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

Detection of human papillomavirus (HPV) in malignant melanoma

The most common type of melanoma is cutaneous melanoma (CM). The predominant mutational signature is that of ultraviolet radiation (UVR) exposure. The Cancer Genome Atlas (TCGA) molecular classification includes four major subtypes of CM based on common genetic alterations involving the following genes: BRAF, NRAS, and NF1, with a small fraction being "triple" wild-type. The two main signaling pathway abnormalities in CM are the mitogen-activated protein kinase (MAPK) pathway and the phosphoinositol-3-kinase (PI3K) pathway. Other less common types include mucosal melanomas (MM) and uveal melanoma (UM), which have a significantly different genomic landscape. Although few studies reported rare cases with HPV-positive (HPV+) melanoma, the clinicopathological and molecular characteristic of this entity has not been well-described. Among the 2084 melanoma cases queried at our institution, we identified seven patients diagnosed with HPV+ melanoma (prevalence 0.03 %), including five instances of CM and two of MM. The majority of cases were positive for HPV16 (n = 6). Most of the patients were elderly and with advanced disease (n = 6), although this finding may be attributed to the relative frequency of our institution testing advanced-stage tumors. Histologically, most cases showed high degree of pleomorphism and high mitotic count (5 or more mitoses/mm2) (n = 6). UVR signature was present in the CM, but not in the MM cases. Alterations in either MAPK and/or PI3K pathways were detected in the majority of cases (n = 6). The most common genetic abnormalities detected in this study occurred in the TERT promoter (TERTp) (n = 5), a finding that has been reported to be associated with aggressive disease. Our data shows that while HPV+ melanoma is rare, identifying this disease entity could help guide therapy given the demonstrated genomic alterations.

Differences and Similarities in Epidemiology and Risk Factors for Cutaneous and Uveal Melanoma

Both cutaneous melanoma (CM) and uveal melanoma (UM) represent important causes of morbidity and mortality. In this review, we evaluate the available knowledge on the differences and similarities between cutaneous melanoma and uveal melanoma, focusing on the epidemiological aspects and risk factors. Uveal melanoma is a rare condition but is the most prevalent primary intra-ocular malignant tumor in adults. Cutaneous melanoma, on the other hand, is significantly more common. While the frequency of cutaneous melanoma has increased in the last decades worldwide, the incidence of uveal melanoma has remained stable. Although both tumors arise from melanocytes, they are very distinct entities biologically, with complex and varied etiologies. Both conditions are encountered more frequently by individuals with a fair phenotype. ultraviolet-radiation is an important, well-documented risk factor for the development of CM, but has shown not to be of specific risk in UM. Although cutaneous and ocular melanomas seem to be inherited independently, there are reported cases of concomitant primary tumors in the same patient.

Clinical Relevance of Targeted Therapy and Immune-Checkpoint Inhibition in Lung Cancer

Lung cancer (LC) represents the second most diagnosed tumor and the malignancy with the highest mortality rate. In recent years, tremendous progress has been made in the treatment of this tumor thanks to the discovery, testing, and clinical approval of novel therapeutic approaches. Firstly, targeted therapies aimed at inhibiting specific mutated tyrosine kinases or downstream factors were approved in clinical practice. Secondly, immunotherapy inducing the reactivation of the immune system to efficiently eliminate LC cells has been approved. This review describes in depth both current and ongoing clinical studies, which allowed the approval of targeted therapies and immune-checkpoint inhibitors as standard of care for LC. Moreover, the present advantages and pitfalls of new therapeutic approaches will be discussed. Finally, the acquired importance of human microbiota as a novel source of LC biomarkers, as well as therapeutic targets to improve the efficacy of available therapies, was analyzed. Therapy against LC is increasingly becoming holistic, taking into consideration not only the genetic landscape of the tumor, but also the immune background and other individual variables, such as patient-specific gut microbial composition. On these bases, in the future, the research milestones reached will allow clinicians to treat LC patients with tailored approaches.

Onset of p53/NF-κB signaling crosstalk in human melanoma cells in response to anti-cancer theabrownin

As a major tea component, theabrownin represents a promising anti-cancer candidate. However, its effect on the melanoma is unknown. To evaluate the in vitro and in vivo anti-melanoma efficacy of TB, we conducted cell viability, immunostaining, comet, and TUNEL assays on human A375 melanoma cells, and employed a zebrafish xenograft model of A375 cells. Real-time PCR (qPCR) and western blot were conducted to explore the molecular mechanisms of TB. In vitro, TB significantly inhibited the proliferation of A375 cells, and A375 cells showed the highest inhibitory rate among the other melanoma cell line (A875) and human dermal fibroblasts. TB triggered DNA damage and induced apoptosis of A375 cells and significantly inhibited the growth of A375 xenograft tumors in zebrafishes. Several key molecular events were activated by TB, including DNA damage-associated p53 and NF-κB pathways, through up-regulation of GADD45α, γ-H2A.X, phospho-ATM(p-ATM), phospho-ATR (p-ATR), phospho-p53 (p-p53), phospho-IKKα/β (p-IKKα/β), phospho-p65 (p-p65), etc. However, the TB-activated molecular events were counteracted by either knockdown of p53 or p65, and only dual knockdown of both p53 and p65 completed counteracted the anti-melanoma efficacy of TB. In conclusion, TB triggered DNA damage and thereby inhibited proliferation and induced cellular senescence and apoptosis of melanoma cells through mechanisms mediated by p53/NF-κB signaling crosstalk. This is the first report on the efficacy and mechanisms of TB on melanoma cells, making TB a promising candidate for anti-melanoma agent development.

