication. The recent development of oncolytic viruses enables targeted delivery and expression of IL-12 at the tumor site, thereby addressing the systemic toxicities associated with traditional cancer therapy. In this study, we constructed an oncolytic virus, VSVΔ51M, based on the commercially available VSV wild-type backbone and further modified it to express human IL-12. Our preclinical data confirmed the safety and limited toxicity of the modified virus, VSV-Δ51M-hIL-12, supporting its potential use for clinical development.

Acenocoumarol, an Anticoagulant Drug, Prevents Melanogenesis in B16F10 Melanoma Cells

Hyperpigmentation can occur in abnormal skin conditions such as melanomas, as well as in conditions including melasma, freckles, age spots, seborrheic keratosis, and café-au-lait spots (flat brown spots). Thus, there is an increasing need for the development of depigmenting agents. We aimed to repurpose an anticoagulant drug as an effective ingredient against hyperpigmentation and apply cosmeceutical agents. In the present study, the anti-melanogenic effects of two anticoagulant drugs, acenocoumarol and warfarin, were investigated. The results showed that both acenocoumarol and warfarin did not cause any cytotoxicity and resulted in a significant reduction in intracellular tyrosinase activity and melanin content in B16F10 melanoma cells. Additionally, acenocoumarol inhibits the expression of melanogenic enzymes such as tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2, suppressing melanin synthesis through a cAMP-dependent, protein kinase (PKA)-dependent downregulation of microphthalmia-associated transcription factor (MITF), a master transcription factor in melanogenesis. Furthermore, anti-melanogenic effects were exerted by acenocoumarol through downregulation of the p38 and JNK signaling pathway and upregulation of extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/glycogen synthesis kinase-3β (GSK-3β) cascades. In addition, the β-catenin content in the cell cytoplasm and nucleus was increased by acenocoumarol through a reduction in the phosphorylated β-catenin (p-β-catenin content). Finally, we tested the potential of acenocoumarol for topical applications by conducting primary human skin irritation tests. Acenocoumarol did not induce any adverse reactions during these tests. Based on the results, it can be concluded that acenocoumarol regulates melanogenesis through various signaling pathways such as PKA, MAPKs, PI3K/Akt/GSK-3β, and β-catenin. These findings suggest that acenocoumarol has the potential to be repurposed as a drug for treating hyperpigmentation symptoms and could provide new insights into the development of therapeutic approaches for hyperpigmentation disorders.

Antimelanoma effect of manool in 2D cell cultures and reconstructed human skin models

Melanoma is the most aggressive and lethal type of skin cancer, characterized by therapeutic resistance. In this context, the present study aimed to investigate the cytotoxic potential of manool, a diterpene from Salvia officinalis L., in human (A375) and murine (B16F10) melanoma cell lines. The analysis of cytotoxicity using the XTT assay showed the lowest IC₅₀ after 48 h of treatment with the manool, being 17.6 and 18.2 µg/ml for A375 and B16F10, respectively. A selective antiproliferative effect of manool was observed on the A375 cells based on the colony formation assay, showing an IC₅₀ equivalent to 5.6 µg/ml. The manool treatments led to 43.5% inhibition of the A375 cell migration at a concentration of 5.0 µg/ml. However, it did not affect cell migration in the B16F10 cells. Cell cycle analysis revealed that the manool interfered in the cell cycle of the A375 cells, blocking the G2/M phase. No changes in the cell cycle were observed in the B16F10 cells. Interestingly, manool did not induce apoptosis in the A375 cells, but apoptosis was observed after treatment of the B16F10 cells. Additionally, manool showed an antimelanoma effect in a reconstructed human skin model. Furthermore, in silico studies, showed that manool is stabilized in the active sites of the tubulin dimer with comparable energy concerning taxol, indicating that both structures can inhibit the proliferation of cancer cells. Altogether, it is concluded that manool, through the modulation of the cell cycle, presents a selective antiproliferative activity and a potential antimelanoma effect.

Quercetin 3-O-Galactoside Isolated from Limonium tetragonum Inhibits Melanogenesis by Regulating PKA/MITF Signaling and ERK Activation

Quercetin 3-O-galactoside (Q3G) is a common dietary flavanol that has been shown to possess several bioactivities, including anti-melanogenesis. However, how Q3G exerts its anti-melanogenic effect has not been studied. The current study, therefore aimed to investigate the anti-melanogenesis potential of Q3G and elucidate the underlying action mechanism in α-melanocyte-stimulating hormone (α-MSH)-induced hyperpigmentation model of B16F10 murine melanoma cells. Results showed that α-MSH stimulation significantly increased tyrosinase (TYR) and melanin production, which were significantly downregulated by Q3G treatment. The treatment with Q3G suppressed the transcriptional and protein expressions of melanogenesis-related enzymes TYR, tyrosinase related protein-1 (TRP-1), and TRP-2, along with the melanogenic transcription factor microphthalmia-associated transcription factor (MITF) in B16F10 cells. It was shown that Q3G downregulated MITF expression and suppressed its transcriptional activity by inhibiting the cAMP-dependent protein kinase A (PKA)-mediated activation of CREB and GSK3β. In addition, MAPK-regulated MITF activation signaling was also involved in the inhibition of melanin production by Q3G. The results suggest that the anti-melanogenic properties of Q3G rationalize further studies in vivo to confirm its action mechanism and consequent utilization as a cosmetic ingredient against hyperpigmentation.

Miglitol, an Oral Antidiabetic Drug, Downregulates Melanogenesis in B16F10 Melanoma Cells through the PKA, MAPK, and GSK3β/β-Catenin Signaling Pathways

Hyperpigmentation is a common condition that causes darker spots or patches on the skin, which often look brown, black, gray, red, or pink. This results in unresolved psychological impact due to high anxiety, depression, and somatoform disorder. We aimed to repurpose an antidiabetic drug, miglitol, as an effective compound against hyperpigmentation when applied as a cosmeceutical agent. The present study investigated the antimelanogenic effects of miglitol and the trehalase inhibitor validamycin A. Miglitol in isolation exhibited no cytotoxicity and significantly reduced the melanin production and intracellular tyrosinase activity in B16F10 melanoma cells. The Western blotting results showed that miglitol reduces the expression of melanogenic regulatory factors, including tyrosinase, tyrosinase-related protein (TRP)-1, TRP-2, and microphthalmia-associated transcription factor (MITF). Mechanistically, miglitol appears to suppress melanin synthesis through cAMP-dependent protein kinase (PKA)-dependent downregulation of MITF, a master transcription factor in melanogenesis. The antimelanogenic effects of miglitol was mediated by downregulation of the p38 signaling pathway and upregulation of extracellular signal-regulated kinase (ERK). Moreover, miglitol decreases P-GSK3β and β-catenin levels compared to those in the untreated group. However, miglitol activated P-β-catenin expression compared to that in the untreated group. Finally, we tested the potential of miglitol in topical application through primary human skin irritation tests on the normal skin (upper back) of 33 volunteers. In these assays, miglitol (125 and 250 μM) did not induce any adverse reactions. Taken together, these findings suggest that the regulation of melanogenesis by miglitol may be mediated by the PKA, MAPK, and GSK3β/β-Catenin signaling pathways and that miglitol might provide new insights into drug repurposing for the treatment of hyperpigmentation symptoms.

