Pathways to melanoma

Biological Effect of Food for Special Medical Purposes (NutramilTM Complex) on Melanoma Cells in In Vitro Study

BACKGROUND/OBJECTIVES

Melanoma malignum is considered the most dangerous form of skin cancer, characterized by the exceptional resistance to many conventional chemotherapies. The aim of this study was to evaluate the effect of NutramilTM Complex (NC)-Food for Special Medical Purpose (FSMP), on two types of melanoma cell lines, primary WM115 and malignant WM266-4.

METHODS

At 24 h after seeding, growth medium was replaced with a medium containing encoded treatments of NC or NC-CC (NutramilTM Complex without calcium caseinate) at various concentrations. Cells were treated for 24, 48, and 72 h.

RESULTS

Our results showed that NutramilTM Complex reduces proliferation of malignant melanoma WM266-4 cells but did not affect the proliferation of WM115 primary melanoma. This was followed by measured down-regulation of selected pro-survival proteins expression in WM266-4 cells, specifically ERK1/2, AKT-1, HSP27, Survivin, and TAK1. Interestingly, our results showed elevated levels of some pro-apoptotic proteins in both cell lines, including Bad, Smad2, p38MAPK, cleaved forms of Caspase-3/7, as well as cleaved PARP.

CONCLUSIONS

Taken together, our results indicate that various melanoma cancer cell lines may respond in a different way to the same compound. They also suggest induction of apoptotic pathway by NutramilTM Complex as the most likely mechanism of its anticarcinogenic activity.

Refining mutanome-based individualised immunotherapy of melanoma using artificial intelligence

Using the particular nature of melanoma mutanomes to develop medicines that activate the immune system against specific mutations is a game changer in immunotherapy individualisation. It offers a viable solution to the recent rise in resistance to accessible immunotherapy alternatives, with some patients demonstrating innate resistance to these drugs despite past sensitisation to these agents. However, various obstacles stand in the way of this method, most notably the practicality of sequencing each patient's mutanome, selecting immunotherapy targets, and manufacturing specific medications on a large scale. With the robustness and advancement in research techniques, artificial intelligence (AI) is a potential tool that can help refine the mutanome-based immunotherapy for melanoma. Mutanome-based techniques are being employed in the development of immune-stimulating vaccines, improving current options such as adoptive cell treatment, and simplifying immunotherapy responses. Although the use of AI in these approaches is limited by data paucity, cost implications, flaws in AI inference capabilities, and the incapacity of AI to apply data to a broad population, its potential for improving immunotherapy is limitless. Thus, in-depth research on how AI might help the individualisation of immunotherapy utilising knowledge of mutanomes is critical, and this should be at the forefront of melanoma management.

Modern Concepts in Melanocytic Tumors

The advent of molecular pathology has fueled unprecedented advances in the diagnosis and understanding of melanocytic tumors. These advances, however, have also generated concepts that may be difficult to grasp for clinical practitioners, who are not always conversant with the array of genetic techniques employed in the laboratory. These same practitioners, however, are being increasingly called on to provide treatments that are often based on the latest molecular findings for melanocytic tumors. We review the most recent concepts in the pathway classification of melanocytic tumors, including intermediate lesions known as melanocytomas. We examine the genetic and molecular techniques used to study these tumors, look at where they overlap, and discuss their limitations and some of the most difficult-to-interpret results.

Melanoma: Molecular genetics, metastasis, targeted therapies, immunotherapies, and therapeutic resistance

Cutaneous melanoma is a common cancer and cases have steadily increased since the mid 70s. For some patients, early diagnosis and surgical removal of melanomas is lifesaving, while other patients typically turn to molecular targeted therapies and immunotherapies as treatment options. Easy sampling of melanomas allows the scientific community to identify the most prevalent mutations that initiate melanoma such as the BRAF, NRAS, and TERT genes, some of which can be therapeutically targeted. Though initially effective, many tumors acquire resistance to the targeted therapies demonstrating the need to investigate compensatory pathways. Immunotherapies represent an alternative to molecular targeted therapies. However, inter-tumoral immune cell populations dictate initial therapeutic response and even tumors that responded to treatment develop resistance in the long term. As the protocol for combination therapies develop, so will our scientific understanding of the many pathways at play in the progression of melanoma. The future direction of the field may be to find a molecule that connects all of the pathways. Meanwhile, noncoding RNAs have been shown to play important roles in melanoma development and progression. Studying noncoding RNAs may help us to understand how resistance - both primary and acquired - develops; ultimately allow us to harness the true potential of current therapies. This review will cover the basic structure of the skin, the mutations and pathways responsible for transforming melanocytes into melanomas, the process by which melanomas metastasize, targeted therapeutics, and the potential that noncoding RNAs have as a prognostic and treatment tool.

