Ultraviolet A and melanoma: a review

Factors Influencing Effects of Low-dose Radiation Exposure

ABSTRACT

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

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

OBJECTIVE

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

DESIGN

Retrospective secondary data analysis.

DATA SOURCES

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

SETTING

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

PARTICIPANTS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

Nanozyme-Engineered Hydrogels for Anti-Inflammation and Skin Regeneration

Inflammatory skin disorders can cause chronic scarring and functional impairments, posing a significant burden on patients and the healthcare system. Conventional therapies, such as corticosteroids and nonsteroidal anti-inflammatory drugs, are limited in efficacy and associated with adverse effects. Recently, nanozyme (NZ)-based hydrogels have shown great promise in addressing these challenges. NZ-based hydrogels possess unique therapeutic abilities by combining the therapeutic benefits of redox nanomaterials with enzymatic activity and the water-retaining capacity of hydrogels. The multifaceted therapeutic effects of these hydrogels include scavenging reactive oxygen species and other inflammatory mediators modulating immune responses toward a pro-regenerative environment and enhancing regenerative potential by triggering cell migration and differentiation. This review highlights the current state of the art in NZ-engineered hydrogels (NZ@hydrogels) for anti-inflammatory and skin regeneration applications. It also discusses the underlying chemo-mechano-biological mechanisms behind their effectiveness. Additionally, the challenges and future directions in this ground, particularly their clinical translation, are addressed. The insights provided in this review can aid in the design and engineering of novel NZ-based hydrogels, offering new possibilities for targeted and personalized skin-care therapies.

Development and evaluation of sunscreen cream containing solid lipid nanoparticles of Spinacia oleraceae

More research is needed to understand the benefits of environmentally safe and human-friendly herbal-based sunscreen agents against ultraviolet (UV) radiation. Because of the toxicity of synthetic chemicals in photoprotective agents, researchers were increasingly focusing on herbal photoprotective formulations. The photoprotective agent's skin retention can be considerably improved by forming solid lipid nanoparticles (SLN). The study's objective is to evaluate the photoprotective potential of sunscreen cream containing spinach (Spinacia oleracea)-loaded SLN. A solvent emulsification technique was used to develop the spinach-loaded SLN. The various characterization techniques of the developed SLN were performed. Out of all the formulations, the optimized one was fitted into cream and estimated for its photoprotective action. The images obtained from scanning electron microscopy (SEM) revealed the morphological characteristics of the prepared SLN. The sunscreen cream's viscosity, spreadability, extrudability, and release rate were within acceptable limits. The formulation's in vitro and in vivo sun protection factor (SPF) was reported to be 15.9 and 14.75, respectively. The results indicated that the prepared formulation possesses good photoprotective action. The accelerated stability tests were carried out with no noticeable changes in the parameters. Our work demonstrated the possibility of using spinach-loaded SLN as a photoprotective agent in cosmetic formulations.

Ultraviolet A radiation exposure and melanoma: a review

The incidence of cutaneous melanoma has been increasing worldwide, and melanoma disproportionately contributes to skin cancer mortality. The pathogenesis of melanoma involves genetic and environmental factors, and while the effects of ultraviolet B radiation on melanoma development are well researched, fewer studies have investigated the role of ultraviolet A (UVA) radiation. We comprehensively reviewed cell, animal and epidemiology studies on the association between UVA exposure and melanomagenesis. UVA radiation has been found to have negative effects on melanocytes due to the induction of oxidative stress, dysregulation of gene transcription and creation of mutagenic photoproducts in DNA. Animal studies demonstrate adverse effects of UVA on melanocytes, including the development of melanoma. Epidemiology studies, of varying quality, that examined participants' exposure to tanning devices which use UVA radiation primarily found that UVA exposure increased the risk for melanoma. Some studies reported larger associations with increased frequency of device use, suggestive of a dose-response relationship. Overall, we found that many studies supported a positive association between UVA exposure and melanoma on both molecular and population levels. Understanding the role of UVA in the development of melanoma will inform the implementation of preventive health interventions, such as those related to sunscreen development and use and increasing restrictions on indoor tanning.