Bacteria-mediated tumor-targeted delivery of tumstatin (54-132) significantly suppresses tumor growth in mouse model by inhibiting angiogenesis and promoting apoptosis

Tumor growth is an angiogenesis-dependent process and accompanied by the formation of hypoxic areas. Tumstatin is a tumor-specific angiogenesis inhibitor that suppresses the proliferation and induces the apoptosis of tumorous vascular endothelial cells. VNP20009, an attenuated Salmonella typhimurium strain, preferentially accumulates in the hypoxic areas of solid tumors. In this study, a novel Salmonella-mediated targeted expression system of tumstatin (VNP-Tum5) was developed under the control of the hypoxia-induced J23100 promoter to obtain anti-tumor efficacy in mice. Treatment with VNP-Tum5 effectively suppressed tumor growth and prolonged survival in the mouse model of B16F10 melanoma. VNP-Tum5 exhibited a higher efficacy in inhibiting the proliferation and inducing the necrosis and apoptosis of B16F10 cells in vitro and in vivo compared with VNP (control). VNP-Tum5 significantly inhibited the proliferation and migration of mouse umbilical vascular endothelial cells to impede angiogenesis. VNP-Tum5 downregulated the expression of anti-vascular endothelial growth factor A, platelet endothelial cell adhesion molecule-1, phosphorylated phosphoinositide 3 kinase, and phosphorylated protein kinase B and upregulated the expression of cleaved-caspase 3 in tumor tissues. This study is the first to use tumstatin-transformed VNP20009 as a tumor-targeted system for treatment of melanoma by combining anti-tumor and anti-angiogenic effects.

Paradoxical Radiosensitizing Effect of Carnosic Acid on B16F10 Metastatic Melanoma Cells: A New Treatment Strategy

Carnosic acid (CA) is a phenolic diterpene characterized by its high antioxidant activity; it is used in industrial, cosmetic, and nutritional applications. We evaluated the radioprotective capacity of CA on cells directly exposed to X-rays and non-irradiated cells that received signals from X-ray treated cells (radiation induced bystander effect, RIBE). The genoprotective capacity was studied by in vivo and in vitro micronucleus assays. Radioprotective capacity was evaluated by clonogenic cell survival, MTT, apoptosis and intracellular glutathione assays comparing radiosensitive cells (human prostate epithelium, PNT2) with radioresistant cells (murine metastatic melanoma, B16F10). CA was found to exhibit a genoprotective capacity in cells exposed to radiation (p < 0.001) and in RIBE (p < 0.01). In PNT2 cells, considered as normal cells in our study, CA achieved 97% cell survival after exposure to 20 Gy of X-rays, eliminating 67% of radiation-induced cell death (p < 0.001), decreasing apoptosis (p < 0.001), and increasing the GSH/GSSH ratio (p < 0.01). However, the administration of CA to B16F10 cells decreased cell survival by 32%, increased cell death by 200% (p < 0.001) compared to irradiated cells, and increased cell death by 100% (p < 0.001) in RIBE bystander cells (p < 0.01). Furthermore, it increased apoptosis (p < 0.001) and decreased the GSH/GSSG ratio (p < 0.01), expressing a paradoxical radiosensitizing effect in these cells. Knowing the potential mechanisms of action of substances such as CA could help to create new applications that would protect healthy cells and exclusively damage neoplastic cells, thus presenting a new desirable strategy for cancer patients in need of radiotherapy.

Imperatorin Positively Regulates Melanogenesis through Signaling Pathways Involving PKA/CREB, ERK, AKT, and GSK3β/β-Catenin

The present study investigated the melanogenic effects of imperatorin and isoimperatorin and the underlying mechanisms of imperatorin using a mouse melanoma B16F10 model. Interestingly, treatment with 25 μM of either imperatorin or isoimperatorin, despite their structural differences, did not produce differences in melanin content and intracellular tyrosinase activity. Imperatorin also activated the expression of melanogenic enzymes, such as tyrosinase (TYR) and tyrosinase-related proteins TYRP-1 and TYRP-2. Mechanistically, imperatorin increases melanin synthesis through the cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA)/cAMP-responsive element-binding protein (CREB)-dependent upregulation of microphthalmia-associated transcription factor (MITF), which is a key transcription factor in melanogenesis. Furthermore, imperatorin exerted melanogenic effects by downregulating extracellular signal-regulated kinase (ERK) and upregulating phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT)/glycogen synthesis kinase-3β (GSK-3β). Moreover, imperatorin increased the content of β-catenin in the cell cytoplasm and nucleus by reducing the content of phosphorylated β-catenin (p-β-catenin). Finally, we tested the potential of imperatorin in topical application through primary human skin irritation tests. These tests were performed on the normal skin (upper back) of 31 volunteers to determine whether 25 or 50 µM of imperatorin had irritation or sensitization potential. During these tests, imperatorin did not induce any adverse reactions. Taken together, these findings suggest that the regulation of melanogenesis by imperatorin can be mediated by signaling pathways involving PKA/CREB, ERK, AKT, and GSK3β/β-catenin and that imperatorin could prevent the pathogenesis of pigmentation diseases when used as a topical agent.

CD47-SIRPα Checkpoint Disruption in Metastases Requires Tumor-Targeting Antibody for Molecular and Engineered Macrophage Therapies

The macrophage checkpoint interaction CD47-SIRPα is an emerging target for cancer therapy, but clinical trials of monoclonal anti-CD47 show efficacy only in liquid tumors when combined with tumor-opsonizing IgG. Here, in challenging metastatic solid tumors, CD47 deletion shows no effect on tumor growth unless combined with otherwise ineffective tumor-opsonization, and we likewise show wild-type metastases are suppressed by SIRPα-blocked macrophages plus tumor-opsonization. Lung tumor nodules of syngeneic B16F10 melanoma cells with CD47 deletion show opsonization drives macrophage phagocytosis of B16F10s, consistent with growth versus phagocytosis calculus for exponential suppression of cancer. Wild-type CD47 levels on metastases in lungs of immunocompetent mice and on human metastases in livers of immunodeficient mice show that systemic injection of antibody-engineered macrophages also suppresses growth. Such in vivo functionality can be modulated by particle pre-loading of the macrophages. Thus, even though CD47-SIRPα disruption and tumor-opsonizing IgG are separately ineffective against established metastatic solid tumors, their combination in molecular and cellular therapies prolongs survival.

Folate-Targeted PEGylated Magnetoliposomes for Hyperthermia-Mediated Controlled Release of Doxorubicin

Doxorubicin (DOX) is a chemotherapeutic agent commonly used for the treatment of solid tumors. However, the cardiotoxicity associated with its prolonged use prevents further adherence and therapeutic efficacy. By encapsulating DOX within a PEGylated liposome, Doxil^® considerably decreased DOX cardiotoxicity. By using thermally sensitive lysolipids in its bilayer composition, ThermoDox^® implemented a heat-induced controlled release of DOX. However, both ThermoDox^® and Doxil^® rely on their passive retention in tumors, depending on their half-lives in blood. Moreover, ThermoDox^® ordinarily depend on invasive radiofrequency-generating metallic probes for local heating. In this study, we prepare, characterize, and evaluate the antitumoral capabilities of DOX-loaded folate-targeted PEGylated magnetoliposomes (DFPML). Unlike ThermoDox^®, DOX delivery via DFPML is mediated by the heat released through dynamic hysteresis losses from magnetothermal converting systems composed by MnFe₂O₄ nanoparticles (NPs) under AC magnetic field excitation—a non-invasive technique designated magnetic hyperthermia (MHT). Moreover, DFPML dismisses the use of thermally sensitive lysolipids, allowing the use of simpler and cheaper alternative lipids. MnFe₂O₄ NPs and DFPML are fully characterized in terms of their size, morphology, polydispersion, magnetic, and magnetothermal properties. About 50% of the DOX load is released from DFPML after 30 min under MHT conditions. Being folate-targeted, in vitro DFPML antitumoral activity is higher (IC₅₀ ≈ 1 μg/ml) for folate receptor-overexpressing B16F10 murine melanoma cells, compared to MCF7 human breast adenocarcinoma cells (IC₅₀ ≈ 4 μg/ml). Taken together, our results indicate that DFPML are strong candidates for folate-targeted anticancer therapies based on DOX controlled release.

