Clinical and molecular overview of immunotherapeutic approaches for malignant skin melanoma: Past, present and future

Traditional therapeutic approaches for malignant melanoma, have proved to be limited and/or ineffective, especially with respect to their role in improving patient survival and tumor recurrence. In this regard, immunotherapy has been demonstrated to be a promising therapeutic alternative, boosting antitumor responses through the modulation of cell signaling pathways involved in the effector mechanisms of the immune system, particularly, the so-called "immunological checkpoints". Clinical studies on the efficacy and safety of immunotherapeutic regimens, alone or in combination with other antitumor approaches, have increased dramatically in recent decades, with very encouraging results. Hence, this review will discuss the current immunotherapeutic regimens used to treat malignant melanoma, as well as the molecular and cellular mechanisms involved. In addition, current clinical studies that have investigated the use, efficacy, and adverse events of immunotherapy in melanoma will also be discussed.

LS-HB-Mediated Photodynamic Therapy Inhibits Proliferation and Induces Cell Apoptosis in Melanoma

Chlorin e6-C-15-ethyl ester (LS-HB), a newly identified photosensitizer, was isolated from chlorin e6. The mechanism of tumor cell death induced by photodynamic therapy with LS-HB (LS-HB-PDT) is still unknown. Here, we investigated the photophysical properties of LS-HB, evaluated the antitumor effect on melanoma in vitro and in vivo, and explored its possible mechanisms. LS-HB not only has an optimal spectral band of red wavelength (660 nm) for photosensitization but also has favorable photostability. More importantly, LS-HB-PDT elicited a potent dose-dependent phototoxic effect in vitro. We discovered that LS-HB located in the mitochondria of B16F10 cells was able to generate excess reactive oxygen species, which subsequently resulted in mitochondrial membrane potential loss and induced apoptosis via caspase-9 and caspase-3 pathways. Moreover, PDT with LS-HB markedly inhibited the growth of melanoma in vivo. Therefore, LS-HB is expected to be an effective potential photosensitizer in antitumor therapy.

Evaluation of the Antitumour and Antiproliferative Effect of Xanthohumol-Loaded PLGA Nanoparticles on Melanoma

Cutaneous melanoma is the deadliest type of skin cancer and current treatment is still inadequate, with low patient survival rates. The polyphenol xanthohumol has been shown to inhibit tumourigenesis and metastasization, however its physicochemical properties restrict its application. In this work, we developed PLGA nanoparticles encapsulating xanthohumol and tested its antiproliferative, antitumour, and migration effect on B16F10, malignant cutaneous melanoma, and RAW 264.7, macrophagic, mouse cell lines. PLGA nanoparticles had a size of 312 ± 41 nm and a PdI of 0.259, while achieving a xanthohumol loading of about 90%. The viability study showed similar cytoxicity between the xanthohumol and xanthohumol-loaded PLGA nanoparticles at 48 h with the IC50 established at 10 µM. Similar antimigration effects were observed for free and the encapsulated xanthohumol. It was also observed that the M1 antitumor phenotype was stimulated on macrophages. The ultimate anti-melanoma effect emerges from an association between the viability, migration and macrophagic phenotype modulation. These results display the remarkable antitumour effect of the xanthohumol-loaded PLGA nanoparticles and are the first advance towards the application of a nanoformulation to deliver xanthohumol to reduce adverse effects by currently employed chemotherapeutics.

Cost-Effectiveness Analysis of Dabrafenib Plus Trametinib and Vemurafenib as First-Line Treatment in Patients with BRAF V600 Mutation-Positive Unresectable or Metastatic Melanoma in China

Objective: To evaluate the cost-effectiveness of dabrafenib plus trametinib combination therapy versus vemurafenib as first-line treatment in patients with BRAF V600 mutation-positive unresectable or metastatic melanoma from a healthcare system perspective in China. Methods: This study employed a partitioned survival model with three health states (progression-free survival, post-progression survival and dead) to parameterize the data derived from Combi-v trial and extrapolated to 30 years. Health states’ utilities were measured by EQ-5D-3L, also sourced from the Combi-v trial. Costs including drug acquisition costs, disease management costs and adverse event costs were based on the Chinese Drug Bidding Database and physician survey in China. The primary outcomes of the model were lifetime costs, life-years (LYs), quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratio (ICER). Deterministic and probabilistic sensitivity analyses were conducted, respectively. Result: Dabrafenib plus trametinib is projected to increase a patient’s life expectancy by 0.95 life-years over vemurafenib (3.03 vs. 2.08) and 1.09 QALY gains (2.48 vs. 1.39) with an incremental cost of $3833. The incremental cost-effectiveness ratio (ICER) was $3511 per QALY. In the probabilistic sensitivity analyses, at a threshold of $33,357 per QALY (three times the gross domestic product (GDP) per capita in China in 2020), the probability of dabrafenib plus trametinib being cost-effective was 90%. In the deterministic sensitivity analyses, the results were most sensitive to the dabrafenib plus trametinib drug costs, vemurafenib drug costs and discount rate of cost. Conclusion: Dabrafenib plus trametinib therapy yields more clinical benefits than vemurafenib. Using a threshold of $33,357 per QALY, dabrafenib plus trametinib is very cost-effective as compared with vemurafenib in China.

Assessment of Trends in Second Primary Cancers in Patients With Metastatic Melanoma From 2005 to 2016

IMPORTANCE

To date, the risk of developing second primary cancers (SPCs) after the first primary melanoma has not been studied in the era of immune checkpoint inhibitors (ICIs).

OBJECTIVE

To assess differences in the risk of SPCs in patients with primary melanoma before (2005-2010) and after (2011-2016) the introduction and approval of ICIs.

DESIGN, SETTING, AND PARTICIPANTS

Population-based cohort study using the Surveillance, Epidemiology, and End Results database from January 2005 to December 2016 of patients diagnosed with metastatic melanoma. Data were analyzed from January 4 to June 30, 2020.

EXPOSURES

Receipt of immunotherapy or other anticancer agents.

MAIN OUTCOMES AND MEASURES

The primary outcome was the development of second primary cancers in patients with melanoma. Standardized incidence ratios (SIRs) were calculated for the development of SPCs before and after the introduction of ICIs.

RESULTS

Among 5016 patients with diagnosed metastatic melanoma, 2888 (58%) were younger than 65 years at the time of diagnosis, and 3441 (69%) were male. From 2005 to 2010, SIRs were 3.24 (95% CI, 0.08-18.04) for small intestine cancer, 1.93 (95% CI, 1.14-3.05) for lung and bronchus cancer, 2.77 (95% CI, 1.02-6.03) for kidney cancer, and 7.29 (95% CI, 2.93-15.02) for myeloma. From 2011 to 2016, SIRs were 9.23 (95% CI, 1.12-33.35) for small intestine cancer, 1.54 (95% CI, 0.71-2.93) for lung and bronchus cancer, 2.66 (95% CI, 0.73-6.82) for kidney cancer, and 5.90 (95% CI, 1.61-15.10) for myeloma. The overall risk of developing SPCs in individuals who survived the first primary melanoma was 65% higher (SIR, 1.65; 95% CI, 1.35-2.00) in the pre-ICIs period and 98% higher (SIR, 1.98; 95% CI, 1.57-2.45) in the post-ICIs period than the overall cancer incidence rate in the general population.

