Major therapeutic developments and current challenges in advanced melanoma

In vitro antiproliferative and apoptotic effects of thiosemicarbazones based on (-)-camphene and R-(+)-limonene in human melanoma cells

A series of 38 thiosemicarbazone derivatives based on camphene and limonene were evaluated for their antiproliferative activity. Among them, 19 were synthesized and characterized using proton and carbon-13 nuclear magnetic resonance (1H and 13C NMR). For initial compound selection, human melanoma cells (SK-MEL-37) were exposed to a single concentration of a compound (100 μM) for 24, 48, and 72 hours, and cell detachment was visually observed. Cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Nineteen compounds (4, 6, 8, 11, 13, 14, 15, 16, 17, 18, 20, 22, 25, 26, 31, 3', 4', 6', and 9') yielded cell viability below 20%. Subsequently, IC50 values for these compounds were determined, ranging from 11.56 to 55.38 μM, after 72 hours of treatment. Compound 17 (o-hydroxybenzaldehyde (-)-camphene-based thiosemicarbazone) demonstrated the lowest IC50 value, followed by compound 4 (benzaldehyde (-) camphene-based thiosemicarbazone) at 12.84 μM. Regarding compound 4, we observed the induction of a characteristic ladder pattern of DNA fragmentation through gel electrophoresis. Furthermore, fluorescence, flow cytometry and scanning microscopy assays revealed morphological changes consistent with apoptosis induction. Additionally, the measurement of caspase 6 and 8 activity in cellular extracts after treatment for 2, 4, 6, and 24 hours suggested the potential involvement of the extrinsic apoptosis pathway in the mechanism of action of compound 4. Further investigations, including molecular docking studies, are required to fully explore the potential of compound 4 and the other selected compounds, highlighting their promising role in future melanoma therapy research.

Assessing the Educational and Supportive Care Needs of Canadian Metastatic Melanoma Patients and Survivors Attending an Outpatient Clinic

The rapid development of metastatic melanoma treatment options has significantly improved overall survival, but paralleled patient educational and supportive care resources have fallen behind. Particularly, the need for grassroots programs targeting environments outside urban centers has grown. Accordingly, an environmental scan of the Durham region in Ontario, Canada, showed the lack of melanoma-specific resources for outpatients. The goal of this study was to identify the needs of metastatic melanoma patients and survivors attending a large outpatient clinic in Durham, and then develop a patient-reviewed intervention plan. Needs were assessed in 5 domains through a melanoma-specific supportive care needs assessment survey. Among 75 surveyed melanoma patients and survivors, high-level needs were identified in 3 domains: psychological, health system information, and melanoma-specific information. Furthermore, domain-specific needs were heightened in specific sociodemographic groups. Based on these survey results, a multifaceted intervention plan was developed to mitigate future needs. The intervention plan was patient-reviewed in focus groups prior to implementation, refining the developed intervention plan.

Converting melanoma-associated fibroblasts into a tumor-suppressive phenotype by increasing intracellular Notch1 pathway activity

Cancer-associated fibroblasts (CAFs) play a crucial role in cancer progression, drug resistance and tumor recurrence. We have recently shown that the Notch pathway determines the tumor-regulatory role of experimentally created ‘CAFs’. Here, we examined the status of Notch signaling in human melanoma-associated fibroblasts (MAFs) versus their normal counterparts and tested whether manipulation of the Notch pathway activity in MAFs alters their tumor-regulatory function. Using tissue microarrays, we found that MAFs exhibit decreased Notch pathway activity compared with normal fibroblasts in adjacent and non-adjacent skin. Consistently, MAFs isolated from human metastatic melanoma exhibited lower Notch activity than did normal human fibroblasts, demonstrating that Notch pathway activity is low in MAFs. We then investigated the effect of increasing Notch pathway activity in MAF on melanoma growth in co-cultures and in a mouse co-graft model. We found that activation of the Notch pathway in MAFs significantly restricted melanoma cell growth in vitro and suppressed melanoma skin growth and tumor angiogenesis in vivo. Our study demonstrates that the Notch signaling is inhibited in MAFs. Increase of Notch pathway activity can confer tumor-suppressive function on MAFs. Thus, targeting melanoma by activating Notch signaling in MAF may represent a novel therapeutic approach.