Natural Citrus flavanone 5-demethylnobiletin stimulates melanogenesis through the activation of cAMP/CREB pathway in B16F10 cells

BACKGROUND

5-demethylnobiletin is a natural polymethoxyflavone which is isolated from the extract of citrus fruits peels. It exhibits a broad spectrum of biological activities such as anti-cancer, anti-inflammatory, cardiovascular protective and neuroprotective effects, however, its effect in melanogenesis remains uninvestigated.

PURPOSE

Melanin synthesis is a very important biological process in curing disease such as vitiligo with depigmentation on the skin. In the current work, we aim to confirm the bioactivity and mechanism of 5-demethylnobiletin in stimulating melanogenesis.

STUDY DESIGN

To confirm the mechanistic role of 5-demethylnobiletin in enhancing melanogenesis, its effect on the activity of tyrosinase, together with the level of microphthalmia-associated transcription factor (MITF), Trp-1, Trp-2, melanocyte-specific marker protein PMEL17, Rab27a, Melanophilin and Myosin VA were studied in B16F10 melanoma cells.

METHODS

Multiple biological assays on melanogenesis-associated proteins such as melanin content detection, tyrosinase activity colorimetric assay, qPCR, western blot analysis, dual-luciferase reporter assay, cAMP activity assay and Fontana-Masson ammoniacal silver staining were used to confirm the role of 5-demethylnobiletin in stimulating melanin synthesis and the transportation of melanosomes.

RESULTS

As confirmed by multiple biological assays, 5-demethylnobiletin is found to stimulate dendrite structure formation in cells, melanin synthesis and the transportation of melanosomes, via inducing the phosphorylation of cAMP response element-binding protein (CREB) and increasing the intracellular levels of cAMP in vitro through the PKA-dependent pathway.

CONCLUSION

The findings suggested that 5-demethylnobiletin may be considered as a potential natural product candidate for patients with pigment disorder.

C-phycocyanin decreases proliferation and migration of melanoma cells: In silico and in vitro evidences

The incidence and number of deaths caused by melanoma have been increasing in recent years, and the pigment C-phycocyanin (C-PC) appears as a possible alternative to treat this disease. So, the objective of this study was to combine in silico and in vitro analysis to understand the main anti-melanoma pathways exerted by C-PC. We evaluated the ability of C-PC to bind to the main cellular targets related in the progression of melanoma through molecular docking, and the reflection of this bind in the biological effects in the B16F10 cell line through in vitro analysis. Our results showed that C-PC was able to bind BRAF and MEK, which are related to the signal transduction pathway for proliferation and survival. There was also an interaction between C-PC and cyclin-dependent kinase 4 and 6. In vitro analysis demonstrated that C-PC decreased B16F10 cell proliferation, as observed by cell viability and mitotic index assays. C-PC also interacted with matrix metalloproteinase 2 and 9 and N-cadherin, which may have caused the decrease in cell migration observed in vitro. Besides that, C-PC interacts with VEGF, a factor responsible for regulating the proliferation and cellular invasion pathways. Finally, C-PC did not alter the cell viability of the non-tumoral melanocytes. Therefore, C-PC is a strong anti-tumor candidate for the treatment of melanoma, since it acts in different cellular pathways of melanoma, without causing damage to non-tumoral cells.

Effects of Bonito Elastin HC on Skin Dryness, Wrinkles, and Pigmentation In Vitro and In Vivo

We investigated the effects of bonito fish (Katsuwonus pelamis) elastin HC (KE) on skin dryness, wrinkles, and pigmentation in vitro and in vivo. In vitro, we evaluated the expression of mRNA genes and proteins related to skin dryness, wrinkles, and pigmentation. HaCaT and HS27 cells were exposed to ultraviolet B radiation (UVB) (50 mJ/cm²), and B16F10 cells were stimulated with 3-isobutyl-1-methylxanthine (IBMX, 250 μg/mL) for 72 h to induce melanin synthesis. All cells were treated with KE (50-400 μg/mL) for 24 h. We found that KE increased the expression of long-chain base 1, dihydroceramide desaturase 1, elastin, hyaluronan synthase 2, and ceramide synthase 4 mRNA or protein as well as hyaluronic acid and sphingomyelin levels in UVB-irradiated HaCaT cells. Moreover, KE regulated factors related to collagen production, wrinkles, and melanin production in UVB-irradiated HS27 cells and IBMX-stimulated B16F10 cells. In vivo, we evaluated skin hydration and the expression of mRNA genes and proteins in the skin, and conducted morphological observations in SKH-I hairless mice (5-week-old male). The mice were exposed stepwise to UVB and given KE (10, 20, and 30 mg/kg b.w.) for 8 weeks. We found that skin hydration and protein or mRNA expression related to skin moisturization were increased in the KE group. Moreover, KE intake increased factors related to collagen production, wrinkles, and melanin production in UVB-irradiated SKH-I hairless mice. These results suggest that KE may have efficacy for the development of treatments for improving skin health.

Biphasic effect of the dietary phytochemical linalool on angiogenesis and metastasis

Cytotoxic chemotherapy dominates the field of cancer treatment. Consequently, anticancer phytochemicals are largely screened on the basis of their cytotoxicity towards cancer cells which are achieved at higher doses, leading to various toxic side effects. Some phytochemicals also showed pro-carcinogenic effects at certain doses. The concept of hormesis has taught us to look into biphasic responses of phytochemicals in a more systematic way. Interestingly, the monoterpenoid alcohol, linalool, also has been reported to display both anti-oxidant and pro-oxidant properties, which prompted us to explore a probable biphasic effect on cancer cells. Cytotoxicity of various concentrations of linalool (0.1-4 mM) was tested on B16F10 murine melanoma cell line, and two sub-lethal concentrations (0.4 and 0.8 mM) were selected for further experiments. 0.4 mM linalool inhibited angiogenesis and metastasis, while 0.8 mM increased them. Similarly, B16F10 cell migration, invasion, and epithelial-mesenchymal transition markers also showed inhibition and induction with lower and higher linalool concentrations, respectively. Chorioallantoic membrane assay, scratch wound assay, and Boyden's chamber were used to analyze angiogenesis and metastasis. Expression of molecular markers such as vascular endothelial growth factor (VEGF) and its receptor phosphorylated VEGF receptor II (p-VEGFRII or p-Flk-1), Hypoxia-inducible factor-1 α (HIF-1α), E-cadherin, and vimentin were detected using Western blot, ELISA, PCR, qPCR, and immunofluorescence. Finally, ChIP assay was performed to evaluate HIF-1α association with VEGF promoter. Interestingly, measurement of intracellular reactive oxygen species at the selected concentrations of linalool using DCFDA in a flow cytometer showed that the phytochemical induced significant amount of ROS at 0.8 mM. This work sheds light on bimodal dose-response relationship exhibited by dietary phytochemicals like linalool, and it should be taken into consideration to elicit a desirable therapeutic effect.

Dibenzoylmethane derivative inhibits melanoma cancer in vitro and in vivo through induction of intrinsic and extrinsic apoptotic pathways

Malignant melanoma has a low incidence, but is the most lethal type of skin cancer. Studies have shown that dibenzoylmethanes (DBMs) have interesting biological activities, including antineoplastic properties. These findings led us to investigate whether news DBM derivatives exert antitumor effects against skin cancers. In a previous study, we found that 1,3-diphenyl-2-benzyl-1,3-propanedione (DPBP) has high in vitro antineoplastic activity against murine B16F10 melanoma cells, with an IC50 of 6.25 μg/mL. In the current study, we used transdermal and topical formulations of DPBP to evaluate its activity and molecular mechanism of action in a murine model of melanoma. The compound induces tumor cell death with high selectivity (selectivity index of 41.94) by triggering apoptosis through intrinsic and extrinsic pathways. DPBP treatment reduced tumor volume as well as serum VEGF-A and uric acid levels. Hepatomegaly and nephrotoxicity were not observed at the tested doses. Histopathological analysis of sentinel lymph nodes revealed no evidence of metastases. According to the observed data, the DPBP compound was effective for the topical treatment of melanoma cancer, suggesting that it acts as a chemotherapeutic or chemopreventive agent.

