Indoor ultraviolet tanning and skin cancer: health risks and opportunities

Unveiling the potential anti-cancer activity of calycosin against multivarious cancers with molecular insights: A promising frontier in cancer research

BACKGROUND

Calycosin may be a potential candidate regarding chemotherapeutic agent, because already some studies against multivarious cancer have been made with this natural compound.

AIM

This review elucidated a brief overview of previous studies on calycosin potential effects on various cancers and its potential mechanism of action.

METHODOLOGY

Data retrieved by systematic searches of Google Scholar, PubMed, Science Direct, Web of Science, and Scopus by using keywords including calycosin, cancer types, anti-cancer mechanism, synergistic, and pharmacokinetic and commonly used tools are BioRender, ChemDraw Professional 16.0, and ADMETlab 2.0.

RESULTS

Based on our review, calycosin is available in nature and effective against around 15 different types of cancer. Generally, the anti-cancer mechanism of this compound is mediated through a variety of processes, including regulation of apoptotic pathways, cell cycle, angiogenesis and metastasis, oncogenes, enzymatic pathways, and signal transduction process. These study conducted in various study models, including in silico, in vitro, preclinical and clinical models. The molecular framework behind the anti-cancer effect is targeting some oncogenic and therapeutic proteins and multiple signaling cascades. Therapies based on nano-formulated calycosin may make excellent nanocarriers for the delivery of this compound to targeted tissue as well as particular organ. This natural compound becomes very effective when combined with other natural compounds and some standard drugs. Moreover, proper use of this compound can reverse resistance to existing anti-cancer drugs through a variety of strategies. Calycosin showed better pharmacokinetic properties with less toxicity in human bodies.

CONCLUSION

Calycosin exhibits excellent potential as a therapeutic drug against several cancer types and should be consumed until standard chemotherapeutics are available in pharma markets.

Skin cancer: understanding the journey of transformation from conventional to advanced treatment approaches

Skin cancer is a global threat to the healthcare system and is estimated to incline tremendously in the next 20 years, if not diagnosed at an early stage. Even though it is curable at an early stage, novel drug identification, clinical success, and drug resistance is another major challenge. To bridge the gap and bring effective treatment, it is important to understand the etiology of skin carcinoma, the mechanism of cell proliferation, factors affecting cell growth, and the mechanism of drug resistance. The current article focusses on understanding the structural diversity of skin cancers, treatments available till date including phytocompounds, chemotherapy, radiotherapy, photothermal therapy, surgery, combination therapy, molecular targets associated with cancer growth and metastasis, and special emphasis on nanotechnology-based approaches for downregulating the deleterious disease. A detailed analysis with respect to types of nanoparticles and their scope in overcoming multidrug resistance as well as associated clinical trials has been discussed.

Global Tanning Bed Advertising: A Comparison of Legal Regulations on Three Continents

Artificial ultraviolet radiation from tanning beds has been classified as carcinogenic by the International Agency for Research on Cancer in 2009. Several countries have subsequently introduced comprehensive legislation regulating commercial indoor tanning. Specific aspects of these regulations address tanning bed advertising and information requirements for tanning bed customers, which have been previously neglected in international comparisons of indoor tanning regulations. We performed a systematic search regarding legislation on these aspects in 131 legislative units across three continents (North America, Australia/New Zealand, Europe). The legal restrictions found varied widely in type and content. In 49 legislative units we identified total (n = 8) or partial legal bans (n = 41) on advertising for indoor tanning, while 64 legislative units enacted 5regulations that necessitate the dissemination of different types of specific health information to tanning bed customers. Nearly 40% of the legislative units of the study region lacked any legislation on these issues altogether. The heterogenous results emphasize the need for an international dialogue between health authorities and governments to harmonize the regulatory framework for tanning bed advertising and information requirements to a level better protecting the public from skin cancer. Our comprehensive international comparison can serve as a starting point for such a harmonization process that may ultimately protect the public worldwide from misleading tanning bed advertising.

The Risk of Melanoma due to Exposure to Sun and Solarium Use in Poland: A Large-Scale, Hospital Based Case - Control Study

OBJECTIVE

The incidence of skin cancer is constantly growing, it is considered a serious problem of public health. Most cases of skin cancer are caused by a combination of non-modifiable genetic, and modifiable environmental risk factors. The study objective was to analyse the correlation between pigmentation traits, excessive sunlight exposure, solarium use and the risk of melanoma development.

METHODS

The study included 480 patients diagnosed with melanoma and 400 within the control group. Subjects diagnosed with the melanoma confirmed by histopathology were invited to take part in the study. The research was based on a clinical, direct, individual, structured, in-depth and focused interview.

RESULTS

The mean age of the study subjects was 44.3 ± 7.86, while in the control group 59.5 (7.93) Most frequently, melanoma was located on the upper extremities (64%). A family history of neoplastic diseases was found in 55% of the patients. The assessment of sunburns showed that only 15%  of the respondents never experienced sunburn, 49% of the study subjects never used solarium. Among patients with multiple sunburns, the risk of developing skin cancer was 1.27 (AOR = 1,27; 95% CI, 1.07-1.55) compared with non-sunburns subjects.

CONCLUSIONS

Risky behaviours including excessive exposure to UV radiation, both natural and artificial, are of special significance in women with fair complexion and fair hair. Indoor tanning is a probable factor of increased skin cancer incidence in younger women, as compared to men.

