Advances in the management of melanoma: targeted therapy, immunotherapy and future directions

Bis-Cinnamamide Derivatives as APE/Ref-1 Inhibitors for the Treatment of Human Melanoma

Human malignant melanoma exhibits imbalances in redox status, leading to activation of many redox-sensitive signaling pathways. APE/Ref-1 is a multifunctional protein that serves as a redox chaperone that regulates many nuclear transcription factors and is an important mechanism in cancer cell survival of oxidative stress. Previous studies showed that APE/Ref-1 is a potential druggable target for melanoma therapy. In this study, we synthesized a novel APE/Ref-1 inhibitor, bis-cinnamoyl-1,12-dodecamethylenediamine (2). In a xenograft mouse model, compound 2 treatment (5 mg/kg) significantly inhibited tumor growth compared to the control group, with no significant systemic toxicity observed. We further synthesized compound 2 analogs to determine the structure-activity relationship based on their anti-melanoma activities. Among those, 4-hydroxyphenyl derivative (11) exhibited potent anti-melanoma activities and improved water solubility compared to its parental compound 2. The IC₅₀ of compound 11 was found to be less than 0.1 μM. Compared to other known APE/Ref-1 inhibitors, compound 11 exhibited increased potency in inhibiting melanoma proliferation. As determined by luciferase reporter analyses, compound 2 was shown to effectively inhibit H₂O₂-activated AP-1 transcription activities. Targeting APE/Ref-1-mediated signaling using pharmaceutical inhibitors is a novel and effective strategy for melanoma treatment with potentially high impact.

The Identification and Validation of a Robust Immune-Associated Gene Signature in Cutaneous Melanoma

BACKGROUND

Cutaneous melanoma is defined as one of the most aggressive skin tumors in the world. An increasing body of evidence suggested an indispensable association between immune-associated gene (IAG) signature and melanoma. This article is aimed at formulating an IAG signature to estimate prognosis of melanoma.

METHODS

434 melanoma patients were extracted from The Cancer Genome Atlas (TCGA) database, and 1811 IAGs were downloaded from the ImmPort database in our retrospective study. The Cox regression analysis and LASSO regression analysis were utilized to establish a prognostic IAG signature. The Kaplan-Meier (KM) survival analysis was performed, and the time-dependent receiver operating characteristic curve (ROC) analysis was further applied to assess the predictive value. Besides, the propensity score algorithm was utilized to balance the confounding clinical factors between the high- and low-risk groups.

RESULTS

A total of six prognostic IAGs comprising of INHA, NDRG1, IFITM1, LHB, GBP2, and CCL8 were eventually filtered out. According to the KM survival analysis, the results displayed a shorter overall survival (OS) in the high-risk group compared to the low-risk group. In the multivariate Cox model, the gene signature was testified as a remarkable prognostic factor (HR = 45.423, P < 0.001). Additionally, the ROC curve analyses were performed which demonstrated our IAG signature was superior to four known biomarkers mentioned in the study. Moreover, the IAG signature was significantly related to immunotherapy-related biomarkers.

CONCLUSION

Our study demonstrated that the six IAG signature played a critical role in the prognosis and immunotherapy of melanoma, which might help clinicians predict patients' survival and provide individualized treatment.

Overexpressed VEPH1 inhibits epithelial-mesenchymal transition, invasion, and migration of human cutaneous melanoma cells through inactivating the TGF-β signaling pathway

