The pathogenesis of melanoma induced by ultraviolet radiation

Melanin: Nature's 4th bioorganic polymer

The pigments known as the melanins are widely recognized for their responsibility in the coloration of human skin, eyes, hair, and minimising the harmful effects of solar ultraviolet radiation. But specialists are aware that the melanins are present in all living kingdoms, barring viruses, and have functionality that extends beyond neutralizing ionising radiation. The ubiquitous presence of melanin in almost all human organs, recognized in recent years, as well as the presence of melanin in organisms that are evolutionarily distant from each other, indicate the fundamental importance of this class of material for all life forms. In this review, we argue for the need to accept melanins as the fourth primordial class of biological polymers, along with nucleic acids, proteins and polysaccharides. We consistently compare the properties of these canonical biological polymers with the properties of melanin and highlight key features that fundamentally distinguish melanins, their function and its mysteries.

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.

Race and Ethnicity, Socioeconomic Factors, and Epigenetic Age Acceleration in Survivors of Childhood Cancer

Importance

Current research in epigenetic age acceleration (EAA) is limited to non-Hispanic White individuals. It is imperative to improve inclusivity by considering racial and ethnic minorities in EAA research.

Objective

To compare non-Hispanic Black with non-Hispanic White survivors of childhood cancer by examining the associations of EAA with cancer treatment exposures, potential racial and ethnic disparity in EAA, and mediating roles of social determinants of health (SDOH).

Design, Setting, and Participants

In this cross-sectional study, participants were from the St Jude Lifetime Cohort, which was initiated in 2007 with ongoing follow-up. Eligible participants included non-Hispanic Black and non-Hispanic White survivors of childhood cancer treated at St Jude Children's Research Hospital between 1962 and 2012 who had DNA methylation data. Data analysis was conducted from February 2023 to May 2024.

Exposure

Three treatment exposures for childhood cancer (chest radiotherapy, alkylating agents, and epipodophyllotoxin).

Main Outcomes and Measures

DNA methylation was generated from peripheral blood mononuclear cell-derived DNA. EAA was calculated as residuals from regressing Levine or Horvath epigenetic age on chronological age. SDOH included educational attainment, annual personal income, and the socioeconomic area deprivation index (ADI). General linear models evaluated cross-sectional associations of EAA with race and ethnicity (non-Hispanic Black and non-Hispanic White) and/or SDOH, adjusting for sex, body mass index, smoking, and cancer treatments. Adjusted least square means (ALSM) of EAA were calculated for group comparisons. Mediation analysis treated SDOH as mediators with average causal mediation effect (ACME) calculated for the association of EAA with race and ethnicity.

Results

Among a total of 1706 survivors including 230 non-Hispanic Black survivors (median [IQR] age at diagnosis, 9.5 [4.3-14.3] years; 103 male [44.8%] and 127 female [55.2%]) and 1476 non-Hispanic White survivors (median [IQR] age at diagnosis, 9.3 [3.9-14.6] years; 766 male [51.9%] and 710 female [48.1%]), EAA was significantly greater among non-Hispanic Black survivors (ALSM = 1.41; 95% CI, 0.66 to 2.16) than non-Hispanic White survivors (ALSM = 0.47; 95% CI, 0.12 to 0.81). Among non-Hispanic Black survivors, EAA was significantly increased among those exposed to chest radiotherapy (ALSM = 2.82; 95% CI, 1.37 to 4.26) vs those unexposed (ALSM = 0.46; 95% CI, -0.60 to 1.51), among those exposed to alkylating agents (ALSM = 2.33; 95% CI, 1.21 to 3.45) vs those unexposed (ALSM = 0.95; 95% CI, -0.38 to 2.27), and among those exposed to epipodophyllotoxins (ALSM = 2.83; 95% CI, 1.27 to 4.40) vs those unexposed (ALSM = 0.44; 95% CI, -0.52 to 1.40). The association of EAA with epipodophyllotoxins differed by race and ethnicity (β for non-Hispanic Black survivors, 2.39 years; 95% CI, 0.74 to 4.04 years; β for non-Hispanic White survivors, 0.68; 95% CI, 0.05 to 1.31 years) and the difference was significant (1.77 years; 95% CI, 0.01 to 3.53 years; P for interaction = .049). Racial and ethnic disparities in EAA were mediated by educational attainment (

Conclusions and Relevance

In this cross-sectional study of childhood cancer survivors, race and ethnicity moderated the association of EAA with epipodophyllotoxin exposure and racial and ethnic differences in EAA were partially mediated by educational attainment and ADI, indicating differential treatment toxic effects by race and ethnicity. These findings suggest that improving social support systems may mitigate socioeconomic disadvantages associated with even greater accelerated aging and reduce health disparities among childhood cancer survivors.

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MESH Headings

• Humans
• Female
• Male
• Cross-Sectional Studies
• Cancer Survivors/statistics & numerical data
• Child
• Socioeconomic Factors
• Epigenesis, Genetic
• Neoplasms/genetics
• Neoplasms/ethnology
• Adolescent
• White People/statistics & numerical data
• White People/genetics
• Black or African American/statistics & numerical data
• Black or African American/genetics
• DNA Methylation
• Adult
• Ethnicity/statistics & numerical data
• Social Determinants of Health/statistics & numerical data

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Grants

• P30 CA021765 NCI NIH HHS
• U01 CA195547 NCI NIH HHS
• U24 CA055727 NCI NIH HHS

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Affiliation(s)

Cheng Chen The Fourth Affiliated Hospital of Soochow University, SuZhou, Jiangsu, China State Key Laboratory of Systems Medicine for Cancer, Center for Single-Cell Omics, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee
Noel-Marie Plonski Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee
Qian Dong Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee
Nan Song College of Pharmacy, Chungbuk National University, Cheongju, Korea
Xijun Zhang Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee
Hemang M. Parikh Health Informatics Institute, Morsani College of Medicine, University of South Florida, Tampa
Emily R. Finch Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee
John Easton Department of Computational Biology, St Jude Children’s Research Hospital, Memphis, Tennessee
Heather L. Mulder Department of Computational Biology, St Jude Children’s Research Hospital, Memphis, Tennessee
Emily Walker Hartwell Center, St Jude Children’s Research Hospital, Memphis, Tennessee
Geoffrey Neale Hartwell Center, St Jude Children’s Research Hospital, Memphis, Tennessee
Yue Pan Department of Biostatistics, St Jude Children’s Research Hospital, Memphis, Tennessee
Qian Li Department of Biostatistics, St Jude Children’s Research Hospital, Memphis, Tennessee
Jinghui Zhang Department of Computational Biology, St Jude Children’s Research Hospital, Memphis, Tennessee
Kevin Krull Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee Department of Psychology, St Jude Children’s Research Hospital, Memphis, Tennessee
Leslie L. Robison Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee
Gregory T. Armstrong Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee
Yutaka Yasui Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee
Kirsten K. Ness Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee
Melissa M. Hudson Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee Department of Oncology, St Jude Children’s Research Hospital, Memphis, Tennessee
Hui Wang State Key Laboratory of Systems Medicine for Cancer, Center for Single-Cell Omics, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
I-Chan Huang Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee
Zhaoming Wang Department of Epidemiology and Cancer Control, St Jude Children’s Research Hospital, Memphis, Tennessee Department of Computational Biology, St Jude Children’s Research Hospital, Memphis, Tennessee

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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.

Journey through the spectacular landscape of melanocortin 1 receptor

The physiological role of α-melanocyte stimulating hormone in regulating integumental pigmentation of many vertebrate species has been recognized since the 1960's. However, its physiological significance for human pigmentation remained enigmatic until the 1990's. α-Melanocyte stimulating hormone and related melanocortins are synthesized locally in the skin, primarily by keratinocytes, in addition to the pituitary gland, and therefore act as paracrine factors for melanocytes. Human melanocytes express the melanocortin 1 receptor, which recognizes α-melanocyte stimulating hormone and the related adrenocorticotropic hormone as agonists. This review summarizes the current knowledge of the pleotropic effects of the activated melanocortin 1 receptor that maintain human melanocyte homeostasis by regulating melanogenesis and the response to environmental stressors, mainly solar radiation. Certain allelic variants of the melanocortin 1 receptor gene are associated with specific pigmentary phenotypes in various human populations. Variants associated with red hair phenotype compromise the function of the encoded receptor. Activation of the human melanocortin 1 receptor regulates eumelanin synthesis and enhances DNA damage response of melanocytes to solar radiation and oxidative stressors. We describe how synthetic selective melanocortin 1 receptor agonists can be efficacious as sunless tanning agents, for treatment of vitiligo and photosensitivity disorders, and for prevention of skin cancer, including melanoma.

