Melanoma Prevention Research Articles

Current Insights into the Role of UV Radiation-Induced Oxidative Stress in Melanoma Pathogenesis

Cutaneous melanoma accounts for the majority of skin cancer-related deaths, and its incidence increases each year. The growing number of melanoma cases, especially in advanced stages, poses a significant socio-medical challenge throughout the world. Extensive research on melanoma pathogenesis identifies UV radiation as the most important factor in melanocytic transformation. Oxidative effects of UV irradiation exert their influence on melanoma pathogenesis primarily through modification of nucleic acids, proteins, and lipids, further disrupting cellular signaling and cell cycle regulation. Its effects extend beyond melanocytes, leading to immunosuppression in the exposed skin tissue, which consequently creates conditions for immune surveillance evasion and further progression. In this review, we focus on the specific molecular changes observed in the UV-dependent oxidative stress environment and their biological consequences in the course of the disease, which have not been considered in previous reviews on melanoma. Nonetheless, data show that the exact role of oxidative stress in melanoma initiation and progression remains unclear, as it affects cancerous cells differently depending on the specific context. A better understanding of the pathophysiological basis of melanoma development holds promise for identifying potential targets, which could lead to effective melanoma prevention strategies.

An attractor state zone precedes neural crest fate in melanoma initiation.

The field cancerization theory suggests that a group of cells containing oncogenic mutations are predisposed to transformation 1, 2 . We previously identified single cells in BRAF V600E ;p53 -/- zebrafish that reactivate an embryonic neural crest state before initiating melanoma 3-5 . Here we show that single cells reactivate the neural crest fate from within large fields of adjacent abnormal melanocytes, which we term the "cancer precursor zone." These cancer precursor zone melanocytes have an aberrant morphology, dysplastic nuclei, and altered gene expression. Using single cell RNA-seq and ATAC-seq, we defined a distinct transcriptional cell attractor state for cancer precursor zones and validated the stage-specific gene expression initiation signatures in human melanoma. We identify the cancer precursor zone driver, ID1, which binds to TCF12 and inhibits downstream targets important for the maintenance of melanocyte morphology and cell cycle control. Examination of patient samples revealed precursor melanocytes expressing ID1, often surrounding invasive melanoma, indicating a role for ID1 in early melanomagenesis. This work reveals a surprising field effect of melanoma initiation in vivo in which tumors arise from within a zone of morphologically distinct, but clinically covert, precursors with altered transcriptional fate. Our studies identify novel targets that could improve early diagnosis and prevention of melanoma.

Immunoinformatic approach to design an efficient multi-epitope peptide vaccine against melanoma.

Melanoma is known to be the most hazardous and life-threatening type of skin cancer. Although numerous treatments have been authorized in recent years, they often result in severe side effects and may not fully cure the disease. To combat this issue, immunotherapy has emerged as a promising approach for the prevention and treatment of melanoma. Specifically, the use of epitope melanoma vaccine, a subset of immunotherapy, has recently gained attention. The aim of this study was to create a multi-epitope melanoma vaccine using immunoinformatic methods. Two well-known antigens, NYESO-1 and MAGE-C2, were selected due to their strong immunogenicity and high expression in melanoma. To enhance the immunogenicity of the peptide vaccine, Brucella cell-surface protein 31 (BCSP31), the G5 domain of resuscitation-promoting factor B (RpfB) adjuvants, and the helper epitope of pan HLADR-binding epitope (PADRE) were incorporated to vaccine construct. These different segments were connected with suitable linkers and the resulting vaccine structure was evaluated for its physicochemical, structural, and immunological properties using computational tools. The designed vaccine was found to have satisfactory allergenicity, antigenicity, and physicochemical parameters. Additionally, a high-quality tertiary structure of the vaccine was achieved through modeling, refinement, and validation. Docking and molecular dynamics studies showed that the vaccine had a stable and appropriate interaction with the cognate TLR2 and TLR4 receptors during the simulation period. Finally, in silico immune simulation analysis revealed a significant increase in the levels of helper and cytotoxic T cells, as well as the cytokines interferon-gamma and interleukin-2, after repeated exposure to the melanoma vaccine. These results suggest that the designed vaccine has the potential to be an effective therapeutic option for melanoma. However, additional in vitro and in vivo validations are crucial to assess real-world efficacy and safety.