Caffeine improves the cytotoxic effect of dacarbazine on B16F10 murine melanoma cells

OBJECTIVE

Caffeine has been studied as a potentiating agent in chemotherapy against some types of cancer, but there are few reports on its effects on melanoma. This study aimed to investigate caffeine's ability to enhance the effects of dacarbazine in vitro.

MATERIALS AND METHODS

Murine melanoma B16F10 cells were treated 24 h with 1-40 µM caffeine. We evaluated cytotoxicity, DNA damage, apoptosis, and oxidative lesion induced by dacarbazine associated with caffeine. The metabolization of these drugs, as well as immunocytochemical labeling, were also evaluated.

CONCLUSIONS

The pre-treatment with caffeine showed to be more effective. Caffeine potentiated dacarbazine-induced cytotoxic effects by increasing dacarbazine biotransformation, apoptosis, DNA damage, and malondialdehyde levels; also, caffeine reduced Ki67 and ERK1/2 nuclear labeling and increased p53 labeling in B16F10 cells. In our experiment, caffeine promoted modifications associated with dacarbazine metabolism by viable cells potentiating this antineoplastic drug. These promising results should be further evaluated in experimental models in vivo.

Hyperphosphorylation of HDAC2 promotes drug resistance in a novel dual drug resistant mouse melanoma cell line model: an in vitro study

Drug-resistant melanoma is very difficult to treat, and a novel approach is needed to overcome resistance. The present study aims at identifying the alternate pathways utilized in the dual drug-resistant mouse melanoma cells (B16F10R) for their survival and proliferation. The dual drug-resistant mouse melanoma, B16F10R, was established by treating the cells with a combination of U0126 (MEK1/2 inhibitor) and LY294002 (PI3K-AKT kinase inhibitor) in a dose-escalating manner till they attained a resistance fold factor of ≥2. The altered phosphoproteome in the B16F10R, as compared to the parental B16F10C, was analyzed using a high-resolution Orbitrap Fusion Tribrid mass spectrometer. Histone deacetylases 2 (HDAC2) was validated for its role in drug resistance by using its inhibitor, valproic acid (VPA). In the B16F10R cells, 363 altered phosphoproteins were identified, among which 126 were hyperphosphorylated, and 137 were hypophosphorylated (1.5-fold change). Pathway analysis shows the altered phosphoproteins are from RNA metabolism and cell cycle proteins. Inhibition of HDAC2 by VPA induces apoptosis in B16F10C and B16F10R. The present study highlights the role of HDAC2, a cell cycle regulator, in the development of resistance to dual drugs in murine melanoma. Therefore, designing leads for targeting HDAC2 along with key signaling pathways may be explored in treatment strategies.

Metformin pretreatment reduces effect to dacarbazine and suppresses melanoma cell resistance

Oxidative stress role on metformin process of dacarbazine (DTIC) inducing resistance of B16F10 melanoma murine cells are investigated. To induce resistance to DTIC, murine melanoma cells were exposed to increasing concentrations of dacarabazine (DTIC-res group). Metformin was administered before and during the induction of resistance to DTIC (MET-DTIC). The oxidative stress parameters of the DTIC-res group showed increased levels of malondialdehyde (MDA), thiol, and reduced nuclear p53, 8-hydroxy-2'-deoxyguanosine (8-OH-DG), nuclear factor kappa B (NF-ĸB), and Nrf2. In presence of metformin in the resistant induction process to DTIC, (MET-DTIC) cells had increased antioxidant thiols, MDA, nuclear p53, 8-OH-DG, Nrf2, and reducing NF-ĸB, weakening the DTIC-resistant phenotype. The exclusive administration of metformin (MET group) also induced the cellular resistance to DTIC. The MET group presented high levels of total thiols, MDA, and reduced percentage of nuclear p53. It also presented reduced nuclear 8-OH-DG, NF-ĸB, and Nrf2 when compared with the control. Oxidative stress and the studied biomarkers seem to be part of the alterations evidenced in DTIC-resistant B16F10 cells. In addition, metformin administration is able to play a dual role according to the experimental protocol, preventing or inducing a DTIC-resistant phenotype. These findings should help future research with the aim of investigating DTIC resistance in melanoma.

In Vitro Anticancer Activity of Nanoformulated Mono- and Di-nuclear Pt Compounds

Nanoformulations of mononuclear Pt complexes cis-PtCl₂ (PPh₃ )₂ (1), [Pt(PPh₃ )₂ (L-Cys)] ⋅ H₂ O (3, L-Cys=L-cysteinate), trans-PtCl₂ (PPh₂ PhNMe₂ )₂ (4; PPh₂ PhNMe₂ =4-(dimethylamine)triphenylphosphine), trans-PtI₂ (PPh₂ PhNMe₂ )₂ (5) and dinuclear Pt cluster Pt₂ (μ-S)₂ (PPh₃ )₄ (2) have comparable cytotoxicity to cisplatin against murine melanoma cell line B16F10. Masking of these discrete molecular entities within the hydrophobic core of Pluronic® F-127 significantly boosted their solubility and stability, ensuring efficient cellular uptake, giving in vitro IC₅₀ values in the range of 0.87-11.23 μM. These results highlight the potential therapeutic value of Pt complexes featuring stable Pt-P bonds in nanocomposite formulations with biocompatible amphiphilic polymers.

Anti-Melanogenic Mechanism of Tetrahydrocurcumin and Enhancing Its Topical Delivery Efficacy Using a Lecithin-Based Nanoemulsion

Tetrahydrocurcumin (THC) has been well known for its superior antioxidant properties. Therefore, it is speculated that it might be effective to relieve oxidative stress-induced diseases, such as skin hyperpigmentation. In this work, an in vitro B16F10 melanoma cell model was used to study the impact of THC on the melanogenic process under stressed conditions. It was demonstrated that THC could effectively inhibit the α-MSH (melanocyte-stimulating hormone) induced melanin production in B16F10 melanoma cells and the expressions of three key enzymes involved with the biosynthetic process of melanin, tyrosinase (TYR), tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2), were all significantly reduced. In addition, an in vitro human keratinocyte cell model was used to investigate the potential protective role of THC on H₂O₂-induced cytotoxicity. It was found that THC could prevent H₂O₂-induced oxidative stress based on the results of both the cell viability study and the intracellular ROS (reactive oxygen species) study assessed by the flow cytometry. Last, THC was formulated into a lecithin based nanoemulsion, and an in vitro Franz diffusion cell study using Strat-M^® membrane concluded that the nanoemulsion could significantly enhance the membrane permeation compared to the unformatted THC suspension. This research demonstrated the anti-melanogenic benefits of THC on the melanoma and keratinocyte cell models and the topical delivery efficacy could be significantly enhanced using a lecithin based nanoemulsion.

Synthesis of pyrazoline fatty chain derivatives and its effects on melanoma cells

Skin cancer is the most common type of cancer in Brazil, representing 30% of all cases. Among these, melanoma represents only 3% of malignant neoplasms; however, it is the most serious and has a high capacity for metastasis. For this reason, it is extremely important to identify more efficient compounds and treatments that stop or decrease the proliferation of melanoma, even in its more advanced stages. This work reports the synthesis and biological evaluation of two homologous series of pyrazoline fatty chain derivatives as potent antitumoral agents in the melanoma B16F10 cell line. Cells were treated with pyrazoline fatty chain compounds (3, 30, 300, and 3000 μM) for 0, 24, 48, and 72 h. Decreased cell viability was observed when using most compounds at different concentrations and times. The structure-activity relationship (SAR) between antitumoral activity and the number of carbons and lipophilicity, as well as the oxygen-sulfur bioisosteric exchange, was evaluated. Among the tested derivatives, the lipophilic compounds 5-hydroxy-5-(trifluoromethyl)-3-undecyl-4,5-dihydro-1H-pyrazole-1-carboxamide (2d) and 5-hydroxy-5-(trifluoromethyl)-3-undecyl-4,5-dihydro-1H-pyrazole-1-thiocarboxamide (3d) showed the best results in the B16F10 cell line, as they produced the best cell viability decrease effects. The presence of fatty unbranched undecyl chain in the molecular structure appears to be important for its antimelanoma properties.