CONCLUSIONS AND RELEVANCE

In this study, an increase in the overall risk of second primary cancers after melanoma after the introduction of immune checkpoint inhibitors was observed. The pattern of SPCs has been altered in the era of systemic therapy. Close monitoring and screening for SPCs may be warranted in patients with metastatic melanoma.

Nuclear factor I/B mediates epithelial-mesenchymal transition in human melanoma cells through ZEB1

The relationship between nuclear factor I/B (NFIB) and cancer attracts growing research interest. NFIB has diverse and specific roles in tumor progression and invasion. However, the potential effects and functions of this transcription factor in melanoma remain unclear. The present study sought to determine the distinguishing properties of NFIB in melanoma cells. Immunohistochemical examination of the tissues of 15 patients with melanoma indicated that the expression of NFIB was high in melanoma specimens, compared with the benign nevus and normal skin specimens. In addition, the relationship between high NFIB expression and low overall survival rate was assessed. Functional studies demonstrated that NFIB enhanced the malignancy of melanoma, including proliferation, migration and invasion. In addition, NFIB silencing in A375 and A875 cell lines inhibited the process of epithelial-mesenchymal transition (EMT), upregulated E-cadherin and zona occludens-1, but suppressed N-cadherin and vimentin expression. These findings may suggest a new function of NFIB in promoting the migration and invasion of melanoma cells. Therefore, the present study further evaluated the association between NFIB and zinc finger protein E-box binding homeobox-1 (ZEB1) in melanoma. Mechanistic experiments revealed that NFIB exerted its roles during EMT by regulating ZEB1. Overall, the present data indicates that NFIB promotes the malignancy of melanoma, particularly EMT, by modulating the ZEB1 axis, such as ZEB2, ATM and CHK1, which may represent a potential molecular therapeutic target in melanoma.

Hydrogen-Peroxide-Responsive Protein Biomimetic Nanoparticles for Photothermal-Photodynamic Combination Therapy of Melanoma

BACKGROUND AND OBJECTIVES

Recently, there has been a rapid increase in the incidences of melanoma, which represents a serious threat to human health. Generally, tumor-microenvironment-responsive nanoparticle-based photothermal-photodynamic combination therapy (PTT-PDT) is characterized by intratumoral response and tumor targeting. In this study, we designed and synthesized hydrogen-peroxide-responsive protein biomimetic nanoparticles (MnO₂ -ICG@BSA) for the treatment of melanoma.

STUDY DESIGN/MATERIALS AND METHODS

Briefly, MnO₂ -ICG@BSA was prepared using a mild protein synthesis method by loading indocyanine green (ICG) into a bovine serum albumin-manganese dioxide complex (MnO₂ @BSA); next, its characteristics were determined. In addition, in vitro biocompatibility and antitumor efficacy were assessed using the classic cell counting kit-8 assay. Moreover, in vivo high-frequency ultrasound and thermal imaging were used to evaluate the oxygen-production capacity and photothermal conversion effect of MnO₂ -ICG@BSA at the tumor site, and Singlet Oxygen Sensor Green (SOSG) was used to measure singlet oxygen levels in the tumor. The antitumor efficacy was assessed based on relative tumor size, bodyweight, survival curves, and hematoxylin and eosin staining.

RESULTS

The results showed that MnO₂ -ICG@BSA has a high photothermal conversion efficiency, a strong singlet oxygen-generation ability, and high photothermal stability. In addition, in vitro PTT-PDT experiments showed that MnO₂ -ICG@BSA has a significant inhibitory effect on the proliferation of B16F10 melanoma cells. Meanwhile, in vivo experiments showed that MnO₂ -ICG@BSA has a significant inhibitory effect on melanoma in mice. Preliminary toxicity studies indicated that MnO₂ -ICG@BSA exhibits low toxicity.

CONCLUSION

From the results, we can conclude that MnO₂ -ICG@BSA could be used in PTT-PDT to treat melanoma, making it a good candidate material for PTT-PDT. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Isorhamnetin Induces Melanoma Cell Apoptosis via the PI3K/Akt and NF-κB Pathways

Malignant melanoma is characterized by its bad prognosis for aggressiveness, drug resistance, and early metastasis. Isorhamnetin (3′-methoxy-3,4′,5,7-tetrahydroxyflavone; IH) is a natural flavonoid that has been investigated for its antitumor effects in breast cancer, colon cancer, and gastric cancer through inducing cell apoptosis. Given its role in tumor inhibition, no research has been conducted concerning its effect against melanoma. In the present study, we found that IH could significantly inhibit B16F10 cell proliferation and migration and induce B16F10 cell apoptosis. The examination on molecular mechanism revealed that IH could suppress the phosphorylation of Akt and the translocation of NF-κB, which are key factors in apoptosis-related pathways. We also detected that this process was related to the bifunctional 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatases 4 (PFKFB4) by PFKFB4 knockdown experiment. In line with in vitro study, we further provided that IH effectively inhibited tumor growth in vivo. Taken together, IH was proven to induce melanoma cell apoptosis in vitro and in vivo, which may serve as a potential agent in malignant melanoma treatment in the future.

Adenosine Signaling Is Prognostic for Cancer Outcome and Has Predictive Utility for Immunotherapeutic Response

PURPOSE

There are several agents in early clinical trials targeting components of the adenosine pathway including A2AR and CD73. The identification of cancers with a significant adenosine drive is critical to understand the potential for these molecules. However, it is challenging to measure tumor adenosine levels at scale, thus novel, clinically tractable biomarkers are needed.

EXPERIMENTAL DESIGN

We generated a gene expression signature for the adenosine signaling using regulatory networks derived from the literature and validated this in patients. We applied the signature to large cohorts of disease from The Cancer Genome Atlas (TCGA) and cohorts of immune checkpoint inhibitor-treated patients.

RESULTS

The signature captures baseline adenosine levels in vivo (r ² = 0.92, P = 0.018), is reduced after small-molecule inhibition of A2AR in mice (r ² = -0.62, P = 0.001) and humans (reduction in 5 of 7 patients, 70%), and is abrogated after A2AR knockout. Analysis of TCGA confirms a negative association between adenosine and overall survival (OS, HR = 0.6, P < 2.2e^-16) as well as progression-free survival (PFS, HR = 0.77, P = 0.0000006). Further, adenosine signaling is associated with reduced OS (HR = 0.47, P < 2.2e^-16) and PFS (HR = 0.65, P = 0.0000002) in CD8⁺ T-cell-infiltrated tumors. Mutation of TGFβ superfamily members is associated with enhanced adenosine signaling and worse OS (HR = 0.43, P < 2.2e^-16). Finally, adenosine signaling is associated with reduced efficacy of anti-PD1 therapy in published cohorts (HR = 0.29, P = 0.00012).

CONCLUSIONS

These data support the adenosine pathway as a mediator of a successful antitumor immune response, demonstrate the prognostic potential of the signature for immunotherapy, and inform patient selection strategies for adenosine pathway modulators currently in development.

MWCNT-mediated combinatorial photothermal ablation and chemo-immunotherapy strategy for the treatment of melanoma

DOX and CpG loaded MWCNT with NIR irradiation could destroy tumor cells by photothermal and chemotherapy and release tumor-associated antigens, thus generating melanoma specific immune response to achieve synergistic therapeutic effect.