50243 Nutritional Supplements and Dietary Components for Melanoma Prevention: A Systematic Review

50243 Nutritional Supplements and Dietary Components for Melanoma Prevention: A Systematic Review

Ambient ultraviolet A, ultraviolet B and risk of melanoma in a nationwide United States cohort, 1984-2014.

Ultraviolet radiation (UVR) exposure is the primary risk factor for melanoma although the relationship is complex. Compared to radiation from UVB wavelengths, UVA makes up a majority of the surface solar UVR, penetrates the skin more deeply, is the principal range emitted by tanning beds, and is less filtered by sunscreens and window glass. Few studies have examined the relationship between ambient UVA and UVB and melanoma risk. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were estimated for the association between satellite-based ambient (based on residential history) UVA, UVB and melanoma in non-Hispanic White participants using data from the United States Radiologic Technologists study, a large, nationwide prospective cohort. Associations of UVA and UVB quartile (Q) were examined in mutually adjusted and stratified models, additionally adjusted for demographic and sun sensitivity characteristics. There were 837 incident melanoma cases among 62,785 participants. Incidence of melanoma was statistically significantly increased for the highest quartile of childhood UVA exposure after adjustment for UVB (IRR = 2.82; 95%CI:1.46,5.44), but not for higher childhood UVB after adjustment for UVA. Childhood UVA was associated with increased melanoma risk within strata of UVB. Childhood UVB was not associated with melanoma after adjustment for UVA, but there was some evidence of lower risk with increased lifetime ambient UVB after UVA adjustment. Melanoma risk was elevated among participants living in locations with high annual childhood and lifetime UVA after controlling for UVB. With confirmation, these findings support increased protection from solar UVA for melanoma prevention.

Multidisciplinary patient-centered approach to the management of skin cancer.

In recent years, new approaches for optimal patient management of cancer have focused on patient-centered care, with integration of tumour-directed treatment and patient-directed supportive and palliative care throughout the disease journey from prevention through screening, diagnosis, treatment, and follow-up. In 2022, at the International Forum of Dermatology (IFD), a scientific session was entirely dedicated to highlight recent developments on patient-centered approaches in skin cancer. An international panel of different groups of participants involved in a patient's journey on the management of skin cancer presented and discussed challenges and barriers that persist in the field of skin cancer prevention and care pathways. Although primary prevention remains a crucial step in the prevention of melanoma, the different surveys performed during the last 20 years demonstrate that the use of sunscreen increases very slowly. Secondary prevention that includes skin screening and diagnostic measures may benefit from the development of digital tools. To improve adherence, patients need accurate, reliable information about their disease and the treatment options, and this type of content that can also be made available on digital tools. Shared decision-making is a hallmark of a patient-centered approach and requires health care providers who can communicate well to patients and their families, underscoring the pivotal role of health care professionals all through the patient journey. Health care providers have a crucial role in supporting patients through their journey in skin cancer. They will benefit from mobile apps and technologies that have been developed recently to address challenges in skin cancer prevention, detection and care, including those that are primarily directed to the patient. However, more peer-reviewed studies are needed as well as regulations to ensure that apps are accurate, reliable, and up to date.