Palliative care in the context of immune and targeted therapies: A qualitative study of bereaved carers' experiences in metastatic melanoma

BACKGROUND

Immune and targeted therapies continue to transform treatment outcomes for those with metastatic melanoma. However, the role of palliative care within this treatment paradigm is not well understood.

AIM

To explore bereaved carers' experiences of immune and targeted therapy treatment options towards end of life for patients with metastatic melanoma.

DESIGN

An interpretive, qualitative study using a social constructivist framework was utilised. Interviews were recorded, transcribed and analysed using grounded theory methods.

SETTING/PARTICIPANTS

Participants (n = 20) were bereaved carers of patients who had received some form of immune and/or targeted therapy at one of three Australian metropolitan melanoma treatment centres.

RESULTS

Carers struggled to reconcile the positive discourse around the success of immune and targeted therapies in achieving long-term disease control, and the underlying uncertainty in predicting individual responses to therapy. Expectations that immune and targeted therapies necessarily provide longer-term survival were evident. Difficulty in prognostication due to clinical uncertainty and a desire to maintain hope resulted in lack of preparedness for treatment failure and end of life.

CONCLUSION

Immune and targeted therapies have resulted in increased prognostic challenges. There is a need to engage, educate and support patients and carers to prepare and plan amid these challenges. Educational initiatives must focus on improving communication between patients, carers and clinicians; the differences between palliative and end-of-life care; and increased competency of clinicians in having goals-of-care discussions. Clinicians must recognise and communicate the benefit of collaborative palliative care to meet patient and family needs holistically and comprehensively.

Mycobacterium bovis BCG in metastatic melanoma therapy

Melanoma is the most aggressive form of skin cancer, with a high mortality rate and with 96,480 new cases expected in 2019 in the USS. BRAF^V600E, the most common driver mutation, is found in around 50% of melanomas, contributing to tumor growth, angiogenesis, and metastatic progression. Dacarbazine (DTIC), an alkylate agent, was the first chemotherapeutic agent approved by the US Food and Drug Administration (FDA) used as a standard treatment. Since then, immunotherapies have been approved for metastatic melanoma (MM) including ipilimumab and pembrolizumab checkpoint inhibitors that help decrease the risk of progression. Moreover, Mycobacterium bovis Bacillus Calmette-Guerin (BCG) serves as an adjuvant therapy that induces the recruitment of natural killer NK, CD4⁺, and CD8⁺ T cells and contributes to antitumor immunity. BCG can be administered in combination with chemotherapeutic and immunotherapeutic agents and can be genetically manipulated to produce recombinant BCG (rBCG) strains that express heterologous proteins or overexpress immunogenic proteins, increasing the immune response and improving patient survival. In this review, we highlight several studies utilizing rBCG immunotherapy for MM in combination with other therapeutic agents.

Uncertain diagnosis and prognosis in advanced melanoma: a qualitative study of the experiences of bereaved carers in a time of immune and targeted therapies

BACKGROUND

Recent advances in advanced melanoma therapies are associated with improved survival for some patients. However, how patients with diagnoses of advanced disease and their carers experience this expanding treatment paradigm is not well understood.

OBJECTIVES

To explore bereaved carers' accounts of the trajectory of advanced melanoma involving treatment by immune or targeted therapies, to build an understanding of their experiences of care relating to diagnosis and prognosis.

METHODS

A qualitative exploratory design, using methods drawn from grounded theory, was adopted. Analyses drew on in-depth interviews with 20 bereaved carers from three metropolitan melanoma treatment centres in Australia. A flexible interview guide and structured approach to concurrent data collection and analysis were applied.

RESULTS

Carers described qualities of the experience, including the shock of diagnosis after a sometimes-innocuous presentation with vague symptoms. They reported an unclear prognosis with complexity arising from interplay between an uncertain disease trajectory and often ambiguous expectations of outcomes of emerging immune and targeted therapies. Uncertainty dominated carers' experiences, increasing the complexity of care planning.

CONCLUSIONS

Effective communication of an advanced melanoma diagnosis and prognosis is critical. Recognition of the uncertainty inherent in the benefit of immune and targeted therapies in a constructive manner may facilitate more timely and effective care-planning conversations between patients, carers and medical specialists.