Resveratrol suppresses melanoma growth by promoting autophagy through inhibiting the PI3K/AKT/mTOR signaling pathway

Resveratrol (RV) is a natural polyphenolic phytoalexin derived from peanuts, red grape skins and red wine, and has been demonstrated to alleviate multiple types of malignancies. However, how RV achieves this in melanoma is unknown. The aim of present study was to investigate the role of RV in melanoma, using Cell Counting Kit-8, flow cytometry and western blot analysis. RV inhibited melanoma cell viability, migration and invasion counteracting melanoma progression. In addition, proteins associated with autophagy, including Beclin 1 and microtubule-associated protein 1A/1B-light chain 3 (LC3)-II/I, were upregulated, whereas p62 expression was downregulated in RV-treated cells. The number of LC3⁺ puncta, which can be applied to represent autophagosome formation, increased following RV treatment, suggesting that RV may trigger autophagy in melanoma cells. Treatment with the autophagy inhibitor, 3-methyladenine, reversed the RV-dependent inhibition of viability, migration and invasion of melanoma cells. RV treatment also reduced the ratios of phosphorylated (p)-AKT/AKT and p-mTOR/mTOR in melanoma cells. In conclusion, these findings suggested that RV may inhibit the viability and migration of melanoma cells through inhibiting the AKT/mTOR pathway, thus triggering autophagy. This indicated that RV may serve as an innovative therapeutic for melanoma treatment.

Functionalization of Nanomaterials and Their Application in Melanoma Cancer Theranostics

Treatment and cure for melanoma, the most aggressive subcategory of skin cancer, still remains a daunting challenge to be circumvented. When metastasized, it requires radiotherapy, chemotherapy, targeted therapy, immunotherapy, etc. as its treatment, although it can be removed by surgical intervention if detected in its early stage. Development of upgraded therapeutic modalities for melanoma facilitating early diagnosis with subsequent excision before metastasis is, therefore, an urgent need. As we witnessed, nanotechnology has become instrumental with its far-reaching ramifications both in diagnosis and treatment of melanoma. In this review we are going to summarize the encouraging developments made in recent times for functionalization of nanoparticles (including liposomes, polymeric, metal, viral, protein nanoparticles) to create numerous theranostics (therapy plus diagnostics) for melanoma. We will also reflect on the melanoma statistics, molecular biology, conventional therapies, ongoing clinical trials, and future outlook.

Cost-effectiveness of dabrafenib and trametinib in combination as adjuvant treatment of BRAF V600E/K mutation-positive melanoma from a US healthcare payer perspective

Objective: The COMBI-AD trial demonstrated the efficacy and safety of dabrafenib and trametinib in combination vs placebo as adjuvant treatment of patients with BRAF V600E/K mutation-positive resected Stage IIIA (lymph node metastasis >1 mm), IIIB, or IIIC melanoma. This analysis evaluated the cost-effectiveness of dabrafenib and trametinib vs observation from a US healthcare payer perspective.Methods: This evaluation employed a non-homogeneous, semi-Markov, cohort model with health states for relapse-free survival (RFS), post-locoregional recurrence (LR), post-distant recurrence (DR) receiving first-line treatment, and post-DR receiving second-line treatment. A 50-year modeling time horizon was used. Transition probabilities were estimated based on individual patient data (IPD) from the COMBI-AD trial. Health-state utilities were estimated using EuroQol (EQ-5D) index values from COMBI-AD and published sources. Direct medical costs associated with treatment of melanoma were considered, including costs of BRAF mutation testing, medication and administration costs for adjuvant and metastatic treatments, costs of treating recurrence, and costs of adverse events. Costs and quality-adjusted life-years (QALYs) were discounted at 3.0% annually.Results: Compared with observation, adjuvant dabrafenib and trametinib was estimated to result in a gain of 2.15 QALYs at an incremental cost of $74,518. The incremental cost-effectiveness ratio (ICER) was estimated to be $34,689 per QALY. In deterministic sensitivity analyses, the ICER was sensitive to the cost of dabrafenib and trametinib and the distribution used for projecting RFS beyond the end of follow-up in the COMBI-AD trial. At a cost-effectiveness threshold of $100,000 per QALY, the probability that dabrafenib and trametinib is cost-effective was estimated to be 92%.Conclusions: Given generally-accepted cost-effectiveness threshold values in the US, dabrafenib plus trametinib is likely to be a cost-effective adjuvant therapy for patients with BRAF mutation positive melanoma. These results may be useful for policy-makers in their deliberations regarding reimbursement and access to this treatment.

Glutathione reductase-mediated thiol oxidative stress suppresses metastasis of murine melanoma cells

Malignant melanoma is a highly metastatic and life-threatening cancer. Reactive oxygen species (ROS) play important roles in cancer initiation and progression including metastasis. It has been reported that the oxidative stress spontaneously generated in circulating melanoma cells was able to suppress distant metastasis in vivo. However, little is known regarding the effects and mechanism of glutathione reductase (GR) inhibition-induced oxidative stress in regulation of melanoma metastasis. Here, we demonstrate that GR inhibition generates oxidative stress and suppresses lung metastasis and subcutaneous growth of melanoma in vivo. In addition, inhibitory effects by GR activity reduction were observed on cell proliferation, colony formation, cell adhesion, migration and invasion in melanoma cells in vitro. GR inhibition-induced oxidative stress was also found to block epithelial-to-mesenchymal transition (EMT) by decreasing the expression of Vimentin, ERK1/2, transcription factor Snail and increasing the expression of E-cadherin. In addition, actin rearrangement, a key element involved in cell motility, was also affected by GR-mediated oxidative stress possibly through protein S-glutathionylation on actin. In conclusion, this study identifies GR as an effective regulator of oxidative stress that affects the multistep processes of metastasis in melanoma cells, and it becomes a potential target for melanoma therapy.

Resveratrol analogue, trans-4,4'-dihydroxystilbene (DHS), inhibits melanoma tumor growth and suppresses its metastatic colonization in lungs

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

The age of enlightenment in melanoma immunotherapy

An updated survival analysis by Callahan et al. published in the February 1, 2018 issue of the Journal of Clinical Oncology reported a 3-year overall survival (OS) rate of 63% for 94 patients with previously treated or untreated advanced melanoma who received ipilimumab and nivolumab as concurrent therapy in a phase 1 dose escalation study CA209–004 (n = 53) or in an expansion cohort with the dose and schedule of concurrent ipilimumab and nivolumab now approved for patients with unresectable or metastatic melanoma (n = 41). While this 3-year OS rate of 63% in patients with measurable, unresectable stage III or IV melanoma is an impressive accomplishment that compares very favorably with historical metastatic melanoma survival rates, findings from larger phase 3 studies are needed to determine whether combination immunotherapy significantly improves survival more than single agent immunotherapy with PD-1 blockade. This Commentary discusses the transition from the dark ages to the age of enlightenment in melanoma immunotherapy and provides a roadmap for a better tomorrow for patients with metastatic melanoma.

Sinomenine inhibits the growth of melanoma by enhancement of autophagy via PI3K/AKT/mTOR inhibition

Background

Melanoma is a common skin tumor in adults with high metastasis and mortality rates. Thus, finding a better effective approach to treat melanoma has become very urgent. Sinomenine (SIN), the major active compound of Sinomenium acutum, has shown antitumorigenic activities in certain cancers. However, its role in melanoma remains unclear.