Causal relationship between sex hormones and cutaneous melanoma: a two-sample Mendelian randomized study

OBJECTIVE

This study aimed to elucidate the genetic aspects of the relationship between sex hormones and cutaneous melanoma risk, providing valuable insights into this complex association.

METHODS

In this study, we used estradiol, bioavailable testosterone, sex hormone-binding globulin, and total testosterone as the exposure and melanoma as the outcome for two-sample Mendelian randomization analysis. In this study, a random-effects inverse-variance weighting (IVW) model was used as the main analysis model, and the corresponding weighted median, simple mode, weighted mode, and Mendelian randomization‒Egger methods were used as supplementary methods. We assessed both heterogeneity and horizontal pleiotropy in our study, scrutinizing whether the analysis results were affected by any individual single nucleotide polymorphism.

RESULTS

The random-effects IVW method indicated that estradiol [odds ratio (OR), 1.000; 95% confidence interval (CI), 0.998-1.003; P = 0.658], bioavailable testosterone (OR = 1.001, 95% CI, 0.999-1.003; P = 0.294), sex hormone-binding globulin (IVW: OR, 1.000; 95% CI, 0.998-1.003; P = 0.658), and total testosterone (IVW: OR, 1.002; 95% CI, 0.999-1.005; P = 0.135) were not genetically linked to cutaneous melanoma. No analyses exhibited heterogeneity, horizontal pleiotropy, or deviations.

CONCLUSION

We were unable to find genetic evidence for a causal relationship between sex hormones and the occurrence of cutaneous melanoma in this study. These results are limited by sample size and population, so the causal relationship between sex hormones and cutaneous melanoma needs to be further studied.

Pathogenic mechanisms and etiologic aspects of Mycobacterium avium subspecies paratuberculosis as an infectious cause of cutaneous melanoma

Infectious etiologies have previously been proposed as causes of both melanoma and non-melanoma skin cancer. This exploratory overview explains and presents the evidence for the hypothesis that a microorganism excreted in infected ruminant animal feces, Mycobacterium avium subspecies paratuberculosis (MAP), is the cause of some cases of cutaneous melanoma (CM). Occupational, residential, and recreational contact with MAP-contaminated feces, soil, sand, and natural bodies of water may confer a higher rate of CM. Included in our hypothesis are possible reasons for the differing rates and locations of CM in persons with white versus nonwhite skin, why CM develops underneath nails and in vulvar skin, why canine melanoma is an excellent model for human melanoma, and why the Bacille Calmette-Guérin (BCG) vaccine has demonstrated efficacy in the prevention and treatment of CM. The pathogenic mechanisms and etiologic aspects of MAP, as a transmittable agent underlying CM risk, are carefully deliberated in this paper. Imbalances in gut and skin bacteria, genetic risk factors, and vaccine prevention/therapy are also discussed, while acknowledging that the evidence for a causal association between MAP exposure and CM remains circumstantial.

Factors Influencing Effects of Low-dose Radiation Exposure

ABSTRACT

It is now well accepted that the mechanisms induced by low-dose exposures to ionizing radiation (LDR) are different from those occurring after high-dose exposures. However, the downstream effects of these mechanisms are unclear as are the quantitative relationships between exposure, effect, harm, and risk. In this paper, we will discuss the mechanisms known to be important with an overall emphasis on how so-called "non-targeted effects" (NTE) communicate and coordinate responses to LDR. Targeted deposition of ionizing radiation energy in cells causing DNA damage is still regarded as the dominant trigger leading to all downstream events whether targeted or non-targeted. We regard this as an over-simplification dating back to formal target theory. It ignores that last 100 y of biological research into stress responses and signaling mechanisms in organisms exposed to toxic substances, including ionizing radiation. We will provide evidence for situations where energy deposition in cellular targets alone cannot be plausible as a mechanism for LDR effects. An example is where the energy deposition takes place in an organism not receiving the radiation dose. We will also discuss how effects after LDR depend more on dose rate and radiation quality rather than actual dose, which appears rather irrelevant. Finally, we will use recent evidence from studies of cataract and melanoma induction to suggest that after LDR, post-translational effects, such as protein misfolding or defects in energy metabolism or mitochondrial function, may dominate the etiology and progression of the disease. A focus on such novel pathways may open the way to successful prophylaxis and development of new biomarkers for better risk assessment after low dose exposures.

Design of Bombyx mori (B. mori) Silk Fibroin Microspheres for Developing Biosafe Sunscreen

Sunscreens play a crucial role in protecting the skin from ultraviolet (UV) damage. However, present commercial sunscreens have a tendency to generate free radicals in the UV window, resulting in serious inflammatory responses and health problems. In this study, we demonstrate that silk fibroin microspheres (SFMPs) assembled from regenerated silk fibroin (SF) could scavenge free radicals while preventing UV irradiation and thus present a promising sunscreen. The SFMP reflected more UV light than SF and presented a higher stability than that of organic commercial sunscreens. In vitro analysis proved that SFMP could more efficiently scavenge the hydroxy radical and reduce the intracellular reactive oxygen than titanium dioxide (TiO2). In vivo experiments exhibited that SFMP provided stronger skin protection against UV irradiation than commercial sunscreens and TiO2. Furthermore, SFMP treatment significantly inhibited the skin inflammatory response. This work suggests that the SFMP has great potential to be developed into a biosafe sunscreen.

Rural-Urban Differences in Sun Exposure and Protection Behaviors in the United States

BACKGROUND

Evidence regarding whether rural residence is a risk factor for skin cancer is mixed. We compared sun exposure and protection behaviors between rural and urban residents by ethno-racial group in the United States.

METHODS

We analyzed data from three (2013-2018) National Health and Nutrition Examination Survey cycles. We compared self-reported sun exposure and protection measures (sunburn, time spent outside, sunscreen use, wearing long sleeves, staying in shade) by rural-urban residential status using survey-weighted logistic regression models stratified by ethno-racial group, adjusting for age, sex, income, education, body mass index, and smoking.

RESULTS

Hispanic rural versus urban residents more often reported sunburns in the past year [41.6% vs. 31.2%, adjusted OR (aOR): 1.46 (1.15-1.86)]. White rural versus urban residents more often spent 2+ hours outside on workdays [42.9% vs. 29.1%, aOR: 1.60 (1.27-2.01)] and non-workdays [72.2% vs. 64.8%, aOR: 1.45 (1.12-1.88)] and less often used sunscreen [26.0% vs. 35.1%, aOR: 0.74 (0.59-0.93)] and stayed in the shade [21.7% vs. 26.7%, aOR: 0.72 (0.57-0.89)]. Black rural versus urban residents stayed in the shade less often [31.6% vs. 43.9%, aOR: 0.60 (0.39-0.91)] but less often spent 2+ hours outside on non-workdays [47.6% vs. 56.8%, aOR: 0.67 (0.51-0.90)].

CONCLUSIONS

Across all ethno-racial groups included, rural residents reported greater sun risk behaviors than urban residents, with some nuances by ethno-racial identity, suggesting rural residence is a potential risk factor for skin cancer.

IMPACT

Sun protection promotion programs should consider rural-urban settings while also accounting for ethno-racial identities.

Vitamin D and Cutaneous Melanoma Risk: An Umbrella Review of Systematic Reviews and Meta-Analyses

Background: Vitamin D (VitD) properties can impact cancer cells. Despite the documented link between VitD levels and prevalence of several cancer types, conflicting findings have been reported for cutaneous melanoma (CM). Objective: This overview aims to compile the evidence from existing systematic reviews and meta-analyses, emphasizing the relationships between VitD serum levels, intake, receptor (VDR) gene polymorphisms, and CM risk. Methods: A literature search in electronic databases was conducted, based on certain inclusion criteria. Results: Twenty-one studies were included. Conflicting evidence between high VitD serum levels, dietary/supplementary intake, and CM risk is highlighted. VDR polymorphisms may play a role in the intricate CM pathogenesis. Also, high serum levels of VitD are associated with improved CM prognosis. Conclusions: This overview showed that the impact of VitD on CM is not clear, and thus further research is suggested to explore its true effect size on CM risk.

25 year trends in cancer incidence and mortality among adults aged 35-69 years in the UK, 1993-2018: retrospective secondary analysis

OBJECTIVE

To examine and interpret trends in UK cancer incidence and mortality for all cancers combined and for the most common cancer sites in adults aged 35-69 years.

DESIGN

Retrospective secondary data analysis.

DATA SOURCES

Cancer registration data, cancer mortality and national population data from the Office for National Statistics, Public Health Wales, Public Health Scotland, Northern Ireland Cancer Registry, NHS England, and the General Register Office for Northern Ireland.