Research progress of microneedles in the treatment of melanoma

Melanoma is an aggressive malignancy deriving from melanocytes, which is characterized by high tendency of metastases and mortality rate. Current therapies for melanoma, like chemotherapy, immunotherapy and targeted therapy, have the problem of systemic exposure of drugs, which will lead to many side effects and premature degradation of drugs. The resulting low drug accumulation at the lesion limits the therapeutic effect on melanoma and makes the cure rate low. As an emerging drug delivery system, microneedles (MNs) can efficiently deliver drugs through the skin, increase the drug distribution in deeper tumor sites and minimize the leakage of therapeutic drugs into adjacent tissues, thus improving the therapeutic effect. In addition, compared with traditional drug delivery methods, MN-based drug delivery system has the advantages of simplicity, safety and little pain. So MNs can be developed for the treatment of melanoma, which can relieve the pain of patients and improve the survival rate. This review aims to introduce an update on the progress of MNs as an innovative strategy for melanoma, especially when MNs combining with different therapies against melanoma, such as chemotherapy, targeted therapy, immunotherapy, photothermal therapy (PTT), photodynamic therapy (PDT) and synergic therapy.

The Genetics of Early-Stage Melanoma in a Veteran Population

To improve understanding of the genetic signature of early-stage melanomas in Veterans, hotspot mutation profiling using next-generation sequencing (NGS) was performed on melanoma tissue samples from patients at the Iowa City Veterans Affairs Medical Center (VAMC). Genetic analysis identified BRAF (36.3%), TP53 (25.9%), NRAS (19.3%), CDKN2A (11.1%), KIT (8.1%), and BAP1 (7.4%) mutations with the highest prevalence. Although common variants in BRAF were detected at lower rates than what is reported for the general population, 55.6% of cases showed activating mutations in the RAS/RAF pathways. Variants in TP53 and KIT were detected at higher rates than in the general population. Veterans with prior history of melanoma were at significantly higher odds of having TP53 mutation (OR = 2.67, p = 0.04). This suggests that TP53 may be a marker for recurrent melanoma and possibly alternative exposures in the military population. This study provides new information regarding the genetics of melanoma in a Veteran population and early-stage melanomas, highlighting risk factors unique to this population and contributing to the conversation about preventing melanoma deaths in US Military personnel.

Cutaneous melanoma survival rates of the elderly are not worse than those of the young, yet they have some specific differences

Introduction

The incidence of cutaneous melanoma among the elderly has increased significantly. Unfavorable survival rates are associated with insufficient patient managements and poor prognostic features in the elderly. We aimed to compare elderly (≥75 years) and younger (<75 years) patients with cutaneous melanoma to determine the differences and the prognostic significance of age.

Materials and Methods

The retrospective data of 117 elderly and 232 younger patients with cutaneous melanoma were compared.

Results

The median age of the elderly patients was 78 years (75-104), and 51.3% of the patients were female. Of the patients, 14.5% were in the metastatic stages. Clinicopathologic factors such as extremity melanomas (P = 0.01), Clark levels IV-V (P = 0.04), ulceration (P = 0.009), and neurotropism (P = 0.03) were significantly more common in elderly patients. However, BRAF mutation was significantly more common in younger patients (P = 0.003). Overall survival (OS) and recurrence-free survival (RFS) rates of both the groups were similar. Lymph node involvement (P < 0.005), distant metastasis (P < 0.005), and relapse of disease (P = 0.02) were associated with poor OS in elderly patients. Tumor-infiltrating lymphocytes was associated with prolonged RFS (P = 0.05), while extremity melanomas (P = 0.01), lymphovascular invasion (P = 0.006), and lymph node involvement (P < 0.005) had negative impact on RFS.

Conclusions

Although elderly patients with cutaneous melanoma had different clinicopathologic features in our series, their survival rates are similar to those of younger patients, which shows that age alone is inadequate to determine the prognosis. Disease stage and a comprehensive geriatric assessment might assist to determine appropriate management.

Melanoma therapeutics: a literature review

Melanoma is a relentless type of skin cancer which involves myriad signaling pathways which regulate many cellular processes. This makes melanoma difficult to treat, especially when identified late. At present, therapeutics include chemotherapy, surgical resection, biochemotherapy, immunotherapy, photodynamic and targeted approaches. These interventions are usually administered as either a single-drug or in combination, based on tumor location, stage, and patients' overall health condition. However, treatment efficacy generally decreases as patients develop treatment resistance. Genetic profiling of melanocytes and the discovery of novel molecular factors involved in the pathogenesis of melanoma have helped to identify new therapeutic targets. In this literature review, we examine several newly approved therapies, and briefly describe several therapies being assessed for melanoma. The goal is to provide a comprehensive overview of recent developments and to consider future directions in the field of melanoma.