Purpose

This study aimed to explore the effects of SIN on melanoma in vitro and in vivo, in addition to exploring the underlying mechanism.

Methods

Mouse melanoma cell B16-F10 treated by SIN was analyzed by CCK8 assay and flow cytometry. Melanoma xenograft model was then established by subcutaneously injection with B16-F10 cells. Tumor growth was measured by immunohistochemistry. To further investigate the relative mechanism, the autophagy and PI3K/Akt/mTOR pathway were examined by immunofluorescence and Western blot.

Results

Our results revealed that SIN dose dependently inhibited the proliferation of B16-F10 cells in vitro and attenuated melanoma growth in vivo. In addition, SIN treatment promoted the apoptosis of B16-F10 cells in a dose-dependent manner, as demonstrated by the increase in apoptotic cells, Bax/Bcl-2 ratio, and caspase-3 activity. Moreover, preconditioning with SIN dramatically enhanced autophagy activity by increasing Beclin-1 and LC3II/LC3I expression, in addition to decreasing p62 expression and augmenting the number of LC3 puncta, in B16-F10 cells. More importantly, autophagy inhibitor chloroquine partly abolished SIN’s effects on cell growth and apoptosis. Furthermore, our results showed that SIN-triggered activation of autophagy was mediated by PI3K/Akt/mTOR signaling pathway.

Conclusion

Our study has identified a novel function of SIN and provided a molecular basis for potential applications of SIN in the treatment of melanoma and other cancers.

Reversal of Resistance in Targeted Therapy of Metastatic Melanoma: Lessons Learned from Vemurafenib (BRAFV600E-Specific Inhibitor)

Malignant melanoma is the most aggressive form of skin cancer and has a very low survival rate. Over 50% of melanomas harbor various BRAF mutations with the most common being the V600E. BRAF^V600E mutation that causes constitutive activation of the MAPK pathway leading to drug-, immune-resistance, apoptosis evasion, proliferation, survival, and metastasis of melanomas. The ATP competitive BRAF^V600E selective inhibitor, vemurafenib, has shown dramatic success in clinical trials; promoting tumor regression and an increase in overall survival of patients with metastatic melanoma. Regrettably, vemurafenib-resistance develops over an average of six months, which renders melanomas resistant to other therapeutic strategies. Elucidation of the underlying mechanism(s) of acquisition of vemurafenib-resistance and design of novel approaches to override resistance is the subject of intense clinical and basic research. In this review, we summarize recent developments in therapeutic approaches and clinical investigations on melanomas with BRAF^V600E mutation to establish a new platform for the treatment of melanoma.

Overexpression of Receptor Tyrosine Kinase EphB4 Triggers Tumor Growth and Hypoxia in A375 Melanoma Xenografts: Insights from Multitracer Small Animal Imaging Experiments

Experimental evidence has associated receptor tyrosine kinase EphB4 with tumor angiogenesis also in malignant melanoma. Considering the limited in vivo data available, we have conducted a systematic multitracer and multimodal imaging investigation in EphB4-overexpressing and mock-transfected A375 melanoma xenografts. Tumor growth, perfusion, and hypoxia were investigated by positron emission tomography. Vascularization was investigated by fluorescence imaging in vivo and ex vivo. The approach was completed by magnetic resonance imaging, radioluminography ex vivo, and immunohistochemical staining for blood and lymph vessel markers. Results revealed EphB4 to be a positive regulator of A375 melanoma growth, but a negative regulator of tumor vascularization. Resulting in increased hypoxia, this physiological characteristic is considered as highly unfavorable for melanoma prognosis and therapy outcome. Lymphangiogenesis, by contrast, was not influenced by EphB4 overexpression. In order to distinguish between EphB4 forward and EphrinB2, the natural EphB4 ligand, reverse signaling a specific EphB4 kinase inhibitor was applied. Blocking experiments show EphrinB2 reverse signaling rather than EphB4 forward signaling to be responsible for the observed effects. In conclusion, functional expression of EphB4 is considered a promising differentiating characteristic, preferentially determined by non-invasive in vivo imaging, which may improve personalized theranostics of malignant melanoma.

MiR-7a is an important mediator in Fas-associated protein with death domain (FADD)-regulated expression of focal adhesion kinase (FAK)

Fas-associated protein with death domain (FADD), a classical adaptor protein mediating apoptotic stimuli-induced cell death, has been reported to engage in several non-apoptotic processes such as T cell and cardiac development and tumorigenesis. Recently, there are several reports about the FADD's involvement in cell migration, however the underlying mechanism remains elusive. Here, we present a new finding that FADD could regulate the expression of FAK, a non-receptor protein tyrosine kinase overexpressed in many cancers, and played an important role in cell migration in murine MEF and melanoma cells with different metastatic potential, B16F10 and B16F1. Moreover, miR-7a, a tumor suppressor which prohibits cell migration and invasion, was up-regulated in FADD-deficient cells. And FAK was verified to be the direct target gene of miR-7a in B16F10 cells. Furthermore, we demonstrate that miR-7a was a necessary mediator in FADD-regulated FAK expression. In contrast to its classical apoptotic role, FADD interference could reduce the rate of cell migration, which could be rescued by inhibiting miR-7a expression. Taken together, our data provide a novel explanation regarding how FADD regulates cell migration in murine melanoma cells.

Dietary Crocin Reverses Melanoma Metastasis

Crocus sativus and its bioactive constituent crocin are well known for anti-tumor potential in different models. However, the efficacy of crocin on in-vivo melanoma metastasis is not yet reported. In this study, melanoma metastatic model was developed by tail vein injection of B16F-10 cells in to C57BL/6 mice. Metastatic mice treated with two different doses of crocin (250 and 500 µg/kg of bodyweight) for 10 days and parameters such as lung metastasis inhibition, mean survival time, lung hydroxyproline, uronic acid and hexosamine levels were analyzed after 21 days of treatment. Then blood was collected and serum gamma glutamyl transpeptidase (g-GGT), sialic acid, tumor necrosis factor alpha (TNF-a), interleukin 10 (IL-10), IL-6, IL-2, and TIMP-1 levels were measured. Further, a lung histological examination was done in crocin treated metastatic mice. Subsequently hallmark metastatic parameters such as matrix metalloproteases (MMPs), extracellular regulated kinase 2 (ERK2), vascular endothelial growth factor (VEGF), and K-ras gene expression were investigated in the lungs of crocin treated metastatic mice. Further, in-vitro adhesion, invasion and migration of B16F-10 cells were examined after 24 h of crocin (5 and 10 µg/mL) treatment. Administration of crocin to tumor bearing C57BL/6 mice reduced the lung metastasis by 85%. Elevated levels of hydroxyproline, uronic acid, hexosamine, serum sialic acid andg-GGT in metastatic control were found to be significantly reduced in crocin treated mice. Crocin also inhibited expression of MMP-2, MMP-9, ERK-2, K-ras, and VEGF. Crocin reduced the ability of B16F-10 cells invasion (p<0.05), migration (p<0.05) and adhesion by upregulating E-cadherin expression. In conclusion, crocin elicited marked anti-metastatic potential by regulating the metastasis induced biomarkers.