Preferentially Expressed Antigen in Melanoma (PRAME) and Human Malignant Melanoma: A Retrospective Study

BACKGROUND

Preferentially expressed antigen in melanoma (PRAME) is a cancer testis antigen (CTA) identified in 1997 through analysis of the specificity of tumor-reactive T-cell clones derived from a patient with metastatic cutaneous melanoma. Although at first it seemed even more specific, various studies have shown that PRAME can also be expressed in the context of atypical lesions that do not correspond solely to the definition of malignant melanoma.

METHODS

A systematic review of English articles was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

126 records were identified in the literature search, of which 9 were duplicates. After screening for eligibility and inclusion criteria, 53 publications were included.

CONCLUSIONS

The advent of a new marker such as PRAME is surely a step forward not only in the diagnostic approach, but also in the immunotherapeutic approach to MM. However, various studies have shown that PRAME can also be expressed in the context of atypical lesions apart from MM and, for this reason, the diagnostic sensitivity and specificity (hence accuracy) are clearly lower. Further studies with larger case series will be necessary to understand better what possibilities are offered in terms of diagnostic reliability by PRAME.

Aetiology and Pathogenesis of Cutaneous Melanoma: Current Concepts and Advances

Melanoma develops from malignant transformations of the pigment-producing melanocytes. If located in the basal layer of the skin epidermis, melanoma is referred to as cutaneous, which is more frequent. However, as melanocytes are be found in the eyes, ears, gastrointestinal tract, genitalia, urinary system, and meninges, cases of mucosal melanoma or other types (e.g., ocular) may occur. The incidence and morbidity of cutaneous melanoma (cM) are constantly increasing worldwide. Australia and New Zealand are world leaders in this regard with a morbidity rate of 54/100,000 and a mortality rate of 5.6/100,000 for 2015. The aim of this review is to consolidate and present the data related to the aetiology and pathogenesis of cutaneous melanoma, thus rendering them easier to understand. In this article we will discuss these problems and the possible impacts on treatment for this disease.

Melanoma density and relationship with the distribution of melanocytic naevi in an Italian population: a GIPMe study--the Italian multidisciplinary group on melanoma

The most frequent site for melanoma is the back in men and the lower limbs in women, where intermittent sun exposure has been reported to be an environmental agent, although studies on age-specific incidence have suggested that melanoma in chronically sun-exposed areas, such as the face, increases with age. To identify the preferential development of melanoma in chronically or intermittently sun-exposed areas and the relationship between body site distribution and parameters such as sex, age, distribution of melanocytic naevi, atypical naevi and actinic keratoses, a prospective epidemiological multicentre study was carried out on all the consecutive melanoma cases diagnosed in a 2-year period from 27 Italian GIPMe centres (GIPMe: the Italian Multidisciplinary Group on Melanoma). Both the relative density of melanoma (RDM), defined as the ratio between observed and expected melanoma for a specific body site, and the average nevi density were identified. The most common melanoma site was the back, a factor that was not affected by either age or sex, even if men had higher density values. Statistically significant higher RDM values were observed in women aged more than 50 years for leg lesions and in the anterior thighs for young women (<50 years), whereas the lowest values were observed in the posterior thighs in women of any age. Facial RDM was statistically significantly higher than expected in both male and female patients more than 50 years of age. Melanoma was associated with a significantly higher atypical naevi density only for the back, chest and thighs. Indeed, facial melanoma was related to the presence of more than four actinic keratoses and not naevi density. To the best of our knowledge, the RDM method was applied for the first time together with naevus density calculation to obtain these data, which strongly substantiate the 'divergent pathway' hypothesis for the development of melanoma, but not find a direct correlation between melanoma and nevi for each anatomical site.

Primary malignant melanoma of the pleura with rapid progression: A case report and literature review

A primary melanocytic lesion arising from the pleura is a rare occurrence. This is the case report of a 36-year-old female patient with a primary pleural melanocytic tumor. The positron emission tomography/computed tomography scan revealed multiple nodular soft tissue thickenings of the left hemipleura and a large amount of pleural effusion in the left hemithorax. The results of the histological examination confirmed the diagnosis of melanoma. The disease progressed 4 months following immunotherapy and chemotherapy and the patient succumbed to the disease 2 months later. This type of tumor appears to exhibit a highly aggressive biological behavior and responds poorly to immunotherapy and chemotherapy, which are characteristics similar to those exhibited by melanomas arising in other regions.