Phytoconstituent-derived zingerone nanoparticles disrupt the cell adhesion mechanism and suppress cell motility in melanoma B16F10 cells

Combining phytochemicals and nanotechnology to improve the unfavorable innate properties of phytochemicals and develop them into potent nanomedicines to enhance antitumor efficacy has become a novel strategy for cancer chemoprevention. Melanoma is the most aggressive, metastatic, and deadly disease of the primary cutaneous neoplasms. In this study, we fabricated phytoconstituent-derived zingerone nanoparticles (NPs) and validated their effects on cell adhesion and motility in melanoma B16F10 cells. Our data indicated that zingerone NPs significantly induced cytotoxicity and anti-colony formation and inhibited cell migration and invasion. Moreover, zingerone NPs dramatically interfered with the cytoskeletal reorganization and markedly delayed the period of cell adhesion. Our results also revealed that zingerone NPs-mediated downregulation of MMPs (matrix metalloproteinases) activity is associated with inhibiting cell adhesion and motility. We further evaluated the effects of zingerone NPs on Src/FAK /Paxillin signaling, our data showed that zingerone NPs significantly inhibited the protein activities of Src, FAK, and Paxillin, indicating that they play important roles in zingerone NP-mediated anti-motility and anti-invasion in melanoma cells. Accordingly, the phytoconstituent-zingerone NPs can strengthen the inhibition of tumor growth, invasion, and metastasis in malignant melanoma. Altogether, these multi-pharmacological benefits of zingerone NPs will effectively achieve the purpose of melanoma prevention and invasion inhibition.

Malignant Melanoma: An Overview, New Perspectives, and Vitamin D Signaling.

Melanoma, originating through malignant transformation of melanin-producing melanocytes, is a formidable malignancy, characterized by local invasiveness, recurrence, early metastasis, resistance to therapy, and a high mortality rate. This review discusses etiologic and risk factors for melanoma, diagnostic and prognostic tools, including recent advances in molecular biology, omics, and bioinformatics, and provides an overview of its therapy. Since the incidence of melanoma is rising and mortality remains unacceptably high, we discuss its inherent properties, including melanogenesis, that make this disease resilient to treatment and propose to use AI to solve the above complex and multidimensional problems. We provide an overview on vitamin D and its anticancerogenic properties, and report recent advances in this field that can provide solutions for the prevention and/or therapy of melanoma. Experimental papers and clinicopathological studies on the role of vitamin D status and signaling pathways initiated by its active metabolites in melanoma prognosis and therapy are reviewed. We conclude that vitamin D signaling, defined by specific nuclear receptors and selective activation by specific vitamin D hydroxyderivatives, can provide a benefit for new or existing therapeutic approaches. We propose to target vitamin D signaling with the use of computational biology and AI tools to provide a solution to the melanoma problem.

Aspirin as a chemopreventive agent for cutaneous melanoma: a literature review.

Rising melanoma rates have spurred interest in preventive strategies. Nonsteroidal anti-inflammatory drugs (NSAIDs), particularly aspirin, show potential in reducing cancer risks. NSAIDs act on cyclooxygenase (COX) enzymes, impacting COX-2 associated with inflammation and cancer progression.This paper explores aspirin's role in cutaneous melanoma prevention, elucidating its mechanisms and acknowledging varying literature outcomes. Rather than providing conclusive recommendations, the review emphasizes the influence of individual factors, contributing to the ongoing dialogue on aspirin's complexities in melanoma prevention. A PubMed search using "Aspirin" AND "Cutaneous melanoma" yielded relevant English-language, peer-reviewed studies. Selection criteria focused exclusively on skin cancers, specifically cutaneous melanoma. Exclusions included studies covering various cancers, some non-dermatologic, and those not evaluating aspirin use independently but in conjunction with NSAIDs. The potential chemopreventive effects of aspirin and NSAIDs against melanoma have gained attention due to their association with a reduced risk of various cancers including gastric, colorectal, and breast. By inhibiting COX enzymes and the NF-κB pathway, these agents theoretically slow malignant cell activities, presenting a prospect for cancer prevention. Aspirin exhibits noteworthy effects, depleting growth-stimulating hormones, generating reactive oxygen species harmful to cancerous cells, and inhibiting COX-2 linked to cancer progression. Limited literature suggests survival benefits with aspirin use in stage II and III melanoma, possibly due to slowing disease progression, evident in smaller Breslow depths. Gender-specific responses to aspirin are notable, with some studies reporting a stronger chemopreventive correlation in females. It's crucial to note that geographic disparities, demographic cohorts, and individual-specific factors are confounding variables that may contribute to conflicting findings regarding aspirin's impact on melanoma. The association between aspirin use and melanoma risk is complex, with conflicting findings across diverse populations. Although it appears that more studies suggest a protective role for aspirin rather than not, evidence lacks consistency. Factors such as gender, geography, race, sun exposure, and health conditions play a role in shaping these varied outcomes, necessitating large-scale, prospective studies research and standardized parameters for more conclusive insights that may help guide tailored clinical strategies for melanoma prevention.