Resource utilization and costs of managing patients with advanced melanoma: a Canadian population-based study

BACKGROUND

The use and detailed costs of services provided for people with advanced melanoma (amel) are not well known. We conducted an analysis to determine the use of health care services and the associated costs delineated by relevant attributable costs, which we defined for subjects in the province of Ontario.

METHODS

Through the Ontario Cancer Data Linkage Project, a cohort of amel patients with diagnoses between 31 August 2005 and 2012 (follow-up to 2013) and with valid International Classification of Diseases (9th revision, Clinical Modification) 172 codes and histology codes was identified. A cohort of individuals with amel having a combination of at least 1 palliative, 1 medical oncology, and 1 hospitalization code was generated. The health system services used by this population were clustered into hospitalization, palliation, physician medical visits, medication, homecare, laboratory, diagnostics, and other resources. Overall rates of use and disaggregated costs were determined by phase of care for the entire cohort.

RESULTS

The mean age for the 2748 individuals in the cohort was 67 years. The greater proportion of the patients were men (65.6%) and were more than 65 years of age (>50%). In this advanced cohort, fewer than 45% of patients were alive 3 years after the malignant melanoma diagnosis. The average annual cost per patient over the time horizon was $6,551. At $15,830, year 1 after diagnosis was the most expensive, followed by year 2, at $8,166.

CONCLUSIONS

Our data provide a baseline for the costs associated with amel treatment. Future studies will include newer agents and comparative effectiveness research for personalized therapies.

PLGA-loaded nanomedicines in melanoma treatment: Future prospect for efficient drug delivery

Current treatment methods for melanoma have some limitations such as less target-specific action, severe side effects and resistance to drugs. Significant progress has been made in exploring novel drug delivery systems based on suitable biochemical mechanisms using nanoparticles ranging from 10 to 400 nm for drug delivery and imaging, utilizing their enhanced penetration and retention properties. Poly-lactide-co-glycolide (PLGA), a copolymer of poly-lactic acid and poly-glycolic acid, provides an ideally suited performance-based design for better penetration into skin cells, thereby having a greater potential for the treatment of melanoma. Moreover, encapsulation protects the drug from deactivation by biological reactions and interactions with biomolecules, ensuring successful delivery and bioavailability for effective treatment. Controlled and sustained delivery of drugs across the skin barrier that otherwise prohibits entry of larger molecules can be successfully made with adequately stable biocompatible nanocarriers such as PLGA for taking drugs through the small cutaneous pores permitting targeted deposition and prolonged drug action. PLGA is now being extensively used in photodynamic therapy and targeted therapy through modulation of signal proteins and drug-DNA interactions. Recent advances made on these nanomedicines and their advantages in the treatment of skin melanoma are highlighted and discussed in this review.

Burden of illness for metastatic melanoma in Canada, 2011-2013

BACKGROUND

Detailed epidemiology for patients with advanced metastatic melanoma in Canada is not well characterized. We conducted an analysis of patients with this disease in the province of Ontario, with the aim being to study the presentation, disease characteristics and course, and treatment patterns for malignant melanoma.

METHODS

In this Canadian observational prospective and retrospective study of patients with malignant melanoma, we used data collected in the Canadian Melanoma Research Network (cmrn) Patient Registry. We identified patients who were seen at 1 of 3 cancer treatment centres between April 2011 and 30 April 2013. Patient data from 2011 and 2012 were collected retrospectively using chart records and existing registry data. Starting January 2013, data were collected prospectively. Variables investigated included age, sex, initial stage, histology, mutation type, time to recurrence, sites of metastases, resectability, and previous therapies.

RESULTS

A cohort of 810 patients with melanoma was identified from the cmrn registry. Mean age was 58.7 years, and most patients were men (60% vs. 40%). Factors affecting survival included unresectable or metastatic melanoma, initial stage at diagnosis, presence of brain metastasis, and BRAF mutation status. The proportion of surviving patients decreased with higher initial disease stages.

CONCLUSIONS

Using registry data, we were able to determine the detailed epidemiology of patients with melanoma in the Canadian province of Ontario, validating the comprehensive and detailed information that can be obtained from registry data.

Quantitative label-free mass spectrometry analysis of formalin-fixed, paraffin-embedded tissue representing the invasive cutaneous malignant melanoma proteome

Understanding the events at a protein level that govern the progression from melanoma in situ to invasive melanoma are important areas of current research to be developed. Recent advances in the analysis of formalin-fixed, paraffin-embedded tissue by proteomics, particularly using the filter-aided sample preparation protocol, has opened up the possibility of studying vast archives of clinical material and associated medical records. In the present study, quantitative protein profiling was performed using tandem mass spectrometry, and the proteome differences between melanoma in situ and invasive melanoma were compared. Biological pathway analyses revealed several signalling pathways differing between melanoma in situ and invasive melanoma, including metabolic pathways and the phosphoinositide 3-kinase-Akt signalling pathway. Selected proteins of interest (14–3-3ε and fatty acid synthase) were subsequently investigated using immunohistochemical analysis of tissue microarrays. Identifying the key proteins that play significant roles in the establishment of a more invasive phenotype in melanoma may ultimately aid diagnosis and treatment decisions.

[18F]MEL050 as a melanin-targeted PET tracer: Fully automated radiosynthesis and comparison to 18F-FDG for the detection of pigmented melanoma in mice primary subcutaneous tumors and pulmonary metastases

INTRODUCTION

Melanoma is a highly malignant cutaneous tumor of melanin-producing cells. MEL050 is a synthetic benzamide-derived molecule that specifically binds to melanin with high affinity. Our aim was to implement a fully automated radiosynthesis of [¹⁸F]MEL050, using for the first time, the AllInOne™ synthesis module (Trasis), and to evaluate the potential of [¹⁸F]MEL050 for the detection of pigmented melanoma in mice primary subcutaneous tumors and pulmonary metastases, and to compare it with that of [¹⁸F]FDG.

METHODS

Automated radiosynthesis of [¹⁸F]MEL050, including HPLC purification and formulation, were performed on an AllInOne™ synthesis module. [¹⁸F]MEL050 was synthesized using a one-step bromine-for-fluorine nucleophilic heteroaromatic substitution. Melanoma models were induced by subcutaneous (primary tumor) or intravenous (pulmonary metastases) injection of B16-F10-luc2 cells in NMRI mice. The maximum percentage of [¹⁸F]MEL050 Injected Dose per g of lung tissue (%ID/g Max) was determined on PET images, compared to [¹⁸F]FDG and correlated to in vivo bioluminescence imaging.

RESULTS

The automated radiosynthesis of [¹⁸F]MEL050 required an overall radiosynthesis time of 48min, with a yield of 13-18% (not-decay corrected) and radiochemical purity higher than 99%. [¹⁸F]MEL050 PET/CT images were concordant with bioluminescence imaging, showing increased radiotracer uptake in all primary subcutaneous tumors and pulmonary metastases of mice. PET quantification of radiotracers uptake in tumors and muscles demonstrated similar tumor-to-background ratio (TBR) with [¹⁸F]MEL050 and [¹⁸F]FDG in subcutaneous tumors and higher TBR with [¹⁸F]MEL050 than with [¹⁸F]FDG in pulmonary metastases.

CONCLUSION

We successfully implemented the radiosynthesis of [¹⁸F]MEL050 using the AllInOne™ module, including HPLC purification and formulation. In vivo PET/CT validation of [¹⁸F]MEL050 was obtained in mouse models of pigmented melanoma, where higher [¹⁸F]MEL050 uptake was observed in sub-millimetric pulmonary metastases, comparatively to [¹⁸F]FDG.