Comparison of Prognostic Factors for Merkel Cell Carcinoma, Mucosal Melanoma and Cutaneous Malignant Melanoma: Insights into Their Etiologies

Little is known about the epidemiology of Merkel cell carcinoma (MCC) and mucosal melanoma (MM). Using the United States (US) National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program data, we compared MCC and MM with cutaneous malignant melanoma (CMM) with respect to incidence rates and prognostic factors to better understand disease etiologies. We describe the proportional incidences of the three cancers along with their survival rates based on 20 years of national data. The incidence rates in 2000–2019 were 203.7 per 1,000,000 people for CMM, 5.9 per 1,000,000 people for MCC and 0.1 per 1,000,000 people for MM. The rates of these cancers increased over time, with the rate of MM tripling between 2000–2009 and 2010–2019. The incidences of these cancers increased with age and rates were highest among non-Hispanic Whites. Fewer MCCs and MMS were diagnosed at the local stage compared with CMM. The cases in the 22 SEER registries in California were not proportional to the 2020 population census but instead were higher than expected for CMM and MCC and lower than expected for MM. Conversely, MM rates were higher than expected in Texas and New York. These analyses highlight similarities in the incidence rates of CMM and MCC—and differences between them and MM rates—by state. Understanding more about MCC and MM is important because of their higher potential for late diagnosis and metastasis, which lead to poor survival.

Localized topical drug delivery systems for skin cancer: Current approaches and future prospects

Topical drug delivery presents a novel substitute to the conventional drug-distribution routes of oral delivery and injection. Apart from the simplicity and non-invasiveness, the skin also serves as a “reservoir” that sustains administration over a period of days. Nanocarriers provide new potential for the treatment of skin disease. The skin’s barrier function offers a considerable obstacle for the potential nanocarriers to infiltrate into the tissue. However, the barrier is partially weakened in case of damage or inflammation, as in the case of skin cancer. Nanoparticles may promote the penetration of the skin. Extensive research has been done into producing nanoparticles for topical distribution; nevertheless, relatively little progress has been achieved in transferring them to the clinic for treating skin malignancies. The prior art features the critical concepts of skin malignancies and techniques in current clinical care. The present review gives a complete viewpoint of the numerous nanoparticle technologies studied for the topical treatment of skin malignancies and outlines the hurdles that hamper its advancement from the bench to the bedside. The review also intends to give knowledge of the routes that control nanoparticle penetration into the skin and their interactions inside the tissue.

Indoor tanning: Evidence surrounding advertised health claims

Indoor tanning continues to remain common, despite evidence of an increased risk of skin cancer from artificial ultraviolet (UV) radiation. In the hopes of gaining customers, the tanning bed industry has marketed health benefits of indoor tanning such as increased vitamin D production, development of a base tan, enhanced mood, and treatment of certain dermatologic conditions. To better educate their patients, providers need a comprehensive reference reviewing the evidence that support or oppose these claims. In this work, we conducted an evidence-based review of the literature to identify and grade studies that investigate health claims related to UV exposure. Results indicate that there is little evidence to support each of these proposed health benefits. Tanning beds emit primarily UVA radiation, which is relatively ineffective at activating vitamin D or mood enhancing pathways, and the effects are minimal in regard to tanning beds generating a protective base tan or treating dermatologic conditions compared with the increased risk of skin cancer. Health care providers must continue to warn and educate patients about the misleading information propagated by the tanning bed industry as well as about the dangers of artificial UV radiation.

UVC-based photoinactivation as an efficient tool to control the transmission of coronaviruses

The ongoing COVID-19 pandemic made us re-realize the importance of environmental disinfection and sanitation in indoor areas, hospitals, and clinical rooms. UVC irradiation of high energy and short wavelengths, especially in the 200-290-nm range possesses the great potential for germicidal disinfection. These properties of UVC allow to damage or destruct the nucleic acids (DNA/RNA) in diverse microbes (e.g., bacteria, fungi, and viruses). UVC light can hence be used as a promising tool for prevention and control of their infection or transmission. The present review offers insights into the historical perspective, mode of action, and recent advancements in the application of UVC-based antiviral therapy against coronaviruses (including SARS CoV-2). Moreover, the application of UVC lights in the sanitization of healthcare units, public places, medical instruments, respirators, and personal protective equipment (PPE) is also discussed. This article, therefore, is expected to deliver a new path for the developments of UVC-based viricidal approach.

Attitudes and Behaviors That Impact Skin Cancer Risk among Men

Despite substantially higher skin cancer risks, little research has investigated men’s attitudes about skin cancer and how those attitudes relate to their risks of developing skin cancer. This study aims to close the gap in research, regarding men’s perceptions and behaviors about skin cancer, sun exposure, and tanning. This study utilized a cross-sectional survey of 705 men recruited from Amazon Mechanical Turk (MTurk), reporting attitudes and behaviors towards sun exposure, tanning, and sun protection. While the majority of men reported large daily outdoor activities, that their skin frequently burns with sun exposure, and riskier perceptions of tanning, only a minority reported daily use of sunscreen or most other sun protective behaviors. More sun protection methods were associated with more frequent use of sunscreen and less positive tanning perceptions. Men consistently engaged in high-risk behaviors for developing skin cancer, but they did not engage highly in protective behaviors to mitigate their risk. The findings can help improve clinical and public health interventions to lower men’s risk of skin cancer with strong messages about sunscreen use and sun protective methods.

From Sea to Skin: Is There a Future for Natural Photoprotectants?