SETTING

23 cancer sites were included in the analysis in the UK.

PARTICIPANTS

Men and women aged 35-69 years diagnosed with or who died from cancer between 1993 to 2018.

MAIN OUTCOME MEASURES

Change in cancer incidence and mortality age standardised rates over time.

RESULTS

The number of cancer cases in this age range rose by 57% for men (from 55 014 cases registered in 1993 to 86 297 in 2018) and by 48% for women (60 187 to 88 970) with age standardised rates showing average annual increases of 0.8% in both sexes. The increase in incidence was predominantly driven by increases in prostate (male) and breast (female) cancers. Without these two sites, all cancer trends in age standardised incidence rates were relatively stable. Trends for a small number of less common cancers showed concerning increases in incidence rates, for example, in melanoma skin, liver, oral, and kidney cancers. The number of cancer deaths decreased over the 25 year period, by 20% in men (from 32 878 to 26 322) and 17% in women (28 516 to 23 719); age standardised mortality rates reduced for all cancers combined by 37% in men (-2.0% per year) and 33% in women (-1.6% per year). The largest decreases in mortality were noted for stomach, mesothelioma, and bladder cancers in men and stomach and cervical cancers and non-Hodgkin lymphoma in women. Most incidence and mortality changes were statistically significant even when the size of change was relatively small.

CONCLUSIONS

Cancer mortality had a substantial reduction during the past 25 years in both men and women aged 35-69 years. This decline is likely a reflection of the successes in cancer prevention (eg, smoking prevention policies and cessation programmes), earlier detection (eg, screening programmes) and improved diagnostic tests, and more effective treatment. By contrast, increased prevalence of non-smoking risk factors are the likely cause of the observed increased incidence for a small number of specific cancers. This analysis also provides a benchmark for the following decade, which will include the impact of covid-19 on cancer incidence and outcomes.

A Review of Current and Pipeline Drugs for Treatment of Melanoma

Malignant melanoma is the most aggressive form of skin cancer. Standard treatment options include surgery, radiation therapy, systemic chemotherapy, targeted therapy, and immunotherapy. Combining these modalities often yields better responses. Surgery is suitable for localized cases, sometimes involving lymph node dissection and biopsy, to assess the spread of the disease. Radiation therapy may be sometimes used as a standalone treatment or following surgical excision. Systemic chemotherapy, while having low response rates, is utilized as part of combination treatments or when other methods fail. The development of resistance to systemic chemotherapies and associated side effects have prompted further research and clinical trials for novel approaches. In the case of advanced-stage melanoma, a comprehensive approach may be necessary, incorporating targeted therapies and immunotherapies that demonstrate significant antitumor activity. Targeted therapies, including inhibitors targeting BRAF, MEK, c-KIT, and NRAS, are designed to block the specific molecules responsible for tumor growth. These therapies show promise, particularly in patients with corresponding mutations. Combination therapy, including BRAF and MEK inhibitors, has been evidenced to improve progression-free survival; however, concerns about resistance and cutaneous toxicities highlight the need for close monitoring. Immunotherapies, leveraging tumor-infiltrating lymphocytes and CAR T cells, enhance immune responses. Lifileucel, an FDA-approved tumor-infiltrating lymphocyte therapy, has demonstrated improved response rates in advanced-stage melanoma. Ongoing trials continue to explore the efficacy of CAR T-cell therapy for advanced melanoma. Checkpoint inhibitors targeting CTLA-4 and PD-1 have enhanced outcomes. Emerging IL-2 therapies boost dendritic cells, enhancing anticancer immunity. Oncolytic virus therapy, approved for advanced melanoma, augments treatment efficacy in combination approaches. While immunotherapy has significantly advanced melanoma treatment, its success varies, prompting research into new drugs and factors influencing outcomes. This review provides insights into current melanoma treatments and recent therapeutic advances.

Photosensibilisierende Antihypertensiva und das Hautkrebsrisiko bei postmenopausalen Frauen: Photosensitizing antihypertensive medication and risk of skin cancer among postmenopausal women

Hintergrund

Es gibt nur wenige prospektive Studien, die die Dosis‐Wirkungs‐Beziehung zwischen der Anwendung einiger photosensibilisierender Antihypertensiva und Hautkrebs untersucht haben.

Patienten und Methodik

Anhand prospektiver Daten aus der Women's Health Initiative Observational Study untersuchten wir den Zusammenhang zwischen der Anwendung von Antihypertensiva und dem Risiko für nicht melanozytären Hautkrebs (NMSC) und dem Melanom bei postmenopausalen Frauen im Alter von 50–79 Jahren (n = 64 918). Dabei wurden multivariable Cox‐Regressionsmodelle (Proportional‐Hazard‐Modelle) verwendet und Hazard Ratios (HR) sowie 95%‐Konfidenzintervalle (KI) berechnet.

Ergebnisse

8777 NMSC und 1227 Melanom‐Fälle wurden beobachtet. Die Anwendung von Antihypertensiva (HR [95%‐KI]: 1,12 [1,07–1,18]), ACE‐Hemmern (1,09 [1,01–1,18]), Kalziumkanalblockern (1,13 [1,05–1,22]), Diuretika (1,20 [1,12–1,27]), Schleifendiuretika (1,17 [1,07–1,28]) und Thiaziden (1,17 [1,03–1,33]) war jeweils mit einem erhöhten NMSC‐Risiko assoziiert. Das NMSC‐Risiko stieg linear mit der Anwendung mehrerer Antihypertensiva (p‐Trend = 0,02) und mit zunehmender Anwendungsdauer (p‐Trend < 0,01) an. Antihypertensiva (1,15 [1,00–1,31]), Angiotensin‐II‐Rezeptorblocker (1,82 [1,05–3,15]) und Diuretika (1,34 [1,13–1,59]) waren jeweils mit einem erhöhten Melanomrisiko assoziiert. Zwischen der Anwendung von Antihypertensiva und der Melanom‐Inzidenz wurde eine Effektmodifikation durch Exposition gegenüber Sonnenlicht‐Exposition beobachtet (p‐Interaktion = 0,02).

Schlussfolgerungen

Die Anwendung von Antihypertensiva allgemein und einiger einzelner Klassen von Antihypertensiva ging mit einer erhöhten Inzidenz von NMSC und Melanomen einher, wobei eine Dosis‐Wirkungs‐Beziehung bestand.

Photosensitizing antihypertensive medication and risk of skin cancer among postmenopausal women

BACKGROUND

Few prospective studies exist with an evaluation of a dose-response relationship between use of some photosensitizing antihypertensive medications and skin cancer.

PATIENT AND METHODS

We used prospective data from the Women's Health Initiative Observational Study to investigate the association between antihypertensive use and risk of non-melanoma skin cancer (NMSC) and melanoma in postmenopausal women aged 50-79 years at baseline (n  =  64,918). Multivariable Cox proportional hazards regression models were used and hazard ratios (HRs) and 95 confidence intervals (CIs) were calculated.

RESULTS

8,777 NMSC and 1,227 melanoma cases were observed. Use of antihypertensives (HR [95% CI]: 1.12 [1.07-1.18]), ACE inhibitors (1.09 [1.01-1.18]), calcium channel blockers (1.13 [1.05-1.22]), diuretics (1.20 [1.12-1.27]), loop diuretics (1.17 [1.07-1.28]), and thiazides (1.17 [1.03-1.33]) were each associated with higher NMSC risk. NMSC risk linearly increased with use of multiple antihypertensives (p-trend  =  0.02) and with longer duration of use (p-trend < 0.01). Antihypertensives (1.15 [1.00-1.31]), angiotensin-II receptor blockers (1.82 [1.05-3.15]), and diuretics (1.34 [1.13-1.59]) were each associated with elevated melanoma risk. Effect modification by solar radiation exposure was found between antihypertensive use and incidence of melanoma (p-interaction  =  0.02).

CONCLUSIONS

Use of antihypertensives overall, and several individual classes thereof, were associated with higher incidence of NMSC and melanoma with dose-response relationship.

Clinical Applications of Sunscreens and Formulation Advancements

Sunscreens cover the big market ratio in terms of cosmetic applications, but the therapeutic necessity of sunscreen still needs to be uncovered in the clinical context. Clinically, sunscreens are being employed more often nowadays as a result of the rising consequences of skin malignancies and the photodamaging effects of UV radiation. Sunscreens are essential to prevent aging by shielding the skin from the harmful effects of ultraviolet (UV) radiation. Over the recent decades, there has been a significant evolution in the usage of sunscreens as photo protectants. The demand for sunscreen formulations will inevitably rise as more people become aware of the protection that sunscreens provide against tanning, photoaging, non-melanoma skin cancers, premalignant skin lesions, and skin melanomas. The novel contemporary formulation techniques are also beneficial in enhancing the product's aesthetic look and quality. Recently, regulatory agencies have also started paying attention to the regulation of the clinical application, efficacy, and safety parameters related to sunscreen. This review underlines the pathophysiological response of UV exposure with the therapeutic applications of sunscreen in various dermatological conditions and the recent formulation advancements in the development of sunscreen.