Boosting the Photoaged Skin: The Potential Role of Dietary Components

Skin photoaging is mainly induced by ultraviolet (UV) irradiation and its manifestations include dry skin, coarse wrinkle, irregular pigmentation, and loss of skin elasticity. Dietary supplementation of nutraceuticals with therapeutic and preventive effects against skin photoaging has recently received increasing attention. This article aims to review the research progress in the cellular and molecular mechanisms of UV-induced skin photoaging. Subsequently, the beneficial effects of dietary components on skin photoaging are discussed. The photoaging process and the underlying mechanisms are complex. Matrix metalloproteinases, transforming growth factors, skin adipose tissue, inflammation, oxidative stress, nuclear and mitochondrial DNA, telomeres, microRNA, advanced glycation end products, the hypothalamic-pituitary-adrenal axis, and transient receptor potential cation channel V are key regulators that drive the photoaging-associated changes in skin. Meanwhile, mounting evidence from animal models and clinical trials suggests that various food-derived components attenuate the development and symptoms of skin photoaging. The major mechanisms of these dietary components to alleviate skin photoaging include the maintenance of skin moisture and extracellular matrix content, regulation of specific signaling pathways involved in the synthesis and degradation of the extracellular matrix, and antioxidant capacity. Taken together, the ingestion of food-derived functional components could be an attractive strategy to prevent skin photoaging damage.

Low-Temperature Argon Plasma Regulates Skin Moisturizing and Melanogenesis-Regulating Markers through Yes-Associated Protein

Extensive water loss and melanin hyperproduction can cause various skin disorders. Low-temperature argon plasma (LTAP) has shown the possibility of being used for the treatment of various skin diseases, such as atopic dermatitis and skin cancer. However, the role of LTAP in regulating skin moisturizing and melanogenesis has not been investigated. In this study, we aimed to determine the effect of LTAP on yes-associated protein (YAP), a major transcriptional coactivator in the Hippo signaling pathway that is involved in skin moisturizing and melanogenesis-regulating markers. In normal human epidermal keratinocytes (NHEKs), the human epidermal keratinocyte line HaCaT, and human dermal fibroblasts (HDFs), we found that LTAP exhibited increased expression levels of YAP protein. In addition, the expression levels of filaggrin (FLG), which is involved in natural moisturizing factors (NMFs), and hyaluronic acid synthase (HAS), transglutaminase (TGM), and involucrin (IVL), which regulate skin barrier and moisturizing, were also increased after exposure to LTAP. Furthermore, collagen type I alpha 1 and type III alpha 1 (COL1A1, COL3A1) were increased after LTAP exposure, but the expression level of matrix metalloproteinase-3 (MMP-3) was reduced. Moreover, LTAP was found to suppress alpha-melanocyte stimulating hormone (α-MSH)-induced melanogenesis in murine melanoma B16F10 cells and normal human melanocytes (NHEMs). LTAP regulates melanogenesis of the melanocytes through decreased YAP pathway activation in a melanocortin 1 receptor (MC1R)-dependent manner. Taken together, our data show that LTAP regulates skin moisturizing and melanogenesis through modulation of the YAP pathway, and the effect of LTAP on the expression level of YAP varies from cell to cell. Thus, LTAP might be developed as a treatment method to improve the skin barrier, moisture content, and wrinkle formation, and to reduce melanin generation.