Systemic network analysis identifies XIAP and IκBα as potential drug targets in TRAIL resistant BRAF mutated melanoma

Metastatic melanoma remains a life-threatening disease because most tumors develop resistance to targeted kinase inhibitors thereby regaining tumorigenic capacity. We show the 2nd generation hexavalent TRAIL receptor-targeted agonist IZI1551 to induce pronounced apoptotic cell death in mutBRAF melanoma cells. Aiming to identify molecular changes that may confer IZI1551 resistance we combined Dynamic Bayesian Network modelling with a sophisticated regularization strategy resulting in sparse and context-sensitive networks and show the performance of this strategy in the detection of cell line-specific deregulations of a signalling network. Comparing IZI1551-sensitive to IZI1551-resistant melanoma cells the model accurately and correctly predicted activation of NFκB in concert with upregulation of the anti-apoptotic protein XIAP as the key mediator of IZI1551 resistance. Thus, the incorporation of multiple regularization functions in logical network optimization may provide a promising avenue to assess the effects of drug combinations and to identify responders to selected combination therapies.

Mapping heterogeneity in patient-derived melanoma cultures by single-cell RNA-seq

Recent technological advances in single-cell genomics make it possible to analyze cellular heterogeneity of tumor samples. Here, we applied single-cell RNA-seq to measure the transcriptomes of 307 single cells cultured from three biopsies of three different patients with a BRAF/NRAS wild type, BRAF mutant/NRAS wild type and BRAF wild type/NRAS mutant melanoma metastasis, respectively. Analysis based on self-organizing maps identified sub-populations defined by multiple gene expression modules involved in proliferation, oxidative phosphorylation, pigmentation and cellular stroma. Gene expression modules had prognostic relevance when compared with gene expression data from published melanoma samples and patient survival data. We surveyed kinome expression patterns across sub-populations of the BRAF/NRAS wild type sample and found that CDK4 and CDK2 were consistently highly expressed in the majority of cells, suggesting that these kinases might be involved in melanoma progression. Treatment of cells with the CDK4 inhibitor palbociclib restricted cell proliferation to a similar, and in some cases greater, extent than MAPK inhibitors. Finally, we identified a low abundant sub-population in this sample that highly expressed a module containing ABC transporter ABCB5, surface markers CD271 and CD133, and multiple aldehyde dehydrogenases (ALDHs). Patient-derived cultures of the BRAF mutant/NRAS wild type and BRAF wild type/NRAS mutant metastases showed more homogeneous single-cell gene expression patterns with gene expression modules for proliferation and ABC transporters. Taken together, our results describe an intertumor and intratumor heterogeneity in melanoma short-term cultures which might be relevant for patient survival, and suggest promising targets for new treatment approaches in melanoma therapy.

Targeting Notch enhances the efficacy of ERK inhibitors in BRAF-V600E melanoma

The discovery of activating BRAF mutations in approximately 50% of melanomas has led to the development of MAPK pathway inhibitors, which have transformed melanoma therapy. However, not all BRAF-V600E melanomas respond to MAPK inhibition. Therefore, it is important to understand why tumors with the same oncogenic driver have variable responses to MAPK inhibitors. Here, we show that concurrent loss of PTEN and activation of the Notch pathway is associated with poor response to the ERK inhibitor SCH772984, and that co-inhibition of Notch and ERK decreased viability in BRAF-V600E melanomas. Additionally, patients with low PTEN and Notch activation had significantly shorter progression free survival when treated with BRAF inhibitors. Our studies provide a rationale to further develop combination strategies with Notch antagonists to maximize the efficacy of MAPK inhibition in melanoma. Our findings should prompt the evaluation of combinations co-targeting MAPK/ERK and Notch as a strategy to improve current therapies and warrant further evaluation of co-occurrence of aberrant PTEN and Notch activation as predictive markers of response to therapy.

Systematic review of psychosocial outcomes for patients with advanced melanoma

BACKGROUND

New advanced melanoma therapies are associated with improved survival; however, quality of survivorship, particularly psychosocial outcomes, for patients overall and those treated with newer therapies is unclear.

OBJECTIVE

Synthesize qualitative and quantitative evidence about psychosocial outcomes for advanced (stage III/IV) melanoma patients.

METHODS

Five databases were searched (01/01/1980 to 31/01/2016). Inclusion criteria were as follows: advanced melanoma patients or sub-group analysis; assessed psychosocial outcomes; and English language.