An oncogenic enhancer promotes melanoma progression via regulating ETV4 expression

BackgroundEnhancers are important gene regulatory elements that promote the expression of critical genes in development and disease. Aberrant enhancer can modulate cancer risk and activate oncogenes that lead to the occurrence of various cancers. However, the underlying mechanism of most enhancers in cancer remains unclear. Here, we aim to explore the function and mechanism of a crucial enhancer in melanoma.MethodsMulti-omics data were applied to identify an enhancer (enh17) involved in melanoma progression. To evaluate the function of enh17, CRISPR/Cas9 technology were applied to knockout enh17 in melanoma cell line A375. RNA-seq, ChIP-seq and Hi-C data analysis integrated with luciferase reporter assay were performed to identify the potential target gene of enh17. Functional experiments were conducted to further validate the function of the target gene ETV4. Multi-omics data integrated with CUT&Tag sequencing were performed to validate the binding profile of the inferred transcription factor STAT3.ResultsAn enhancer, named enh17 here, was found to be aberrantly activated and involved in melanoma progression. CRISPR/Cas9-mediated deletion of enh17 inhibited cell proliferation, migration, and tumor growth of melanoma both in vitro and in vivo. Mechanistically, we identified ETV4 as a target gene regulated by enh17, and functional experiments further support ETV4 as a target gene that is involved in cancer-associated phenotypes. In addition, STAT3 acts as a transcription factor binding with enh17 to regulate the transcription of ETV4.ConclusionsOur findings revealed that enh17 plays an oncogenic role and promotes tumor progression in melanoma, and its transcriptional regulatory mechanisms were fully elucidated, which may open a promising window for melanoma prevention and treatment.

Membrane-fused and mannose-targeted vesicles as immunoenhanced biomimetic nanovaccines for prevention and therapeutics of melanoma

Melanoma is a tumor sensitive to immune response and its immunotherapy has been a research hotspot in recent years. By fusion of melanoma cell membranes and bacterial exosomes through sequential extrusion, we herein design a three-in-one multi-antigenic nanovaccine, namely TBM, to rapidly target immune system. TBM can induce RAW264.7 macrophage cells to differentiate into M1 type cells to release cytotoxic cytokines. It can also promote the maturation and antigen presentation of bone marrow-derived dendritic cells, thus activating spleen T cells to kill B16F10 melanoma cells in vitro. TBM can significantly inhibit the growth and metastasis of melanoma in vivo, and prolong the lifetime of mice, suggesting the preventive effects of vaccines. Further, we integrate cell membranes from mouse melanoma tissues into a novel personalized therapeutic vaccine, namely autologous TBM (ATBM). ATBM combined with Anti PD1 can activate anti-tumor immune response and increase the survival rate of melanoma allografted mice, as supported by eukaryotic reference mRNA-Seq transcriptome sequencing. Generally, this study demonstrates the preventive and therapeutic effects of biomimetic nanovaccines against melanoma, which may be extended to design personalized tumor vaccines for all tumors with immunogenicity, showing great clinical perspectives.

Nanoemulsified Essential Oil of Melaleuca leucadendron Leaves for Topical Application: In Vitro Photoprotective, Antioxidant and Anti-Melanoma Activities.