Review of Wearable and Portable Sensors for Monitoring Personal Solar UV Exposure

Sunlight is one of the main environmental resources that keeps all the organisms alive on earth. The ultraviolet (UV) radiation from the sun is essential for vitamin D synthesis in the human body, which is crucial for bone and muscle health. In addition, sun exposure also helps to reduce the risk of some cardiovascular diseases and cancers. However, excessive UV exposure can lead to adverse effects, including some eye diseases, premature aging, sunburn and skin cancers. The solar UV irradiance itself depends on many environmental factors. In fact, the UV index reported in weather forecasts is an estimation under cloudless conditions. Personal UV exposure also depends on one's outdoor activities and habits. Furthermore, the UV intake depends on the skin sensitivity. Therefore, there is a need for research into monitoring the optimal daily UV exposure for health benefits, without developing potential health risks. To facilitate the monitoring of solar UV intensity and cumulative dose, a variety of UV sensors have been developed in the past few decades and many are commercially available. Examples of sensors being marketed are: portable UV dosimeter, wearable UV radiometer, personal UV monitor, and handheld Solarmeter®. Some of the UV sensors can be worn as personal health monitors, which promote solar exposure protection. The paper provides a comprehensive review of the wearable and portable UV sensors for monitoring personal UV exposure, including a discussion of their unique advantages and limitations. Proposals are also presented for possible future research into reliable and practical UV sensors for personal UV exposure monitoring.

Review of medical image recognition technologies to detect melanomas using neural networks

BACKGROUND

Melanoma is one of the most aggressive types of cancer that has become a world-class problem. According to the World Health Organization estimates, 132,000 cases of the disease and 66,000 deaths from malignant melanoma and other forms of skin cancer are reported annually worldwide ( https://apps.who.int/gho/data/?theme=main ) and those numbers continue to grow. In our opinion, due to the increasing incidence of the disease, it is necessary to find new, easy to use and sensitive methods for the early diagnosis of melanoma in a large number of people around the world. Over the last decade, neural networks show highly sensitive, specific, and accurate results.

OBJECTIVE

This study presents a review of PubMed papers including requests «melanoma neural network» and «melanoma neural network dermatoscopy». We review recent researches and discuss their opportunities acceptable in clinical practice.

METHODS

We searched the PubMed database for systematic reviews and original research papers on the requests «melanoma neural network» and «melanoma neural network dermatoscopy» published in English. Only papers that reported results, progress and outcomes are included in this review.

RESULTS

We found 11 papers that match our requests that observed convolutional and deep-learning neural networks combined with fuzzy clustering or World Cup Optimization algorithms in analyzing dermatoscopic images. All of them require an ABCD (asymmetry, border, color, and differential structures) algorithm and its derivates (in combination with ABCD algorithm or separately). Also, they require a large dataset of dermatoscopic images and optimized estimation parameters to provide high specificity, accuracy and sensitivity.

CONCLUSIONS

According to the analyzed papers, neural networks show higher specificity, accuracy and sensitivity than dermatologists. Neural networks are able to evaluate features that might be unavailable to the naked human eye. Despite that, we need more datasets to confirm those statements. Nowadays machine learning becomes a helpful tool in early diagnosing skin diseases, especially melanoma.

Exploring the photo protective potential of solid lipid nanoparticle-based sunscreen cream containing Aloe vera

Nowadays, the sunscreen creams are composed of mostly synthetic chemicals and other organic compounds which were found to enter into the blood stream on topical application raising concerns in the scientific community. The scientific community has now shifted their attention to herbal formulations due to toxicity of these synthetic molecules. Aloe vera is a xerophitic plant having excellent anti-oxidant properties. The permeation effect and drug stability of the drug candidate can be significantly enhanced by formulating it into solid lipid nanoparticles (SLN). The main objectives of the study were to formulate and evaluate Aloe vera-loaded SLN sunscreen cream and to determine its photoprotective potential. The Aloe vera-loaded SLNs were formulated by microemulsification technique. The developed SLNs were studied for its entrapment efficiency, poly dispersity index (PDI), zeta potential, particle size, and other characterization techniques. Finally, the optimized SLNs were incorporated into the sunscreen cream and evaluated for its spreadability, viscosity, extrudability, drug content, in vitro drug release, ex vivo permeation, determination of sun protection factor (SPF), skin irritation test, and accelerated stability studies. The in vitro SPF was found out to be 16.9 ± 2.44 and the in vivo SPF observed to be approximately 14.81 ± 3.81, respectively. Stability studies were performed under accelerated conditions and no appreciable changes in the parameters were noticed. The solid lipid nanoparticles of Aloe vera were incorporated into a cream and the SPF of the resultant sunscreen cream was found to be on par with the sunscreens that were currently available in the market.