Ethyl Acetate Fraction from a Catalpa ovata G. Don Extract Inhibits ɑ-MSH-Induced Melanogenesis through the cAMP/CREB Pathway

The whitening effect of reducing skin pigmentation is one of the most important goals of cosmetics. The purpose of this study was to determine whether Catalpa ovata extract and its fractions have potential as natural skin-lightening agents. Initially, we screened various fractions of Catalpa ovata extract using an in vitro antioxidant assay. Then, the inhibitory effects of C. ovata extract and its fraction on melanogenesis and the related mechanisms were investigated in B16F1 melanoma cells. The results showed that the ethyl acetate fraction (EF) from C. ovata extract markedly inhibited melanin synthesis in a dose-dependent manner at non-toxic concentrations. Furthermore, EF downregulated both the protein and mRNA levels of tyrosinase, which is a specific enzyme that catalyzes the conversion of tyrosine into melanin. We also found that EF decreased the microphthalmia-associated transcription factor (MITF) at the protein and mRNA levels. EF increased the phosphorylation of ERK and suppressed the phosphorylation of JNK and p38 in ɑ-MSH-induced B16F1 cells. These results indicate that EF can regulate the MAPK pathway. In addition, EF has an anti-melanogenic effect via the downregulation of intracellular cyclic-AMP (cAMP). Nineteen major compounds of EF were identified using LC-MS/MS. Taken together, these results suggest that EF may be a potential anti-melanogenic agent for use in skin-whitening cosmetics and in topical treatments for hyperpigmentation disorders.

Quality by design-based development and optimization of fourth-generation ternary solid dispersion of standardized Piper longum extract for melanoma therapy

The study aimed to enhance the solubility, dissolution, and oral bioavailability of standardized Piper longum fruits ethanolic extract (PLFEE) via fourth-generation ternary solid dispersion (SD) for melanoma therapy. With the use of solvent evaporation method, the standardized PLFEE was formulated into SD, optimized using Box-Wilson's central composite design (CCD), and evaluated for pharmaceutical performance and in vivo anticancer activity against melanoma (B16F10)-bearing C57BL/6 mice. The optimized SD showed good accelerated stability, high yield, drug content, and content uniformity for bioactive marker piperine (PIP). The X-ray diffraction (XRD), differential scanning calorimetry (DSC), polarized light microscopy (PLM), and selected area electron diffraction (SAED) analysis revealed its amorphous nature. The attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and high-performance thin layer chromatography (HPTLC) revealed the compatibility of excipients with the PLFEE. The contact angle measurement and in vitro dissolution study revealed excellent wetting of SD and improved dissolution profile as compared to the plain PLFEE. The in vivo oral bioavailability of SD reflected a significant (p < 0.05) improvement in bioavailability (Frel = 188.765%) as compared to plain extract. The in vivo tumor regression study revealed the improved therapeutic activity of SD as compared to plain PLFEE. Further, the SD also improved the anticancer activity of dacarbazine (DTIC) as an adjuvant therapy. The overall result revealed the potential of developed SD for melanoma therapy either alone or as an adjuvant therapy with DTIC.

Distinctive lower incidence rates of cutaneous melanoma on the hips and lower extremities of men

BACKGROUND

Cutaneous melanomas (CMs) are more frequently found on the trunk in men, and on the hip and lower extremities (legs) in women. This discrepancy has been attributed to greater exposure to ultraviolet (UV) radiation of women's legs due to their dressing habits.

OBJECTIVES

To understand the sex difference in the bodily distribution of CMs, especially those on the legs.

METHODS

This was a cancer registry-based cohort study. CM incidences, relative tumour density and tumour mutational burdens (TMBs) were compared among different body sites in different sex and racial groups using the SEER (Surveillance, Epidemiology, and End Results) and TCGA SKCM (The Cancer Genome Atlas skin cutaneous melanoma) databases.

RESULTS

White men had lower rates and lower relative tumour density (RTD) of CMs on their legs compared with the rest of their body sites, or compared with White women. Men classified by SEER into racial groups other than White did not show such a trend. White women had comparable RTDs among different body sites. The ratios between the 'White' and the 'other' groups were used to evaluate the approximate effect of sun exposure at different body sites, which further validated a distinct protective effect of men's legs in melanoma. TMB on leg melanomas was lower than on other sites in both sexes.

CONCLUSIONS

The legs of both sexes in White patients show lower RTDs and lower levels of TMB, suggesting a weaker association with UV exposure. Furthermore, White men are especially protected against CM on their legs, suggesting an unknown intrinsic protective factor as compared with women.

Natural tyrosinase enzyme inhibitors: A path from melanin to melanoma and its reported pharmacological activities

The skin containing melanin pigment acts as a protective barrier and counteracts the UVR and other environmental stressors to maintain or restore disrupted cutaneous homeostasis. The production of melanin pigment is dependent on tyrosine levels. L-tyrosine and L-dihydroxyphenylalanine (L-DOPA) can serve both as a substrates and intermediates of melanin synthetic pathway and as inducers and positive regulators of melanogenesis. The biosynthesis of melanin is stimulated upon exposure to UVR, which can also stimulate local production of hormonal factors, which can stimulate melanoma development by altering the chemical properties of eu- and pheomelanin. The process of melanogenesis can be altered by several pathways. One involves activation of POMC, with the production of POMC peptides including MSH and ACTH, which increase intracellular cAMP levels, which activates the MITF, and helps to stimulate tyrosinase (TYR) expression and activity. Defects in OCA1 to 4 affects melanogenic activity via posttranslational modifications resulting in proteasomal degradation and reducing pigmentation. Further, altering, the MITF factor, helps to regulate the expression of MRGE in melanoma, and helps to increase the TYR glycosylation in ER. CRH stimulates POMC peptides that regulate melanogenesis and also by itself can stimulate melanogenesis. The POMC, P53, ACTH, MSH, MC1R, MITF, and 6-BH4 are found to be important regulators for pigmentation. Melanogenesis can affect melanoma behaviour and inhibit immune responses. Therefore, we reviewed natural products that would alter melanin production. Our special focus was on targeting melanin synthesis and TYR enzyme activity to inhibit melanogenesis as an adjuvant therapy of melanotic melanoma. Furthermore, this review also outlines the current updated pharmacological studies targeting the TYR enzyme from natural sources and its consequential effects on melanin production.

Autoimmune alleles at the major histocompatibility locus modify melanoma susceptibility

Autoimmunity and cancer represent two different aspects of immune dysfunction. Autoimmunity is characterized by breakdowns in immune self-tolerance, while impaired immune surveillance can allow for tumorigenesis. The class I major histocompatibility complex (MHC-I), which displays derivatives of the cellular peptidome for immune surveillance by CD8+ T cells, serves as a common genetic link between these conditions. As melanoma-specific CD8+ T cells have been shown to target melanocyte-specific peptide antigens more often than melanoma-specific antigens, we investigated whether vitiligo- and psoriasis-predisposing MHC-I alleles conferred a melanoma-protective effect. In individuals with cutaneous melanoma from both The Cancer Genome Atlas (n = 451) and an independent validation set (n = 586), MHC-I autoimmune-allele carrier status was significantly associated with a later age of melanoma diagnosis. Furthermore, MHC-I autoimmune-allele carriers were significantly associated with decreased risk of developing melanoma in the Million Veteran Program (OR = 0.962, p = 0.024). Existing melanoma polygenic risk scores (PRSs) did not predict autoimmune-allele carrier status, suggesting these alleles provide orthogonal risk-relevant information. Mechanisms of autoimmune protection were neither associated with improved melanoma-driver mutation association nor improved gene-level conserved antigen presentation relative to common alleles. However, autoimmune alleles showed higher affinity relative to common alleles for particular windows of melanocyte-conserved antigens and loss of heterozygosity of autoimmune alleles caused the greatest reduction in presentation for several conserved antigens across individuals with loss of HLA alleles. Overall, this study presents evidence that MHC-I autoimmune-risk alleles modulate melanoma risk unaccounted for by current PRSs.

