Tanning bed use and melanoma: Establishing risk and improving prevention interventions

Neural recordings can differentiate between spontaneously metastasizing melanomas and melanomas with low metastatic potential

Multiple studies report that melanomas are innervated tumors with sensory and sympathetic fibers where these neural fibers play crucial functional roles in tumor growth and metastasis with branch specificity. Yet there is no study which reports the direct neural recording and its pattern during in-vivo progression of the cancer. We performed daily neural recordings from male and female mice bearing orthotopic metastasizing- melanomas and melanomas with low metastatic poential, derived from B16-F10 and B16-F1 cells, respectively. Further, to explore the origins of neural activity, 6-Hydroxidopamine mediated chemical sympathectomy was performed followed by daily microneurographic recordings. We also performed the daily bioluminescent imaging to track in vivo growth of primary tumors and distant metastasis to the cranial area. Our results show that metastasizing tumors display high levels of neural activity while tumors with low metastatic potential lack it indicating that the presence of neural activity is linked to the metastasizing potential of the tumors. Moreover, the neural activity is not continuous over the tumor progression and has a sex-specific temporal patterns where males have two peaks of high neural activity while females show a single peak. The neural peak activity originated in peripheral sympathetic nerves as sympathectomy completely eliminated the peak activity in both sexes. Peak activities were highly correlated with the distant metastasis in both sexes. These results show that sympathetic neural activity is crucially involved in tumor metastasis and has sex-specific role in malignancy initiation.

Skin Cancer Prevention across the G7, Australia and New Zealand: A Review of Legislation and Guidelines

Incidence rates of melanoma and keratinocyte skin cancers have been on the rise globally in recent decades. While there has been a select focus on personal sun protection awareness, to our knowledge, there is a paucity of legislation in place to help support citizens' efforts to protect themselves from the harmful effects of ultraviolet radiation (UVR). Given this, we conducted a comprehensive review of legislation and guidelines pertaining to a variety of sun protection-related topics in countries of the Group of Seven (G7), Australia and New Zealand. Australia was the only country to have banned tanning beds for individuals of all ages, while other select countries have instituted bans for minors. In workplace policy, there is very little recognition of the danger of occupational UVR exposure in outdoor workers, and thus very few protective measures are in place. With regard to sports and recreation, certain dermatological/professional associations have put forward recommendations, but no legislation was brought forward by government bodies outside of Australia and New Zealand. With regard to youth, while there are various guidelines and frameworks in place across several countries, adherence remains difficult in the absence of concrete legislation and standardization of procedures. Finally, only Australia and a few select jurisdictions in the United States have implemented sales tax exemptions for sunscreen products. In light of our findings, we have made several recommendations, which we anticipate will help reduce the rates of melanoma and keratinocyte cancers in years to come. However, minimizing UVR exposure is not without risk, and we, therefore, suggest the promotion of vitamin D supplementation in conjunction with sun protective practices to limit potential harm.

Review: The Key Factors to Melanomagenesis

Melanoma is the most dangerous form of skin cancer that develops from the malignant transformation of the melanocytes located in the basal layer of the epidermis (cutaneous melanoma). Melanocytes may also be found in the meninges, eyes, ears, gastrointestinal tract, genito-urinary system, or other mucosal surfaces (mucosal melanoma). Melanoma is caused by an uncontrolled proliferation of melanocytes, that at first may form a benign lesion (nevogenesis), but in time, it may transition to melanoma, determining what it is named, melanomagenesis. Some tumors may appear spontaneously (de novo melanoma) or on preexisting lesions (nevus-associated melanoma). The exact cause of melanoma may not be fully understood yet, but there are some factors that initiate and promote this malignant process. This study aims to provide a summary of the latest articles regarding the key factors that may lead to melanomagenesis. The secondary objectives are to reveal the relationship between nevi and melanoma, to understand the cause of "de novo" and "nevus-associated melanoma" and highlight the differences between these subtypes.

Photoprotective activities of Lignosus rhinocerus in UV-irradiated human keratinocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Lignosus rhinocerus, also known as Tiger Milk Mushroom has been used traditionally to treat a variety of human conditions, including asthma, diabetes, respiratory disease, skin allergy, and food poisoning. The reported activities of Lignosus rhinocerus extracts include anti-inflammatory, anti-oxidant, anti-asthmatic, anti-microbial, anti-cancer, neuroprotection, and immune modulation effects. However, its effect on human skin is not well documented, including human skin exposed to ultraviolet light (UV). Exposure to UV can trigger various cellular responses, including inflammation, oxidative stress, DNA damage, cell death, and cellular aging.