A review of novel therapies for melanoma

This review summarizes results from major recent trials regarding novel therapeutic agents in melanoma. The topics discussed include targeted therapy with BRAF (V-RAF murine sarcoma viral oncogene homolog B) inhibitors (vemurafenib and dabrafenib), MEK (mitogen-activated protein kinase kinase) inhibitors (trametinib), bcr-abl/c-kit/PDGF-R inhibitors (imatinib), and angiogenesis inhibitors (bevacizumab and aflibercept), as well as immunotherapy with anti-CTLA-4 (anti-cytotoxic T-lymphocyte antigen-4) antibodies (ipilimumab), anti-PD (anti-programmed death receptor) antibodies (nivolumab and lambrolizumab), and anti-PD-L (anti-programmed death ligand) antibodies. Various combinations of these agents, as well as adjunctive GM-CSF (granulocyte-macrophage colony-stimulating factor), T-VEC (talimogene laherparepvec) oncolytic viruses, and novel chemotherapeutic agents, are also described. Despite the tremendous advances that these novel treatments have created, optimal therapeutic agent selection remains a highly individualized decision. Melanoma therapy has vastly progressed since the days when dacarbazine was the sole option for advanced melanoma patients. The molecular understanding of melanoma pathogenesis has yielded a brighter future for advanced melanoma patients.

Analysis of the B-RafV600E mutation in cutaneous melanoma patients with occupational sun exposure

Sun-exposure is one of the risk factors associated with the development of a cutaneous neoplasm. In melanoma, the Ras-Raf-MEK-ERK (MAPK) signaling pathway is constitutively activated through multiple mechanisms, including B-RAF mutation. It has been hypothesized that B-RAF mutations in melanocytic lesions arise from DNA damage induced by ultraviolet (UV) radiation. However, it is still discussed if B-RAF mutations are associated with melanoma patients exposed to the sun. Therefore, in the present study, the known B-RAF^V600E mutation was analysed in melanoma samples from 30 indoor and 38 outdoor workers. B-RAF^V600E mutation was detected in 52 and 73% of outdoor workers and indoor workers, respectively. Of note, this mutation was identified in 12 of 14 (85%) melanoma of the trunk diagnosed in indoor workers and in 9 of 19 (47%) samples from outdoor workers (p=0.03). By analyzing melanomas of other body sites, no statistical difference in the frequency of B-RAF^V600E mutation was identified between the groups of workers. It appears that the mutation detected among indoor workers may be associated with a recreational or intermittent exposure to the sun, as usually the trunk is a sun-protected body site. Overall, these data indicate that the B-RAF^V600E mutation detected in melanoma is not associated with a chronic exposure to the sun. Mutations detected in other genes may also contribute to melanoma development in the subset of patients exposed to UV radiation.

Raf kinase inhibitor protein (RKIP) and phospho-RKIP expression in melanomas

Melanoma, a cancer notorious for its high potential to metastasize, arises from melanocytes, cells dedicated to melanin production and located in the basal layer of the epidermis. Raf-1 kinase inhibitor protein (RKIP) is an inhibitory molecule that down-regulates the effects of the Ras/Raf/MEK/ERK signaling pathway. The aim of this study was to examine the expression of RKIP and pRKIP in melanomas at different stages. We evaluated the RKIP and pRKIP protein by immunohistochemistry in control skin, pigmented nevi and melanomas, and through Western blotting in human normal melanocytes and in four different melanoma-derived cell lines (WM35, A375, M14, and A2058). Our results demonstrated a correlation between the expression of RKIP and pRKIP, and metastatic ability in melanoma cells. This raises the possibility to analyze both RKIP and pRKIP in all melanomas. Down-regulation of both RKIP and pRKIP expression could represent a useful marker of metastatic melanoma. On the contrary for non-metastatic melanoma, especially in Clark I and II, low RKIP and high pRKIP expression could be indicative. In conclusion, the observed negative correlation of the RKIP and pRKIP expression in metastatic melanomas indicates that expression of these proteins may become a prognostic marker for the progression of human cutaneous melanoma. We propose that the investigation of both RKIP and pRKIP may provide a useful tool indicative for metastatic or non-metastatic melanoma in different Clark's level melanomas. Further studies are required to verify the molecular background of the observed RKIP and pRKIP variations.

Melanoma metastasis: new concepts and evolving paradigms

Melanoma progression is typically depicted as a linear and stepwise process in which metastasis occurs relatively late in disease progression. Significant evidence suggests that in a subset of melanomas, progression is much more complex and less linear in nature. Epidemiologic and experimental observations in melanoma metastasis are reviewed here and are incorporated into a comprehensive model for melanoma metastasis, which takes into account the varied natural history of melanoma formation and progression.

Skin melanoma: from systematic biology to the personalized therapy

Systematic biology is a new field of biomedicine based on the integrative approach to molecular mechanisms of the operation of living systems including in case of the development of pathological processes. In this connection, up-to-date therapeutic approaches to skin melanoma treatment can be considered on the basis of key changes in intermolecular interactions taking place during tumor development.