Malignant melanoma has a profound influence on populations around the world, with the underlying mechanisms controlling this disease yet to be fully identified. Hence, the current study aimed to investigate effects associated with VEPH1 on epithelial-mesenchymal transition (EMT), proliferation, invasion, migration and the apoptosis of human cutaneous melanoma (CM) cells through the TGF-β signaling pathway. Microarray-based gene analysis was initially performed to screen the CM-related differentially expressed genes. The expression of VEPH1, TGF-β signaling pathway- and EMT-related genes in CM tissues and cell lines was subsequently evaluated. Gain-of- and loss-of-function experiments were conducted to examine the effects of VEPH1 and the TGF-β signaling pathway on the expression of EMT-related genes, cell proliferation, migration, invasion, cell cycle and apoptosis in vitro. Finally, tumor formation in nude mice was conducted. VEPH1 was lowly expressed and regulated the progression of CM with involvement in the TGF-β signaling pathway. Human CM tissues were noted to activate the TGF-β signaling pathway and EMT. A375 cells treated with overexpressed VEPH1 plasmids or/and TGF-β signaling pathway inhibitor SB-431542 displayed diminished TGF-β, SMAD4, Vimentin and N-cadherin expression while the expression of E-cadherin was elevated, accompanied by decreased cell proliferation, migration, invasion, inhibited cell cycle entry. However, si-VEPH1 or TGF-β signaling pathway activator contributed to reverse results. Taken together, the key findings of the current study present evidence suggesting that VEPH1 protects against human CM by inhibiting the activation of the TGF-β signaling pathway, highlighting its potential as a target for the prognosis and diagnosis of CM.

Economic burden of toxicities associated with treating metastatic melanoma in eight countries

BACKGROUND

Information on costs of managing adverse events (AEs) associated with current treatments in metastatic melanoma is limited. This study estimates costs of AEs in eight countries: Australia (AU), Canada (CA), France (FR), Germany (GE), Italy (IT), the Netherlands (NL), Spain (ES), and the UK.

METHODS

A literature search was conducted to identify grade 3/4 AEs from product label, published trials, conference abstracts, and treatment guidelines. Resource utilization for the management of each type of AE was determined via interviews with 5 melanoma clinicians in each country. Outpatient and inpatient costs were estimated for each type of AE using country-specific tariffs or government/published sources.

RESULTS

In outpatient settings, the most costly AEs per incident included cutaneous squamous cell carcinoma (CSCC) (€1063, £720; NL/UK), anemia (€1443, €1329, €1285; ES/IT/FR), peripheral neuropathy (€1289; ES), and immune-related diarrhea (AUS$1,121; AU). In inpatient settings, the most costly AEs per hospitalization included hypophysitis (€10,265; €5316; CAN$9735; AUS$7231: ES/FR/CA/AU), dyspnea (€9077; GE), elevated liver enzymes (€6913, CAN$8030, AUS$6594; FR/CA/AU), CSCC (CAN$8934; CA), peripheral neuropathy (€6977, €4144, CAN$9472; NL/ES/CA), and diarrhea (£4284, €4113; UK/ES).

CONCLUSIONS

Costs of managing AEs can be significant, and thus effective treatments with lower rates of severe AEs would be valuable.

IGF-1 contributes to the expansion of melanoma-initiating cells through an epithelial-mesenchymal transition process

Melanoma is a particularly virulent human cancer, due to its resistance to conventional treatments and high frequency of metastasis. Melanomas contain a fraction of cells, the melanoma-initiating cells (MICs), responsible for tumor propagation and relapse. Identification of the molecular pathways supporting MICs is, therefore, vital for the development of targeted treatments. One factor produced by melanoma cells and their microenvironment, insulin-like growth factor-1 (IGF- 1), is linked to epithelial-mesenchymal transition (EMT) and stemness features in several cancers.We evaluated the effect of IGF-1 on the phenotype and chemoresistance of B16-F10 cells. IGF-1 inhibition in these cells prevented malignant cell proliferation, migration and invasion, and lung colony formation in immunodeficient mice. IGF-1 downregulation also markedly inhibited EMT, with low levels of ZEB1 and mesenchymal markers (N-cadherin, CD44, CD29, CD105) associated with high levels of E-cadherin and MITF, the major regulator of melanocyte differentiation. IGF-1 inhibition greatly reduced stemness features, including the expression of key stem markers (SOX2, Oct-3/4, CD24 and CD133), and the functional characteristics of MICs (melanosphere formation, aldehyde dehydrogenase activity, side population). These features were associated with a high degree of sensitivity to mitoxantrone treatment.In this study, we deciphered new connections between IGF-1 and stemness features and identified IGF-1 as instrumental for maintaining the MIC phenotype. The IGF1/IGF1-R nexus could be targeted for the development of more efficient anti-melanoma treatments. Blocking the IGF-1 pathway would improve the immune response, decrease the metastatic potential of tumor cells and sensitize melanoma cells to conventional treatments.