Melanoma, primarily caused by solar ultraviolet (UV) radiation, can be prevented by the use of sunscreens. However, the use of synthetic sunscreens raises environmental concerns. Natural compounds with antioxidant photoprotective properties and cytotoxic effects against cancer cells can be promising for the prevention and treatment of melanoma with less environmental effect. This study focuses on Melaleuca leucadendron essential oil (EO) for photoprotection and antitumor applications. EO was hydrodistilled from M. leucadendron leaves with a 0.59% yield. Gas chromatography-mass spectrometry detected monoterpenes and sesquiterpenes. Nanoemulsions were prepared with (NE-EO) and without EO (NE-B) using the phase inversion method, showing good stability, spherical or oval morphology, and a pseudoplastic profile. Photoprotective activity assessed spectrophotometrically showed that the NE-EO was more effective than NE-B and free EO. Antioxidant activity evaluated by DPPH and ABTS methods indicated that pure and nanoemulsified EO mainly inhibited the ABTS radical, showing IC50 40.72 and 5.30 µg/mL, respectively. Cytotoxicity tests on L-929 mouse fibroblasts, NGM human melanocyte, B16-F10 melanoma, and MeWo human melanoma revealed that EO and NE-EO were more cytotoxic to melanoma cells than to non-tumor cells. The stable NE-EO demonstrates potential for melanoma prevention and treatment. Further research is required to gain a better understanding of these activities.

Developing Engineered Nano-Immunopotentiators for the Stimulation of Dendritic Cells and Inhibition and Prevention of Melanoma.

This study aims to utilize PEGylated poly (lactic-co-glycolic acid) (PLGA) nanoparticles as a delivery system for simultaneous administration of the BRAFV600E peptide, a tumor-specific antigen, and imiquimod (IMQ). The objective is to stimulate dendritic cell (DC) maturation, activate macrophages, and facilitate antigen presentation in C57BL6 mice. PEG-PLGA-IMQ-BRAFV600E nanoparticles were synthesized using a PLGA-PEG-PLGA tri-block copolymer, BRAFV600E, and IMQ. Characterization included size measurement and drug release profiling. Efficacy was assessed in inhibiting BPD6 melanoma cell growth and activating immature bone marrow DCs, T cells, macrophages, and splenocyte cells through MTT and ELISA assays. In vivo, therapeutic and immunogenic effects potential was evaluated, comparing it to IMQ + BRAFV600E and PLGA-IMQ-BRAFV600E nanoparticles in inhibiting subcutaneous BPD6 tumor growth. The results highlight the successful synthesis of PEG-PLGA-IMQ-BRAFV600E nanoparticles (203 ± 11.1nm), releasing 73.4% and 63.2% of IMQ and BARFV600E, respectively, within the initial 48h. In vitro, these nanoparticles demonstrated a 1.3-fold increase in potency against BPD6 cells, achieving ~ 2.8-fold enhanced cytotoxicity compared to PLGA-IMQ-BRAFV600E. Moreover, PEG-PLGA-IMQ-BRAFV600E exhibited a 1.3-fold increase in potency for enhancing IMQ cytotoxic effects and a 1.1- to ~ 2.4-fold increase in activating DCs, T cells, macrophages, and splenocyte cells compared to IMQ-BRAFV600E and PLGA-IMQ-BRAFV600E. In vivo, PEG-PLGA-IMQ-BRAFV600E displayed a 1.3- to 7.5-fold increase in potency for inhibiting subcutaneous BPD6 tumor growth compared to the other formulations. The findings suggest that PEG-PLGA nanoparticles effectively promote DC maturation, T cell activation, and potentially macrophage activation. The study highlights the promising role of this nanocomposite in vaccine development.

Lipid traits and lipid-lowering drug target genes and risk of melanoma: a mendelian randomization study.