Risk factors for the development of a second melanoma in patients with cutaneous melanoma

BACKGROUND

Cutaneous melanoma patients have an increased risk of developing other neoplasms, especially cutaneous neoplasms and other melanomas. Identifying factors associated with an increased risk might be useful in the development of melanoma guidelines.

OBJECTIVES

To identify risk factors related to the development of a second primary melanoma in a series of patients diagnosed with sporadic melanoma and to establish the estimated incidence rate.

METHODS

A longitudinal study based on prospective follow-up information of patients diagnosed with sporadic cutaneous melanoma at our centre from 2000 to 2015 was performed. Cumulative incidence was estimated based on competing risk models, and the association of characteristics with the risk of a second melanoma was performed by Cox proportional hazard models.

RESULTS

Out of 1447 patients included in the study, after a median follow-up of 61 months, 55 patients (3.8%) developed a second melanoma. Fair hair colour, more than 100 common melanocytic nevi and the presence of more than 50 cherry angiomas were independently associated with the development of a second melanoma. The site and the histological subtype of the first and second melanomas were not consistent. The second melanomas were thinner than the first ones.

CONCLUSIONS

Fair-haired and multiple-nevi patients might benefit from more intensive prevention measures. The finding of cherry angiomas as a risk factor suggests that these lesions could be markers of skin sun damage in the setting of certain degree of genetic susceptibility.

Flexible Self-Powered Real-Time Ultraviolet Photodetector by Coupling Triboelectric and Photoelectric Effects

The portable UV photodetector is used to timely remind humans of overexposure to UV radiation. However, the traditional UV photodetector cannot meet the practical demands, and the power supply problem hinders its further development. In this work, we demonstrated a flexible, transparent, and self-powered UV photodetector by coupling of triboelectric and photoelectric effects. The device integrates a flexible ZnO nanoparticle (NP) UV photodetector, a transparent- and flexible-film-based TENG (TFF-TENG), commercial chip resistors, and LEDs on the PET thin film. The TFF-TENG could harvest mechanical energy from finger tapping and sliding motion and power the ZnO NP UV photodetector to realize self-powered detection. The voltage of the constant resistors connected with the UV photodetector in series changes from 0.5 to 19 V under the UV light with power intensities increasing from 0.46 to 21.8 mW/cm², and the voltage variation is reflected by the number of LEDs directly. The excellent flexibility and transparency of the device could extend its application scenarios; for example, such a portable device could be applied to real-time monitoring of the UV radiation to remind humans of intense UV light.

Mechanisms of UV-induced mutations and skin cancer

Ultraviolet (UV) irradiation causes various types of DNA damage, which leads to specific mutations and the emergence of skin cancer in humans, often decades after initial exposure. Different UV wavelengths cause the formation of prominent UV-induced DNA lesions. Most of these lesions are removed by the nucleotide excision repair pathway, which is defective in rare genetic skin disorders referred to as xeroderma pigmentosum. A major role in inducing sunlight-dependent skin cancer mutations is assigned to the cyclobutane pyrimidine dimers (CPDs). In this review, we discuss the mechanisms of UV damage induction, the genomic distribution of this damage, relevant DNA repair mechanisms, the proposed mechanisms of how UV-induced CPDs bring about DNA replication-dependent mutagenicity in mammalian cells, and the strong signature of UV damage and mutagenesis found in skin cancer genomes.