In the last few decades, the thinning of the ozone layer due to increased atmospheric pollution has exacerbated the negative effects of excessive exposure to solar ultraviolet radiation (UVR), and skin cancer has become a major public health concern. In order to prevent skin damage, public health advice mainly focuses on the use of sunscreens, along with wearing protective clothing and avoiding sun exposure during peak hours. Sunscreens present on the market are topical formulations that contain a number of different synthetic, organic, and inorganic UVR filters with different absorbance profiles, which, when combined, provide broad UVR spectrum protection. However, increased evidence suggests that some of these compounds cause subtle damage to marine ecosystems. One alternative may be the use of natural products that are produced in a wide range of marine species and are mainly thought to act as a defense against UVR-mediated damage. However, their potential for human photoprotection is largely under-investigated. In this review, attention has been placed on the molecular strategies adopted by marine organisms to counteract UVR-induced negative effects and we provide a broad portrayal of the recent literature concerning marine-derived natural products having potential as natural sunscreens/photoprotectants for human skin. Their chemical structure, UVR absorption properties, and their pleiotropic role as bioactive molecules are discussed. Most studies strongly suggest that these natural products could be promising for use in biocompatible sunscreens and may represent an alternative eco-friendly approach to protect humans against UV-induced skin damage.

Pharmacologic manipulation of skin pigmentation

Skin complexion is among the most recognizable phenotypes between individuals and is mainly determined by the amount and type of melanin pigment deposited in the epidermis. Persons with dark skin complexion have more of a brown/black pigment known as eumelanin in their epidermis whereas those with fair skin complexions have less. Epidermal eumelanin acts as a natural sunblock by preventing incoming UV photons from penetrating into the skin and therefore protects against UV mutagenesis. By understanding the signaling pathways and regulation of pigmentation, strategies can be developed to manipulate skin pigmentation to improve UV resistance and to diminish skin cancer risk.

A Framework of Major Tumor-Promoting Signal Transduction Pathways Implicated in Melanoma-Fibroblast Dialogue

Simple Summary

Melanoma cells reside in a complex stromal microenvironment, which is a critical component of disease onset and progression. Mesenchymal or fibroblastic cell type are the most abundant cellular element of tumor stroma. Factors secreted by melanoma cells can activate non-malignant associated fibroblasts to become melanoma associate fibroblasts (MAFs). MAFs promote tumorigenic features by remodeling the extracellular matrix, supporting tumor cells proliferation, neo-angiogenesis and drug resistance. Additionally, environmental factors may contribute to the acquisition of pro-tumorigenic phenotype of fibroblasts. Overall, in melanoma, perturbed tissue homeostasis contributes to modulation of major oncogenic intracellular signaling pathways not only in tumor cells but also in neighboring cells. Thus, targeted molecular therapies need to be considered from the reciprocal point of view of melanoma and stromal cells.

Abstract

The development of a modified stromal microenvironment in response to neoplastic onset is a common feature of many tumors including cutaneous melanoma. At all stages, melanoma cells are embedded in a complex tissue composed by extracellular matrix components and several different cell populations. Thus, melanomagenesis is not only driven by malignant melanocytes, but also by the altered communication between melanocytes and non-malignant cell populations, including fibroblasts, endothelial and immune cells. In particular, cancer-associated fibroblasts (CAFs), also referred as melanoma-associated fibroblasts (MAFs) in the case of melanoma, are the most abundant stromal cells and play a significant contextual role in melanoma initiation, progression and metastasis. As a result of dynamic intercellular molecular dialogue between tumor and the stroma, non-neoplastic cells gain specific phenotypes and functions that are pro-tumorigenic. Targeting MAFs is thus considered a promising avenue to improve melanoma therapy. Growing evidence demonstrates that aberrant regulation of oncogenic signaling is not restricted to transformed cells but also occurs in MAFs. However, in some cases, signaling pathways present opposite regulation in melanoma and surrounding area, suggesting that therapeutic strategies need to carefully consider the tumor–stroma equilibrium. In this novel review, we analyze four major signaling pathways implicated in melanomagenesis, TGF-β, MAPK, Wnt/β-catenin and Hyppo signaling, from the complementary point of view of tumor cells and the microenvironment.

Significance of 5-S-Cysteinyldopa as a Marker for Melanoma

Melanoma is one of the most lethal and malignant cancers and its incidence is increasing worldwide, and Japan is not an exception. Although there are numerous therapeutic options for melanoma, the prognosis is still poor once it has metastasized. The main concern after removal of a primary melanoma is whether it has metastasized, and early detection of metastatic melanoma would be effective in improving the prognosis of patients. Thus, it is very important to identify reliable methods to detect metastases as early as possible. Although many prognostic biomarkers (mainly for metastases) of melanoma have been reported, there are very few effective for an early diagnosis. Serum and urinary biomarkers for melanoma diagnosis have especially received great interest because of the relative ease of sample collection and handling. Several serum and urinary biomarkers appear to have significant potential both as prognostic indicators and as targets for future therapeutic methods, but still there are no efficient serum and urinary biomarkers for early detection, accurate diagnosis and prognosis, efficient monitoring of the disease and reliable prediction of survival and recurrence. Levels of 5-S-cysteinyldopa (5SCD) in the serum or urine as biomarkers of melanoma have been found to be significantly elevated earlier and to reflect melanoma progression better than physical examinations, laboratory tests and imaging techniques, such as scintigraphy and echography. With recent developments in the treatment of melanoma, studies reporting combinations of 5SCD levels and new applications for the treatment of melanoma are gradually increasing. This review summarizes the usefulness of 5SCD, the most widely used and well-known melanoma marker in the serum and urine, compares 5SCD and other useful markers, and finally its application to other fields.

Nanoparticles for topical drug delivery: Potential for skin cancer treatment

Nanoparticles offer new opportunities for the treatment of skin diseases. The barrier function of the skin poses a significant challenge for nanoparticles to permeate into the tissue, although the barrier is partially compromised in case of injury or inflammation, as in the case of skin cancer. This may facilitate the penetration of nanoparticles. Extensive research has gone into developing nanoparticles for topical delivery; however, relatively little progress has been made in translating them to the clinic for treating skin cancers. We summarize the types of skin cancers and practices in current clinical management. The review provides a comprehensive outlook of the various nanoparticle technologies tested for topical therapy of skin cancers and summarizes the obstacles that impede its progress from the bench-to-bedside. The review also aims to provide an understanding of the pathways that govern nanoparticle penetration into the skin and a critical analysis of the approaches used to study nanoparticle interactions within the tissue.