Synthesis and cytotoxicity evaluation of aryl triazolic derivatives and their hydroxymethine homologues against B16 melanoma cell line

In this manuscript we describe synthesis and cytotoxicity evaluation of some triazolic derivatives against B16 melanoma cell line. For this purpose, we transformed a set of aromatic aldehydes into terminal alkynes, using Besthmann-Ohira reagent, and we made the corresponding hydroxymethyl homologated alkynes by an acetylene Grignard reagent. These generated two sets of alkynes were then subjected to a copper(I)-catalyzed alkyne-azide cycloaddition reaction (CuAAC) using a solid-supported catalyst (Amberlyst A-21 CuI), with a third set composed of organic azides. Synthesized triazoles were then tested in vitro against B16 melanoma cell line. Amongst them, compounds a1b1 (R(1) = p-nitrophenyl, R(2) = benzyl), a4b1 (R(1) = naphthyl, R(2) = benzyl) and a4b5 (R(1) = naphthyl, R(2) = (R/S)- dioxolane) showed the best activity against B16 melanoma cells, with IC50 of 5.12, 3.89 and 6.60 μM respectively.

A randomized, controlled phase III trial of nab-Paclitaxel versus dacarbazine in chemotherapy-naïve patients with metastatic melanoma

BACKGROUND

The efficacy and safety of nab-paclitaxel versus dacarbazine in patients with metastatic melanoma was evaluated in a phase III randomized, controlled trial.

PATIENTS AND METHODS

Chemotherapy-naïve patients with stage IV melanoma received nab-paclitaxel 150 mg/m(2) on days 1, 8, and 15 every 4 weeks or dacarbazine 1000 mg/m(2) every 3 weeks. The primary end point was progression-free survival (PFS) by independent radiologic review; the secondary end point was overall survival (OS).

RESULTS

A total of 529 patients were randomized to nab-paclitaxel (n = 264) or dacarbazine (n = 265). Baseline characteristics were well balanced. The majority of patients were men (66%), had an Eastern Cooperative Oncology Group status of 0 (71%), and had M1c stage disease (65%). The median PFS (primary end point) was 4.8 months with nab-paclitaxel and 2.5 months with dacarbazine [hazard ratio (HR), 0.792; 95.1% confidence interval (CI) 0.631-0.992; P = 0.044]. The median OS was 12.6 months with nab-paclitaxel and 10.5 months with dacarbazine (HR, 0.897; 95.1% CI 0.738-1.089; P = 0.271). Independently assessed overall response rate was 15% versus 11% (P = 0.239), and disease control rate (DCR) was 39% versus 27% (P = 0.004) for nab-paclitaxel versus dacarbazine, respectively. The most common grade ≥3 treatment-related adverse events were neuropathy (nab-paclitaxel, 25% versus dacarbazine, 0%; P < 0.001), and neutropenia (nab-paclitaxel, 20% versus dacarbazine, 10%; P = 0.004). There was no correlation between secreted protein acidic and rich in cysteine (SPARC) status and PFS in either treatment arm.

CONCLUSIONS

nab-Paclitaxel significantly improved PFS and DCR compared with dacarbazine, with a manageable safety profile.

Ipilimumab for advanced melanoma: experience from the Spanish Expanded Access Program

Ipilimumab, a fully human, recombinant, monoclonal antibody to cytotoxic T-lymphocyte antigen 4 improves overall survival (OS) in previously treated and untreated metastatic melanoma. This retrospective analysis reports data gathered by a questionnaire on the demographics, outcomes, and toxicity of ipilimumab administered through an Expanded Access Program (EAP). Ipilimumab 3 mg/kg was administered intravenously every 3 weeks for four cycles to adults with metastatic melanoma. Efficacy outcomes included complete response, partial response (PR), progressive disease, stabilized disease, and OS. EAP data were collected from EAP physicians. A subgroup analysis examined efficacy in elderly patients (≥70 years) and factors predictive of survival were identified. Of 355 requests for ipilimumab, resulting in 288 treatments, completed questionnaires were received for 153 ipilimumab recipients (median age 58 years, 57.2% men). Efficacy was evaluated in 144 patients: complete response in 1.3%, PR in 9.6%, PR with previous progression 8.4%, stabilized disease in 14.5%, and progressive disease in 66.2%. The median OS was 6.5 months (199 days); 1-year survival was 32.9%. Predictive survival factors included lymphocytes over 1000/ml (P=0.0008) and lactate dehydrogenase more than 1.5×upper limit of normal (P=0.003). Cutaneous, hepatic, and gastrointestinal toxicities were mild. In 30 patients aged more than 70 years, ipilimumab efficacy and tolerability was similar to that of the overall population. In the clinical practice setting, ipilimumab is effective and well tolerated in patients with advanced melanoma, including elderly patients, when administered at the recommended dosage. Ipilimumab improves treatment options for patients who, until recently, have had little hope of an improved prognosis.

Metformin upregulates E-cadherin and inhibits B16F10 cell motility, invasion and migration

Malignant melanoma is a highly metastatic cancer, and has a poor prognosis once metastasis has occurred. E-cadherin downregulation is associated with a poorer prognosis in various types of cancer, including lung, ovarian, cervical and prostate. In the majority of cancer cell lines, E-cadherin upregulation inhibits cell motility, migration and invasiveness, and reduces tumor metastasis in in vivo models. In the present study, the inhibitory effects of metformin on the motility, invasion and migration of the B16F10 murine melanoma cell line, and the possible molecular mechanisms underlying this effect were investigated. B16F10 cells were treated with various concentrations of metformin for 24 h and their motility, migration and invasion were tested using a wound-healing assay, a migration assay and a matrigel invasion assay, respectively. Furthermore, the expression of E-cadherin was measured by immunocytochemistry, western blotting and reverse transcription-quantitative polymerase chain reaction. The results showed that metformin effectively upregulated the expression of E-cadherin, and inhibited B16F10 cell motility, migration and invasion, in a dose-dependent manner. This suggested that the inhibition of motility, migration and invasion of B16F10 cells by metformin may be associated with the upregulation of E-cadherin expression, indicating that metformin may have a role in the treatment of melanoma.

Potential roles of abnormally expressed long noncoding RNA UCA1 and Malat-1 in metastasis of melanoma

Melanoma is a highly aggressive skin cancer with increasing incidence worldwide. Long noncoding RNAs (lncRNAs), a group of nonprotein-coding transcripts longer than 200 nucleotides, are pervasively transcribed in the genome and are emerging as new players in tumorigenesis. The primary objective of this study was to investigate the role of six cancer-related lncRNAs in pairs of melanoma and adjacent normal tissues (ANTs). A total of 63 primary melanoma, paired ANTs, and metastatic lesions were collected in a Chinese population. Real-time PCR analysis was carried out to compare a series of cancer-related lncRNAs among primary melanoma tissues, ANTs, and metastatic lesions. In in-vitro studies, transwell migration assay was carried out to estimate the migration abilities of melanoma cells with different expression levels of urothelial carcinoma-associated 1 (UCA1) or metastasis-associated lung adenocarcinoma transcript 1 (Malat-1) lncRNAs. We found that UCA1 and Malat-1 lncRNAs were markedly more increased in melanomas than in paired ANTs (P<0.05). Melanomas at later stages (stages 3-4) showed higher expression of UCA1 lncRNA than those at early stages (stages 1-2) (P=0.455). In melanomas with lymph node metastasis, the metastatic lesions had a relatively higher expression of Malat-1 lncRNA than in paired primary tumors (P=0.414). Knockdown of UCA1 or Malat-1 lncRNA could attenuate the migrational ability of melanoma cells in in-vitro studies. Increased expression of UCA1 and Malat-1 lncRNAs might have a correlation with melanoma metastasis.