Anti-genotoxic and anti-mutagenic effects of melatonin supplementation in a mouse model of melanoma

Melanoma, an aggressive skin cancer originating from melanocytes, can metastasize to the lungs, liver, cortex, femur, and spinal cord, ultimately resulting in DNA mutagenic effects. Melatonin is an endogenous hormone and free radical scavenger that possesses the ability to protect the DNA and to exert anti-proliferative effects in melanoma cells. The aim of this study was to evaluate the effects of B16F10 melanoma cells and the effects of melatonin supplementation on genotoxic parameters in murine melanoma models. Thirty-two male C57Bl/6 mice were divided in the following four groups: PBS + vehicle (n = 6), melanoma + vehicle (n = 10), PBS + melatonin (n = 6), and melanoma + melatonin (n = 10). The melanoma groups received a B16F10 cell injection, and melatonin was administered during 60 days. After treatment, tumor sizes were evaluated. DNA damage within the peripheral blood, lungs, liver, cortex, and spinal cord was determined using comet assay, and the mutagenicity within the bone marrow was determined using the micronucleus test. B16F10 cells effectively induced DNA damage in all tissues, and melatonin supplementation decreased DNA damage in the blood, liver, cortex, and spinal cord. This hormone exerts anti-tumor activity via its anti-proliferative, antioxidative, and pro-apoptotic effects. As this result was not observed within the lungs, we hypothesized that melatonin can induce apoptosis in cancer cells, and this was not evaluated by comet assay. This study provides evidence that melatonin can reduce the genotoxicity and mutagenicity caused by B16F10 cells.

Melatonin-Induced Cytoskeleton Reorganization Leads to Inhibition of Melanoma Cancer Cell Proliferation

Neuroindole melatonin, a hormone synthesized during the night mainly-but not exclusively-by the pineal gland of all vertebrates, functions as an adapting signal to the light-dark cycle. Its antioxidant, neuroprotective, anti-inflammatory, and antitumor properties are all well-known and widely reported. Melanoma is one of the most common carcinomas among developed countries and a type of tumor particularly difficult to fight back in medium/advanced stages. In contrast to other types of cancer, influence of melatonin on melanoma has been scarcely investigated. Thus, we have chosen the murine melanoma model B16-F10 cell line to study antiproliferative and antitumoral actions of melatonin. For this purpose, we combined both, cell culture and in vivo models. Melatonin reduced either, growth rate or migration of B16-F10 cells. Furthermore, melanin synthesis was altered by melatonin, promoting its synthesis. Melatonin also induced a G2/M cell cycle arrest and altered the cytoskeletal organization. To corroborate these results, we tested the effect of melatonin in the in vivo model of B16-F10 cell injection in the tail vein, which causes numerous lung metastases. Two different strategies of melatonin administration were used, namely, in drinking water, or daily intraperitoneal injection. However, contrary to what occurred in cell culture, no differences were observed between control and melatonin treated groups. Results obtained led us to conclude that melatonin exerts an antiproliferative and anti-migrating effect on this melanoma model by interfering with the cytoskeleton organization, but this pharmacological effect cannot be translated in vivo as the indole did not prevent metastasis in the murine model, suggesting that further insights into the effects of the indole in melanoma cells should be approached to understand this apparent paradox.

In situ antioxidant activity of a dermo-cosmetic product: A randomized controlled clinical study

Ultraviolet light enhances the generation of reactive oxygen species that are responsible for skin photoageing. The aim of this randomized, vehicle- and active-controlled double-blind, intra-individual monocentric study was to evaluate in situ the antioxidant activity of a dermo-cosmetic product in photoaged skin. Twenty healthy volunteers had defined skin areas randomized to receive a topical product containing 3 antioxidants (pre-tocopheryl® , retinaldehyde and glycylglycine ole-amide), its vehicle and a positive antioxidant control cream. The products were applied daily for 30-day period. The skin areas were exposed to a controlled dose of UVA rays, and the skin oxidative status was evaluated 4 and 24 hours post-UVA exposure at D0 (basal value) and after 15 and 30 days of product application. Skin layers were collected by stripping, and antioxidant capacity was measured using the ferric reducing ability of a plasma assay. Lipid peroxidation (LPO) was assessed using the malonyldialdehyde test. The tested product significantly improved the skin antioxidant capacity after 15 and 30 days and significantly decreased the basal level of the skin LPO. The skin LPO level significantly decreased 4 and 24 hours after UVA exposure at 15 and 30 days. These findings were comparable to positive control treated sites and were significantly different from the vehicle and untreated sites. This minimally invasive methodology enabled a quantitative evaluation of potent antioxidant activity in situ in the stratum corneum reflecting real-life skin conditions and confirming the benefits of the topical application of a product containing 3 antioxidants in the prevention of UVA-induced oxidative damage.