A cross-sectional analysis of skin cancer risk in patients receiving narrow-band ultraviolet B phototherapy: an evaluation of 100 patients

Narrow-band ultraviolet B (NB-UVB) phototherapy is an effective and widely used treatment modality for psoriasis and other inflammatory skin diseases. The carcinogenic effect of PUVA treatment has been investigated extensively, but there is very scarce data about the role of NB-UVB in the development of skin cancer. The aim of this study was to investigate the potential carcinogenic risk of NB-UVB therapy in various skin disorders. In this cross-sectional study, we evaluated 100 patients who had received whole-body NB-UVB treatment and 100 age- and sex-matched controls. Phototherapy unit database was used to identify patients. A total of 100 patients (53 males and 47 females) treated with NB-UVB and 100 controls were included in the study. The patient group revealed no cases of melanoma or non-melanoma skin cancer, while ten of them were found to have solar lentigines. Basal cell carcinoma in a patient and nine patients with solar lentigines were detected in the control group. There was no statistically significant difference between patient and control groups in terms of skin cancer and solar lentigines. This study does not provide evidence for an increased skin cancer risk in patients treated with NB-UVB phototherapy. However, we have detected the occurence of 10 cases of solar lentigines. Still, definitive prospective longitudinal studies with a greater number of patients and prolonged follow-up are required to specifically address skin cancer risk in relation to NB-UVB phototherapy.

Assessing the content and comprehensiveness of provincial and territorial indoor tanning legislation in Canada

INTRODUCTION

Canadian provincial and territorial governments have enacted legislation in response to health risks of artificial ultraviolet radiation from indoor tanning. This legislation, which differs from jurisdiction to jurisdiction, regulates the operation of indoor tanning facilities. The content and comprehensiveness of such legislation-and its differences across jurisdictions-have not been analyzed. To address this research gap, we conducted a systematic, comprehensive scan and content analysis on provincial and territorial indoor tanning legislation, including regulations and supplementary information.

METHODS

Legislative information was collected from the Canadian Legal Information Institute database and an environmental scan was conducted to locate supplementary information. Through a process informed by the content of the legislation, previous research and health authority recommendations, we developed a 59-variable codebook. Descriptive statistics were calculated.

RESULTS

All provinces and one of three territories have legislation regulating indoor tanning. Areas of strength across jurisdictions are youth access restrictions (n = 11), posting of warning signs (n = 11), penalties (n = 11) and restrictions on advertising and marketing targeted to youth (n = 7). Few jurisdictions, however, cover areas such as protective eyewear (n = 4), unsupervised tanning (n = 4), provisions for inspection frequency (n = 4), misleading health claims in advertisements directed toward the general public (n = 2) and screening of high-risk clients (n = 0).

CONCLUSION

All provinces and one territory have made progress in regulating the indoor tanning industry, particularly by prohibiting youth and using warning labels to communicate risk. Legislative gaps should be addressed in order to better protect Canadians from this avoidable skin cancer risk.

Upregulation of PD-L1 via HMGB1-Activated IRF3 and NF-κB Contributes to UV Radiation-Induced Immune Suppression

Solar ultraviolet radiation (UVR) suppresses skin immunity, which facilitates initiation of skin lesions and establishment of tumors by promoting immune evasion. It is unclear whether immune checkpoints are involved in the modulation of skin immunity by UVR. Here, we report that UVR exposure significantly increased expression of immune checkpoint molecule PD-L1 in melanoma cells. The damage-associated molecular patterns molecule HMGB1 was secreted by melanocytes and keratinocytes upon UVR, which subsequently activated the receptor for advanced glycation endproducts (RAGE) receptor to promote NF-κB- and IRF3-dependent transcription of PD-L1 in melanocytes. UVR exposure significantly reduced the susceptibility of melanoma cells to CD8⁺ T-cell-dependent cytotoxicity, which was mitigated by inhibiting the HMGB1/TBK1/IRF3/NF-κB cascade or by blocking the PD-1/PD-L1 checkpoint. Taken together, our findings demonstrate that UVR-induced upregulation of PD-L1 contributes to immune suppression in the skin microenvironment, which may promote immune evasion of oncogenic cells and drive melanoma initiation and progression. SIGNIFICANCE: These findings identify PD-L1 as a critical component of UV-induced immune suppression in the skin, which facilitates immunoevasion of oncogenic melanocytes and development of melanoma.See related commentary by Sahu, p. 2805.

cAMP-mediated regulation of melanocyte genomic instability: A melanoma-preventive strategy

Malignant melanoma of the skin is the leading cause of death from skin cancer and ranks fifth in cancer incidence among all cancers in the United States. While melanoma mortality has remained steady for the past several decades, melanoma incidence has been increasing, particularly among fair-skinned individuals. According to the American Cancer Society, nearly 10,000 people in the United States will die from melanoma this year. Individuals with dark skin complexion are protected damage generated by UV-light due to the high content of UV-blocking melanin pigment in their epidermis as well as better capacity for melanocytes to cope with UV damage. There is now ample evidence that suggests that the melanocortin 1 receptor (MC1R) is a major melanoma risk factor. Inherited loss-of-function mutations in MC1R are common in melanoma-prone persons, correlating with a less melanized skin complexion and poorer recovery from mutagenic photodamage. We and others are interested in the MC1R signaling pathway in melanocytes, its mechanisms of enhancing genomic stability and pharmacologic opportunities to reduce melanoma risk based on those insights. In this chapter, we review melanoma risk factors, the MC1R signaling pathway, and the relationship between MC1R signaling and DNA repair.