Analysis of Genetic Alterations in Cutaneous Malignant Melanomas Unveils Unique Loco-Regional Variations and Novel Predictors of Metastatic Potential

ABSTRACT

Cutaneous malignant melanoma is an aggressive cancer that contributes significantly to cancer-related mortality. Over the years, a deeper scrutiny of melanoma biology has led to identification of diverse evolutionary patterns involving various genetic pathways. This study attempts to further understand the genetic landscape of cutaneous malignant melanoma in terms of loco-regional variations and malignant potential. Thirty-five cases of cutaneous malignant melanoma were retrieved from the archives and were classified based on location of the primary tumor and presence or absence of metastatic disease. Next-generation sequencing data consisting of base substitutions, copy number variations, indels, and rearrangements in a total of 324 genes were analyzed for recurrent genetic alterations. Statistical analysis was performed using IBM SPSS26 software. Mutations in KDM gene family were found in 62.5% of the melanomas in the head and neck as compared with 10% in melanomas of the extremity and trunk (P = 0.03). Mutations in the RAS gene family were found in 70% of melanomas in the extremities as compared to 12.5% in melanomas of the head and neck (P = 0.003). BTK gene mutations were found exclusively in melanomas of the head and neck (P = 0.032). CREBBP mutations were seen in 50% of the nonmetastatic melanomas as compared with 3.57% of metastatic melanomas (P = 0.005). This study highlights the loco-regional variations in cutaneous malignant melanoma for genetic alterations involving the KDM, RAS, and BTK gene family. In addition, the CREBBP mutational status is identified as a potential prognostic marker for predicting metastatic potential in cutaneous malignant melanomas.

CD200 Blockade Modulates Tumor Immune Microenvironment but Fails to Show Efficacy in Inhibiting Tumor Growth in a Murine Model of Melanoma

CD200-CD200R pathway regulates immune responses and has been implicated in the pathogenesis of a number of cancer types. CD200 blockade is considered a strategy for immunotherapy of CD200-positive cancers such as melanoma. Thus, it is critical to understand the potential impacts of CD200 blockade in a more human relevant tumor model. In this study, we evaluated these issues using the CD200⁺ Yumm1.7 mouse melanoma model. Yumm1.7 cells bear Braf/Pten mutations resembling human melanoma. We found that Yumm1.7 tumors grow significantly faster in CD200R^–/– mice compared to wild type mice. Analysis of tumor immune microenvironment (TIME) revealed that tumors from CD200R^–/– or anti-CD200 treated mice had downregulated immune cell contents and reduced TCR clonality compared to tumors from untreated wild type mice. T cells also showed impaired effector functions, as reflected by reduced numbers of IFN-γ⁺ and TNF-α⁺ T cells. Mechanistically, we found upregulation of the CCL8 gene in CD200R^–/– tumors. In vitro co-culture experiments using Yumm1.7 tumor cells with bone marrow derived macrophages (BMDM) from WT and CD200R^–/– mice confirmed upregulation of macrophage CCL8 in the absence of CD200-CD200R interaction. Finally, we found that anti-CD200 therapy failed to show efficacy either alone or in combination with checkpoint inhibitors such as anti-PD-1 or anti-CTLA4 in inhibiting Yumm1.7 tumor growth. Given that CD200R-deficiency or anti-CD200 treatment leads to reduced T cell responses in TME, using blockade of CD200 as an immunotherapy for cancers such as melanoma should be practiced with caution.

Current Trends of Immunotherapy in the Treatment of Cutaneous Melanoma: A Review

Cutaneous melanoma remains a severe public health threat, with annual incidence increasing slowly but steadily over 4 decades. While early-stage melanomas can typically be treated with complete surgical excision with favorable results, the development of metastatic cancer, which is related to a lower survival rate, is linked to the primary tumor's rising stage and other high-risk features. Even though the first discoveries of an immunological anti-tumor response were published about a century ago, immunotherapy has only been a feasible therapeutic option for cutaneous melanoma in the last 30 years. Nonetheless, for the treatment of various cancers, including metastatic melanoma, the area of cancer immunotherapy has made significant progress in the last decade. As a result, melanoma continues to be the subject of several preclinical and clinical investigations to further understand cancer immunobiology and test different tumor immunotherapies. Immunotherapy's resistance to radiation and cytotoxic chemotherapy is one of its most distinguishing features. Furthermore, the discovery of biomarkers will aid in patient stratification and management during immunotherapy treatment. In this article, we discuss current knowledge and recent developments in immune-mediated therapy of melanoma.

A Review of Epidemiology and Cancer Biology of Malignant Melanoma

Malignant melanoma is a neoplasm originating in the melanocytes in the skin. Although malignant melanoma is the third most common cutaneous cancer, it is recognized as the main cause of skin cancer-related mortality, and its incidence is rising. The natural history of malignant melanoma involves an inconsistent and insidious skin cancer with great metastatic potential. Increased ultra-violet (UV) skin exposure is undoubtedly the greatest risk factor for developing cutaneous melanoma; however, a plethora of risk factors are now recognized as causative. Moreover, modern oncology now considers melanoma proliferation a complex, multifactorial process with a combination of genetic, epigenetic, and environmental factors all known to be contributory to tumorgenesis. Herein, we wish to outline the epidemiological, molecular, and biological processes responsible for driving malignant melanoma proliferation.

Identification of Key miRNAs in the Treatment of Dabrafenib-Resistant Melanoma

Dabrafenib resistance is a significant problem in melanoma, and its underlying molecular mechanism is still unclear. The purpose of this study is to research the molecular mechanism of drug resistance of dabrafenib and to explore the key genes and pathways that mediate drug resistance in melanoma. GSE117666 was downloaded from the Gene Expression Omnibus (GEO) database and 492 melanoma statistics were also downloaded from The Cancer Genome Atlas (TCGA) database. Besides, differentially expressed miRNAs (DEMs) were identified by taking advantage of the R software and GEO2R. The Database for Annotation, Visualization, and Integrated Discovery (DAVID) and FunRich was used to perform Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis to identify potential pathways and functional annotations linked with melanoma chemoresistance. 9 DEMs and 872 mRNAs were selected after filtering. Then, target genes were uploaded to Metascape to construct protein-protein interaction (PPI) network. Also, 6 hub mRNAs were screened after performing the PPI network. Furthermore, a total of 4 out of 9 miRNAs had an obvious association with the survival rate (P < 0.05) and showed a good power of risk prediction model of over survival. The present research may provide a deeper understanding of regulatory genes of dabrafenib resistance in melanoma.