Development of broad spectrum mycosporine loaded sunscreen formulation from Ulva fasciata delile

Ba.ckground: Sunscreen formulations primarily offer protection against UV induced damages however nowadays it also maintains skin natural physiological conditions. Current global market is flooded with numerous sunscreen products which offer protection to skin against several UV induced damages. However most of these sunscreen formulations offers narrow spectrum protection against UV and also suffer from stability as well as toxicity related issues.

Methods: Present work aims to isolate mycosporine amino acid (Mgy) from green alga namely Ulva fasciata (U. fasciata) and study its sunscreen potential against widely used domestic marketed formulation. Stability evaluations were also performed for almost 90 days.

Results: Results demonstrated that the isolated compound, mycosporine glycine (Mgy) preserved physicochemical properties of the product and offered good stability for all formulations throughout the experimental period. Furthermore, Mgy loaded carbopol gel showed better sunscreen protection against marketed formulation in a concentration dependent manner. (7.709).

Conclusion: (6.806) Novel Myg loaded gel was proved to demonstrate several quality characteristics that may unlock new prospects for the production of more efficient, safe, and economic skin-care products.

Macroenvironment-gene-microenvironment interactions in ultraviolet radiation-induced melanomagenesis

Cutaneous malignant melanoma is one of the few major cancers that continue to exhibit a positive rate of increase in the developed world. A wealth of epidemiological data has undisputedly implicated ultraviolet radiation (UVR) from sunlight and artificial sources as the major risk factor for melanomagenesis. However, the molecular mechanisms of this cause-and-effect relationship remain murky and understudied. Recent efforts on multiple fronts have brought unprecedented expansion of our knowledge base on this subject and it is now clear that melanoma is caused by a complex interaction between genetic predisposition and environmental exposure, primarily to UVR. Here we provide an overview of the effects of the macroenvironment (UVR) on the skin microenvironment and melanocyte-specific intrinsic (mostly genetic) landscape, which conspire to produce one of the deadliest malignancies.

'High dose' vs. 'medium dose' UVA1 phototherapy in italian patients with severe atopic dermatitis

BACKGROUND

The current evidences attest UVA1 phototherapy as effective in the treatment of severe atopic dermatitis (AD). Furthermore, in this indication, 'medium dose' is as effective as 'high dose' regimen. To date, a randomized comparison study evaluating the effectiveness as well as safety of different UVA1 protocols in different skin types in the treatment of adult patients with severe AD is still lacking.

OBJECTIVE

The aim of the present study was to compare the safety and the efficacy of medium and high dose UVA1 either in fair or in dark skin types.

METHODS

Twenty-seven adult patients with severe AD were consecutively included in a randomized, controlled, open, two arms trial Severity of AD was determined by means of SCORAD index and clinical improvement was also monitored. A total of 13 out of 27 patients were treated with high dose (130 J/cm2 ) UVA1 protocol while 14 out of 27 patients received medium dose (60 J/cm2 ) UVA1 protocol. Phototherapy was performed five times weekly up to 3 weeks. Before and after UVA1 treatment each patient was evaluated for skin pigmentation through Melanin Index (MI) quantitative evaluation.

RESULTS

Skin status improved in all patients resulting in a reduction of SCORAD index in all groups. Our results demonstrated that among patients with darker skin types and higher MI, high dose UVA1 was significantly more effective than medium dose (P < 0.0001) while within the groups with skin type II, no significant differences between high and medium dose protocols were observed.