Our study aimed to investigate the role of lipids in melanoma risk and the effect of lipid-lowering drug targets on melanoma. Using Mendelian Randomization analysis, we examined the genetic agents of nine lipid-lowering drugs and their association with melanoma risk. We found that genetically proxied inhibition of HMGCR, ABCG5/ABCG8, and ANGPTL3 was associated with a reduced risk of melanoma. On the other hand, inhibition of LPL and Apo-B100 was significantly associated with an increased risk of melanoma. Sensitivity analyses did not reveal any statistical evidence of bias from pleiotropy or genetic confounding. We did not find a robust association between lipid traits NPC1L1, PCSK9, APOC3 inhibition, and melanoma risk. These findings were validated using two independent lipid datasets. Our analysis also revealed that HMGCR, ANGPTL3, and ABCG5/ABCG8 inhibitors reduced melanoma risk independent of their effects on lipids. This suggests that these targets may have potential for melanoma prevention or treatment. In conclusion, our study provides evidence for a causal role of lipids in melanoma risk and highlights specific lipid-lowering drug targets that may be effective in reducing the risk of melanoma. These findings contribute to the understanding of the underlying mechanisms of melanoma development and provide potential avenues for further research and therapeutic interventions.

Probiotic-derived amphiphilic exopolysaccharide self-assembling adjuvant delivery platform for enhancing immune responses

Enhancing immune response activation through the synergy of effective antigen delivery and immune enhancement using natural, biodegradable materials with immune-adjuvant capabilities is challenging. Here, we present NAPSL.p that can activate the Toll-like receptor 4 (TLR4) pathway, an amphiphilic exopolysaccharide, as a potential self-assembly adjuvant delivery platform. Its molecular structure and unique properties exhibited remarkable self-assembly, forming a homogeneous nanovaccine with ovalbumin (OVA) as the model antigen. When used as an adjuvant, NAPSL.p significantly increased OVA uptake by dendritic cells. In vivo imaging revealed prolonged pharmacokinetics of NAPSL. p-delivered OVA compared to OVA alone. Notably, NAPSL.p induced elevated levels of specific serum IgG and isotype titers, enhancing rejection of B16-OVA melanoma xenografts in vaccinated mice. Additionally, NAPSL.p formulation improved therapeutic effects, inhibiting tumor growth, and increasing animal survival rates. The nanovaccine elicited CD4+ and CD8+ T cell-based immune responses, demonstrating the potential for melanoma prevention. Furthermore, NAPSL.p-based vaccination showed stronger protective effects against influenza compared to Al (OH)3 adjuvant. Our findings suggest NAPSL.p as a promising, natural self-adjuvanting delivery platform to enhance vaccine design across applications.

PRESOLRE: study protocol for a primary school-based, cluster randomised controlled trial of three sun exposure risk prevention strategies on Reunion Island

IntroductionReunion Island, a French overseas department, is located in the southern hemisphere, close to the Capricorn tropic. This island has a multicultural and multiethnic population of 860 000 inhabitants, a...

Mortality trend of cutaneous melanoma in Montenegro from 1990-2018.