Knowledge and Protective Behaviors About Skin Cancer Among Nursing Students in the West Black Sea Region of Turkey

Skin cancer is an important health problem worldwide among cancer types and results in death at a minimum level in the case of early diagnosis. Therefore, the application of prevention programs is vital. Nurses by definition take responsibility for programs in prevention, early diagnosis, and screening for cancer. This study was conducted to determine the extent of skin cancer knowledge and protective behaviors among nursing students in the West Black Sea Region of Turkey. This cross-sectional, descriptive study was conducted between February and May 2015. The study sample consisted of 965 nursing students. Data were collected by means of a questionnaire form. Nursing students had a moderate level of knowledge, with average scores of 24.35 ± 3.66. The knowledge levels of first-year students were lowest compared with other years. It was determined that, among nursing students, the percentage of "negative behaviors" in response to skin cancer protective behaviors was higher than for "positive behaviors." The results of this study highlight the knowledge level and skin cancer protective behaviors of nursing students. Training, seminars, and workshops that teach about risk factors, early detection, protective behaviors, and skin self-examination skills could increase the knowledge level of nursing students.

Mycosporine-Like Amino Acids: Potential Health and Beauty Ingredients

Human skin is constantly exposed to damaging ultraviolet radiation (UVR), which induces a number of acute and chronic disorders. To reduce the risk of UV-induced skin injury, people apply an additional external protection in the form of cosmetic products containing sunscreens. Nowadays, because of the use of some chemical filters raises a lot of controversies, research focuses on exploring novel, fully safe and highly efficient natural UV-absorbing compounds that could be used as active ingredients in sun care products. A promising alternative is the application of multifunctional mycosporine-like amino acids (MAAs), which can effectively compete with commercially available filters. Here, we outline a complete characterization of these compounds and discuss their enormous biotechnological potential with special emphasis on their use as sunscreens, activators of cells proliferation, anti-cancer agents, anti-photoaging molecules, stimulators of skin renewal, and functional ingredients of UV-protective biomaterials.

A Topical Solution to the Sunless Tanning Problem

Skin cancer is the most commonly diagnosed type of cancer and is strongly associated with UV exposure and skin pigmentation. Recent advances in pharmacologic non-UV tanning methods open the possibility of preventing melanoma and non-melanoma skin cancer, especially in people who do not tan in the sun.

Paracrine regulation of melanocyte genomic stability: a focus on nucleotide excision repair

UV radiation is a major environmental risk factor for the development of melanoma by causing DNA damage and mutations. Resistance to UV damage is largely determined by the capacity of melanocytes to respond to UV injury by repairing mutagenic photolesions. The nucleotide excision repair (NER) pathway is the major mechanism by which cells correct UV photodamage. This multistep process involves the basic steps of damage recognition, isolation, localized strand unwinding, assembly of a repair complex, excision of the damage-containing strand 3' and 5' to the photolesion, synthesis of a sequence-appropriate replacement strand, and finally ligation to restore continuity of genomic DNA. In melanocytes, the efficiency of NER is regulated by several hormonal pathways including the melanocortin and endothelin signaling pathways. Elucidating molecular mechanisms by which melanocyte DNA repair is regulated offers the possibility of developing novel melanoma-preventive strategies to reduce UV mutagenesis, especially in UV-sensitive melanoma-prone individuals.

Hormonal Regulation of the Repair of UV Photoproducts in Melanocytes by the Melanocortin Signaling Axis

Melanoma is the deadliest form of skin cancer because of its propensity to spread beyond the primary site of disease and because it resists many forms of treatment. Incidence of melanoma has been increasing for decades. Although ultraviolet radiation (UV) has been identified as the most important environmental causative factor for melanoma development, UV-protective strategies have had limited efficacy in melanoma prevention. UV mutational burden correlates with melanoma development and tumor progression, underscoring the importance of UV in melanomagenesis. However, besides amount of UV exposure, melanocyte UV mutational load is influenced by the robustness of nucleotide excision repair, the genome maintenance pathway charged with removing UV photoproducts before they cause permanent mutations in the genome. In this review, we highlight the importance of the melanocortin hormonal signaling axis on regulating efficiency of nucleotide excision repair in melanocytes. By understanding the molecular mechanisms by which nucleotide excision repair can be increased, it may be possible to prevent many cases of melanoma by reducing UV mutational burden over time.

Melanoma and non-melanoma skin cancer in psoriatic patients treated with high-dose phototherapy

OBJECTIVES

The carcinogenic effect of plus ultraviolet A (PUVA)-therapy in psoriatic patients has been widely demonstrated, while data on the safety of narrow band (311 nm) ultraviolet B (nb-UVB) are scarce. We investigated the occurrence of melanoma and non-melanoma skin cancer (NMSC) in psoriatic patients treated with nb-UVB or PUVA-therapy.

METHODS

This retrospective study included patients affected by psoriasis, who had been treated with nb-UVB or PUVA-therapy. Clinical data and phenotypic risk factors were collected and a total body examination was performed at a routine appointment during the study period.

RESULTS

We examined 92 patients (60 males and 32 females; mean age: 53.5 years, range: 20-83 years) treated with PUVA-therapy (42/92, 45%) or with nb-UVB (50/92, 55%) for 1-28 years (mean: 7.1 years). Among patients treated with PUVA, nine skin tumors (one melanoma, seven basal cell carcinoma (BCCs) and one squamous cell carcinoma (SCC)) were detected in 2/42 (4.7%) patients, while in the nb-UVB group, 14 skin tumors including two melanomas, four BCCs, and eight SCCs were diagnosed in 6/50 (12%) patients.