AIM OF THE STUDY

The study aims to investigate the effects of methanolic extract prepared from cultured Lignosus rhinocerus (herein referred to as TM02 and its methanol extract as TM02-ME) on UV-irradiated human keratinocytes.

MATERIALS AND METHODS

Powdered stock of TM02 was dissolved and sequentially extracted with different solvents to prepare the extracts and the methanol extract was subsequently characterized based on its bio-activities on HaCaT human keratinocytes. The keratinocytes were pre-treated with the methanol extract followed by UV-irradiation. Cellular responses of the HaCaT cells such as cell viability, DNA damage, as well as gene and protein expressions that were responsive to the treatments, were characterized by using bio-assays, including reverse-transcription based PCR, Western blot, cell viability, and mitochondrial Cytochrome C release assays.

RESULTS

TM02-ME protected HaCaT cells from UV-induced DNA damage and cell death in a dose-dependent manner. Pre-treatment of HaCaT cells with TM02-ME led to a 39% reduction of cyclobutane pyrimidine dimers (CPD) and up-regulated the gene expression of REV1 and SPINK5 in UVB-irradiated HaCaT cells when compared to the control. In addition, TM-02-ME treated HaCaT cells increased the expression of BCL-XL and BCL-2 proteins which coincided with the down-regulation of mitochondrial Cyt. C release in the UV-B irradiated HaCaT cells. The results were further supported by data that showed the stable clones of HaCaT cells stably expressed BCL-XL were resistant to UVB-induced cell death.

CONCLUSIONS

^__The results showed that TM02-ME confers photoprotective activities to UVB-irradiated HaCaT cells, leading to a reduction in DNA damage and cell death as well as up-regulated the expression of REV1 and SPINK5 which are involved in DNA repair and skin barrier function, respectively. The up-regulation of pro-survival members of the BCL-2 family by TM02-ME confers protection against UVB-induced cell death.

Netrin-1 Stimulates Migration of Neogenin Expressing Aggressive Melanoma Cells

Netrin-1 is a neural guidance factor that regulates migration and positioning of neural crest-derived cells during embryonic development. Depending on the type of Netrin-1 receptor expression, cells are either attracted or repulsed by Netrin-1. Postnatal expression of Netrin-1 is detected in brain, colon, liver, and kidney, which are common sites of cancer metastasis, including melanoma. Thus, understanding the dynamics between Netrin-1 and its receptors could explain the attraction of melanoma towards these Netrin-1-expressing tissues. Here, we investigate whether the Netrin-1-attractive receptor Neogenin can affect migration of melanoma cells towards a Netrin-1 source. Results from Western blot (WB) analysis show higher expression of Neogenin in aggressive compared to non-aggressive melanoma cells. Cell migration experiments show increased migration of Neogenin-expressing aggressive melanoma cells towards exogenous, soluble recombinant human Netrin-1 and towards a Netrin-1-expressing cell line. Furthermore, WB reveals ERK1/2 activation and increased N-cadherin expression in Neogenin-expressing aggressive melanoma cells treated with rhNetrin-1. Moreover, treatment with anti-Neogenin blocking antibody caused decreased migration towards Netrin-1-expressing cells and reduced ERK1/2 activity in Neogenin-expressing aggressive melanoma cells. These results suggest Neogenin may play a role during migration of melanoma cells towards Netrin-1 via ERK1/2 signaling.

Melanoma Management: From Epidemiology to Treatment and Latest Advances

Simple Summary

Melanoma is a major public health issue that claims the lives of thousands of people every year. Furthermore, the outlook for the coming years is not encouraging with increasing morbidity and mortality trends. This review aims to offer an updated overview of various aspects related to cutaneous melanoma, from epidemiology, etiology, clinical presentation, prevention, diagnosis and staging. Moreover, conventional treatments currently available as well as the latest advances in clinical trials regarding new drugs and/or combinations, including nanotechnology-based strategies are also reviewed.