Anti-Proliferative, Pro-Apoptotic, Anti-Migrative and Tumor-Inhibitory Effects and Pleiotropic Mechanism of Theaflavin on B16F10 Melanoma Cells

Purpose

Theaflavin (TF) is a primary pigment of tea, exhibiting anti-proliferative, pro-apoptotic and anti-metastatic activities on cancer cell lines. However, it is unknown whether TF is effective in treating melanoma cells.

Methods

To determine the effects of TF on melanoma cells, we conducted in vitro assays of cell viability, DAPI staining, wound healing, transwell, and flow cytometry as well as in vivo experiments on B16F10-bearing mouse model. Real-time PCR (qPCR) and Western blot (WB) were conducted to explore the molecular actions of TF.

Results

The cell viability assay showed that TF exerted inhibitory effect on B16F10 cells in a dose-dependent manner from 40 to 400 μg/mL, with IC₅₀ values ranging from 223.8±7.1 to 103.7±7.0 μg/mL. Moreover, TF induced early and late apoptosis and inhibited migration/invasion of B16F10 cells in a dose-dependent manner, indicating its pro-apoptotic and anti-migrative effects. In vivo, TF significantly inhibited B16F10 tumor size in mice model from 40 to 120 mg/kg, which exerted higher effect than that of cisplatin. The molecular data showed that TF significantly up-regulated the mRNA expressions of pro-apoptotic genes (Bax, Casp3, Casp8, c-fos, c-Jun, and c-Myc), up-regulated the protein expressions of apoptosis-related p53 and JNK signaling molecules (ASK1, phosphorylated Chk1/2, cleaved caspase 3, phosphorylated JNK, c-JUN, cleaved PARP, and phosphorylated p53), and down-regulated the protein expressions of proliferation-related MEK/ERK and PI3K/AKT signaling molecules (phosphorylated MEK1/2, phosphorylated ERK1/2, phosphorylated PI3K, and phosphorylated AKT) as well as the expressions of MMP2 and MMP9.

Conclusion

It can be concluded that TB exhibited anti-proliferative, pro-apoptotic, anti-migrative, and tumor-inhibitory effects on melanoma cells through pleiotropic actions on the above pathways. This study provides new evidence of anti-melanoma efficacy and mechanism of TF, contributing to the development of TF-derived natural products for melanoma therapy.

Radiation-Induced Bystander Effect: Loss of Radioprotective Capacity of Rosmarinic Acid In Vivo and In Vitro

In radiation oncology, the modulation of the bystander effect is a target both for the destruction of tumor cells and to protect healthy cells. With this objective, we determine whether the radioprotective capacity of rosmarinic acid (RA) can affect the intensity of these effects. Genoprotective capacity was obtained by determining the micronuclei frequencies in in vivo and in vitro assays and the cell survival was determined by the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay) (MTT) assay in three cell lines (PNT2, TRAMPC1 and B16F10), both in direct exposure to X-rays and after the production of radiation-induced bystander effect. The administration of RA in irradiated cells produced a decrease in the frequency of micronuclei both in vivo and in vitro, and an increase in cell survival, as expression of its radioprotective effect (p < 0.001) attributable to its ability to scavenge radio-induced free radicals (ROS). However, RA does not achieve any modification in the animals receiving serum or in the cultures treated with the irradiated medium, which expresses an absence of radioprotective capacity. The results suggest that ROS participates in the formation of signals in directly irradiated cells, but only certain subtypes of ROS, the cytotoxic products of lipid peroxidation, participate in the creation of lesions in recipient cells.

Design of DOX-GNRs-PNIPAM@PEG-PLA Micelle With Temperature and Light Dual-Function for Potent Melanoma Therapy

Objective: The aim of this study was to construct light and temperature dual-sensitive micellar carriers loaded with doxorubicin (DOX) and gold nanorods (DOX-GNRs-PNIPAM@PEG-PLA, DAPP) for melanoma therapy. Methods: The DAPP self-assembled using fine-tuned physicochemical properties in water. The DAPP structure, temperature- and photo-sensitivity, drug-release, in-vitro serum stability, and cytotoxicity against melanoma B16F10 cells were evaluated in detail. The corresponding in-vitro and in-vivo therapeutic mechanisms were then evaluated using a B16F10-melanoma bearing BALB/c nude mouse model (B16F10). Results: The light and temperature sensitive micellar drug-delivery system assembled from block copolymer and gold nanorods exhibited a narrow particle size and size distribution, good biocompatibility, well-designed photo-temperature conversion, controlled drug release, and high serum stability. Compared with the free DOX- and PBS-treated groups, the cell endocytosis-mediated cytotoxicity and intra-tumor accumulation of DAPP was markedly enhanced by the NIR-light exposure and induced potent in-vivo tumor inhibitory activity. Conclusion: The design of DAPP, a dual-functional micellar drug-delivery system with temperature- and light-sensitive properties, offers a new strategy for skin-cancer therapy with a potent therapeutic index.

Novel Oncolytic Herpes Simplex Virus 1 VC2 Promotes Long-Lasting, Systemic Anti-melanoma Tumor Immune Responses and Increased Survival in an Immunocompetent B16F10-Derived Mouse Melanoma Model

Current oncolytic virotherapies possess limited response rates. However, when certain patient selection criteria are used, oncolytic virotherapy response rates have been shown to increase.

Oncolytic virotherapy (OVT) is now understood to be an immunotherapy that uses viral infection to liberate tumor antigens in an immunogenic context to promote the development of antitumor immune responses. The only currently FDA-approved oncolytic virotherapy, T-Vec, is a modified type 1 herpes simplex virus (HSV-1). While T-Vec is associated with limited response rates, its modest efficacy supports the continued development of novel OVT viruses. Herein, we test the efficacy of a recombinant HSV-1, VC2, as an OVT in a syngeneic B16F10-derived mouse model of melanoma. VC2 possesses mutations that block its ability to enter neurons via axonal termini. This greatly enhances its safety profile by precluding the ability of the virus to establish latent infection. VC2 has been shown to be a safe, effective vaccine against both HSV-1 and HSV-2 infection in mice, guinea pigs, and nonhuman primates. We found that VC2 slows tumor growth rates and that VC2 treatment significantly enhances survival of tumor-engrafted, VC2-treated mice over control treatments. VC2-treated mice that survived initial tumor engraftment were resistant to a second engraftment as well as colonization of lungs by intravenous introduction of tumor cells. We found that VC2 treatment induced substantial increases in intratumoral T cells and a decrease in immunosuppressive regulatory T cells. This immunity was critically dependent on CD8⁺ T cells and less dependent on CD4⁺ T cells. Our data provide significant support for the continued development of VC2 as an OVT for the treatment of human and animal cancers.

IMPORTANCE Current oncolytic virotherapies possess limited response rates. However, when certain patient selection criteria are used, oncolytic virotherapy response rates have been shown to increase. This, in addition to the increased response rates of oncolytic virotherapy in combination with other immunotherapies, suggests that oncolytic viruses possess significant therapeutic potential for the treatment of cancer. As such, it is important to continue to develop novel oncolytic viruses as well as support basic research into their mechanisms of efficacy. Our data demonstrate significant clinical potential for VC2, a novel type 1 oncolytic herpes simplex virus. Additionally, due to the high rates of survival and the dependence on CD8⁺ T cells for efficacy, our model will enable study of the immunological correlates of protection for VC2 oncolytic virotherapy and oncolytic virotherapy in general. Understanding the mechanisms of efficacious oncolytic virotherapy will inform the rational design of improved oncolytic virotherapies.