Perspectives on the application of nanotechnology in photodynamic therapy for the treatment of melanoma

Malignant melanoma is the most aggressive form of skin cancer and has been traditionally considered difficult to treat. The worldwide incidence of melanoma has been increasing faster than any other type of cancer. Early detection, surgery, and adjuvant therapy enable improved outcomes; nonetheless, the prognosis of metastatic melanoma remains poor. Several therapies have been investigated for the treatment of melanoma; however, current treatment options for patients with metastatic disease are limited and non-curative in the majority of cases. Photodynamic therapy (PDT) has been proposed as a promising minimally invasive therapeutic procedure that employs three essential elements to induce cell death: a photosensitizer, light of a specific wavelength, and molecular oxygen. However, classical PDT has shown some drawbacks that limit its clinical application. In view of this, the use of nanotechnology has been considered since it provides many tools that can be applied to PDT to circumvent these limitations and bring new perspectives for the application of this therapy for different types of diseases. On that ground, this review focuses on the potential use of developing nanotechnologies able to bring significant benefits for anticancer PDT, aiming to reach higher efficacy and safety for patients with malignant melanoma.

RUNX2 is overexpressed in melanoma cells and mediates their migration and invasion

In the present study, we investigated the role of the transcription factor RUNX2 in melanomagenesis. We demonstrated that the expression of transcriptionally active RUNX2 was increased in melanoma cell lines as compared with human melanocytes. Using a melanoma tissue microarray, we showed that RUNX2 levels were higher in melanoma cells as compared with nevic melanocytes. RUNX2 knockdown in melanoma cell lines significantly decreased Focal Adhesion Kinase expression, and inhibited their cell growth, migration and invasion ability. Finally, the pro-hormone cholecalciferol reduced RUNX2 transcriptional activity and decreased migration of melanoma cells, further suggesting a role of RUNX2 in melanoma cell migration.

Insulin induces drug resistance in melanoma through activation of the PI3K/Akt pathway

Introduction

There is currently no curative treatment for melanoma once the disease spreads beyond the original site. Although activation of the PI3K/Akt pathway resulting from genetic mutations and epigenetic deregulation of its major regulators is known to cause resistance of melanoma to therapeutic agents, including the conventional chemotherapeutic drug dacarbazine and the Food and Drug Administration-approved mutant BRAF inhibitors vemurafenib and dabrafenib, the role of extracellular stimuli of the pathway, such as insulin, in drug resistance of melanoma remains less understood.

Objective

To investigate the effect of insulin on the response of melanoma cells to dacarbazine, and in particular, the effect of insulin on the response of melanoma cells carrying the BRAF^V600E mutation to mutant BRAF inhibitors. An additional aim was to define the role of the PI3K/Akt pathway in the insulin-triggered drug resistance.

Methods

The effect of insulin on cytotoxicity induced by dacarbazine or the mutant BRAF inhibitor PLX4720 was tested by pre-incubation of melanoma cells with insulin. Cytotoxicity was determined by the MTS assay. The role of the PI3K/Akt pathway in the insulin-triggered drug resistance was examined using the PI3K inhibitor LY294002 and the PI3K and mammalian target of rapamycin dual inhibitor BEZ-235. Activation of the PI3K/Akt pathway was monitored by Western blot analysis of phosphorylated levels of Akt.

Results

Recombinant insulin attenuated dacarbazine-induced cytotoxicity in both wild-type BRAF and BRAF^V600E melanoma cells, whereas it also reduced killing of BRAF^V600E melanoma cells by PLX4720. Nevertheless, the protective effect of insulin was abolished by the PI3K and mTOR dual inhibitor BEZ-235 or the PI3K inhibitor LY294002.

Conclusion

Insulin attenuates the therapeutic efficacy of dacarbazine and PLX4720 in melanoma cells, which is mediated by activation of the PI3K/Akt pathway and can be overcome by PI3K inhibitors.

A possible cross-talk between autophagy and apoptosis in generating an immune response in melanoma

Melanoma is the most aggressive form of skin cancer, responsible for the majority of skin cancer related deaths. Thus, the search for natural molecules which can effectively destroy tumors while promoting immune activation is essential for designing novel therapies against metastatic melanoma. Here, we report for the first time that a natural triterpenoid, Ganoderic acid DM (GA-DM), induces an orchestrated autophagic and apoptotic cell death, as well as enhanced immunological responses via increased HLA class II presentation in melanoma cells. Annexin V staining and flow cytometry showed that GA-DM treatment induced apoptosis of melanoma cells, which was supported by a detection of increased Bax proteins, co-localization and elevation of Apaf-1 and cytochrome c, and a subsequent cleavage of caspases 9 and 3. Furthermore, GA-DM treatment initiated a possible cross-talk between autophagy and apoptosis as evidenced by increased levels of Beclin-1 and LC3 proteins, and their timely interplay with apoptotic and/or anti-apoptotic molecules in melanoma cells. Despite GA-DM's moderate cytotoxicity, viable cells expressed high levels of HLA class II proteins with improved antigen presentation and CD4+ T cell recognition. The antitumor efficacy of GA-DM was also investigated in vivo in murine B16 melanoma model, where GA-DM treatment slowed tumor formation with a significant reduction in tumor volume. Taken together, these findings demonstrate the potential of GA-DM as a natural chemo-immunotherapeutic capable of inducing a possible cross-talk between autophagy and apoptosis, as well as improved immune recognition for sustained melanoma tumor clearance.

Electrochemotherapy: an effective local treatment of cutaneous and subcutaneous melanoma metastases

Treatment of multiple cutaneous and subcutaneous melanoma metastases is still represents a therapeutic challenge for both dermatologists and oncologists. Electrochemotherapy (ECT) is a promising therapeutic procedure, owing to its ability to improve the penetration of cytotoxic drugs into cancer cells by application of current electric pulses. The aim of our study is to evaluate efficacy, tolerability and long-term efficacy of ECT in the treatment of advanced metastatic melanoma. Thirty patients affected by a total of 654 cutaneous and subcutaneous melanoma metastatic nodules were recruited. All patients were treated after they had undergone to a mild general anesthesia. Intravenous Bleomicina solution was administered 8 minutes before the application of electric pulses, generated by a Cliniporator (TM) (the device validated for ECT). The objective response rate of 100% (67.28% complete response and 32.72% partial response) was observed. A total of 214 metastatic lesions from 24 patients received a second ECT session, among them 141 showed a further complete response. Twenty-four months later, the local tumor control rate was 72%. The results of this study seem to demonstrate that ECT is an effective and valid therapeutic tool for the treatment of cutaneous metastases from melanoma. ECT can be considered a first-line palliative treatment since it is able to alleviate pain and reduce the tumor's spontaneous bleeding with a significant improve of patients' quality of life.