Quantitative assessment of the influence of X-ray repair cross-complementing group 3 rs861539 polymorphism and cutaneous melanoma susceptibility

Previous studies evaluating the association between X-ray repair cross-complementing group 3 (XRCC3) rs861539 polymorphism and cutaneous melanoma susceptibility reported conflicting findings. To draw a more precise association between XRCC3 rs861539 polymorphism and cutaneous melanoma susceptibility, we searched PubMed, EMBASE and Web of Science for case-control studies. A total of eight case-control studies including 3463 cases of melanoma and 4216 controls were included in the meta-analysis. Overall, no significant associations were found between XRCC3 rs861539 polymorphism and cutaneous melanoma susceptibility under all four genetic models (TT vs CC: OR 0.99, 95 % CI 0.86-1.14; TC vs CC: OR 0.92, 95 % CI 0.83-1.01; dominant model: OR 0.94, 95 % CI 0.85-1.03; recessive model: OR 1.05, 95 % CI 0.92-1.19). In the subgroup by source of control, no significant associations were found in hospital-based and population-based subgroup. This meta-analysis suggested that the XRCC3 rs861539 polymorphism was not a risk factor for cutaneous melanoma susceptibility.

β-NaGdF4:Eu3+ nanocrystal markers for melanoma tumor imaging

Europium doped nanocrystals can be optimized to be successfully used as visualization markers for i.e. melanoma tumor.

Costs, resource utilization, and treatment patterns for patients with metastatic melanoma in a commercially insured setting

OBJECTIVE

To estimate real-world healthcare costs, resource utilization, and treatment patterns among metastatic melanoma (MM) patients who received a therapy recommended in current treatment guidelines during 2011 and 2012, following approval in the US of novel therapies (ipilimumab and vemurafenib).

RESEARCH DESIGN AND METHODS

Administrative claims data were used in a retrospective, longitudinal, open cohort study. Adult MM patients were identified using ICD-9 codes. Therapy-based patient cohorts and index dates were defined by the first receipt of a therapy of interest: ipilimumab, vemurafenib, paclitaxel (alone and in combination), interleukin-2, dacarbazine (alone and in combination), or temozolomide. The follow-up period extended until the end of eligibility or data availability. A multivariate regression model was used to compare outcomes of the ipilimumab and vemurafenib cohorts, controlling for baseline and demographic characteristics.

MAIN OUTCOME MEASURES

Direct healthcare costs (2013 US dollars) and utilization (incidence rates) were measured on a per-patient-per-month (PPPM) basis for each treatment cohort. Treatment patterns were assessed, including the frequency of patients receiving a second therapy of interest.

RESULTS

The study population included 834 patients (265 ipilimumab, 234 vemurafenib, 174 paclitaxel, 104 interleukin-2, 46 dacarbazine, and 11 temozolomide). Costs ranged from $10,879 PPPM (temozolomide) to $35,472 PPPM (ipilimumab). Adjusted total costs were $18,337 PPPM higher for the ipilimumab vs. the vemurafenib cohort (p < 0.001), primarily due to higher outpatient costs. Multivariate analysis did not find significant differences in resource utilization between ipilimumab and vemurafenib, except that ipilimumab patients had fewer outpatient visits (excluding treatment visits). Ipilimumab and vemurafenib patients received a second therapy of interest (12% and 11%, respectively) less frequently than interleukin-2 and dacarbazine patients.

CONCLUSIONS

The cost and resource utilization burden of MM is high and varies substantially across treatment cohorts. The two novel therapies, ipilimumab and vemurafenib, have quickly been adopted and are the most frequently used therapies. The results observed during the approximately 6 month follow-up period may not be representative of the full clinical experience of patients with MM.

Current evidences on the XPG Asp1104His polymorphism and melanoma susceptibility: a meta-analysis based on case-control studies

Previous studies evaluating the association between the XPG Asp1104His polymorphism and melanoma susceptibility remained controversial. To draw a more precise estimation of the relationship, a total of eight published case-control studies containing 5,212 cases and 7,045 controls were included for meta-analysis. Overall, a significant association was found between the XPG Asp1104His polymorphism and melanoma susceptibility for the dominant model (OR = 2.42, 95 % CI = 2.26-2.60). In subgroup analysis by source of control, there was an obvious association was found among Population-based subgroup for the dominant model CC+GC vs GG (OR 2.51, 95 % CI 2.28-2.77), among the Hospital-based subgroup, an obvious association was also found for the dominant model CC+GC vs GG (OR 2.34, 95 % CI 2.12-2.58). This meta-analysis suggested that the XPG Asp1104His polymorphism was a risk factor for melanoma susceptibility.