Melanin-Decolorizing Activity of Antioxidant Enzymes, Glutathione Peroxidase, Thiol Peroxidase, and Catalase

Melanin is the most important factor to determine skin color. Many research efforts are being undertaken to decompose the already-produced melanin compounds in skin for beauty. This research investigated the effects on reducing melanin color of the three antioxidant enzymes, Glutathione peroxidase (GPX), Thiol peroxidase (TPX), and Catalase, in lysosomal fraction. Melanin solution was treated with the enzymes and hydrogen peroxide, then reacted for 48 h. GPX and TPX decolorized melanin, and between them, GPX was more efficient, but Catalase was not effective. GPX also inhibited the production of melanin in B16F10 melanoma cells. GPX, which is present in almost all microorganisms, plays an important role in the cellular defense mechanism by reactive oxygen species. In addition, it was not cytotoxic, but was significantly effective in decolorizing melanin color. Therefore, in the biological and microbiological field, its possibility of utilization in skin whitening cosmetic is high.

Effect of Rosmarinic Acid and Ionizing Radiation on Glutathione in Melanoma B16F10 Cells: A Translational Opportunity

To explain a paradoxical radiosensitizing effect of rosmarinic acid (RA) on the melanoma B16F10 cells, we analyzed the glutathione (GSH) intracellular production on this cell (traditionally considered radioresistant) in comparison with human prostate epithelial cells (PNT2) (considered to be radiosensitive). In PNT2 cells, the administration of RA increased the total GSH content during the first 3 h (p < 0.01) as well as increased the GSH/oxidized glutathione (GSSG) ratio in all irradiated cultures during all periods studied (1h and 3h) (p < 0.001), portraying an increase in the radioprotective capacity. However, in B16F10 cells, administration of RA had no effect on the total intracellular GSH levels, decreasing the GSH/GSSG ratio (p < 0.01); in addition, it caused a significant reduction in the GSH/GSSG ratio in irradiated cells (p < 0.001), an expression of radioinduced cell damage. In B16F10 cells, the administration of RA possibly activates the metabolic pathway of eumelanin synthesis that would consume intracellular GSH, thereby reducing its possible use as a protector against oxidative stress. The administration of this type of substance during radiotherapy could potentially protect healthy cells for which RA is a powerful radioprotector, and at the same time, cause significant damage to melanoma cells for which it could act as a radiosensitive agent.

Effects of Coriandrum sativum on Migration and Invasion Abilities of Cancer Cells

Coriandrum sativum (coriander) is an annual herb in the Apiaceae family. Its leaves and seeds are used for cooking. Coriander has several beneficial functions such as anti-inflammatory, analgesic and anti-cancer effects. Although anti-carcinogenic potential of coriander has been known well, the effects of coriander on cancer metastasis have not yet been fully elucidated. In the present study, the effects of coriander on migration and invasion were investigated in vitro and in vivo by using human hepatocellular carcinoma cell line (HepG2) and mouse melanoma cell line (B16F10). The migration and invasion abilities of cancer cells had been evaluated by trans-well double chamber and these abilities were significantly impaired by treatment of cancer cells with coriander extract whose concentration did not affect proliferation. The treatment of cancer cells with coriander extract significantly reduced both matrix metalloproteinase 2 (MMP-2) and urokinase-type plasminogen activator (u-PA) activities, which were involved in cell migration and invasion, in their conditioned media. Furthermore, coriander extract suppressed the phosphorylation of Erk 1 or IkB in B16F10 cells, and inhibited the expression of MMP-2 or u-PA mRNA. After injection of B16F10 cells into the tail vein of C57BL/6J mice, the number of metastatic regions in lungs were counted. Mice fed with diet containing coriander possessed a smaller number of metastatic regions than those fed with control diet. It was suggested that coriander extract might have the abilities to suppress cancer cell migration and invasion, indicating that coriander provides the improvement of cancer prognosis.

The progression of metastatic melanoma augments a pro-oxidative milieu locally but not systemically

Malignant melanoma is the most dangerous form of skin cancer. Despite new therapies for melanoma treatment, effective therapy is mainly limited by excessive metastasis. Currently, the factors determining metastasis development are not elucidated, but oxidative stress was suggested to be involved. To this end, we analyzed oxidative stress parameters during the metastatic development using the syngeneic B16F10 melanoma model. An increase in blood plasma lipid peroxidation occurred at the earliest stage of the disease, with a progressive decrease in oxidative damage and an increase in antioxidant defense. Vice versa, increased lipid peroxidation and 3-nitrotyrosine, and decreased antioxidant parameters were observed in the metastatic nodules throughout the disease. This was concomitant with a progressive increase in vascular endothelial growth factor and proliferating cell nuclear antigen. We conclude that the oxidative stress in the bloodstream decreases during the metastatic process and that nitrosative stress increases during the proliferation and growth of metastatic nodules in the tumor microenvironment. These results will help to better understand the role of oxidative stress during melanoma metastasis.

Structure-activity relationship study of cytotoxic neolignan derivatives using multivariate analysis and computation-aided drug design

Dehydrodieugenol B and five related natural neolignans were isolated from the Brazilian plant species Nectandra leucantha. Three of these compounds were shown to be active against murine (B16F10) and human (A2058) melanoma cells but non-toxic to human fibroblasts (T75). These results stimulated the preparation of a series of 23 semi-synthetic derivatives in order to explore structure-activity relationships and study the biological potential of these derivatives against B16F10 and A2058 cell lines. These structurally-related neolignan derivatives were analyzed by multivariate statistics and machine learning, which indicated that the most important characteristics were related to their three-dimensional structure and, mainly, to the substituents on the neolignan skeleton. The results suggested that the presence of hydroxyl or alkoxyl groups at positions 3, 4 and 5 (with appropriate sidechains) promoted an increase in electropological and charge density, which seem to be important for biological activity against murine (B16F10) and human (A2058) melanoma cells.

Cold Atmospheric Plasma Is a Potent Tool to Improve Chemotherapy in Melanoma In Vitro and In Vivo

Malignant melanoma is a devastating disease. Because of its aggressiveness, it also serves as a model tumor for investigating novel therapeutic avenues. In recent years, scientific evidence has shown that cold atmospheric plasma (CAP) might be a promising modality in cancer therapy. In this study, we aimed to evaluate the effect of CAP generated by an argon plasma jet alone or in combination with dacarbazine (DAC) on melanoma cells in vitro and in vivo. The effects of the CAP on inducing lipid peroxidation and nitric oxide production were higher in B16 melanoma cells in comparison to non-malignant L929 cells. Assays on cell growth, apoptosis, and expression of genes related to, e.g., autophagic processes, showed CAP to have a substantial impact in melanoma cells while there were only minoreffects in L929 cells. In vivo, both CAP monotherapy and combination with DAC significantly decreased tumor growth. These results suggest that CAP not only selectively induces cell death in melanoma but also holds promises in combination with chemotherapy that might lead to improved tumor control.