Applications of nanotechnology for melanoma treatment, diagnosis, and theranostics

Melanoma is the most aggressive type of skin cancer and has very high rates of mortality. An early stage melanoma can be surgically removed, with a survival rate of 99%. However, metastasized melanoma is difficult to cure. The 5-year survival rates for patients with metastasized melanoma are still below 20%. Metastasized melanoma is currently treated by chemotherapy, targeted therapy, immunotherapy and radiotherapy. The outcome of most of the current therapies is far from optimistic. Although melanoma patients with a mutation in the oncogene v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) have an initially higher positive response rate to targeted therapy, the majority develop acquired drug resistance after 6 months of the therapy. To increase treatment efficacy, early diagnosis, more potent pharmacological agents, and more effective delivery systems are urgently needed. Nanotechnology has been extensively studied for melanoma treatment and diagnosis, to decrease drug resistance, increase therapeutic efficacy, and reduce side effects. In this review, we summarize the recent progress on the development of various nanoparticles for melanoma treatment and diagnosis. Several common nanoparticles, including liposome, polymersomes, dendrimers, carbon-based nanoparticles, and human albumin, have been used to deliver chemotherapeutic agents, and small interfering ribonucleic acids (siRNAs) against signaling molecules have also been tested for the treatment of melanoma. Indeed, several nanoparticle-delivered drugs have been approved by the US Food and Drug Administration and are currently in clinical trials. The application of nanoparticles could produce side effects, which will need to be reduced so that nanoparticle-delivered drugs can be safely applied in the clinical setting.

Functional classification of cellular proteome profiles support the identification of drug resistance signatures in melanoma cells

Drug resistance is a major obstacle in melanoma treatment. Recognition of specific resistance patterns, the understanding of the patho-physiology of drug resistance, and identification of remaining options for individual melanoma treatment would greatly improve therapeutic success. We performed mass spectrometry-based proteome profiling of A375 melanoma cells and HeLa cells characterized as sensitive to cisplatin in comparison to cisplatin resistant M24met and TMFI melanoma cells. Cells were fractionated into cytoplasm, nuclei and secretome and the proteome profiles classified according to Gene Ontology. The cisplatin resistant cells displayed increased expression of lysosomal as well as Ca²⁺ ion binding and cell adherence proteins. These findings were confirmed using Lysotracker Red staining and cell adhesion assays with a panel of extracellular matrix proteins. To discriminate specific survival proteins, we selected constitutively expressed proteins of resistant M24met cells which were found expressed upon challenging the sensitive A375 cells. Using the CPL/MUW proteome database, the selected lysosomal, cell adherence and survival proteins apparently specifying resistant cells were narrowed down to 47 proteins representing a potential resistance signature. These were tested against our proteomics database comprising more than 200 different cell types/cell states for its predictive power. We provide evidence that this signature enables the automated assignment of resistance features as readout from proteome profiles of any human cell type. Proteome profiling and bioinformatic processing may thus support the understanding of drug resistance mechanism, eventually guiding patient tailored therapy.

Synthesis and in vitro evaluation of potential anticancer activity of mono- and bis-1,2,3-triazole derivatives of bis-alkynes

In order to find new molecules with cytotoxic activity against cancer cells, we prepared bis-akyne amides derived from propiolic acid. The bis-alkynes were then transformed in their mono-1,2,3-triazole analogs onto the amide side, due to its greater reactivity, using a catalyst-free Huisgen's reaction. The mono-triazoles were then subjected to the copper (I)-catalyzed version of the previous reaction (CuAAC), using a supported catalyst, to produce bis-triazoles. All products were obtained pure after simple trituration or filtration procedures. All synthetic compounds were tested in vitro for their cytotoxic activity using B16 melanoma cells. Four compounds (7, 23, 25 and 33) showed activities in the micromolar range (<21 μM) whereas three compounds (3, 22 and 38) presented activity at low micromolar concentrations (<10 μM), and two analogs (2 and 13) were active at nanomolar levels (<1 μM).

RIN1 exhibits oncogenic property to suppress apoptosis and its aberrant accumulation associates with poor prognosis in melanoma

Malignant melanoma is an increasing disease in China, and its molecular mechanisms of development and progression are limited. The objective of this study was to investigate the expression of Ras interaction/interference 1 (RIN1) protein and its clinical significance in human melanoma. Immunohistochemistry was performed to detect the expression of RIN1 in 81 melanoma patients with a 5-year follow-up. The prognosis of the patients, classified by the clinicopathologic features and RIN1 expression, was assessed by multivariate analysis. RIN1 levels were then analyzed with overall survival (OS), progression-free survival (PFS), and recurrence-free survival (RFS) in the cohort. The biological function was determined by proliferation assay, flow cytometry analysis through knocking down of RIN1 in melanoma cells A375, as well as caspase-3 activation and PARP cleavage were detected by western blot or fluorometric assay. Data showed that RIN1 was overexpressed in melanoma samples. High-level RIN1 expression was observed in 49.4 % (40 of 81 cases), associated with thickness grade (P = 0.008) and lymph node metastasis (P < 0.001). Two distinguished subgroups were segregated by RIN1 levels within this set comparing prognostication of OS, PFS, and RFS. Importantly, RIN1 level was revealed as the significant independent prognostic factor for death and progression but a weak contribution for recurrence. Moreover, knock down of RIN1 expression in A375 cells, suppressed cell proliferation and induced apoptosis through caspase-3 activation and PARP cleavage. RIN1 expression could be a potential prognostic predictor for the melanoma patients and provide a potential target therapy for melanoma treatment.

Synthetic retinoid CD437 induces apoptosis and acts synergistically with TRAIL receptor-2 agonist in malignant melanoma

The novel synthetic retinoid, CD437, shows potent anti-tumor activity in a range of different cancer cell lines and now serves as a prototype for development of new retinoid related molecules (RRMs). The purpose of this study was to examine the effect and cellular targets of CD437 in the human metastatic melanoma cell lines FEMX-1 and WM239. We showed that treatment with CD437 led to cell cycle arrest and induced apoptosis through both the extrinsic- and intrinsic pathways (caspase 8, -9 and PARP cleavage) in both cell lines. Interestingly, apoptosis was induced independently of DNA-fragmentation in FEMX-1 cells, and appeared partially caspase-independent in the WM239 cells. Additionally, up-regulation of CHOP mRNA and cathepsin D protein expression, following retinoid treatment, suggests involvement of the endoplasmatic reticulum (ER) and lysosomes, respectively. Combination of suboptimal concentrations of CD437 and lexatumumab, a TRAIL death receptor-2 agonist, resulted in synergistic reduction of viable cells, along with increased PARP cleavage. These results indicate that CD437 has a strong anti-neoplastic effect alone and in combination with lexatumumab in melanoma cell lines.

Targeted therapy for brain metastases

The prevention and treatment of brain metastases is an increasingly important challenge in oncology. Improved understanding of the molecular pathogenesis of a number of cancers has led to the development of highly active targeted therapies for patients with specific oncogenic events. Such therapies include EGFR inhibitors for lung cancer, HER2/neu inhibitors for breast cancer, and BRAF inhibitors for melanoma. This review will discuss the development of these targeted therapy approaches, existing data about their role in the management of brain metastasis, and opportunities and challenges for future research in this critical area.