Strategic outline of interventions targeting extracellular matrix for promoting healthy longevity

The extracellular matrix (ECM), composed of interlinked proteins outside of cells, is an important component of the human body that helps maintain tissue architecture and cellular homeostasis. As people age, the ECM undergoes changes that can lead to age-related morbidity and mortality. Despite its importance, ECM aging remains understudied in the field of geroscience. In this review, we discuss the core concepts of ECM integrity, outline the age-related challenges and subsequent pathologies and diseases, summarize diagnostic methods detecting a faulty ECM, and provide strategies targeting ECM homeostasis. To conceptualize this, we built a technology research tree to hierarchically visualize possible research sequences for studying ECM aging. This strategic framework will hopefully facilitate the development of future research on interventions to restore ECM integrity, which could potentially lead to the development of new drugs or therapeutic interventions promoting health during aging.

The PI3K-Akt-mTOR and Associated Signaling Pathways as Molecular Drivers of Immune-Mediated Inflammatory Skin Diseases: Update on Therapeutic Strategy Using Natural and Synthetic Compounds

The dysregulated phosphatidylinositol-3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) signaling pathway has been implicated in various immune-mediated inflammatory and hyperproliferative dermatoses such as acne, atopic dermatitis, alopecia, psoriasis, wounds, and vitiligo, and is associated with poor treatment outcomes. Improved comprehension of the consequences of the dysregulated PI3K/Akt/mTOR pathway in patients with inflammatory dermatoses has resulted in the development of novel therapeutic approaches. Nonetheless, more studies are necessary to validate the regulatory role of this pathway and to create more effective preventive and treatment methods for a wide range of inflammatory skin diseases. Several studies have revealed that certain natural products and synthetic compounds can obstruct the expression/activity of PI3K/Akt/mTOR, underscoring their potential in managing common and persistent skin inflammatory disorders. This review summarizes recent advances in understanding the role of the activated PI3K/Akt/mTOR pathway and associated components in immune-mediated inflammatory dermatoses and discusses the potential of bioactive natural products, synthetic scaffolds, and biologic agents in their prevention and treatment. However, further research is necessary to validate the regulatory role of this pathway and develop more effective therapies for inflammatory skin disorders.

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.

Exploring Mycosporine-like Amino Acid UV-Absorbing Natural Products for a New Generation of Environmentally Friendly Sunscreens

Human skin needs additional protection from damaging ultraviolet radiation (UVR: 280-400 nm). Harmful UVR exposure leads to DNA damage and the development of skin cancer. Available sunscreens offer chemical protection from detrimental sun radiation to a certain extent. However, many synthetic sunscreens do not provide sufficient UVR protection due to the lack of photostability of their UV-absorbing active ingredients and/or the lack of ability to prevent the formation of free radicals, inevitably leading to skin damage. In addition, synthetic sunscreens may negatively affect human skin, causing irritation, accelerating skin aging and even resulting in allergic reactions. Beyond the potential negative effect on human health, some synthetic sunscreens have been shown to have a harmful impact on the environment. Consequently, identifying photostable, biodegradable, non-toxic, and renewable natural UV filters is imperative to address human health needs and provide a sustainable environmental solution. In nature, marine, freshwater, and terrestrial organisms are protected from harmful UVR through several important photoprotective mechanisms, including the synthesis of UV-absorbing compounds such as mycosporine-like amino acids (MAAs). Beyond MAAs, several other promising, natural UV-absorbing products could be considered for the future development of natural sunscreens. This review investigates the damaging impact of UVR on human health and the necessity of using sunscreens for UV protection, specifically UV-absorbing natural products that are more environmentally friendly than synthetic UV filters. Critical challenges and limitations related to using MAAs in sunscreen formulations are also evaluated. Furthermore, we explain how the genetic diversity of MAA biosynthetic pathways may be linked to their bioactivities and assess MAAs' potential for applications in human health.

Incidental sun exposures as a source of sunburn among rural compared to urban residents in the United States

PURPOSE

Melanoma incidence is higher in rural than in urban areas in the United States, possibly due to greater incidental sun exposures from rural outdoor-focused lifestyles and occupational patterns. Our aim was to compare activities at the time of a sunburn between rural and urban residents.

METHODS

Utilizing the nationally representative 2019 cross-sectional Health Information National Trends Survey (HINTS), we report odds ratios (OR) and confidence intervals (CI) from logistic regression models comparing self-reported activities at most recent sunburn among rural versus urban adults.

FINDINGS

About one-third of participants (37.2%) reported a sunburn in the past year, higher in urban (38.0%) than in rural populations (32.5%). At the time of most recent sunburn, swimming (36.6%) and working outside a home (29.4%) were the most commonly reported activities. Working on a job (30.4% vs 10.4%; OR: 3.30, 95% CI: 1.33, 8.20) or outside the house (38.7% vs 28.1%; OR: 1.86, 95% CI: 1.03, 3.33) were more common, while exercising or sunbathing were less common, among rural compared to urban participants.

CONCLUSIONS

Incidental sun exposures during outdoor-focused rural occupations and work outside the house may be critical skin cancer prevention targets in rural populations; outdoor exercise and sunbathing may be more important in urban populations; incidental exposures while swimming may be important in both populations.

A UVR-sensor wearable device intervention to reduce sun exposure in melanoma survivors: Results from a randomized controlled trial

BACKGROUND

Melanoma survivors are at increased risk of developing a second primary melanoma; however, some report sub-optimal sun behaviors and sunburns. We tested the effectiveness of a wearable device with ultraviolet radiation (UVR)-sensing technology to improve sun behaviors and reduce sunburns in cutaneous melanoma survivors.

MATERIALS AND METHODS

We conducted a randomized controlled trial using Shade 2, a commercially available wrist device that measures UVR. The intervention group received the device and mobile application notifications about their exposure and prompts to use sunscreen. The control group received the device and a separate research mobile application without information about their exposure or notifications. Participants wore the device for 12 weeks and self-reported sun behaviors before, during, and after the intervention. The primary outcome was a composite score of sun protection behaviors at week 12.

RESULTS

386 participants were randomized (186 control, 182 intervention). Most were female and 5+ years past their first melanoma diagnosis. The average age was 56 years. Most (93%) completed the study, though 40% experienced device issues. No meaningful differences were observed in self-reported sun protection behaviors at week 12 (controls 3.0±0.5 vs. intervention 2.9±0.5, p = 0.06), any sunburn during the intervention period (controls 14.4% vs. intervention 12.7%, p = 0.75), or average daily objective UVR exposure (controls median 87 vs. intervention 83 J/m2, p = 0.43).

CONCLUSION

Wearing a device that measured and alerted melanoma survivors to UVR exposure did not result in different sun behaviors, exposure, or sunburns relative to controls. The technology needs refinement before further attempts to assess the effectiveness of self-monitoring UVR exposure.

CLINICAL TRIALS REGISTRATION

NCT03927742.

Mechanistic Aspects of the Effect of Flanking Nucleotide Sequence on CPD Formation and CPD Self-Repair in DNA

A cyclobutane pyrimidine dimer (CPD) is a photolesion which is produced by a cycloaddition reaction between two stacked pyrimidine bases upon UV light absorption. Because of its harmful effect on important cellular processes involving DNA and especially its relevance to skin cancer, the mechanisms of how a CPD is formed or repaired have been studied extensively, and it has been demonstrated that flanking nucleotide sequences play a crucial role in CPD formation or self-repair. Understanding the mechanisms behind this sequence dependence of CPD formation or self-repair is of great importance because it can give us valuable information on which sequence will be vulnerable to this DNA photodamage. This Perspective focuses on the mechanisms of how flanking nucleotide sequences affect CPD formation or self-repair, especially highlighting the role of computational studies in this field.

Aspirin Protects against UVB-Induced DNA Damage through Activation of AMP Kinase

The anti-inflammatory and chemopreventive activities of aspirin (ASA) may be mediated through its cyclooxygenase inhibitor function. We have previously shown that ASA can protect against UVR-induced skin inflammation and DNA damage; however, the role of inflammation in UV-induced DNA damage and the mechanism underlying ASA protection are poorly characterized. Using immunodeficient NOD scid gamma mice and immunocompetent C57BL/6 mice treated with immune cell‒depleting antibodies, we found that inflammation was not required for UVB-induced 8-oxoguanine and cyclobutane pyrimidine dimers in vivo. Unlike ASA, neither its immediate metabolite salicylate nor the cyclooxygenase inhibitor indomethacin reduced UVB-induced 8-oxoguanine or cyclobutane pyrimidine dimers in melanocyte Melan-a or keratinocyte HaCat cells in vitro. Moreover, addition of prostaglandin E₂ did not reverse the protective effect of ASA on UVB-treated cells. Phosphorylation of the 5' AMP protein kinase, observed in ASA-treated cells, could be blocked by the 5' AMP protein kinase inhibitor compound C. Compound C or 5' AMP protein kinase knockdown partially reduced ASA-mediated protection against UVB-induced DNA damage. Finally, injection of compound C partially reversed the protective effect of ASA on UVB-treated mouse skin in vivo. These studies suggest that ASA confers protection against UVB-induced DNA damage through the activation of 5' AMP protein kinase rather than through cyclooxygenase inhibition.