Molecular biomarkers in clinical development: what could we learn from the clinical trial registry?

Aim: Objective of this research is to assess whether the trend of stratified medicine widely discussed in scientific literature is translated into real clinical trials registered in ClinicalTrials.gov . Methods: By semi-automatic screening of over 150,000 trials, we filtered trials with stratified biomarker to analyze their therapeutic focus, major drivers and elucidated the impact of stratified biomarker programs on trial duration and completion. Results: >5% of trials are using molecular biomarker for stratification; duration of such trials is longer. 21% of them are done in late stages and Oncology is the major focus. Conclusion: Trials with stratified biomarker in drug development has quadrupled in last decade but represents a small part of all interventional trials reflecting multiple co-developmental challenges of therapeutic compounds and companion diagnostics.

Visualization of melanoma tumor with lectin-conjugated rare-earth doped fluoride nanocrystals

AIM

To develop specific fluorescent markers for melanoma tumor visualization, which would provide high selectivity and reversible binding pattern, by the use of carbohydrate-recognizing proteins, lectins, combined with the physical ability for imaging deep in the living tissues by utilizing red and near infrared fluorescent properties of specific rare-earth doped nanocrystals (NC).

METHODS

B10F16 melanoma cells were inoculated to C57BL/6 mice for inducing experimental melanoma tumor. Tumors were removed and analyzed by lectin-histochemistry using LABA, PFA, PNA, HPA, SNA, GNA, and NPL lectins and stained with hematoxylin and eosin. NPL lectin was conjugated to fluorescent NaGdF4:Eu(3+)-COOH nanoparticles (5 nm) via zero length cross-linking reaction, and the conjugates were purified from unbound substances and then used for further visualization of histological samples. Fluorescent microscopy was used to visualize NPL-NaGdF4:Eu(3+) with the fluorescent emission at 600-720 nm range.

RESULTS

NPL lectin selectively recognized regions of undifferentiated melanoblasts surrounding neoangiogenic foci inside melanoma tumor, PNA lectin recognized differentiated melanoblasts, and LCA and WGA were bound to tumor stroma regions. NPL-NaGdF4:Eu(3+) conjugated NC were efficiently detecting newly formed regions of melanoma tumor, confirmed by fluorescent microscopy in visible and near infrared mode. These conjugates possessed high photostability and were compatible with convenient xylene-based mounting systems and preserved intensive fluorescent signal at samples storage for at least 6 months.

CONCLUSION

NPL lectin-NaGdF4:Eu(3+) conjugated NC permitted distinct identification of contours of the melanoma tissue on histological sections using red excitation at 590-610 nm and near infrared emission of 700-720 nm. These data are of potential practical significance for development of glycans-conjugated nanoparticles to be used for in vivo visualization of melanoma tumor.

Quantitative assessment of the association between XPC Lys939Gln polymorphism and cutaneous melanoma risk