Clinical Implications of Acquired BRAF Inhibitors Resistance in Melanoma

Understanding the role of mitogen-activated protein kinase (MAPK) pathway-activating mutations in the development and progression of melanoma and their possible use as therapeutic targets has substantially changed the management of this neoplasm, which, until a few years ago, was burdened by severe mortality. However, the presence of numerous intrinsic and extrinsic mechanisms of resistance to BRAF inhibitors compromises the treatment responses’ effectiveness and durability. The strategy of overcoming these resistances by combination therapy has proved successful, with the additional benefit of reducing side effects derived from paradoxical activation of the MAPK pathway. Furthermore, the use of other highly specific inhibitors, intermittent dosing schedules and the association of combination therapy with immune checkpoint inhibitors are promising new therapeutic strategies. However, numerous issues related to dose, tolerability and administration sequence still need to be clarified, as is to be expected from currently ongoing trials. In this review, we describe the clinical results of using BRAF inhibitors in advanced melanoma, with a keen interest in strategies aimed at overcoming resistance.

Recent advances in the management of cutaneous malignant melanoma: our case cohort

Decades of research into the management of cutaneous malignant melanoma have proven it to be a 'tough nut to crack', and its incidence has continued to increase over the last 30 years. Surgery remains a gold standard for early-stage melanoma with five-year survival of 98% for stage I disease, and 90% for stage II. Nonetheless, patients with stage III disease are at a higher risk, resulting in local recurrence as well as distant metastasis. Research regarding the control of metastatic malignant melanoma of the head and neck has evolved. Currently the search is on to understand metastatic malignant melanoma as a heterogeneous disease both at the molecular and clinical level. This paper focuses on the latest systemic therapy for metastatic disease of the head and neck, including cytotoxic chemotherapy, immunotherapy, and target therapy. The new eighth edition of tumour staging, and the sequelae for malignant melanoma, sentinel lymph node biopsy (SLNB), surgical intervention, and its benefits and shortfalls, are discussed. Also, the outcome of our cohort series of patients with metastatic cutaneous malignant melanoma who were treated with systemic combination therapy in Dorset is presented.

Cutaneous melanoma and the immunotherapy revolution (Review)

In a relatively short period of time, treatment strategies for metastatic melanoma have radically changed leading to an unprecedented improvement in patient survival. In this period, immunotherapy options have evolved from cytokine‑based approaches to antibody‑mediated inhibition of immune checkpoints, cancer vaccines and pharmacological modulation of the melanoma microenvironment. Combination of immunotherapy strategies and the association of immune checkpoint inhibitors (ICIs) with BRAF V600 targeted therapy show encouraging results. The future of drug development in this field is promising. The comprehension of primary and acquired resistance mechanisms to ICIs and the dissection of melanoma immunobiology will be instrumental for the development of new treatment strategies and to improve clinical trial design. Moreover, biomarker discovery will help patient stratification and management during immunotherapy treatment. In this review, we summarize landmark clinical trials of immune checkpoint inhibitors in advanced melanoma and discuss the rational for immunotherapy combinations. Immunotherapy approaches at early stage of clinical development and recent advances in melanoma immunotherapy biomarker development are also discussed.

Regressive melanoma in a female patient: A case report

Regressive melanoma is a phenomenon characterized by partial or complete replacement of cutaneous melanoma by fibrotic structures as a result of local host immune response. The dermoscopic features include 'scar-like' depigmentation that can be described as hypopigmented to pigmented macules, pink macules, linear-irregular vessels, globular vessel pattern, hyperpigmented macular remnants, blue gray 'peppered' papular remnants and white transverse bands. Fully regressive melanoma is very rare, and, in majority of cases, the tumor is associated with metastases, so the prognosis is very poor due to this fact. Regressive melanomas are rare since it represents an advance stage of melanoma evolution. Their treatment requires a collaboration between the dermatologist and the oncologist in order to improve the quality of life of the patient and also the survival rate.

Functional Roles of Matrix Metalloproteinases and Their Inhibitors in Melanoma

The extracellular matrix (ECM) plays an important role in the regulation of the tissue microenvironment and in the maintenance of cellular homeostasis. Several proteins with a proteolytic activity toward several ECM components are involved in the regulation and remodeling of the ECM. Among these, Matrix Metalloproteinases (MMPs) are a class of peptidase able to remodel the ECM by favoring the tumor invasive processes. Of these peptidases, MMP-9 is the most involved in the development of cancer, including that of melanoma. Dysregulations of the MAPKs and PI3K/Akt signaling pathways can lead to an aberrant overexpression of MMP-9. Even ncRNAs are implicated in the aberrant production of MMP-9 protein, as well as other proteins responsible for the activation or inhibition of MMP-9, such as Osteopontin and Tissue Inhibitors of Metalloproteinases. Currently, there are different therapeutic approaches for melanoma, including targeted therapies and immunotherapies. However, no biomarkers are available for the prediction of the therapeutic response. In this context, several studies have tried to understand the diagnostic, prognostic and therapeutic potential of MMP-9 in melanoma patients by performing clinical trials with synthetic MMPs inhibitors. Therefore, MMP-9 may be considered a promising molecule for the management of melanoma patients due to its role as a biomarker and therapeutic target.