Every year, melanoma claims over 20,000 lives in Europe. In Montenegro, as in Europe, numerous campaigns have been initiated to raise public awareness about the importance of melanoma prevention and its early detection. Thus, accompanying current diagnostic and therapeutic protocols, new methods of melanoma diagnosis and treatment have been implemented. Studying the trend enables the identification of the groups most burdened by mortality and assesses whether there has been a change in trends based on interventions aiming to reduce mortality. The objective of this study is to evaluate the mortality trend from cutaneous melanoma in Montenegro for the period 1990-2018. We have utilized national data on the causes of death from melanoma, code 179 from the ninth and C43 from the tenth revision of the International Classification of Diseases, categorized by gender and age groups. The study utilized various regression techniques, including Joinpoint regression in the Joinpoint Program, Poisson regression, and linear regression in the SPSS 26th Program, to describe the trend. In Montenegro, during the period from 1990 to 2018, a total of 281 individuals died (51.6% male and 48.4% female). This ranks as the 13th leading cancer in terms of mortality among all cancers. The average age-standardized rate was 1.1 deaths per 100,000 (1.2 for males and 1.0 for females). The number of death cases has been increasing on average by 3.3% annually [average annual percentage change (AAPC) (95% CI) = 3.3 (1.7-4.9); p<0.001] on an overall level and by 5.4% annually among males [AAPC (95% CI) = 5.4 (3.6-7.3); p<0.001] due to the rises in the age groups 55-64 years and 65-74 years with an average annual percent change of respectively 3.2% [AAPC (95% CI) = 3.2 (0.8-5.8); p=0.012] and 5.4% [AAPC (95% CI) = 5.4 (2.7-8.1); p<0.001] overall level, and 4.8% [AAPC (95% CI) = 4.8 (2.4-7.3); p<0.001] and 7.5% [AAPC (95% CI) = 7.5 (4.9-10.2); p<0.001] among males. For females, an increase of 1.1% was recorded, which was not statistically significant [AAPC (95% CI) = 1.1 (-0.8-3.0); p=0.255]. Furthermore, there was a noted increase in the rates at an overall level [β (95% CI) = 0.027 (0.008-0.046); p=0.007] and in the age group 65-74 years [β (95% CI) = 0.249 (0.090-0.407); p=0.003], as well as among males at an overall level [β (95% CI) = 0.052 (0.025-0.079); p<0.001] and for age groups 45-54 years [β (95% CI) = 0.102 (0.011-0.193); p=0.030] and 65-74 [β (95% CI) = 0.410 (0.144-0.676); p=0.004]. In contrast, the rates for females remained constant. The three age groups most burdened by melanoma skin cancer mortality are 65-74 years (23.5%), 55-64 years (21.7%) and 75-84 years (19.2%). The results of regression analyses indicate a significant rise in both the number of death cases and mortality rates overall, specifically among males in Montenegro. In females, however, the increase in the number of death cases and rates is not statistically significant. Preventive campaign activities should be redirected towards the most vulnerable groups in terms of mortality, namely males and the elderly population.

Vitamin D in Melanoma: Potential Role of Cytochrome P450 Enzymes.

Vitamin D is a promising anticancer agent for the prevention and treatment of several cancers, including melanoma. Low 25-hydroxyvitamin D levels, a routinely used marker for vitamin D, have been suggested as one of the factors in the development and progression of melanoma. The parent vitamin D needs activation by cytochrome P450 (CYP) enzymes to exert its actions via the vitamin D receptor (VDR). This review discusses the role of vitamin D in melanoma and how CYP-mediated metabolism can potentially affect the actions of vitamin D. Through interacting with the retinoid X receptor, VDR signaling leads to anti-inflammatory, antioxidative, and anticancer actions. Calcitriol, the dihydroxylated form of vitamin D3, is the most active and potent ligand of VDR. CYP27A1, CYP27B1, and CYP2R1 are involved in the activation of vitamin D, whereas CYP24A1 and CYP3A4 are responsible for the degradation of the active vitamin D. CYP24A1, the primary catabolic enzyme of calcitriol, is overexpressed in melanoma tissues and cells. Several drug classes and natural health products can modulate vitamin D-related CYP enzymes and eventually cause lower levels of vitamin D and its active metabolites in tissues. Although the role of vitamin D in the development of melanoma is yet to be fully elucidated, it has been proposed that melanoma prevention may be significantly aided by increased vitamin D signaling. Furthermore, selective targeting of the catabolic enzymes responsible for vitamin D degradation could be a plausible strategy in melanoma therapy. Vitamin D signaling can be improved by utilizing dietary supplements or by modulating CYP metabolism. A positive association exists between the intake of vitamin D supplements and improved prognosis for melanoma patients. Further investigation is required to determine the function of vitamin D supplementation and specific enzyme targeting in the prevention of melanoma.