Previous studies evaluating the association between XPC Lys939Gln polymorphism and cutaneous melanoma risk reported conflicting findings. We searched PubMed and Embase databases up to May 16, 2013 to identify eligible studies on the association between XPC Lys939Gln polymorphism and cutaneous melanoma risk. Finally, a total of seven case-control studies including 3,971 cases of cutaneous melanoma and 5,873 controls were included in the meta-analysis. Statistical analysis was performed with STATA version 11.0. Odds ratios (ORs) with 95 % confidence intervals (95 % CIs) were used to assess the strength of the association. Overall, there was no association between XPC Lys939Gln polymorphism and cutaneous melanoma risk under all five genetic models (Gln vs. Lys: OR = 1.11, 95 % CI = 0.98-1.26, P = 0.10; GlnGln vs. LysLys: OR = 1.26, 95 % CI = 0.98-1.61, P = 0.07; LysGln vs. LysLys: OR = 1.04, 95 % CI = 0.88-1.22, P = 0.64; GlnGln/LysGln vs. LysLys: OR = 1.10, 95 % CI = 0.92-1.31, P = 0.29; GlnGln vs. LysLys/LysGln: OR = 1.19, 95 % CI = 0.99-1.43, P = 0.06). Subgroup analysis in Caucasians showed that there was an obvious association between XPC Lys939Gln polymorphism and cutaneous melanoma risk in Caucasians (GlnGln vs. LysLys/LysGln: OR = 1.12, 95 % CI = 1.00-1.25, P = 0.05). Sensitivity analysis by omitting one study in turns showed that the significance of the pooled ORs was not stable. In addition, there was some evidence of publication bias in the meta-analysis, and meta-analyses of the studies with large sample size did not find the obvious association between XPC Lys939Gln polymorphism and cutaneous melanoma risk in Caucasians. Therefore, there is little evidence for the association between XPC Lys939Gln polymorphism and cutaneous melanoma risk.

Hypodermal metastasis of malignant melanoma to the cheek

INTRODUCTION

On the basis of a case of hypodermal metastasis of malignant melanoma to the cheek and a review of the literature, we analyze treatment and recent progress in metastatic malignant melanoma.

CASE-REPORT

A 55-year-old woman presented with a facial hypodermal metastasis of a slow-growing melanoma of the ankle that had been treated by surgery.

DISCUSSION/CONCLUSION

Metastatic malignant melanoma treatment, which was usually palliative when surgical resection was not feasible, has been improved by innovations in immunotherapy (ipilimumab) and targeted therapy (vemurafenib). Genetic profiling is an interesting line of research to improve short-term prognosis in these tumors.

Molecular targeted therapies in metastatic melanoma

The advent of personalized medicine has ushered in a new era for cancer therapy with a significant impact on the management of advanced melanoma. Molecular targeted therapies have shown promise in the management of various malignancies, including melanoma, with lower toxicity profiles and better overall survival as compared with conventional therapy. The discovery of BRAF mutations in melanoma led to the development of BRAF inhibitors for the treatment of advanced melanoma. However, growing concerns over drug resistance to molecular targeted therapies including BRAF inhibitors, have spurred efforts to elucidate additional molecular targets for the treatment of advanced melanoma. In this review, we discuss the known molecular aberrations in melanoma, current and novel targeted approaches in its treatment, and drug resistance patterns.

The curcumin analog DM-1 induces apoptotic cell death in melanoma

The main difficulty in the successful treatment of metastatic melanoma is that this type of cancer is known to be resistant to chemotherapy. Chemotherapy remains the treatment of choice, and dacarbazine (DTIC) is the best standard treatment. The DM-1 compound is a curcumin analog that possesses several curcumin characteristics, such as antiproliferative, antitumor, and antimetastatic properties. The objective of this study was to evaluate the signaling pathways involved in melanoma cell death after treatment with DM-1 compared to the standard agent for melanoma treatment, DTIC. Cell death was evaluated by flow cytometry for annexin V and iodide propide, cleaved caspase 8, and TNF-R1 expression. Hoechst 33342 staining was evaluated by fluorescent microscopy; lipid peroxidation and cell viability (MTT) were evaluated by colorimetric assays. The antiproliferative effects of the drugs were evaluated by flow cytometry for cyclin D1 and Ki67 expression. Mice bearing B16F10 melanoma were treated with DTIC, DM-1, or both therapies. DM-1 induced significant apoptosis as indicated by the presence of cleaved caspase 8 and an increase in TNF-R1 expression in melanoma cells. Furthermore, DM-1 had antiproliferative effects in this the same cell line. DTIC caused cell death primarily by necrosis, and a smaller melanoma cell population underwent apoptosis. DTIC induced oxidative stress and several physiological changes in normal melanocytes, whereas DM-1 did not significantly affect the normal cells. DM-1 antitumor therapy in vivo showed tumor burden decrease with DM-1 monotherapy or in combination with DTIC, besides survival rate increase. Altogether, these data confirm DM-1 as a chemotherapeutic agent with effective tumor control properties and a lower incidence of side effects in normal cells compared to DTIC.