CONCLUSIONS

A noteworthy number of NMSC were diagnosed in this Mediterranean population of patients exposed to high-dose UV treatment. A thorough risk-benefit evaluation should always be done before UV treatment and patients should be carefully monitored for skin cancer during and after treatment discontinuation.

Indoor Tanning, Skin Cancer and the Young Female Patient: A Review of the Literature

Young, non-Hispanic white females represent the population most likely to use indoor tanning facilities. This population may be at increased risk of skin cancer as recent meta-analyses support a strong association between cutaneous malignancy and indoor tanning. Public perception of the purported health benefits of indoor tanning may be partially to blame for the popularity of tanning salons as a desire to prepare skin prior to sun exposure is among the most commonly cited motivations for indoor tanning. Improving education and counseling to address misconceptions regarding tanning safety will require the participation of healthcare providers for both physical and psychological screenings as well as for information dissemination. This review presents the association between tanning bed use and skin cancer, biological effects of UV radiation exposure, UV burden associated with tanning devices, public perception of tanning, demographic and psychological profile of indoor tanners, and current legislation regulating tanning bed use.

Adolescent and young adult patients with cancer: a milieu of unique features

Adolescent and young adult (AYA) patients with cancer are a unique category of patients who, depending on age at time of diagnosis, might receive treatment from oncologists specializing either in the treatment of children or adults. In the USA, AYA oncology generally encompasses patients 15-39 years of age. AYA patients with cancer typically present with diseases that span the spectrum from 'paediatric' cancers (such as acute lymphoblastic leukaemia [ALL] and brain tumours) to 'adult' tumours (such as breast cancer and melanoma), as well as cancers that are largely unique to their age group (such as testicular cancer and bone tumours). Research indicates that outcomes of AYA patients with cancer are influenced not only by the treatment provided, but also by factors related to 'host' biology. In addition to the potential biological and cancer-specific differences between AYAs and other patients with cancer, AYA patients also often have disparate access to clinical trials and suffer from a lack of age-appropriate psychosocial support services and health services, which might influence survival as well as overall quality of life. In this Review, these issues are discussed, with a focus on two types of AYA cancer--ALL and melanoma--highlighting findings arising from the use of emerging technologies, such as whole-genome sequencing.

UV signaling pathways within the skin

The effects of UVR on the skin include tanning, carcinogenesis, immunomodulation, and synthesis of vitamin D, among others. Melanocortin 1 receptor polymorphisms correlate with skin pigmentation, UV sensitivity, and skin cancer risk. This article reviews pathways through which UVR induces cutaneous stress and the pigmentation response. Modulators of the UV tanning pathway include sunscreen agents, MC1R activators, adenylate cyclase activators, phosphodiesterase 4D3 inhibitors, T oligos, and MITF regulators such as histone deacetylase (HDAC)-inhibitors. UVR, as one of the most ubiquitous carcinogens, represents both a challenge and enormous opportunity in skin cancer prevention.

Skin cancer: role of ultraviolet radiation in carcinogenesis

UV radiation is a carcinogen known to play a role in the development of non-melanoma and melanoma skin cancers. Acute and chronic exposure to UV radiation causes clinical and biological effects that promote the unregulated proliferation of skin cells. In recent decades, changes in climate and increased air pollution have led to environmental changes that increase UV light transmission. In this chapter, we discuss sources of UV radiation that are relevant to human health, as well as the acute and chronic effects that result from UV radiation exposure.

UV radiation and the skin

UV radiation (UV) is classified as a "complete carcinogen" because it is both a mutagen and a non-specific damaging agent and has properties of both a tumor initiator and a tumor promoter. In environmental abundance, UV is the most important modifiable risk factor for skin cancer and many other environmentally-influenced skin disorders. However, UV also benefits human health by mediating natural synthesis of vitamin D and endorphins in the skin, therefore UV has complex and mixed effects on human health. Nonetheless, excessive exposure to UV carries profound health risks, including atrophy, pigmentary changes, wrinkling and malignancy. UV is epidemiologically and molecularly linked to the three most common types of skin cancer, basal cell carcinoma, squamous cell carcinoma and malignant melanoma, which together affect more than a million Americans annually. Genetic factors also influence risk of UV-mediated skin disease. Polymorphisms of the melanocortin 1 receptor (MC1R) gene, in particular, correlate with fairness of skin, UV sensitivity, and enhanced cancer risk. We are interested in developing UV-protective approaches based on a detailed understanding of molecular events that occur after UV exposure, focusing particularly on epidermal melanization and the role of the MC1R in genome maintenance.

Beneficial effects of UV radiation other than via vitamin D production

Most of the positive effects of solar radiation are mediated via ultraviolet-B (UVB) induced production of vitamin D in skin. However, several other pathways may exist for the action of ultraviolet (UV) radiation on humans as focused on in this review. One is induction of cosmetic tanning (immediate pigment darkening, persistent pigment darkening and delayed tanning). UVB-induced, delayed tanning (increases melanin in skin after several days), acts as a sunscreen. Several human skin diseases, like psoriasis, vitiligo, atopic dermatitis and localized scleroderma, can be treated with solar radiation (heliotherapy) or artificial UV radiation (phototherapy). UV exposure can suppress the clinical symptoms of multiple sclerosis independently of vitamin D synthesis. Furthermore, UV generates nitric oxide (NO), which may reduce blood pressure and generally improve cardiovascular health. UVA-induced NO may also have antimicrobial effects and furthermore, act as a neurotransmitter. Finally, UV exposure may improve mood through the release of endorphins.