Abstract

Melanoma is the deadliest skin cancer, whose morbidity and mortality indicators show an increasing trend worldwide. In addition to its great heterogeneity, melanoma has a high metastatic potential, resulting in very limited response to therapies currently available, which were restricted to surgery, radiotherapy and chemotherapy for many years. Advances in knowledge about the pathophysiological mechanisms of the disease have allowed the development of new therapeutic classes, such as immune checkpoint and small molecule kinase inhibitors. However, despite the incontestable progress in the quality of life and survival rates of the patients, effectiveness is still far from desired. Some adverse side effects and resistance mechanisms are the main barriers. Thus, the search for better options has resulted in many clinical trials that are now investigating new drugs and/or combinations. The low water solubility of drugs, low stability and rapid metabolism limit the clinical potential and therapeutic use of some compounds. Thus, the research of nanotechnology-based strategies is being explored as the basis for the broad application of different types of nanosystems in the treatment of melanoma. Future development focus on challenges understanding the mechanisms that make these nanosystems more effective.

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.

Perceptions of Risk and Responses to Tanning Bed Warning Labels: A Pilot Study

Tanning bed use has been linked to increases in skin cancer among young women. Although a causal relationship between ultraviolet radiation emitted by tanning beds and melanoma is well established, it is unclear if tanning bed users are aware of the risk and how they would respond to a warning message. Two hundred and ten women aged 16–29 who had used a tanning bed at least once in the last year were asked about their perceptions of risk and their responses to a warning label. Participants were already aware that tanning beds could cause cancer, but after viewing a warning label, most people said they would stop or reduce their tanning bed use. Reactions to a prototype warning label were encouraging and future research should pursue the possibility that current guidelines for tanning bed warning labels may need to be revised.

Photoprotection by clothing: A review

Clothing is recognized by leading health agencies as a primary method to protect against the harmful effects of photodamage caused by ultraviolet (UV) radiation and visible light. The photoprotective capacity of clothing is commonly measured as the ultraviolet protective factor (UPF). While the technology driving photoprotective clothing has been well-established, there continues to be efforts to discover new materials to improve the UPF of clothing. Here, we show increased Google searches for photoprotective clothing over the last decade, suggesting a high level of public interest in photoprotective clothing. In addition, we investigate the frequency of UPF-graded photoprotective clothing sold by large retail stores featured in Fortune 1000. We review factors that alter the UPF of clothing and describe emerging textile technologies used to increase clothing's photoprotective capacity. Finally, we compare how photoprotective clothing is regulated among different countries, the importance of photoprotective clothing in occupational health, and research in visible light and clothing photoprotection.

Skin Cancer Risk Perception and Tanning Bed Use: A Population-Based Survey to Identify Persons at Risk for Melanoma in Olmsted County, Minnesota

BACKGROUND

Cutaneous melanoma is strongly associated with tanning bed use.

OBJECTIVE

To describe local residents' knowledge, attitudes, and behavior regarding skin cancer and tanning bed use and to estimate prevalence of high risk for melanoma.

MATERIALS AND METHODS

A survey was mailed to 886 local residents (549, aged 18-39 years; 337, aged ≥40 years). Logistic and linear regression and univariate and multivariable analysis were used to assess perceived risk and skin cancer knowledge.

RESULTS

The response rate was 21%; 55% of the younger group and 37% of the older group had used indoor tanning, and prevalence of high risk for melanoma according to a skin cancer risk calculator was 18% in the younger group and 33% in the older group. Individuals with high risk scores were more likely to correctly perceive that they were at high risk for skin cancer. Most participants with high risk scores and those who previously used tanning beds reported low likelihood of future indoor tanning.

CONCLUSION

Female sex, high risk score, and previous indoor tanning were associated with participants' views of higher skin cancer risk. No specific knowledge gaps were identified. Understanding community residents' attitudes about skin cancer and indoor tanning can help guide interventions.

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

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

Risk factors for melanoma by anatomical site: an evaluation of aetiological heterogeneity

BACKGROUND

Melanoma aetiology has been proposed to have two pathways, which are determined by naevi and type of sun exposure and related to the anatomical site where melanoma develops.

OBJECTIVES

We examined associations with melanoma by anatomical site for a comprehensive set of risk factors including pigmentary and naevus phenotypes, ultraviolet radiation exposure and polygenic risk.

METHODS

We analysed harmonized data from 2617 people with incident first invasive melanoma and 975 healthy controls recruited through two population-based case-control studies in Australia and the UK. Questionnaire data were collected by interview using a single protocol, and pathway-specific polygenic risk scores were derived from DNA samples. We estimated adjusted odds ratios using unconditional logistic regression that compared melanoma cases at each anatomical site with all controls.