Viral Vector-Based Melanoma Gene Therapy

Gene therapy applications of oncolytic viruses represent an attractive alternative for cancer treatment. A broad range of oncolytic viruses, including adenoviruses, adeno-associated viruses, alphaviruses, herpes simplex viruses, retroviruses, lentiviruses, rhabdoviruses, reoviruses, measles virus, Newcastle disease virus, picornaviruses and poxviruses, have been used in diverse preclinical and clinical studies for the treatment of various diseases, including colon, head-and-neck, prostate and breast cancer as well as squamous cell carcinoma and glioma. The majority of studies have focused on immunotherapy and several drugs based on viral vectors have been approved. However, gene therapy for malignant melanoma based on viral vectors has not been utilized to its full potential yet. This review represents a summary of the achievements of preclinical and clinical studies using viral vectors, with the focus on malignant melanoma.

Alternative Splicing of RAD6B and Not RAD6A is Selectively Increased in Melanoma: Identification and Functional Characterization

Rad6B, a principal component of the translesion synthesis pathway, and activator of canonical Wnt signaling, plays an essential role in cutaneous melanoma development and progression. As Rad6 is encoded by two genes, namely, UBE2A (RAD6A) and UBE2B (RAD6B), in humans, we compared their expressions in melanomas and normal melanocytes. While both genes are weakly expressed in normal melanocytes, Rad6B is more robustly expressed in melanoma lines and patient-derived metastatic melanomas than RAD6A. The characterization of RAD6B transcripts revealed coexpression of various splice variants representing truncated or modified functional versions of wild-type RAD6B in melanomas, but not in normal melanocytes. Notably, two RAD6B isoforms with intact catalytic domains, RAD6BΔexon4 and RAD6Bintron5ins, were identified. We confirmed that RAD6BΔexon4 and RAD6Bintron5ins variants are expressed as 14 and 15 kDa proteins, respectively, with functional in vivo ubiquitin conjugating activity. Whole exome sequence analysis of 30 patient-derived melanomas showed RAD6B variants coexpressed with wild-type RAD6B in all samples analyzed, and RAD6Bintron5ins variants were found in half the cases. These variants constitute the majority of the RAD6B transcriptome in contrast to RAD6A, which was predominantly wild-type. The expression of functional RAD6B variants only in melanomas reveals RAD6B's molecular heterogeneity and its association with melanoma pathogenesis.

T cell pathology in skin inflammation

Forming the outer body barrier, our skin is permanently exposed to pathogens and environmental hazards. Therefore, skin diseases are among the most common disorders. In many of them, the immune system plays a crucial pathogenetic role. For didactic and therapeutic reasons, classification of such immune-mediated skin diseases according to the underlying dominant immune mechanism rather than to their clinical manifestation appears to be reasonable. Immune-mediated skin diseases may be mediated mainly by T cells, by the humoral immune system, or by uncontrolled unspecific inflammation. According to the involved T cell subpopulation, T cell-mediated diseases may be further subdivided into T1 cell-dominated (e.g., vitiligo), T2 cell-dominated (e.g., acute atopic dermatitis), T17/T22 cell-dominated (e.g., psoriasis), and Treg cell-dominated (e.g., melanoma) responses. Moreover, T cell-dependent and -independent responses may occur simultaneously in selected diseases (e.g., hidradenitis suppurativa). The effector mechanisms of the respective T cell subpopulations determine the molecular changes in the local tissue cells, leading to specific microscopic and macroscopic skin alterations. In this article, we show how the increasing knowledge of the T cell biology has been comprehensively translated into the pathogenetic understanding of respective model skin diseases and, based thereon, has revolutionized their daily clinical management.

Targeting the ERK Signaling Pathway in Melanoma

The discovery of the role of the RAS/RAF/MEK/ERK pathway in melanomagenesis and its progression have opened a new era in the treatment of this tumor. Vemurafenib was the first specific kinase inhibitor approved for therapy of advanced melanomas harboring BRAF-activating mutations, followed by dabrafenib and encorafenib. However, despite the excellent results of first-generation kinase inhibitors in terms of response rate, the average duration of the response was short, due to the onset of genetic and epigenetic resistance mechanisms. The combination therapy with MEK inhibitors is an excellent strategy to circumvent drug resistance, with the additional advantage of reducing side effects due to the paradoxical reactivation of the MAPK pathway. The recent development of RAS and extracellular signal-related kinases (ERK) inhibitors promises to add new players for the ultimate suppression of this signaling pathway and the control of pathway-related drug resistance. In this review, we analyze the pharmacological, preclinical, and clinical trial data of the various MAPK pathway inhibitors, with a keen interest for their clinical applicability in the management of advanced melanoma.

Cutaneous melanoma: From pathogenesis to therapy (Review)

In less than 10 years, melanoma treatment has been revolutionized with the approval of tyrosine kinase inhibitors and immune checkpoint inhibitors, which have been shown to have a significant impact on the prognosis of patients with melanoma. The early steps of this transformation have taken place in research laboratories. The mitogen‑activated protein kinase (MAPK) pathway, phosphoinositol‑3‑kinase (PI3K) pathway promote the development of melanoma through numerous genomic alterations on different components of these pathways. Moreover, melanoma cells deeply interact with the tumor microenvironment and the immune system. This knowledge has led to the identification of novel therapeutic targets and treatment strategies. In this review, the epidemiological features of cutaneous melanoma along with the biological mechanisms involved in its development and progression are summarized. The current state‑of‑the‑art of advanced stage melanoma treatment strategies and the currently available evidence of the use of predictive and prognostic biomarkers are also discussed.