Evidence for a new paradigm for ultraviolet exposure: a universal schedule that is skin phototype independent

BACKGROUND

The Food and Drug Administration has published guidelines for manufacturer-recommended exposure schedules for ultraviolet (UV) tanning, intended to limit acute and delayed damage from UV exposure. These guidelines recommend that exposure schedules be adjusted for skin phototype. However, it has been shown that the dose necessary to produce tanning is similar for phototypes 2-4.

METHODS

We observed tanning in phototypes 2 and 3 from repeated UV exposures over a 5-week period. Pigmentation was evaluated visually, instrumentally, and through Fontana-Masson staining of biopsies.

RESULTS

The resultant pigmentation was equal or greater in phototype 3 compared with phototype 2 - both visually and instrumentally - measured on day 31 of the exposure protocol. The amount of melanin measured in biopsies taken 24 h postexposure was also greater in phototype 3 compared with phototype 2.

CONCLUSION

Published data on tanning in phototypes 4 and 5 support our findings that higher phototypes can develop pigmentation more efficiently than lower phototypes. Therefore, a universal exposure schedule (based on sensitivity of phototype 2) can be used for all phototypes that are expected to engage in indoor tanning. This approach will result in a reduction of the UV burden for skin phototypes 3 and above.

Tanning themselves to death: a new teen fad

Incidence rates of melanoma continue to rise, especially in young women, despite the enormous body of evidence that identifies ultraviolet radiation as a skin carcinogen. It is time for a change in societal norms, an increase in counseling of young adults about the risks of indoor tanning facilities, and to prevent young adults from tanning by introducing new legislation.

Rescue of the transcription factors Sp1 and NFI in human skin keratinocytes through a feeder-layer-dependent suppression of the proteasome activity

Co-culturing human skin keratinocytes along with a feeder layer has proven to considerably improve their proliferative properties by delaying massive induction of terminal differentiation. Through a yet unclear mechanism, we recently reported that irradiated 3T3 (i3T3) fibroblasts used as a feeder layer increase the nuclear content of Sp1, a positive transcription factor (TF) that plays a critical role in many cellular functions including cell proliferation, into both adult skin keratinocytes and newborn skin keratinocytes. In this study, we examined the influence of i3T3 on the expression and DNA binding of NFI, another TF important for cell proliferation and cell cycle progression, and attempted to decipher the mechanism by which the feeder layer contributes at maintaining higher levels of these TFs in skin keratinocytes. Our results indicate that co-culturing both adult skin keratinocytes and newborn skin keratinocytes along with a feeder layer dramatically increases glycosylation of NFI and may prevent it from being degraded by the proteasome.

Use of tanning beds and incidence of skin cancer

PURPOSE

We sought to evaluate the risk effect of tanning bed use on skin cancers among teenage and young adults. We also expected to determine whether a dose-response relationship was evident.

PATIENTS AND METHODS

We observed 73,494 female nurses for 20 years (from 1989 to 2009) in a large and well-characterized cohort in the United States and investigated whether frequency of tanning bed use during high school/college and at ages 25 to 35 years were associated with a risk of basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma. We used Cox proportional hazards models and carefully adjusted for host risk factors, ultraviolet index of residence, and sun exposure behaviors at a young age.

RESULTS

During follow-up, 5,506 nurses were diagnosed with BCC, 403 with SCC, and 349 with melanoma. The multivariable-adjusted hazard ratio (HR) of skin cancer for an incremental increase in use of tanning beds of four times per year during both periods was 1.15 (95% CI, 1.11 to 1.19; P < .001) for BCC, 1.15 (95% CI, 1.01 to 1.31; P = .03) for SCC, and 1.11 (95% CI, 0.97 to 1.27; P = .13) for melanoma. Compared with tanning bed use at ages 25 to 35 years, we found a significantly higher risk of BCC for use during high school/college (multivariable-adjusted HR for use more than six times per year compared with no use was 1.73 during high school/college v 1.28 at ages 25 to 35 years; P for heterogeneity < .001).

CONCLUSION

Our data provide evidence for a dose-response relationship between tanning bed use and the risk of skin cancers, especially BCC, and the association is stronger for patients with a younger age at exposure.

Lifetime history of indoor tanning in young people: a retrospective assessment of initiation, persistence, and correlates

Background

Despite educational and public health campaigns to convey the risks of indoor tanning, many individuals around the world continue to engage in this behavior. Few descriptive studies of indoor tanning have collected information pertaining to the lifetime history of indoor tanning, thereby limiting our ability to understand indoor tanning patterns and potentially target interventions for individuals who not only initiate, but continue to persistently engage in indoor tanning.

Methods

In-person interviews elicited detailed retrospective information on lifetime history of indoor tanning among white individuals (n = 401) under age 40 seen by a dermatologist for a minor benign skin condition. These individuals were controls in a case-control study of early-onset basal cell carcinoma. Outcomes of interest included ever indoor tanning in both males and females, as well as persistent indoor tanning in females - defined as females over age 31 who tanned indoors at least once in the last three or all four of four specified age periods (ages 11-15, 16-20, 21-30 and 31 or older). Multivariate logistic regression was used to identify sociodemographic and lifestyle correlates of ever and persistent indoor tanning in females.

Results

Approximately three-quarters (73.3%) of females and 38.3% of males ever tanned indoors, with a median age of initiation of 17.0 and 21.5, respectively. Among indoor tanners, 39.3% of females and 21.7% of males reported being burned while indoor tanning. Female ever indoor tanners were younger, had darker color eyes, and sunbathed more frequently than females who never tanned indoors. Using unique lifetime exposure data, 24.7% of female indoor tanners 31 and older persistently tanned indoors starting as teenagers. Female persistent indoor tanners drank significantly more alcohol, were less educated, had skin that tanned with prolonged sun exposure, and sunbathed outdoors more frequently than non-persistent tanners.