RESULTS

When cases were compared with control participants, there were stronger associations for many naevi vs. no naevi for melanomas on the trunk, and upper and lower limbs than on the head and neck (P-heterogeneity < 0·001). Very fair skin (vs. olive/brown skin) was more weakly related to melanoma on the trunk than to melanomas at other sites (P-heterogeneity = 0·04). There was no significant difference by anatomical site for polygenic risk. Increased weekday sun exposure was positively associated with melanoma on the head and neck but not on other sites.

CONCLUSIONS

We found evidence of aetiological heterogeneity for melanoma, supporting the dual pathway hypothesis. These findings enhance understanding of risk factors for melanoma and can guide prevention and skin examination education and practices.

Sunburn, Sun Safety and Indoor Tanning Among Schoolchildren in Ireland

Objectives: We present patterns of sunburn, sun safety behaviors and indoor tanning bed use in a nationally representative sample of schoolchildren aged 10–17. These behaviors were explored across gender, age, and social class groups.

Methods: Within the Health Behaviour in School-aged Children (HBSC) Ireland study, 10,271 young people (aged 13.54 ± 1.92, percentage girls 53.3%) reported frequency of sun safety behaviors, sunburn, and frequency and circumstances of indoor tanning bed use.

Results: Children frequently experienced sunburn (90% lifetime, 74% last year), and 3% reported never using any sun protection. Applying sunscreen and wearing sunglasses were the most commonly used sun safety measures; other ways of sun protection were less popular. Indoor tanning bed use was reported by around 5%, and a large proportion of users were not advised of any indoor tanning safety measures. Sun safety behaviors varied by age and gender, with some socio-economic differences in tanning bed use. An association was found between frequency of family holidays abroad and sunburn.

Conclusion: Targeted interventions are needed to increase sun safety behaviors and eliminate tanning bed use among children in Ireland.

Epidemiology and Prevention of Cutaneous Cancer

Cutaneous malignancy is becoming an increasing public health burden in terms of morbidity and cost, associated with changing environmental exposures and increased longevity of the general and the immunosuppressed population. Yet the understanding of the scope of this problem is hindered by lack of robust registries for nonmelanoma skin cancer. The risk factor responsible for most of these cancers, exposure to ultraviolet radiation, can be mitigated. However, greater consensus is necessary to enact effective prevention and screening programs. New developments, including identification of biomarkers and use of artificial intelligence, show promise for targeting screening efforts.

Indoor tanning exposure in association with multiple primary melanoma

BACKGROUND

Patients with primary cutaneous melanoma are at increased risk for subsequent new primary melanomas. Indoor tanning is a recognized risk factor for melanoma. This study was aimed at determining the association between indoor tanning and the occurrence of multiple primary melanoma.

METHODS

This was a retrospective case-control study of cases with multiple primary melanoma and sex-matched controls with single primary melanoma retrieved at a 1:2 ratio from the Biological Sample and Nevus Bank of the Melanoma Center of the University of Pittsburgh Cancer Institute. Logistic regression models were used to examine the association between multiple primary melanoma and risk factors.

RESULTS

In total, 330 patients (39.1% men) with a median age of 51 years were enrolled. Compared with patients who had a single primary melanoma, patients with multiple melanomas were younger at the diagnosis of their first primary melanoma and were more likely to be discovered at stage 0 or I and to have had indoor tanning exposure, a family history of melanoma, atypical moles, dysplastic nevi, and a Breslow thickness less than 1 mm. Compared with patients' first melanomas, subsequent melanomas were more likely to be thinner or in situ. The estimated probability of the locus for the second primary being the same as that for the first primary melanoma was 34%. In a multivariate analysis after adjustments for age, a family history of melanoma, the presence of atypical and dysplastic nevi, and recreational sun exposure, indoor tanning remained significantly associated with the occurrence of multiple primary melanoma (odds ratio, 2.75; 95% confidence interval, 1.07-7.08; P = .0356).

CONCLUSIONS

Indoor tanning is associated with an increased risk of second primary melanoma. Subsequent melanomas are more likely to be thin or in situ and to occur in different anatomic locations.