MMP-9 overexpression is associated with intragenic hypermethylation of MMP9 gene in melanoma

Tumor spreading is associated with the degradation of extracellular matrix proteins, mediated by the overexpression of matrix metalloproteinase 9 (MMP-9). Although, such overexpression was linked to epigenetic promoter methylation, the role of intragenic methylation was not clarified yet. Melanoma was used as tumor model to investigate the relationship between the DNA intragenic methylation of MMP9 gene and MMP-9 overexpression at transcriptional and protein levels. Computational analysis revealed DNA hypermethylation within the intragenic CpG-2 region of MMP9 gene in melanoma samples with high MMP-9 transcript levels. In vitro validation showed that CpG-2 hotspot region was hypermethylated in the A375 melanoma cell line with highest mRNA and protein levels of MMP-9, while low methylation levels were observed in the MEWO cell line where MMP-9 was undetectable. Concordant results were demonstrated in both A2058 and M14 cell lines. This correlation may give further insights on the role of MMP-9 upregulation in melanoma.

Phenotype characterization of human melanoma cells resistant to dabrafenib

In the present study, the phenotype of melanoma cells resistant to dabrafenib (a B-RAF inhibitor) was investigated, to shed more light on melanoma resistance to B-RAF inhibition. Melanoma cells resistant to dabrafenib were generated using 3 different cell lines, A375, 397 and 624.38, all carrying B-RAF^V600E, and they were characterized by cytofluorometric analysis, Ion Torrent technology, immunofluorescence and biochemistry. All dabrafenib-resistant cells showed, in addition to a re-activation of MAPK signaling, morphological changes compared to their sensitive counterparts, accompanied by an increase in CD90 (mesenchymal marker) expression and a decrease in E-cadherin (epithelial marker) expression, suggesting an epithelial-to-mesenchymal-like phenotypic transition. However, melanoma cells with TGF-β1-induced epithelial-to-mesenchymal transition (EMT) were more sensitive to dabrafenib treatment compared to the sensitivity noted in the non-TGF-β1-induced EMT melanoma cells, suggesting that TGF-β1-induced EMT was not associated with dabrafenib resistance. Although dabrafenib-resistant cells exhibited increased cell motility and E-cadherin/vimentin reorganization, as expected in EMT, all of them showed unvaried E-cadherin mRNA and unchanged Snail protein levels, while Twist1 protein expression was decreased with the exception of A375 dabrafenib-resistant melanoma cells, where it was unaffected. These findings suggest a distinct active EMT-like process adopted by melanoma cells under drug exposure. Furthermore, dabrafenib-resistant cells exhibited stem cell-like features, with Oct4 translocation from the cytoplasm to peri-nuclear sites and nuclei, and increased CD20 expression. In conclusion, our data, in addition to confirming that resistance to dabrafenib is dependent on re-activation of MAPK signaling, suggest that this resistance is linked to a distinct active EMT-like process as well as stem-cell features adopted by melanoma cells.

Overexpression of CTHRC1 in human melanoma promotes tumorigenesis targeted by miRNA155

Most of human malignant melanoma is metastatic and invasive, which has poor therapeutic response and poor prognosis as well as high incidence worldwide. CTHRC1 was overexpressed in metastatic primary melanomas. The relationship between CTHRC1 and miRNA in affecting the melanoma has not been studied. This study was aimed to explore the function of CTHRC1 in human melanoma and finding its regulator miRNA. CTHRC1 and miR155 expression in cancer tissues and paracancer tissues was examined. The cell proliferation, cell cycle, cell migration and cell invasion was evaluated in M21 cell transfected with CTHRC1 siRNA or miR155. The mRNA expression of miR155 in cancer tissues was lower than that in paracancer tissues. The mRNA expression of CTHRC1 in the cancer tissues was higher than that in corresponding paracancer tissues. The mRNA expression of CTHRC1 in the M21 cells was decreased by treated with miR155 mimic. CTHRC1 promoted the cell proliferation, cell cycle process, cell migration and invasion capacity and prevented the cell from apoptosis. miR155 inhibited the cell proliferation, cell migration and cell invasion, arrested the cell cycle process at G1 phase and enhanced the cell apoptosis. The luciferases reporter assay showed that miR155 bound to the 3'-UTR of CTHRC1 and regulated the expression of CTHRC1, further influenced the functions of CTHRC1 in human melanoma development. The study contributed to unearthing a novel potential predictor and therapeutic targets of human melanoma. CTHRC1 was a potential independent predictor and therapeutic target for human melanoma.

Standardization of A375 human melanoma models on chicken embryo chorioallantoic membrane and Balb/c nude mice

Cutaneous melanoma is a metastatic disease characterized by high resistance to treatment, the incidence of which has alarmingly increased worldwide over the past years. A thorough characterization of tumor onset, progression and metastasis is compulsory to overcome the gaps existent in melanoma biology. The present study suggests a well-established protocol and a detailed histological description of human melanoma models in ovo and in vivo obtained by the inoculation of A375 cells to chick embryo chorioallantoic membrane (CAM) and Balb/c nude mice. The inoculation of A375 cells on CAM led to the formation of compact primary and secondary tumors on day 4 post-inoculation, with mean surface area values of 2.2±0.4 mm² and 1.5±0.3 mm², respectively. Moreover, the vessels around the tumors presented a spike wheel pattern, indicating a strong angiogenic reaction. All the injected mice, apart from one, developed solid polypoid primary tumors with lobulated surfaces and intense vascularization, and achromic epithelioid malignant melanocytes with vesiculous nuclei and necrosis area were detected. Metastasis was histologically confirmed in only 30% of the mice with the tumor xenografts. These data indicate that the standardization protocols proposed are complex and reproducible, and can be further employed for the therapeutic surveillance of antiangiogenic and anticancer agents.