Melanoma-associated melanocortin 1 receptor variants confer redox signaling-dependent protection against oxidative DNA damage

Cutaneous melanoma, a lethal skin cancer, arises from malignant transformation of melanocytes. Solar ultraviolet radiation (UVR) is a major environmental risk factor for melanoma since its interaction with the skin generates DNA damage, either directly or indirectly via oxidative stress. Pheomelanin pigments exacerbate oxidative stress in melanocytes by UVR-dependent and independent mechanisms. Thus, oxidative stress is considered to contribute to melanomagenesis, particularly in people with pheomelanic pigmentation. The melanocortin 1 receptor gene (MC1R) is a major melanoma susceptibility gene. Frequent MC1R variants (varMC1R) associated with fair skin and red or yellow hair color display hypomorphic signaling to the cAMP pathway and are associated with higher melanoma risk. This association is thought to be due to production of photosensitizing pheomelanins as well as deficient induction of DNA damage repair downstream of varMC1R. However, the data on modulation of oxidative DNA damage repair by MC1R remain scarce. We recently demonstrated that varMC1R accelerates clearance of reactive oxygen species (ROS)-induced DNA strand breaks in an AKT-dependent manner. Here we show that varMC1R also protects against ROS-dependent formation of 8-oxodG, the most frequent oxidative DNA lesion. Since the base excision repair (BER) pathway mediates clearance of these DNA lesions, we analyzed induction of BER enzymes in human melanoma cells of varMC1R genotype. Agonist-mediated activation of both wildtype (wtMC1R) and varMC1R significantly induced OGG and APE-1/Ref1, the rate-limiting BER enzymes responsible for repair of 8-oxodG. Moreover, we found that NADPH oxidase (NOX)-dependent generation of ROS was responsible for AKT activation and oxidative DNA damage repair downstream of varMC1R. These observations provide a better understanding of the functional properties of melanoma-associated MC1R alleles and may be useful for the rational development of strategies to correct defective varMC1R responses for efficient photoprotection and melanoma prevention in fair-skinned individuals.

A Social Media-Delivered Melanoma Prevention Program for Young Women Engaged in Frequent UV Tanning: Protocol for a Randomized Controlled Trial.

Rates of melanoma have increased dramatically in the United States over the past 25 years, and it has become among the most prevalent cancers for young adult women. Intentional skin tanning leads to a pattern of intense and intermittent UV radiation exposure that is associated with increased risk of melanoma. Frequent tanning is most common among young women and is linked to a variety of sociocultural pressures that negatively impact body image and drive appearance control behaviors. Unfortunately, there are no established interventions designed for frequent tanners. This intervention addresses this gap with unique content informed by body image and acceptance-based interventions. The intervention is delivered using Facebook secret groups, an approach designed to support behavior change and ensure scalability. This study aims to describe the rationale and methodology of a randomized controlled trial of a melanoma prevention program targeting young women engaged in frequent indoor or outdoor UV tanning. Participants are women aged 18-25 years who report high-risk tanning (ie, at least 10 indoor tanning sessions in the past 12 months or 10 outdoor sessions in the previous summer). After recruitment and screening, participants completed a baseline survey and were randomly assigned to receive the intervention or an attention-matched control condition. Both conditions were 8-week-long Facebook groups (approximately 25 members each) with daily posting of content. Follow-up surveys are administered at 3, 8, and 18 months after baseline. The primary trial outcome is the combined number of indoor and outdoor tanning sessions reported at the 8-month follow-up. Hypothesized intervention mediators are assessed at the 3-month follow-up. This project was funded by a National Cancer Institute award (R01 CA218068), and the trial procedures were approved by the University of Kentucky Institutional Review Board in February 2020. Trial recruitment and enrollment occurred in 6 waves of data collection, which started in February 2022 and closed in May 2023. The study is closed to enrollment but remains open for follow-ups, and this protocol report was prepared before data analyses. As of February 2024, all participants have completed the 8-month follow-up assessment, and data collection is scheduled to close by the end of 2024 after the collection of the 18-month follow-up. This trial will contribute unique knowledge to the field of skin cancer prevention, as no fully powered trials have examined the efficacy of an intervention designed for frequent indoor or outdoor tanning. The trial may also contribute evidence of the value in translating principles of body image and acceptance-based interventions into the field of skin cancer prevention and beyond. If successful, the use of the Facebook platform is intended to aid in dissemination as it provides a way to embed the intervention into individuals' everyday routines. ClinicalTrials.gov NCT03441321; https://clinicaltrials.gov/study/NCT03441321. DERR1-10.2196/56562.