The role of a cosmetologist in the area of health promotion and health education: A systematic review

Background: Contemporary cosmetology, apart from beautifying and caring for the human body, deals also with prevention aimed at maintaining health and physical fitness as long as possible. The profession of a cosmetologist so understood is closely related to the modern concept of health promotion, the part of which is health education. The objective of this review was to evaluate whether a cosmetologist may be a health promoter, and whether a beauty salon mayserve as a place for conducting educational programs.

Methods: A systematic review was done using several electronic databases such as PubMed(including MEDLINE), Web of Science Core Collection, Scopus, Embase, and Academic Search Ultimate (EBSCO) and related keywords. The studies published in English between 2008 and 2018 which had specifically mentioned the role of a cosmetologist in the area of health promotion and health education were included.

Results: In total, 7 articles met the study criteria. It was found that cosmetologists have the potential to promote pro-health activities. The results of this review also suggest that beauty salons are suitable places for increasing pro-health awareness and can be successfully used to conduct educational programs about healthy lifestyle, as well as skin, breast and cervical cancer prevention.

Conclusion: A well-educated and aware of health risks cosmetologist seems to be the right person to transmit and spread knowledge about the proper lifestyle in her workplace and the local environment. A beauty salon, as a place of social interaction, may constitute an area of implementation of pro-health educational programs.

Increasing melanoma incidence in the elderly in North-East Hungary: is this a more serious problem than we thought?

There is a great need for efficient and cost-effective melanoma screening, but this is not yet solved. Epidemiological studies on trends in melanoma incidence by tumour thickness, anatomical site and demographical data can help to improve public health efforts regarding earlier melanoma diagnosis. We aimed to study the trends in the incidence and characteristics of patients and their melanoma in North-East Hungary from 2000 to 2014. Data were obtained from a university hospital-based registry. A total of 1509 cutaneous invasive melanomas of 1464 patients were included in the study. A moderate but significant increase in incidence was observed in the region [average annual percentage change: 3.04 (0.07; 6.11); P = 0.045], with a breakpoint in 2007. From 2001 to 2007, the trend was increasing [APC: 9.84 (3.52; 16.55); P=0.006], but it stalled from 2007 [APC: -2.45 (-5.99; 1.23); P = 0.164]. However, in the age groups over the age of 60 years, where the standardised incidence was the highest, the incidence continued to rise. Furthermore, older age, male sex and trunk or lower extremity localization were found to be associated with thicker melanomas. Our results support that regular screening examination for melanoma would be desirable for people over the age of 60 years.

Role of PGE-2 and Other Inflammatory Mediators in Skin Aging and Their Inhibition by Topical Natural Anti-Inflammatories

Human skin aging is due to two types of aging processes, “intrinsic” (chronological) aging and “extrinsic” (external factor mediated) aging. While inflammatory events, triggered mainly by sun exposure, but also by pollutants, smoking and stress, are the principle cause of rapid extrinsic aging, inflammation also plays a key role in intrinsic aging. Inflammatory events in the skin lead to a reduction in collagen gene activity but an increase in activity of the genes for matrix metalloproteinases. Inflammation also alters proliferation rates of cells in all skin layers, causes thinning of the epidermis, a flattening of the dermo-epidermal junction, an increase in irregular pigment production, and, finally, an increased incidence of skin cancer. While a large number of inflammatory mediators, including IL-1, TNF-alpha and PGE-2, are responsible for many of these damaging effects, this review will focus primarily on the role of PGE-2 in aging. Levels of this hormone-like mediator increase quickly when skin is exposed to ultraviolet radiation (UVR), causing changes in genes needed for normal skin structure and function. Further, PGE-2 levels in the skin gradually increase with age, regardless of whether or not the skin is protected from UVR, and this smoldering inflammation causes continuous damage to the dermal matrix. Finally, and perhaps most importantly, PGE-2 is strongly linked to skin cancer. This review will focus on: (1) the role of inflammation, and particularly the role of PGE-2, in accelerating skin aging, and (2) current research on natural compounds that inhibit PGE-2 production and how these can be developed into topical products to retard or even reverse the aging process, and to prevent skin cancer.

A systematic review of compliance with indoor tanning legislation

BACKGROUND

Many jurisdictions have enacted indoor tanning legislation in response to the health risks of artificial ultraviolet (UV) radiation exposure. Key components of these legislations include banning minors' access, requiring parental consent or accompaniment, providing protective eyewear, posting health warning signs, and communicating important health risk information. However, legislation must be complied with to be impactful. Evidence around compliance with indoor tanning legislations has not been synthesized and is an important step toward determining changes in practice due to legislation.