Medical Gas Plasma Jet Technology Targets Murine Melanoma in an Immunogenic Fashion

Medical technologies from physics are imperative in the diagnosis and therapy of many types of diseases. In 2013, a novel cold physical plasma treatment concept was accredited for clinical therapy. This gas plasma jet technology generates large amounts of different reactive oxygen and nitrogen species (ROS). Using a melanoma model, gas plasma technology is tested as a novel anticancer agent. Plasma technology derived ROS diminish tumor growth in vitro and in vivo. Varying the feed gas mixture modifies the composition of ROS. Conditions rich in atomic oxygen correlate with killing activity and elevate intratumoral immune-infiltrates of CD8+ cytotoxic T-cells and dendritic cells. T-cells from secondary lymphoid organs of these mice stimulated with B16 melanoma cells ex vivo show higher activation levels as well. This correlates with immunogenic cancer cell death and higher calreticulin and heat-shock protein 90 expressions induced by gas plasma treatment in melanoma cells. To test the immunogenicity of gas plasma treated melanoma cells, 50% of mice vaccinated with these cells are protected from tumor growth compared to 1/6 and 5/6 mice negative control (mitomycin C) and positive control (mitoxantrone), respectively. Gas plasma jet technology is concluded to provide immunoprotection against malignant melanoma both in vitro and in vivo.

Nanoliposomal Encapsulation Enhances In Vivo Anti-Tumor Activity of Niclosamide against Melanoma

BACKGROUND

Niclosamide is an FDA-approved and old anti-helminthic drug used to treat parasitic infections. Recent studies have shown that niclosamide has broad anti-tumor effects relevant to the treatment of cancer. However, this drug has a low aqueous solubility hindering its systemic use. Herein, we report the preparation and characterization of niclosamide nanoliposomes and their in vivo anti-tumor effects.

METHODS

Nanoliposomes were prepared using thin-film method and the drug was encapsulated with a remote loading method. The nanoliposomes were investigated by the observation of morphology, analysis of particle size and zeta potential. Additionally, qualitative and quantitative analyses were performed using HPLC. We assessed the in vitro cytotoxicity of the nanoliposomal niclosamide on B16F10 melanoma cells. Inhibition of tumor growth was investigated in C57BL/6 mice bearing B16F0 melanoma cancer.

RESULTS

Analytical results indicated that the nanoliposomal system is a homogeneous and stable colloidal dispersion of niclosamide particles. Atomic force microscopy images and particle size analysis revealed that all niclosamide particles had a spherical shape with a diameter of approximately 108nm. According to in vitro and in vivo studies, nanoliposomal niclosamide exhibited a better anti-tumor activity against B16F10 melanoma tumor compared with free niclosamide.

CONCLUSION

Nanoliposomal encapsulation enhanced the aqueous solubility of niclosamide and improved its anti-tumor properties.

NLGP Attenuates Murine Melanoma and Carcinoma Metastasis by Modulating Cytotoxic CD8+ T Cells

Neem leaf glycoprotein (NLGP), a natural immunomodulator, attenuates murine carcinoma and melanoma metastasis, independent of primary tumor growth and alterations in basic cellular properties (cell proliferation, cytokine secretion, etc.). Colonization event of invasion–metastasis cascade was primarily inhibited by NLGP, with no effect on metastasis-related invasion, migration, and extravasation. High infiltration of interferon γ (IFN-γ)–secreting cytotoxic CD8⁺ T cells [CD44⁺, CD69⁺, GranB⁺, IFN-γ⁺, and interleukin 2⁺] was documented in the metastatic site of NLGP-treated mice. Systemic CD8⁺ T cell depletion abolished NLGP-mediated metastasis inhibition and reappeared upon adoptive transfer of NLGP-activated CD8⁺ T cells. Interferon γ-secreting from CD8⁺ T cells inhibit the expression of angiogenesis regulatory vascular endothelial growth factor and transforming growth factor β and have an impact on the prevention of colonization. Neem leaf glycoprotein modulates dendritic cells (DCs) for proper antigen presentation by its DC surface binding and upregulation of MHC-I/II, CD86, and CCR7. Neem leaf glycoprotein–treated DCs specifically imprint CXCR3 and CCR4 homing receptors on activated CD8⁺ T cells, which helps to infiltrate into metastatic sites to restrain colonization. Such NLGP's effect on DCs is translation dependent and transcription independent. Studies using ovalbumin, OVA_257−264, and crude B16F10 antigen indicate MHC-I upregulation depends on the quantity of proteasome degradable peptide and only stimulates CD8⁺ T cells in the presence of antigen. Overall data suggest NLGP inhibits metastasis, in conjunction with tumor growth restriction, and thus might appear as a promising next-generation cancer immunotherapeutic.

Inhibitory Effects of Ginsenoside Ro on the Growth of B16F10 Melanoma via Its Metabolites

Ginsenoside Ro (Ro), a major saponin derived and isolated from Panax ginseng C.A. Meyer, exerts multiple biological activities. However, the anti-tumour efficacy of Ro remains unclear because of its poor in vitro effects. In this study, we confirmed that Ro has no anti-tumour activity in vitro. We explored the anti-tumour activity of Ro in vivo in B16F10 tumour-bearing mice. The results revealed that Ro considerably suppressed tumour growth with no significant side effects on immune organs and body weight. Zingibroside R1, chikusetsusaponin IVa, and calenduloside E, three metabolites of Ro, were detected in the plasma of Ro-treated tumour-bearing mice and showed excellent anti-tumour effects as well as anti-angiogenic activity. The results suggest that the metabolites play important roles in the anti-tumour efficacy of Ro in vivo. Additionally, the haemolysis test demonstrated that Ro has good biocompatibility. Taken together, the findings of this study demonstrate that Ro markedly suppresses the tumour growth of B16F10-transplanted tumours in vivo, and its anti-tumour effects are based on the biological activity of its metabolites. The anti-tumour efficacy of these metabolites is due, at least in part, to its anti-angiogenic activity.

Resveratrol-mediated inhibition of cyclooxygenase-2 in melanocytes suppresses melanogenesis through extracellular signal-regulated kinase 1/2 and phosphoinositide 3-kinase/Akt signalling

Resveratrol (3,5,4'-trihydroxy-trans-stilbene), has been reported to exert a variety of important pharmacological effects including anti-inflammatory, anticancer, and direct inhibition of tyrosinase. This study aimed to examine the expression of melanogenic molecules following down-regulation of cyclooxygenase (COX)-2 expression by resveratrol and the related signal transduction pathways in mouse B16F10 melanoma cells and zebrafish larvae. We report that resveratrol suppressed COX-2 in melanocytes and decreased the expressions of tyrosinase and microphthalmia-associated transcription factor (MITF). Furthermore, inhibition of COX-2 with NS398 enhanced resveratrol-reduced tyrosinase and MITF expression. Resveratrol also induced phosphorylation of extracellular signal-regulated 1/2 (ERK1/2) and phosphoinositide-3 (PI-3)-kinase/Akt. Inhibition of ERK1/2 or PI-3K/Akt by PD98059 and LY294002 restored the decreased tyrosinase activity and MITF expression via resveratrol-mediated down-regulation of COX-2. Additionally, resveratrol inhibited body pigmentation in zebrafish. These results indicated that resveratrol inhibited melanogenesis by down-regulating COX-2 via ERK1/2 and PI-3K/Akt pathways in B16F10 cells.

A New Tyrosinase Inhibitor from the Red Alga Symphyocladia latiuscula (Harvey) Yamada (Rhodomelaceae)

A marine red alga, Symphyocladia latiuscula (Harvey) Yamada (Rhodomelaceae), is a rich source of bromophenols with a wide array of biological activities. This study investigates the anti-tyrosinase activity of the alga. Moderate activity was demonstrated by the methanol extract of S. latiuscula, and subsequent column chromatography identified three bromophenols: 2,3,6-tribromo-4,5-dihydroxybenzyl methyl alcohol (1), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (2), and bis-(2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether) (3). Bromophenols 1 and 3 exhibited potent competitive tyrosinase inhibitory activity against l-tyrosine substrates, with IC₅₀ values of 10.78 ± 0.19 and 2.92 ± 0.04 μM, respectively. Against substrate l-3,4-dihydroxyphenylalanine (l-DOPA), compounds 1 and 3 demonstrated moderate activity, while 2 showed no observable effect. The experimental data were verified by a molecular docking study that found catalytic hydrogen and halogen interactions were responsible for the activity. In addition, compounds 1 and 3 exhibited dose-dependent inhibitory effects in melanin and intracellular tyrosinase levels in α-melanocyte-stimulating hormone (α-MSH)-induced B16F10 melanoma cells. Compounds 3 and 1 were the most effective tyrosinase inhibitors. In addition, increasing the bromine group number increased the mushroom tyrosinase inhibitory activity.