RESULTS

Fifty-two studies met review criteria (4 qualitative, 48 quantitative). Trials comprise mostly medical not psychosocial interventions, with psychosocial outcomes assessed within broader quality of life measures. Patients receiving chemotherapy or IFN-alpha showed decreased emotional and social function and increased distress. Five trials of newer therapies appeared to show improvements in emotional and social function. Descriptive studies suggest that patients with advanced, versus localized disease, had decreased emotional and social function and increased distress. Contributors to distress were largely unexplored, and no clear framework described coping/adjustment trajectories. Patients with advanced versus localized disease had more supportive care needs, particularly amount, quality, and timing of melanoma-related information, communication with and emotional support from clinicians. Limitations included: lack of theoretical underpinnings guiding study design; inconsistent measurement approaches; small sample sizes; non-representative sampling; and cross-sectional design.

CONCLUSIONS

Quality trial evidence is needed to clarify the impact of treatment innovations for advanced melanoma on patients' psychosocial well-being. Survivorship research and subsequent translation of that knowledge into programs and services currently lags behind gains in the medical treatment of advanced melanoma, a troubling circumstance that requires immediate and focused attention.

Ubiquitin ligase UBE3C promotes melanoma progression by increasing epithelial-mesenchymal transition in melanoma cells

Melanoma is the most aggressive type of skin cancer, exhibiting extensive local invasion and early distant metastasis. Aberrant expression of ubiquitin-protein ligase E3C (UBE3C) plays a key role in tumor development and progression. In the present study, we analyzed UBE3C expression in samples of cancerous and normal skin tissue. Levels of UBE3C expression were much higher in primary and metastatic melanoma tissues than in normal skin, cutaneous squamous cell carcinoma or basal cell carcinoma. Melanoma cells overexpressing UBE3C frequently exhibited a mesenchymal phenotype, including reduced expression of the epithelial marker E-cadherin and expression of the mesenchymal marker vimentin. Knockdown of UBE3C expression in melanoma cells significantly suppressed melanoma growth and progression. Furthermore, silencing UBE3C led to increased E-cadherin expression and decreased vimentin and Snail1 expression. Thus UBE3C promotes melanoma progression, possibly by inducing epithelial-mesenchymal transition in melanoma cells. Inhibiting UBE3C activity may suppress melanoma invasion and metastasis and may represent a targeted therapeutic approach.

Nanotechnology-based strategies for combating toxicity and resistance in melanoma therapy

Drug toxicity and resistance remain formidable challenges in cancer treatment and represent an area of increasing attention in the case of melanoma. Nanotechnology represents a paradigm-shifting field with the potential to mitigate drug resistance while improving drug delivery and minimizing toxicity. Recent clinical and pre-clinical studies have demonstrated how a diverse array of nanoparticles may be harnessed to circumvent known mechanisms of drug resistance in melanoma to improve therapeutic efficacy. In this review, we discuss known mechanisms of resistance to various melanoma therapies and possible nanotechnology-based strategies that could be used to overcome these barriers and improve the pharmacologic arsenal available to combat advanced stage melanoma.

Infrared spectra of primary melanomas can predict response to chemotherapy: The example of dacarbazine

Metastatic melanomas are highly aggressive and median survival is 6-9months for stage IV patients in the absence of treatment with anti-tumor activity. Dacarbazine is an alkylating agent that has been widely used in the treatment of metastatic melanomas and that could be still used in combination with targeted or immune therapies. Indeed, therapeutic benefits of these treatments in monotherapy are poor and one option to improve them is to combine drugs and/or to better anticipate the individual response to a defined treatment. To our best knowledge and to date, there is no test available to predict the response of a patient to dacarbazine. We show here that examination of melanoma histological sections by infrared micro-spectroscopy reveals the sensitivity of the cancer to dacarbazine. Unsupervised analysis of the FTIR spectra evidences spontaneous and significant clustering of infrared spectra into two groups that match the clinical responsiveness of the patients to dacarbazine used as a first-line treatment. A supervised model resulted in 83% of the patient status (responder/non-responder) being correctly identified. The spectra revealed a key modification in the nature and quantity of lipids in the cells of both groups.

Identification of translational dermatology research priorities in the U.K.: results of an electronic Delphi exercise

BACKGROUND

Translational research is the direct application of basic and applied research to patient care. It is estimated that there are at least 2000 different skin diseases; thus, there are considerable challenges in seeking to undertake research on each of these disorders.