NF‑κB inhibition is associated with OPN/MMP‑9 downregulation in cutaneous melanoma

The development of cutaneous melanoma is influenced by genetic factors, including BRAF mutations and environmental factors, such as ultraviolet exposure. Its progression has been also associated with the involvement of several tumour microenvironmental molecules. Among these, nuclear factor‑κB (NF‑κB) has been indicated as a key player of osteopontin (OPN) and matrix metalloproteinase‑9 (MMP‑9) activation. However, whether NF‑κB plays a role in the development and progression of melanoma in association with the OPN/MMP‑9 axis according to the BRAFV600E mutation status has not been investigated in detail to date. Thus, in the present study, in order to shed light on this matter, 148 patients with melanoma and 53 healthy donors were recruited for the analysis of OPN, MMP‑9 and NF‑κB. Significantly higher circulating levels of OPN and MMP‑9 were observed in the patients with melanoma when compared to the healthy donors. Similar data were obtained for NF‑κB p65 activity. The OPN levels did not differ significantly between melanomas with or without BRAFV600E mutation. However, as regards NF‑κB and MMP‑9, significant differences were observed between the melanomas with or without BRAFV600E mutation. To determine whether NF‑κB inhibition is associated with a decrease in the levels of OPN and MMP‑9, peripheral blood mononuclear cells from 29 patients with melanoma were treated with the NF‑κB inhibitor, dehydroxymethylepoxyquinomycin (DHMEQ), with or without OPN. As expected, the inhibition of NF‑κB induced a marked decrease in both the OPN and MMP‑9 levels. Furthermore, the decrease in MMP‑9 levels was higher among melanomas harbouring the BRAFV600E mutation. Overall, our data suggest that the activation of MMP‑9 is associated with the BRAFV600E mutation status. Furthermore, such an activation is mediated by NF‑κB, suggesting its role as therapeutic target in patients with melanoma.

Occupational exposure to pesticides as a possible risk factor for the development of chronic diseases in humans (Review)

It is well known that pesticides are widely used compounds. In fact, their use in agriculture, forestry, fishery and the food industry has granted a huge improvement in terms of productive efficiency. However, a great number of epidemiological surveys have demonstrated that these toxic compounds can interact and exert negative effects not only with their targets (pests, herbs and fungi), but also with the rest of the environment, including humans. This is particularly relevant in the case of workers involved in the production, transportation, preparation and application of these toxicants. Accordingly, a growing body of evidence has demonstrated the correlation between occupational exposure to pesticides and the development of a wide spectrum of pathologies, ranging from eczema to neurological diseases and cancer. Pesticide exposure is often quite difficult to establish, as many currently used modules do not take into account all of the many variables that can occur in a diverse environment, such as the agricultural sector, and the assessment of the real risk for every single worker is problematic. Indeed, the use of personal protection equipment is necessary while handling these toxic compounds, but education of workers can be even more important: personal contamination with pesticides may occur even in apparently harmless situations. This review summarises the most recent findings describing the association between pesticide occupational exposure and the development of chronic diseases.

Occupational exposure to carcinogens: Benzene, pesticides and fibers (Review)

It is well known that the occupational exposure to contaminants and carcinogens leads to the development of cancer in exposed workers. In the 18th century, Percivall Pott was the first to hypothesize that chronic exposure to dust in the London chimney sweeps was associated with an increased risk of developing cancer. Subsequently a growing body of evidence indicated that other physical factors were also responsible for oncogenic mutations. Over the past decades, many carcinogens have been found in the occupational environment and their presence is often associated with an increased incidence of cancer. Occupational exposure involves several factors and the association between carcinogens, occupational exposure and cancer is still unclear. Only a fraction of factors is recognized as occupational carcinogens and for each factor, there is an increased risk of cancer development associated with a specific work activity. According to the International Agency for Research on Cancer (IARC), the majority of carcinogens are classified as 'probable' and 'possible' human carcinogens, while, direct evidence of carcinogenicity is provided in epidemiological and experimental studies. In the present review, exposures to benzene, pesticides and mineral fibers are discussed as the most important cancer risk factors during work activities.

Effects of mutations in Wnt/β-catenin, hedgehog, Notch and PI3K pathways on GSK-3 activity-Diverse effects on cell growth, metabolism and cancer

Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase that participates in an array of critical cellular processes. GSK-3 was first characterized as an enzyme that phosphorylated and inactivated glycogen synthase. However, subsequent studies have revealed that this moon-lighting protein is involved in numerous signaling pathways that regulate not only metabolism but also have roles in: apoptosis, cell cycle progression, cell renewal, differentiation, embryogenesis, migration, regulation of gene transcription, stem cell biology and survival. In this review, we will discuss the roles that GSK-3 plays in various diseases as well as how this pivotal kinase interacts with multiple signaling pathways such as: PI3K/PTEN/Akt/mTOR, Ras/Raf/MEK/ERK, Wnt/beta-catenin, hedgehog, Notch and TP53. Mutations that occur in these and other pathways can alter the effects that natural GSK-3 activity has on regulating these signaling circuits that can lead to cancer as well as other diseases. The novel roles that microRNAs play in regulation of the effects of GSK-3 will also be evaluated. Targeting GSK-3 and these other pathways may improve therapy and overcome therapeutic resistance.

Computational modeling in melanoma for novel drug discovery

INTRODUCTION

There is a growing body of evidence highlighting the applications of computational modeling in the field of biomedicine. It has recently been applied to the in silico analysis of cancer dynamics. In the era of precision medicine, this analysis may allow the discovery of new molecular targets useful for the design of novel therapies and for overcoming resistance to anticancer drugs. According to its molecular behavior, melanoma represents an interesting tumor model in which computational modeling can be applied. Melanoma is an aggressive tumor of the skin with a poor prognosis for patients with advanced disease as it is resistant to current therapeutic approaches.