CONCLUSION

Our study, confirms previous observations that UVA1 phototherapy should be considered among the first approaches in the treatment of patients with severe generalized AD and also demonstrates that in darker skin types, high dose UVA1 phototherapy is more effective than medium dose in the treatment of adult patients with severe AD.

The key role of UVA-light induced oxidative stress in human Xeroderma Pigmentosum Variant cells

The UVA component of sunlight induces DNA damage, which are basically responsible for skin cancer formation. Xeroderma Pigmentosum Variant (XP-V) patients are defective in the DNA polymerase pol eta that promotes translesion synthesis after sunlight-induced DNA damage, implying in a clinical phenotype of increased frequency of skin cancer. However, the role of UVA-light in the carcinogenesis of these patients is not completely understood. The goal of this work was to characterize UVA-induced DNA damage and the consequences to XP-V cells, compared to complemented cells. DNA damage were induced in both cells by UVA, but lesion removal was particularly affected in XP-V cells, possibly due to the oxidation of DNA repair proteins, as indicated by the increase of carbonylated proteins. Moreover, UVA irradiation promoted replication fork stalling and cell cycle arrest in the S-phase for XP-V cells. Interestingly, when cells were treated with the antioxidant N-acetylcysteine, all these deleterious effects were consistently reverted, revealing the role of oxidative stress in these processes. Together, these results strongly indicate the crucial role of oxidative stress in UVA-induced cytotoxicity and are of interest for the protection of XP-V patients.

Baohuoside-I suppresses cell proliferation and migration by up-regulating miR-144 in melanoma

CONTEXT

Baohuoside-I was reported to induce apoptosis in non-small-cell lung cancer and inhibit the growth of multiple myeloma cells. The antitumour potential of baohuoside-I has not been demonstrated in melanoma yet.

OBJECTIVE

To investigate the potential antitumour activity of baohuoside-I against melanoma and elucidate its underlying molecular mechanism.

MATERIALS AND METHODS

Cell viability was evaluated by MTT assay. The malignant invasion capacity was measured with trans-well assay. The relative expression change of microRNAs was profiled with microarray. TargetScan was utilized for prediction of target gene of miR-144. Regulatory effect of miR-144 on SMAD1 was determined by dual luciferase reporter assay. Endogenous SMAD1 protein in response to ectopic expression of miR-144 was determined by immunoblotting. Xenograft mice were employed to evaluate antitumour potential of baohuoside-I (25 mg/kg by tail intravenous injection every two days) in vivo.

RESULTS

Baohuoside-I significantly inhibited proliferation (45 ± 4% reduction in M14 and 35 ± 3% reduction in MV3 at 24 h) and migration (70 ± 4% reduction in M14 and 72 ± 3% reduction in MV3) in melanoma cells. Mechanistically, baohuoside-I up-regulated miR-144 expression levels (3 ± 0.2-fold). Silence of miR-144 reversed the inhibition of baohuoside-I in melanoma. We have identified that SMAD1 was the novel target of miR-144. Moreover, baohuoside-I suppressed melanoma in vivo (52 ± 8% reduction in xenograft tumour size at day 20).

CONCLUSIONS

Our data suggested significant antitumour potential of baohuoside-I against melanoma both in vitro and in vivo, which warrants further laboratory investigation and clinical trial.