Leathesia difformis Extract Inhibits α-MSH-Induced Melanogenesis in B16F10 Cells via Down-Regulation of CREB Signaling Pathway

Leathesia difformis (L.) Areschoug (L. difformis) is a species of littoral brown algae of the class Phaeophyceae. Only a few studies on the apoptotic, antiviral, and antioxidant properties of L. difformis have been reported, and its inhibitory effect on melanin synthesis has not been studied. The aim of this study was to investigate the anti-melanogenic effect of L. difformis extract on α-melanocyte-stimulating hormone (α-MSH)-induced B16F10 melanocytes and its mechanism of action. L. difformis was extracted using 80% ethanol (LDE) and then fractioned between ethyl acetate (LDE-EA) and water (LDE-A). Our data demonstrated that LDE-EA significantly inhibited melanin level and cellular tyrosinase activity in α-MSH-stimulated B16 cells. In addition, the expression of genes associated with melanin synthesis, such as microphthalmia-associated transcription factor (Mitf), tyrosinase (Tyr), tyrosinase-related protein-1 (Trp-1), dopachrome tautomerase (Dct), and melanocortin 1 receptor (Mc1r) was down-regulated by LDE-EA treatment. Moreover, LDE-EA decreased p-CREB levels, which suggests that the inhibition of the cAMP/PKA/CREB pathways may be involved in the anti-melanogenic effect of LDE-EA. Thus, this study revealed that LDE-EA is an effective inhibitor of hyperpigmentation through inhibition of CREB pathways and may be considered as a potential therapeutic agent for hyperpigmentation disorders.

In Situ Vaccination of Tumors Using Plant Viral Nanoparticles

Viral nanoparticles are self-assembling units that are being developed and applied for a variety of applications. While most clinical uses involve animal viruses, a plant-derived virus, cowpea mosaic virus (CPMV) has been shown to have antitumor properties in mice when applied as in situ vaccine. Here we describe the production and characterization of CPMV and its use as in situ vaccines in the context of cancer. Subsequent analyses to obtain efficacy or mechanistic data are also detailed.

Evaluation of 99m Tc-MccJ25 peptide analog in mice bearing B16F10 melanoma tumor as a diagnostic radiotracer

OBJECTIVES

Despite recent advances in treatment modalities, cancer remains a major source of morbidity and mortality throughout the world. Currently, the development of sensitive and specific molecular imaging probes for early diagnosis of cancer is still a problematic challenge. Previous studies have been shown that some of the antimicrobial peptides (AMPs) exhibit a broad spectrum of cytotoxic activity against cancerous cells in addition to their antimicrobial activities. MicrocinJ25 (MccJ25) is an antimicrobial peptide that is produced by Escherichia coli (E. coli) strain. The aim of this study was to investigate the potential of a new peptide radiopharmaceutical derived from MccJ25 for diagnosis of melanoma tumor bearing C57BL/6 mice.

METHODS

A 14 amino acid analog of MccJ25 was labeled with technetium-99m (99mTc) through hydrazinonicotinamide (HYNIC) chelator and tricine as coligand. In vivo tumor uptake and tissue distribution were evaluated. The in vivo biodistribution studies were determined in C57BL/6 mice bearing B16F10 tumor.

RESULTS

The amount of non-peptide related 99mTc-impurities that measured by thin layer chromatography (TLC) did not exceed 5% of the total radioactivity. The in vitro binding to B16F10 cells was 30.73 ± 0.9% after 1 h incubation at 37°C, and saturation binding experiments showed good affinity for radio-complex (Kd=47.98±6.25 nM). The melanoma tumor was clearly visible up 1 h post-injection by gamma camera imaging.

CONCLUSION

The results showed that 99mTc-labeld peptide could be a promising candidate as a targeting radiopharmaceutical for melanoma tumor imaging in mice.

Evaluation of the Novel Synthetic Tyrosinase Inhibitor (Z)-3-(3-bromo-4-hydroxybenzylidene)thiochroman-4-one (MHY1498) In Vitro and In Silico

Tyrosinase is a key enzyme in melanin synthesis, catalyzing the initial rate-limiting steps of melanin synthesis. Abnormal and excessive melanin synthesis is the primary cause of serious skin disorders including melasma, senile lentigo, freckles, and age spots. In attempts to find potent and safe tyrosinase inhibitors, we designed and synthesized a novel compound, (Z)-3-(3-bromo-4-hydroxybenzylidene)thiochroman-4-one (MHY1498), and evaluated its tyrosinase inhibitory activity in vitro and in silico. The chemical structures of (Z)-3-benzylidenethiochroman-4-one analogues, including the novel compound MHY1498, were rationally designed and synthesized as hybrid structures of reported potent tyrosinase inhibitors, which were confirmed both in vitro and in vivo: (Z)-5-(substituted benzylidene)thiazolidine-2,4-diones (Compound A) and 2-(substituted phenyl)benzo[d]thiazoles (Compound B). During screening, MHY1498 showed a strong dose-dependent inhibitory effect on mushroom tyrosinase. The IC50 value of MHY1498 (4.1 ± 0.6 μM) was significantly lower than that of the positive control, kojic acid (22.0 ± 4.7 μM). In silico molecular multi-docking simulation and inhibition mechanism studies indicated that MHY1498 interacts competitively with the tyrosinase enzyme, with greater affinity for the active site of tyrosinase than the positive control. Furthermore, in B16F10 melanoma cells treated with α-melanocyte-stimulating hormone, MHY1498 suppressed both melanin production and tyrosinase activity. In conclusion, our data demonstrate that MHY1498, a synthesized novel compound, effectively inhibits tyrosinase activity and has potential for treating hyperpigmentation and related disorders.

Resorcinolic lipid 3-heptyl-3,4,6-trimethoxy-3H-isobenzofuran-1-one is a strategy for melanoma treatment

AIMS

Previous studies performed by our research group indicated that cytosporone analogues are capable of prevent or repair DNA damages. This work presents the evaluation of the activity of AMS35AA for metastatic murine melanoma cells (B16F10) in experimental model in vitro and, in pre-clinic assay of metastatic melanoma in vivo, using mice lineage C57BL/6.

MAIN METHODS

In vitro assays were performed: MTT and comet assay, flow cytometry evaluation, gene expression assay by RT-PCR, qualitative evaluation of cell death using B16F10 cells. In vivo assays: micronucleus and comet assay, splenic phagocytosis, melanoma murine model and histopathological analysis, using mice lineage C57BL/6 (n = 20).

KEY FINDINGS

In vitro results performed by MTT assay showed that AMS35AA is cytotoxic for B16F10 cells (p < 0.05). Based on comet assay the genotoxicity of the IC₅₀ was determined (95.83 μg/mL) (p < 0.05). These data were corroborated by flow cytometry analysis after the treatment with AMS35AA, which indicates the cellular death by apoptosis (p < 0.05) and increasing of ATR, p53, p21 and GADD45 gene expressions verified using RT-PCR. With respect to in vivo results, it was observed that AMS35AA did not show genotoxic activity. Data of tumor volume ex vivo indicate reduction of tumor for the treated animals with AMS35AA up to 15.84×, which is superior to Dacarbazina (50 mg/Kg, p.c.; i.p.).

SIGNIFICANCE

In summary, the study showed that AMS35AA reveals relevant results regarding to cytotoxicity of B16F10 murine melanoma cells, inducing death by apoptosis via mitochondrial and/or mediated by DNA damages.