OBJECTIVES

This electronic Delphi (e-Delphi) exercise was conducted in order to generate a list of translational dermatology research questions that are regarded as a priority for further investigations.

METHODS

During the first phase of the e-Delphi exercise, 228 research questions were generated by an expert panel that included clinical academic dermatologists, clinical dermatologists, nonclinical scientists, dermatology trainees and representatives from patient support groups.

RESULTS

Following completion of the second and third phases, 40 questions on inflammatory skin disease, 20 questions on structural skin disorders/genodermatoses, 37 questions on skin cancer and eight miscellaneous questions were designated as priority translational dermatology research questions (PRQs). In addition to PRQs on a variety of disease areas (including multiple PRQs on psoriasis, eczema, squamous cell carcinoma and melanoma), there were a number of cross-cutting themes that identified a need to investigate mechanisms/pathogenesis of disease and the necessity to improve treatments for patients with skin disease.

CONCLUSIONS

It is predicted that this list of PRQs will help to provide a strategic direction for translational dermatology research in the U.K. and that addressing this list of questions will ultimately provide clinical benefit for substantial numbers of patients with skin disorders.

Sphaeropsidin A shows promising activity against drug-resistant cancer cells by targeting regulatory volume increase

Despite the recent advances in the treatment of tumors with intrinsic chemotherapy resistance, such as melanoma and renal cancers, their prognosis remains poor and new chemical agents with promising activity against these cancers are urgently needed. Sphaeropsidin A, a fungal metabolite whose anticancer potential had previously received little attention, was isolated from Diplodia cupressi and found to display specific anticancer activity in vitro against melanoma and kidney cancer subpanels in the National Cancer Institute (NCI) 60-cell line screen. The NCI data revealed a mean LC50 of ca. 10 µM and a cellular sensitivity profile that did not match that of any other agent in the 765,000 compound database. Subsequent mechanistic studies in melanoma and other multidrug-resistant in vitro cancer models showed that sphaeropsidin A can overcome apoptosis as well as multidrug resistance by inducing a marked and rapid cellular shrinkage related to the loss of intracellular Cl(-) and the decreased HCO3 (-) concentration in the culture supernatant. These changes in ion homeostasis and the absence of effects on the plasma membrane potential were attributed to the sphaeropsidin A-induced impairment of regulatory volume increase (RVI). Preliminary results also indicate that depending on the type of cancer, the sphaeropsidin A effects on RVI could be related to Na-K-2Cl electroneutral cotransporter or Cl(-)/HCO3 (-) anion exchanger(s) targeting. This study underscores the modulation of ion-transporter activity as a promising therapeutic strategy to combat drug-resistant cancers and identifies the fungal metabolite, sphaeropsidin A, as a lead to develop anticancer agents targeting RVI in cancer cells.

Theranostic properties of a survivin-directed molecular beacon in human melanoma cells

Survivin is an inhibitor of apoptosis overexpressed in different types of tumors and undetectable in most terminally differentiated normal tissues. In the current study, we sought to evaluate the in vitro theranostic properties of a molecular beacon-oligodeoxynucleotide (MB) that targets survivin mRNA. We used laser scanning confocal microscopy to study MB delivery in living cells and real-time PCR and western blot to assess selective survivin-targeting in human malignant melanoma cells. We further assess the pro-apoptotic effect of MB by measuring internucleosomal DNA fragmentation, dissipation of mitochondrial membrane potential (MMP) and changes in nuclear morphology. Transfection of MB into A375 and 501 Mel cells generated high signal intensity from the cytoplasm, while no signal was detected in the extracellular environment and in survivin-negative cells (i.e., human melanocytes and monocytes). MB time dependently decreased survivin mRNA and protein expression in melanoma cells with the maximum effect reached at 72 h. Treatment of melanoma cells with MB induced apoptosis by significant changes in MMP, accumulation of histone-complexed DNA fragments in the cytoplasm and nuclear condensation. MB also enhanced the pro-apoptotic effect of standard chemotherapeutic drugs tested at clinically relevant concentrations. The MB tested in the current study conjugates the ability of imaging with the pharmacological silencing activity against survivin mRNA in human melanoma cells and may represent an innovative approach for cancer diagnosis and treatment.