Evidence-based laboratory medicine in oncology drug development: from biomarkers to diagnostics

BACKGROUND

The promise of targeted therapies in molecularly defined subsets of cancer has led to a transformation of the process of drug development in oncology. To target cancer successfully and precisely requires high-quality translational data. Such data can be generated by the use of biomarkers that answer key questions in drug development.

CONTENT

Translational data for aiding in decision-making and driving cancer drug development can be generated by systematic assessments with biomarkers. Types of biomarkers that support decisions include: pharmacodynamic assessments for selecting the best compound or dosage; assessment of early tumor response with tissue biomarkers and imaging, mutation, and other assessment strategies for patient selection; and the use of markers of organ injury to detect toxicity and improve safety. Tactics used to generate biomarker data include fit-for-purpose assay validation and real-time biomarker assessments. Successfully translated and clinically informative biomarkers can mature into novel companion diagnostic tests that expand the practice of laboratory medicine.

SUMMARY

Systematic biomarker assessments are a key component of the clinical development of targeted therapies for cancer. The success of these biomarker assessments requires applying basic principles of laboratory medicine to generate the data required to make informed decisions. Successful biomarkers can transition into diagnostic tests that expand the laboratory medicine armamentarium.

Comparison of the influence of photodynamic reaction on the Me45 and MEWO cell lines in vitro

Aim of the study

Photodynamic therapy (PDT) is an approved, minimally invasive and highly selective therapeutic approach to a variety of tumors. It is based on specific photosensitizer accumulation in the tumor tissue, followed by irradiation with visible light. The photochemical interactions of the photosensitizer, light and molecular oxygen produce singlet oxygen and other reactive oxygen forms. The imbalance between ROS generation and antioxidant capacity of the body gives rise to oxidative stress in the cell, which initiates cell death in PDT. The aim of this study was to investigate the effect of photodynamic reactions in human melanoma cell lines.

Material and methods

Photofrin^® (Ph) was used for the photodynamic reaction in vitro as a photosensitizer. The primary cell line was MEWO cell line (granular fibroblasts), derived from a human melanoma. As a recurrent cell line we used Me45 cell line, derived from a lymph node metastasis of skin melanoma. We compared cell viability (MTT assay) to determine the effectiveness of applied therapy. The intracellular distribution of photosensitizer (Photofrin) and localization of mitochondria (Mito-Tracker Green) were detected by confocal microscopy.

Results

We observed that Me45 and MEWO cell viability was dependent on the time of incubation after irradiation. In the recurrent cell line Ph accumulated mainly in the mitochondrial membranes and in MEWO cells also in the cytoplasm. The primary melanoma cell line exhibited significantly reduced cellular proliferation (below 50%) after photodynamic reaction with Ph.

Conclusions

The applied photodynamic reaction was more effective in primary melanoma cells. Additionally, mitochondrial localization of Ph can lead to disturbances of mitochondrial transmembrane potential and finally to release of apoptotic proteins.

The involvement of Notch signaling in melanoma vasculogenic mimicry

Notch signaling plays an important role in tumor angiogenesis. Recent studies suggest that Notch signaling also regulates the progression of primary melanomas toward an aggressive phenotype. The aim of this study was to investigate the involvement of Notch signaling pathway in organization of tumor cells into capillary-like structures (CLS), the phenomenon also known as vasculogenic mimicry (VM). Here, we show that Notch signaling cascade was constitutively active in melanoma cell lines we used. Blocking Notch signaling with the γ-secretase inhibitors, DAPT, dibenzazepine or Jagged1 neutralizing antibody resulted in stabilization of CLS indicating that Notch signaling pathway attenuates melanoma VM. We further studied this phenomenon on melanomas grafted in nude mice. Compared to control, VM channels in DAPT-treated grafted melanoma became larger and more branched. DAPT-treated melanomas also exhibited an up-regulation of MMP-2 and VEGFR1, both known as VM mediators. Moreover, we did not observe necrosis in VM channels areas of DAPT-treated melanomas. These findings indicate that VM regulated by Notch signaling may present a novel target in melanoma therapy.

Genetic and molecular characterization of uveal melanoma cell lines

The recent identification of frequent activating mutations in GNAQ or GNA11 in uveal melanoma provides an opportunity to better understand the pathogenesis of this melanoma subtype and to develop rational therapeutics to target the cellular effects mediated by these mutations. Cell lines from uveal melanoma tumors are an essential tool for these types of analyses. We report the mutation status of relevant melanoma genes, expression levels of proteins of interest, and DNA fingerprinting of a panel of uveal melanoma cell lines used in the research community.