Skin Cancer Management: Current Scenario And Future Perspectives

Skin cancer is a life-threatening disease and has caused significant loss to human health across the globe. Its prevalence has been increasing every year and is one of the common malignancies in the case of organ transplant recipients, of which 95% constitute basal cell and squamous cell carcinomas. The prime factor causing skin cancer is UV radiation. Around the 20th century, sunlight was the primary cause of skin cancer. A novel hypothesis by US scientists stated that cutaneous melanoma was mainly due to recurrent exposure to the sun, whereas keratinocyte cancer occurred due to progressive accumulation of sun exposure. Management of skin cancer is done via various approaches, including cryotherapy, radiotherapy, and photodynamic therapy. Post-discovery of X-rays, radiotherapy has proven to treat skin cancers to some extent, but the indications are uncertain since it depends upon the type of tumour and surgical treatment required for the patient. Due to various limitations of skin cancer treatment and increased severity, there is a requirement for cost-effective, novel, and efficient treatment. Various nanocarriers such as SLNs, magnetic nanoparticles, gold nanoparticles, carbon nanotubes, etc., are the potential carriers in the management and prognosis of both non-melanoma and melanoma skin cancer. Various research and review databases and patent reports have been studied, and information compiled to extract the results. The review also discusses the role of various nanocarriers in treating and diagnosing skin cancer.

High-fidelity detection, subtyping, and localization of five skin neoplasms using supervised and semi-supervised learning

Background

Skin cancers are the most common malignancies diagnosed worldwide. While the early detection and treatment of pre-cancerous and cancerous skin lesions can dramatically improve outcomes, factors such as a global shortage of pathologists, increased workloads, and high rates of diagnostic discordance underscore the need for techniques that improve pathology workflows. Although AI models are now being used to classify lesions from whole slide images (WSIs), diagnostic performance rarely surpasses that of expert pathologists.

Objectives

The objective of the present study was to create an AI model to detect and classify skin lesions with a higher degree of sensitivity than previously demonstrated, with potential to match and eventually surpass expert pathologists to improve clinical workflows.

Methods

We combined supervised learning (SL) with semi-supervised learning (SSL) to produce an end-to-end multi-level skin detection system that not only detects 5 main types of skin lesions with high sensitivity and specificity, but also subtypes, localizes, and provides margin status to evaluate the proximity of the lesion to non-epidermal margins. The Supervised Training Subset consisted of 2188 random WSIs collected by the PathologyWatch (PW) laboratory between 2013 and 2018, while the Weakly Supervised Subset consisted of 5161 WSIs from daily case specimens. The Validation Set consisted of 250 curated daily case WSIs obtained from the PW tissue archives and included 50 "mimickers". The Testing Set (3821 WSIs) was composed of non-curated daily case specimens collected from July 20, 2021 to August 20, 2021 from PW laboratories.

Results

The performance characteristics of our AI model (i.e., Mihm) were assessed retrospectively by running the Testing Set through the Mihm Evaluation Pipeline. Our results show that the sensitivity of Mihm in classifying melanocytic lesions, basal cell carcinoma, and atypical squamous lesions, verruca vulgaris, and seborrheic keratosis was 98.91% (95% CI: 98.27%, 99.55%), 97.24% (95% CI: 96.15%, 98.33%), 95.26% (95% CI: 93.79%, 96.73%), 93.50% (95% CI: 89.14%, 97.86%), and 86.91% (95% CI: 82.13%, 91.69%), respectively. Additionally, our multi-level (i.e., patch-level, ROI-level, and WSI-level) detection algorithm includes a qualitative feature that subtypes lesions, an AI overlay in the front-end digital display that localizes diagnostic ROIs, and reports on margin status by detecting overlap between lesions and non-epidermal tissue margins.

Conclusions

Our AI model, developed in collaboration with dermatopathologists, detects 5 skin lesion types with higher sensitivity than previously published AI models, and provides end users with information such as subtyping, localization, and margin status in a front-end digital display. Our end-to-end system has the potential to improve pathology workflows by increasing diagnostic accuracy, expediting the course of patient care, and ultimately improving patient outcomes.

UVA Radiation, DNA Damage, and Melanoma

Melanoma is a lethal type of skin tumor that has been linked with sunlight exposure chiefly in fair-skinned human populations. Wavelengths from the sun that can reach the earth's surface include UVA radiation (320-400 nm) and UVB radiation (280-320 nm). UVB effectively induces the formation of dimeric DNA photoproducts, preferentially the cyclobutane pyrimidine dimers (CPDs). The characteristic UVB signature mutations in the form of C to T mutations at dipyrimidine sequences are prevalent in melanoma tumor genomes and have been ascribed to deamination of cytosines within CPDs before DNA polymerase bypass. However, evidence from epidemiological, animal, and other experimental studies also suggest that UVA radiation may participate in melanoma formation. The DNA damage relevant for UVA includes specific types of CPDs at TT sequences and perhaps oxidative DNA damage to guanine, both induced by direct or indirect, photosensitization-mediated chemical and biophysical processes. We summarize the evidence for a potential role of UVA in melanoma and discuss some of the mechanistic pathways of how UVA may induce mutagenesis in melanocytes.

Anti-proliferative and pro-apoptotic effects of curcumin on skin cutaneous melanoma: Bioinformatics analysis and in vitro experimental studies

Objective: To reveal the potential mechanisms of curcumin for the treatment of skin cutaneous melanoma (SKCM) and its identify novel prognostic biomarkers.

Methods: We searched the Cancer Genome Atlas and Traditional Chinese Medicine Systems Pharmacology database for the data on SKCM and curcumin. We conducted data analysis using R and online tools. The propagation and migration of SKCM cells were assessed with CCK-8 and scratch wound assays, respectively. We assessed apoptosis by TUNEL assay and western blot.

Results: The survival analysis revealed that the mRNA expressions of DPYD, DPYS, LYN, PRKCQ, and TLR1 were significantly related to a favorable overall survival in SKCM patients. Additionally, the mRNA expression level of DPYD was associated with GPI, LYN, PCSK9, PRKCQ, and TLR1 mRNAs. GSEA results showed that the prognostic hub genes were augmented with ultraviolet, apoptosis, and metastasis. Curcumin expressed proliferation and migration of SK-MEL-1 cells (p < 0.05), and induced apoptosis (p < 0.05) significantly.

Conclusion: Curcumin may have potential therapeutic effects in SKCM by inhibiting cell proliferation and migration and inducing apoptosis by regulating oxygen-related signaling pathways. The hub genes might be identified as novel biomarkers for SKCM.

Identification of an endoplasmic reticulum stress-associated gene signature to predict the immune status and prognosis of cutaneous melanoma

Besides protecting normal cells from various internal and external perturbations, endoplasmic reticulum (ER) stress is also directly related to the pathogenesis of cutaneous melanoma (CM). However, due to the lack of specific molecular biomarkers, ER stress has not been considered a novel treatment target for CM. Here, we identified ER stress-related genes involved in the prognosis of CM patients and constructed an effective model for the prognostic prediction of these patients. First, gene expression data of CM and normal skin tissues from the Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) databases were retrieved to identify differentially expressed ER stress-related genes in CM. Meanwhile, an independent cohort obtained from the Gene Expression Omnibus (GEO) database was used for validation. The ER stress genes (ZBP1, DIABLO, GNLY, FASLG, AURKA, TNFRSF21, and CD40LG) that were associated with CM prognosis were incorporated into our prognostic model. The functional analyses indicated that the prognostic model was correlated with patient survival, gender, and cancer growth. Multivariate and univariate Cox regressions revealed that the constructed model could serve as an independent prognostic factor for CM patients. The pathway enrichment analysis showed that the risk model was enriched in different immunity and cancer progression-associated pathways. Moreover, the signature model was significantly connected with the immune subtypes, infiltration of immune cells, immune microenvironment, as well as tumor stem cells. The gene function analysis revealed that 7 ER stress genes were differentially expressed in CM patients and were significantly associated with prognosis and several antitumor drugs. Overall, our current model presented predictive value for the prognosis of CM patients and can be further used in the development of novel therapeutic strategies for CM.