Conclusions

Indoor tanning was strikingly common in this population, especially among females. Persistent indoor tanners had other high-risk behaviors (alcohol, sunbathing), suggesting that multi-faceted behavioral interventions aimed at health promotion/disease prevention may be needed in this population.

Banning children and youth younger than 18 years of age from commercial tanning facilities

Cutaneous malignant melanoma has increased more than three-fold in the past 35 years. Because damage is cumulative, exposure to ultraviolet radiation early in life elevates a risk that is increased further as individuals use artificial sources of ultraviolet radiation. The full impact and scope of damage caused by year-round indoor tanning may take years to appreciate given the long latency period for most skin cancers. Teenagers are frequent visitors to tanning parlours, with girls being more frequent and sustained users. The tanning industry disputes the World Health Organization's and the International Agency for Research on Cancer's classification of their product as a Class 1 physical carcinogen. Tanning parlours have sought to establish and maintain a client-base among teenagers. Consequently, the Canadian Paediatric Society is joining other prominent health organizations in support of a ban on the use of commercial tanning facilities by Canadian children and youth younger than 18 years of age.

Epidemiology of basal cell carcinoma

Basal cell carcinoma is the most common malignant neoplasm in humans and its incidence has increased over the last decades. Its high frequency significantly burdens the health system, making the disease a public health issue. Despite the low mortality rates and the rare occurrence of metastases, the tumor may be locally invasive and relapse after treatment, causing significant morbidity. Exposure to ultraviolet radiation is the main environmental risk factor associated with its cause. However, other elements of risk are described, such as light skin phototypes, advanced age, family history of skin carcinoma, light eyes and blond hair, freckles in childhood and immunosuppression. Behavioral aspects such as occupational sun exposure, rural labor and sunburns at a young age also play a role. Between 30% and 75% of the sporadic cases are associated with patched hedgehog gene mutation, but other genetic changes are also described. The tumor is commonly found in concomitance with skin lesions related to chronic sun exposure, such as actinic keratoses, solar lentigines and facial telangiectasia. The prevention of basal cell carcinoma is based on the knowledge of risk factors, early diagnosis and treatment, as well as on the adoption of specific measures, particularly in susceptible populations. The authors present a review of the epidemiology of basal cell carcinoma.

Geography, facilities, and promotional strategies used to encourage indoor tanning in New York City

There is emerging evidence for the relationship between indoor tanning and melanoma. Eighty-five indoor tanning facilities in New York City were observed to determine number of tanning machines, pricing, promotions, products, and hours. Census data by zip code was used to determine population density, gender, race, age, percent living in poverty, percent unemployed, and percent college educated of areas in which tanning facilities were located. Pricing varied by the type of machine, number of sessions purchased, and single versus bundled sessions. Facilities were located in areas that had greater population density and slightly greater median age. Compared with the zip code areas with no facilities, those with tanning facilities had a higher proportion of white residents; a lower proportion of residents living in poverty and unemployed; and a higher proportion of residents with a college education. Our data suggest that the strategic location of facilities and promotions used in NYC seek to maximize patronage by those with comparatively high levels of income and education and who may be more influenced by the social desirability of artificial tanning. Long-term interventions aimed at changing social norms regarding tan skin are needed.

Reduction of 8-oxodGTP in the nucleotide pool by hMTH1 leads to reduction in mutations in the human lymphoblastoid cell line TK6 exposed to UVA

UVA has been suggested to play an important role in UV-induced mutagenesis. The mechanisms by which UVA induces mutations are still a matter of debate. Our aim was to investigate the protective capacity of hMTH1, a nucleotide pool sanitization enzyme with 8-oxodGTPase activity. Human B lymphoblastoid cells were stably transfected with shRNA directed against hMTH1. Clonogenic survival, mutations, intracellular and extracellular levels of 8-oxodG (8-oxo-7, 8-dihydro-2'-deoxyguanosine) and dG in the nucleotide pool of UVA-irradiated transfected and non-transfected cells were investigated. Mutations were determined in the thymidine kinase locus. Intracellular 8-oxodG and dG were measured using a modified ELISA and HPLC, respectively, after extraction of the nucleotide pool and conversion of nucleotides to their corresponding nucleosides. 8-oxodG in the medium was measured using ELISA. UVA-induced mutations were significantly higher while the survival was slightly lower in transfected compared to non-transfected cells. The increased mutation rate in transfected cells at increased exposure correlated with enhanced levels of 8-oxodG in the nucleotide pool, and a somewhat reduced level of 8-oxodG in the medium. The results indicate that the nucleotide pool is a significant target for UVA-induced mutations and implicates that hMTH1 plays an important role in protecting cells from UVA-induced oxidative stress.

Adverse effects of ultraviolet radiation from the use of indoor tanning equipment: time to ban the tan

The incidence of melanoma skin cancer is increasing rapidly, particularly among young women in the United States. Numerous studies have documented an association between the use of indoor tanning devices and an increased risk of skin cancer, especially in young women. Studies have shown that ultraviolet exposure, even in the absence of erythema or burn, results in DNA damage. Countries and regulatory bodies worldwide have recognized the health risks associated with indoor tanning. In the United States, 32 states have passed legislation to regulate the indoor tanning industry, but there is an urgent need to restrict the use of indoor tanning devices at the federal level. The Food and Drug Administration is currently reviewing the classification of these devices. For all of these reasons, the Food and Drug Administration should prohibit the use of tanning devices by minors and reclassify tanning devices to at least class II to protect the public from the preventable cancers and other adverse effects caused by ultraviolet radiation from indoor tanning.