AREAS COVERED

This review discusses the basics of computational modeling in melanoma drug discovery and development. Discussion includes the in silico discovery of novel molecular drug targets, the optimization of immunotherapies and personalized medicine trials.

EXPERT OPINION

Mathematical and computational models are gradually being used to help understand biomedical data produced by high-throughput analysis. The use of advanced computer models allowing the simulation of complex biological processes provides hypotheses and supports experimental design. The research in fighting aggressive cancers, such as melanoma, is making great strides. Computational models represent the key component to complement these efforts. Due to the combinatorial complexity of new drug discovery, a systematic approach based only on experimentation is not possible. Computational and mathematical models are necessary for bringing cancer drug discovery into the era of omics, big data and personalized medicine.

Akt inhibitors in cancer treatment: The long journey from drug discovery to clinical use (Review)

Targeted cancer therapies are used to inhibit the growth, progression, and metastasis of the tumor by interfering with specific molecular targets and are currently the focus of anticancer drug development. Protein kinase B, also known as Akt, plays a central role in many types of cancer and has been validated as a therapeutic target nearly two decades ago. This review summarizes the intracellular functions of Akt as a pivotal point of converging signaling pathways involved in cell growth, proliferation, apoptotis and neo‑angiogenesis, and focuses on the drug design strategies to develop potent anticancer agents targeting Akt. The discovery process of Akt inhibitors has evolved from adenosine triphosphate (ATP)‑competitive agents to alternative approaches employing allosteric sites in order to overcome the high degree of structural similarity between Akt isoforms in the catalytic domain, and considerable structural analogy to the AGC kinase family. This process has led to the discovery of inhibitors with greater specificity, reduced side-effects and lower toxicity. A second generation of Akt has inhibitors emerged by incorporating a chemically reactive Michael acceptor template to target the nucleophile cysteines in the catalytic activation loop. The review outlines the development of several promising drug candidates emphasizing the importance of each chemical scaffold. We explore the pipeline of Akt inhibitors and their preclinical and clinical examination status, presenting the potential clinical application of these agents as a monotherapy or in combination with ionizing radiation, other targeted therapies, or chemotherapy.

MiR-21: an environmental driver of malignant melanoma?

Since the mid-1950’s, melanoma incidence has been rising steadily in industrialized Caucasian populations, thereby pointing to the pivotal involvement of environmental factors in melanomagenesis. Recent evidence underlines the crucial role of microRNA (miR) signaling in cancer initiation and progression. Increased miR-21 expression has been observed during the transition from a benign melanocytic lesion to malignant melanoma, exhibiting highest expression of miR-21. Notably, common BRAF and NRAS mutations in cutaneous melanoma are associated with increased miR-21 expression. MiR-21 is an oncomiR that affects critical target genes of malignant melanoma, resulting in sustained proliferation (PTEN, PI3K, Sprouty, PDCD4, FOXO1, TIPE2, p53, cyclin D1), evasion from apoptosis (FOXO1, FBXO11, APAF1, TIMP3, TIPE2), genetic instability (MSH2, FBXO11, hTERT), increased oxidative stress (FOXO1), angiogenesis (PTEN, HIF1α, TIMP3), invasion and metastasis (APAF1, PTEN, PDCD4, TIMP3). The purpose of this review is to provide translational evidence for major environmental and individual factors that increase the risk of melanoma, such as UV irradiation, chemical noxes, air pollution, smoking, chronic inflammation, Western nutrition, obesity, sedentary lifestyle and higher age, which are associated with increased miR-21 signaling. Exosomal miR-21 induced by extrinsic and intrinsic stimuli may be superimposed on mutation-induced miR-21 pathways of melanoma cells. Thus, oncogenic miR-21 signaling may be the converging point of intrinsic and extrinsic stimuli driving melanomagenesis. Future strategies of melanoma treatment and prevention should thus aim at reducing the burden of miR-21 signal transduction.

Malignant melanoma in elderly patients: biological, surgical and medical issues

Malignant melanoma is an aggressive tumor with a poor prognosis for patients with advanced disease. Over the last decades, its incidence and mortality has increased in elderly population, impacting significantly on healthcare costs, considering the increase in average age of the world population. Older age is recognized as an independent poor prognostic factor for melanoma, but the scientific community now is wondering if elderly melanoma patients have worse outcome because they are not receiving the same treatment as their younger counterparts. This article summarizes current data on elderly melanoma prevention and early detection and its subsequent management, underling the differences observed between older and younger patients. It also describes age-associated alterations in immunity and how these may impact on anti-melanoma response.

Emerging targeted therapies for melanoma treatment (review)

Cutaneous melanoma is an aggressive cancer with a poor prognosis for patients with advanced disease. The identification of several key molecular pathways implicated in the pathogenesis of melanoma has led to the development of novel therapies for this devastating disease. In melanoma, both the Ras/Raf/MEK/ERK (MAPK) and the PI3K/AKT (AKT) signalling pathways are constitutively activated through multiple mechanisms. Targeting various effectors of these pathways with pharmacologic inhibitors may inhibit melanoma cell growth and angiogenesis. Ongoing clinical trials provide hope to improve progression-free survival of patients with advanced melanoma. This review summarizes the most relevant studies focused on the specific action of these new molecular targeted agents. Mechanisms of resistance to therapy are also discussed.