Analysis of melanoma tumor antigens and immune subtypes for the development of mRNA vaccine

Melanoma has a high degree of malignancy and mortality. While there are some hopeful clinical trials for melanoma treatment in progress, they have not yet to yield significant long-term cure rates. Cancer vaccines including mRNA are currently one of the most promising strategy for tumor immunotherapy. The aim of this study was to analyze the potential tumor antigens in melanoma that could be used to develop mRNA vaccines and identify suitable vaccine populations. The gene expression data and complete clinical information of 471 melanoma samples and 1 normal tissue were retrieved from TCGA. Then, 812 samples of normal skin and their corresponding gene expression data were obtained from GTEx. Overexpressed genes, mutated genes and IRDEGs are used to identify potential tumor antigens. The relationship between the expression level of potential antigen and prognosis was analyzed in GEPIA, and then the immune cell infiltration was estimated based on TIMER algorithm. The expression profiles of IRDEGs were used to identify consensus clusters and immune subtypes of melanoma. Finally, mutational status and immune microenvironment characterization in immune subtypes were analyzed. Five tumor antigens (PTPRC, SIGLEC10, CARD11, LILRB1, ADAMDEC1) were identified as potential tumor antigens according to overexpressed genes, mutated genes and immune-related genes. They were all associated with OS, DFS and APCs. We identified two immune subtypes of melanoma, named IS1 and IS2, which exhibit different clinical features and immune landscapes. Based on the different immune landscape, we may conclude that IS1 is immunophenotypically "cold", while IS2 is "hot". The present research implicates that PTPRC, SIGLEC10, CARD11, LILRB1 and ADAMDEC1 may be the antigenic targets for melanoma mRNA vaccines and IS2 patients may be more effective to these vaccines.

Transcription factor YY1 contributes to human melanoma cell growth through modulating the p53 signaling pathway

BACKGROUND

Melanoma has a higher mortality rate than any other skin cancer, and its cases are increasing. The transcription factor YY1 has been proven to be involved in tumor progression; however, the role of YY1 in melanoma is not well understood.

METHODS

This study investigates how YY1 functions in melanoma progression, and it also elucidates the underlying mechanisms involved.

RESULTS

We have found that in clinical human melanoma tissues, YY1 is overexpressed compared to YY1 expression in normal melanocytes and skin tissues. Cellular immunofluorescence shows that YY1 is mainly located in the nucleus. YY1 knockdown reduces proliferation, migration, and invasion of melanoma cell lines. Moreover, the apoptosis rate of cells is significantly increased in low-YY1 environments. The overexpression of YY1 resulted in decreased apoptotic rates in melanoma cells. YY1 also affects the expression of EMT-related proteins. Additional experiments reveal that YY1 knockdown disrupts the interaction of MDM2-p53, and that it both stabilizes and increases p53 activity. The upregulation of p53 expression in turn stimulates p21 expression just as it suppresses CDK4 expression, which then induces cells that were arrested in the G1 phase. The effect then is to constrain cell proliferation in melanoma cells. Upon activation of the p53 pathway, Bax, a pro-apoptotic protein, is upregulated, and Bcl-2, an anti-apoptotic protein, was downregulated in A375 cells.

CONCLUSIONS

The findings of this study provide novel insights into the pathology of melanoma as well as the role that YY1 plays in tumor progression. The findings also suggest that targeting YY1 has the potential to improve the diagnosis and treatment of melanoma.

Differential Induction of Reactive Oxygen Species and Expression of Antioxidant Enzymes in Human Melanocytes Correlate with Melanin Content: Implications on the Response to Solar UV and Melanoma Susceptibility

Constitutive pigmentation determines the response to sun exposure and the risk for melanoma, an oxidative stress-driven tumor. Using primary cultures of human melanocytes, we compared the effects of constitutive pigmentation on their antioxidant response to solar UV. The quantitation of eumelanin and pheomelanin showed that the eumelanin content and eumelanin to pheomelanin ratio correlated inversely with the basal levels of reactive oxygen species (ROS). Irradiation with 7 J/cm2 solar UV increased ROS generation without compromising melanocyte viability. Among the antioxidant enzymes tested, the basal levels of heme oxygenase-1 (HO-1) and the glutamate cysteine ligase catalytic subunit and modifier subunit (GCLC and GCLM) correlated directly with the eumelanin and total melanin contents. The levels of HO-1 and GCLM decreased at 6 h but increased at 24 h post-solar UV. Consistent with the GCLC and GCLM levels, the basal glutathione (GSH) content was significantly lower in light than in dark melanocytes. The expression of HMOX1, GCLC, GCLM, and CAT did not correlate with the melanin content and was reduced 3 h after solar UV irradiation, particularly in lightly pigmented melanocytes. Solar UV increased p53 and lipid peroxidation, which correlated inversely with the eumelanin and total melanin contents. These intrinsic differences between light and dark melanocytes should determine their antioxidant response and melanoma risk.

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.

Role of Presenilin-1 in Aggressive Human Melanoma

Presenilin-1 (PS-1), a component of the gamma (γ)-secretase catalytic complex, has been implicated in Alzheimer’s disease (AD) and in tumorigenesis. Interestingly, AD risk is inversely related to melanoma, suggesting that AD-related factors, such as PS-1, may affect melanomagenesis. PS-1 has been shown to reduce Wnt activity by promoting degradation of beta-catenin (β-catenin), an important Wnt signaling partner. Since Wnt is known to enhance progression of different cancers, including melanoma, we hypothesized that PS-1 could affect Wnt-associated melanoma aggressiveness. Western blot results showed that aggressive melanoma cells expressed significantly lower levels of both PS-1 and phosphorylated-β-catenin (P-β-catenin) than nonaggressive melanoma cells. Immunohistochemistry of human melanoma samples showed significantly reduced staining for PS-1 in advanced stage melanoma compared with early stage melanoma. Furthermore, γ-secretase inhibitor (GSI) treatment of aggressive melanoma cells was followed by significant increases in PS-1 and P-β-catenin levels, suggesting impaired Wnt signaling activity as PS-1 expression increased. Finally, a significant reduction in cell migration was associated with the higher levels of PS-1 and P-β-catenin in the GSI-treated aggressive melanoma cells. We demonstrate for the first time that PS-1 levels can be used to assess melanoma aggressiveness and suggest that by enhancing PS-1 expression, Wnt-dependent melanoma progression may be reduced

The Many Faces of G Protein-Coupled Receptor 143, an Atypical Intracellular Receptor

GPCRs transform extracellular stimuli into a physiological response by activating an intracellular signaling cascade initiated via binding to G proteins. Orphan G protein-coupled receptors (GPCRs) hold the potential to pave the way for development of new, innovative therapeutic strategies. In this review we will introduce G protein-coupled receptor 143 (GPR143), an enigmatic receptor in terms of classification within the GPCR superfamily and localization. GPR143 has not been assigned to any of the GPCR families due to the lack of common structural motifs. Hence we will describe the most important motifs of classes A and B and compare them to the protein sequence of GPR143. While a precise function for the receptor has yet to be determined, the protein is expressed abundantly in pigment producing cells. Many GPR143 mutations cause X-linked Ocular Albinism Type 1 (OA1, Nettleship-Falls OA), which results in hypopigmentation of the eyes and loss of visual acuity due to disrupted visual system development and function. In pigment cells of the skin, loss of functional GPR143 results in abnormally large melanosomes (organelles in which pigment is produced). Studies have shown that the receptor is localized internally, including at the melanosomal membrane, where it may function to regulate melanosome size and/or facilitate protein trafficking to the melanosome through the endolysosomal system. Numerous additional roles have been proposed for GPR143 in determining cancer predisposition, regulation of blood pressure, development of macular degeneration and signaling in the brain, which we will briefly describe as well as potential ligands that have been identified. Furthermore, GPR143 is a promiscuous receptor that has been shown to interact with multiple other melanosomal proteins and GPCRs, which strongly suggests that this orphan receptor is likely involved in many different physiological actions.

Did human evolution in skin of color enhance the TEWL barrier?

United States will soon be a nation of color; however, much of our knowledge of normal skin disease, and treatment thereof is based on white skin. We and others have attempted to elucidate any potential differences and advantages/disadvantages in skin function that have emerged during homo sapiens evolution post major migration from Eastern Africa. We investigated differences in one stratum corneum function by examining transepidermal water loss (TEWL) measurements in skin of color compared to Caucasian skin. TEWL, a measure of insensible water loss through stratum corneum, plays a major role in human survival. A comprehensive literature search was conducted to procure relevant papers that measured baseline TEWL in skin of color and Caucasian skin. The data show wide contradiction in results for all skin of color groups and white skin and, therefore, no conclusion can be made based on this question. We suggest this variation may be due to experimental confounding variables that impact TEWL quantification, such as anatomic site and sample size subject to further analysis and focus.