METHODS

A systematic review was conducted to obtain peer-reviewed literature about compliance with indoor tanning legislation worldwide. Six databases were searched, resulting in 12,398 citations. Sixteen studies met the inclusion criteria (peer-reviewed scientific studies, published in English, focused primarily on compliance with indoor tanning legislations, and focused on commercial indoor tanning in indoor tanning facilities).

RESULTS

Compliance with most aspects of indoor tanning legislation varied widely. There was good compliance for provision of protective eyewear (84 to 100%; mean = 92%; SD = 8). Compliance with age restrictions ranged from 0 to 100% (mean = 65%; SD = 25), while compliance with posting warning labels in the required locations within a tanning facility ranged from 8 to 72% (mean = 44%; SD = 27). Variation in compliance may be due to true differences, study methodology, or temporal trends.

CONCLUSIONS

Variability in compliance with indoor tanning legislation, as found in this systematic review, indicates the legislations may not be having their intended protective effects on the public's health. The reasons for such low and varied compliance with certain aspects of legislation, and high compliance with other aspects of legislation, deserve further attention in future research to inform best practices around ensuring high and consistent compliance with indoor tanning legislations worldwide.

Roles of UVA radiation and DNA damage responses in melanoma pathogenesis

The growing incidence of melanoma is a serious public health issue that merits a thorough understanding of potential causative risk factors, which includes exposure to ultraviolet radiation (UVR). Though UVR has been classified as a complete carcinogen and has long been recognized for its ability to damage genomic DNA through both direct and indirect means, the precise mechanisms by which the UVA and UVB components of UVR contribute to the pathogenesis of melanoma have not been clearly defined. In this review, we therefore highlight recent studies that have addressed roles for UVA radiation in the generation of DNA damage and in modulating the subsequent cellular responses to DNA damage in melanocytes, which are the cell type that gives rise to melanoma. Recent research suggests that UVA not only contributes to the direct formation of DNA lesions but also impairs the removal of UV photoproducts from genomic DNA through oxidation and damage to DNA repair proteins. Moreover, the melanocyte microenvironment within the epidermis of the skin is also expected to impact melanomagenesis, and we therefore discuss several paracrine signaling pathways that have been shown to impact the DNA damage response in UV-irradiated melanocytes. Lastly, we examine how alterations to the immune microenvironment by UVA-associated DNA damage responses may contribute to melanoma development. Thus, there appear to be multiple avenues by which UVA may elevate the risk of melanoma. Protective strategies against excess exposure to UVA wavelengths of light therefore have the potential to decrease the incidence of melanoma. Environ. Mol. Mutagen. 59:438-460, 2018. © 2018 Wiley Periodicals, Inc.

Influence of maternal and own genotype at tanning dependence-related SNPs on sun exposure in childhood

Background

Research suggests there may be a genetic influence on the likelihood of becoming tanning dependent (TD). The way in which mothers regulate their children’s sun exposure may be affected by being TD. We investigated the associations between single nucleotide polymorphisms (SNPs) related to being TD and early sun exposure.

Methods

Data from the Avon Longitudinal Study of Parents and Children (ALSPAC) were used. Associations between 17 TD related SNPs in children and their mothers and 10 sun exposure variables in children (assessed via questionnaire at age 8) were analyzed in logistic and ordinal logistic regressions. Analyses were adjusted for principal components of population structure and age (at time of questionnaire response). Models with additional adjustment for maternal or offspring genotypes were also tested. Secondary analyses included adjustment for sex and skin pigmentation.

Results

Among ALSPAC children, the rs29132 SNP in the Vesicle-associated membrane protein-associated protein A (VAPA) gene was associated with five sun exposure variables whilst the rs650662 SNP in the Opioid Receptor Mu 1 (OPRM1) gene was associated with three. The remaining SNPs did not show associations beyond what was expected by chance. After Bonferroni correction one SNP in the children was associated with an increased likelihood of using sun cream whilst in the sun at 8 years old (rs60050811 in the Spermatogenesis and Centriole Associated 1 (SPATC1) gene, OR per C allele = 1.34, 95% CI 1.11–1.62, p = .003). In the mothers, rs650662 in OPRM1 was associated with the use of a lower factor of sun cream in their children, (OR per A allele = 0.89, 95% CI 0.82–0.96, p = .002). Whilst rs2073478 in the Aldehyde Dehydrogenase 1 Family Member B1 (ALDH1B1) gene was associated with a reduced odds of their child using a sun block or cream with a 4 star rating (OR per T allele = 0.68, 95% CI 0.53–0.88, p = .003). Similar but weaker associations were observed for the main findings in the secondary analyses.