Skin cancer, including related pathways and therapy and the role of luteolin derivatives as potential therapeutics

Cutaneous malignant melanoma is the fastest growing and the most aggressive form of skin cancer that is diagnosed. However, its incidence is relatively scarce compared to the highest mortality rate of all skin cancers. The much more common skin cancers include nonmelanoma malignant skin cancers. Moreover, over the past several decades, the frequency of all skin cancers has increased much more dynamically than that of almost any other type of cancer. Among the available therapeutic options for skin cancers, chemotherapy used immediately after the surgical intervention has been an essential element. Unfortunately, the main problem with conventional chemopreventive regimens involves the lack of response to treatment and the associated side effects. Hence, there is a need for much more effective anticancer drugs. Correspondingly, the targeted alternatives have involved phytochemicals, which are safer chemotherapeutic agents and exhibit competitive anticancer activity with high therapeutic efficacy. Among polyphenolic compounds, some flavonoids and their derivatives, which are mostly found in medicinal plants, have been demonstrated to influence the modulation of signaling pathways at each stage of the carcinogenesis process, which is also important in the context of skin cancers. Hence, this review focuses on an exhaustive overview of the therapeutic effects of luteolin and its derivatives in the treatment and prevention of skin cancers. The bioavailability and structure–activity relationships of luteolin derivatives are also discussed. This review is the first such complete account of all of the scientific reports concerning this particular group of natural compounds that target a specific area of neoplastic diseases.

A Randomized Double-blind Placebo-controlled Trial of Oral Aspirin for Protection of Melanocytic Nevi Against UV-induced DNA Damage

DNA damage plays a role in ultraviolet (UV)-induced melanoma. We previously showed that aspirin (ASA) can suppress prostaglandin-E2 (PGE2) and protect melanocytes from UV-induced DNA damage in mice, and suggested that taking ASA before acute sun exposure may reduce melanoma risk. We conducted a prospective randomized placebo-controlled trial to determine if orally administered ASA could suppress PGE2 in plasma and nevi and protect nevi from UV-induced DNA damage. After obtaining plasma and determining the minimal erythemal dose (MED) in 95 subjects at increased risk for melanoma, they were randomized to receive a daily dose of placebo, 81 mg ASA, or 325 mg ASA, in double-blind fashion for one month. After this intervention, one nevus was irradiated (dose = 1 or 2 MED) using a solar simulator. One day later, MED was re-determined, a second plasma sample was obtained, and the UV-irradiated nevus and an unirradiated nevus were removed. ASA metabolites were detected in the second plasma sample in subjects in the ASA arms. There were no significant differences in the pre- and post-intervention MED between those patients receiving ASA and placebo. Significantly reduced PGE2 levels were detected in plasma (second vs. first samples) and in nevi (both unirradiated and UV-treated) in subjects receiving ASA compared to placebo. Comparing UV-treated nevi from the ASA and placebo cohorts, however, did not reveal significant reductions in CD3-cell infiltration or 8-oxoguanine and cyclobutane pyrimidine dimers. Thus ASA did not effectively protect nevi from solar-simulated UV-induced inflammation and DNA damage under the conditions examined. PREVENTION RELEVANCE: Despite promising rationale, ASA at conventional dosing was not able to protect nevi against UV-induced DNA damage under the conditions examined.See related Spotlight, p. 71.

Knowledge and Attitudes of Cypriots on Melanoma Prevention: Is there a Public Health Concern?

Background

Melanoma is the deadliest type of skin cancer. It is the eighth most common cancer in males and the tenth in females in Cyprus, an island in the Mediterranean with a high ultraviolet (UV) index. Cyprus is expected to be strongly affected by climate change and consequently, melanoma will likely become an increasing public health problem. Melanoma prevention is possible; however, it is unknown if people living in Cyprus are aware of melanoma and prevention methods. To this end, we used a validated survey to evaluate the level of melanoma knowledge and factors associated with it in the Cypriot population.

Methods

We conducted a 47-item survey with sections on demographics, knowledge of melanoma and risk factors, attitudes toward relevant health practices, and protective behaviors among six hundred Cypriot residents from October 2015 to April 2016.

Results

Our results revealed that only 59% of participants check their skin for moles, 87% protect their skin from the sun during summer holidays, and 57% do not take measures to protect their skin from the sun during non-holiday periods. Protective behavior was positively associated with educational level (P=0.016) and district of residence (P<0.0001). Melanoma knowledge was positively associated with education level (P=0.002) and district of residence (P=0.004). Level of Concern was positively associated with age (P=0.026) and education level (P=0.041).

Conclusions

There are gaps in melanoma knowledge and prevention practices in the study population. Further education on melanoma and its prevention should be specifically targeted to individuals of lower education levels as well as teenagers, such that protective behaviors for melanoma are adopted early in life.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12324-0.

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.

Pulmonary metastatic melanoma: current state of diagnostic imaging and treatments

Melanoma is the deadliest form of skin cancer with an estimated incidence of over 160,000 cases annually and about 41,000 melanoma-related deaths per year worldwide. Malignant melanoma (MM) primarily occurs in the skin but has been described in other organs. Although the respiratory system is generally afflicted by tumors such as lung cancer, it is also rarely affected by primary MM. The estimated incidence of pulmonary MM of the lung accounts for 0.01% of all primary lung tumors. The current understanding of pulmonary MM of the lung pathophysiology and its management are not well established. We aim to survey current clinical modalities with a focus on diagnostic imaging and therapeutic intervention to guide providers in the management of patients with a high index of suspicion.

Dietary supplementation with sulforaphane ameliorates skin aging through activation of the Keap1-Nrf2 pathway

Visible impairments in skin appearance, as well as a subtle decline in its functionality at the molecular level, are hallmarks of skin aging. Activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-pathway, which is important in controlling inflammation and oxidative stress that occur during aging, can be triggered by sulforaphane (SFN), an isothiocyanate found in plants from the Brassicaceae family. This study aimed to assess the effects of SFN intake on age-related skin alterations. Male C57BL6 young (2 months) and old (21 months) mice were treated for 3 months with SFN diet (442.5 mg per kg) or control diet. The antioxidant capacities of the skin were increased in old SFN-treated animals as measured by mRNA levels of Nrf2 (P<.001) and its target genes NQO1 (P<.001) and HO1 (P<.01). Protein expression for Nrf2 was also increased in old SFN fed animals (P<.01), but not the protein expression of NQO1 or HO1. Additionally, ROS and MMP9 protein levels were significantly decreased (P<.05) in old SFN fed animals. Histopathological analysis confirmed that there was no difference in epidermal thickness in old, when compared to young, SFN treated animals, while the dermal layer thickness was lower in old vs. young, treated animals (P<.05). Moreover, collagen deposition was improved with SFN treatment in young (P<.05) and structurally significantly improved in the old mice (P<.001). SFN dietary supplementation therefore ameliorates skin aging through activation of the Nrf2-pathway.

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.

A novel pyroptosis-associated gene signature for immune status and prognosis of cutaneous melanoma

Background

Cutaneous melanoma (CM) is a life-threatening destructive malignancy. Pyroptosis significantly correlates with programmed tumor cell death and its microenvironment through active host-tumor crosstalk. However, the prognostic value of pyroptosis-associated gene signatures in CM remains unclear.

Methods

Gene profiles and clinical data of patients with CM were downloaded from The Cancer Genome Atlas (TCGA) to identify differentially expressed genes associated with pyroptosis and overall survival (OS). We constructed a prognostic gene signature using LASSO analysis, then applied immune cell infiltration scores and Kaplan-Meier, Cox, and pathway enrichment analyses to determine the roles of the gene signature in CM. A validation cohort was collected from the Gene Expression Omnibus (GEO) database.

Results

Four pyroptosis-associated genes were identified and incorporated into a prognostic gene signature. Integrated bioinformatics findings showed that the signature correlated with patient survival and was associated with tumor growth and metastasis. The results of Gene Set Enrichment Analysis of a risk signature indicated that several enriched pathways are associated with cancer and immunity. The risk signature for immune status significantly correlated with tumor stem cells, the immune microenvironment, immune cell infiltration and immune subtypes. The expression of four pyroptosis genes significantly correlated with the OS of patients with CM and was related to the sensitivity of cancer cells to several antitumor drugs. A signature comprising four genes associated with pyroptosis offers a novel approach to the prognosis and survival of patients with CM and will facilitate the development of individualized therapy.