Conclusions

We found weak evidence to suggest that genes previously associated with TD are associated with sun exposure in children of European ancestry from southwest England.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0575-z) contains supplementary material, which is available to authorized users.

Mechanisms and prevention of UV-induced melanoma

Melanoma is the deadliest form of skin cancer and its incidence is rising, creating a costly and significant clinical problem. Exposure to ultraviolet (UV) radiation, namely UVA (315-400 nm) and UVB (280-315 nm), is a major risk factor for melanoma development. Cumulative UV radiation exposure from sunlight or tanning beds contributes to UV-induced DNA damage, oxidative stress, and inflammation in the skin. A number of factors, including hair color, skin type, genetic background, location, and history of tanning, determine the skin's response to UV radiation. In melanocytes, dysregulation of this UV radiation response can lead to melanoma. Given the complex origins of melanoma, it is difficult to develop curative therapies and universally effective preventative strategies. Here, we describe and discuss the mechanisms of UV-induced skin damage responsible for inducing melanomagenesis, and explore options for therapeutic and preventative interventions.

Recent Successes and Future Directions in Immunotherapy of Cutaneous Melanoma

The global health burden associated with melanoma continues to increase while treatment options for metastatic melanoma are limited. Nevertheless, in the past decade, the field of cancer immunotherapy has witnessed remarkable advances for the treatment of a number of malignancies including metastatic melanoma. Although the earliest observations of an immunological antitumor response were made nearly a century ago, it was only in the past 30 years, that immunotherapy emerged as a viable therapeutic option, in particular for cutaneous melanoma. As such, melanoma remains the focus of various preclinical and clinical studies to understand the immunobiology of cancer and to test various tumor immunotherapies. Here, we review key recent developments in the field of immune-mediated therapy of melanoma. Our primary focus is on therapies that have received regulatory approval. Thus, a brief overview of the pathophysiology of melanoma is provided. The purported functions of various tumor-infiltrating immune cell subsets are described, in particular the recently described roles of intratumoral dendritic cells. The section on immunotherapies focuses on strategies that have proved to be the most clinically successful such as immune checkpoint blockade. Prospects for novel therapeutics and the potential for combinatorial approaches are delineated. Finally, we briefly discuss nanotechnology-based platforms which can in theory, activate multiple arms of immune system to fight cancer. The promising advances in the field of immunotherapy signal the dawn of a new era in cancer treatment and warrant further investigation to understand the opportunities and barriers for future progress.

College tanning behaviors, attitudes, beliefs, and intentions: A systematic review of the literature

Despite well-established links between exposure to ultraviolet radiation (UVR) and skin cancer, UVR-based tanning behaviors persist among college students. Understanding tanning motivations, perceptions, barriers, and demographic characteristics of this population is critical to modifying these behaviors, but is limited by variability in study design, sample size, and outcomes measured in the current literature. To help clarify the tanning behaviors of this population and provide a concise reference for future studies, this review examines existing reports to determine the comparability of tanning behaviors across multiple U.S. college populations. A systematic review of the literature was performed in July 2016 to identify studies investigating tanning behaviors among U.S. college students. Twenty-three studies met inclusion criteria. High rates of indoor tanning (IT) and outdoor tanning (OT) were found among college students. Key motivators included appearance, emotion, health perceptions, and the influence of parents, peers, and the media. Misconceptions regarding skin protection, low rates of sun protective behaviors, and tanning dependence were barriers against safe UVR exposure. Understudied demographic factors may account for variance in observed tanning behaviors, emphasizing the need for standardization efforts to consistently identify trends associated with geographical region, age, year in college, and sex. The findings presented in this review reaffirm that college students are at high risk for tanning-associated skin cancer, emphasizing the critical need for effective, targeted interventions. Improved interventions will reduce the burden of skin cancer within this group, ultimately contributing to longer, healthier lives.