Plasticity of differentiated cells in wound repair and tumorigenesis, part II: skin and intestine

Recent studies have identified and begun to characterize the roles of regenerative cellular plasticity in many organs. In Part I of our two-part Review, we discussed how cells reprogram following injury to the stomach and pancreas. We introduced the concept of a conserved cellular program, much like those governing division and death, which may allow mature cells to become regenerative. This program, paligenosis, is likely necessary to help organs repair the numerous injuries they face over the lifetime of an organism; however, we also postulated that rounds of paligenosis and redifferentiation may allow long-lived cells to accumulate and store oncogenic mutations, and could thereby contribute to tumorigenesis. We have termed the model wherein differentiated cells can store mutations and then unmask them upon cell cycle re-entry the ‘cyclical hit’ model of tumorigenesis. In the present Review (Part II), we discuss these concepts, and cell plasticity as a whole, in the skin and intestine. Although differentiation and repair are arguably more thoroughly studied in skin and intestine than in stomach and pancreas, it is less clear how mature skin and intestinal cells contribute to tumorigenesis. Moreover, we conclude our Review by discussing plasticity in all four organs, and look for conserved mechanisms and concepts that might help advance our knowledge of tumor formation and advance the development of therapies for treating or preventing cancers that might be shared across multiple organs.

Summary: This final installment of a two-part Review discusses how cycles of dedifferentiation and redifferentiation can promote tumorigenesis in the skin and intestine, showing how plasticity in these continuously renewing tissues might contribute to tumorigenesis.

Inhibitory effects of extracellular superoxide dismutase on ultraviolet B-induced melanogenesis in murine skin and melanocytes

AIMS

Several anti-melanogenic molecules have been developed or identified, but their uses are limited due to either adverse effects or instability during the treatment. We aimed to evaluate the effects of extracellular superoxide dismutase (SOD3), a powerful antioxidant, as a candidate anti-melanogenic molecule.

MAIN METHODS

UVB-induced reactive oxygen species (ROS) production and proliferation in melan-a cells was evaluated by 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate staining and bromodeoxyuridine incorporation assay, respectively. Quantitative real-time polymerase chain reaction and western blot were performed to detect the melanogenesis-related gene expression and downstream signaling. Anti-melanogenic effects of SOD3 were also evaluated using SOD3 transgenic mice under UVB exposure in-vivo condition.

KEY FINDINGS

SOD3 inhibited UVB-induced proliferation, ROS production and melanogenesis in melanocytes. Measurement of melanin content and tyrosinase activity assays showed that SOD3 significantly inhibited melanin synthesis. Moreover, these suppressive effects of SOD3 were dependent on the endothelin-1 (ET-1)/endothelin B receptor, protein kinase C, melanocortin 1 receptor/protein kinase A, Wnt7a/β-catenin, and mitogen-activated protein kinase pathways, with concomitant downregulation of microphthalmia-associated transcription factor, tyrosinase, and tyrosinase-related proteins 1, dopachrome tautomerse. Interestingly, SOD3 was found to inhibit transforming growth factor-beta 1 (TGF-β1) to inactivate the ET-1 signaling pathway, and finally prevents the production of melanin.

SIGNIFICANCE

Our results provide novel insights into the role of SOD3 in melanocyte homeostasis and its uses as a potential biomedicine to treat hyperpigmentary conditions of the skin.

UVA, metabolism and melanoma: UVA makes melanoma hungry for metastasis

Ultraviolet (UV) radiation has a plethora of effects on human tissues. In the UV spectrum, wavelengths above 320 nm fall into the UVA range, and for these, it has been shown that they induce reactive oxygen species (ROS), DNA mutations and are capable to induce melanoma in mice. In addition to this, it was recently shown that UVA irradiation and UVA-induced ROS also increase glucose metabolism of melanoma cells. UVA irradiation causes a persistent increase in glucose consumption, accompanied by increased glycolysis, increased lactic acid production and activation of the pentose phosphate pathway. Furthermore, it was shown that the enhanced secretion of lactic acid is important for invasion of melanoma in vitro. The current knowledge of this link between UVA, metabolism and melanoma, possible mechanisms of UVA-induced glucose metabolism and their starting points are discussed in this review with focus on ROS- and UVA-induced cellular stress signalling, DNA damage signalling and DNA repair systems. When looking at the benefits of UVA-induced glucose metabolism, it becomes apparent that there are more advantages of these metabolic changes than one would expect. Besides the role of lactic acid as initiator of protease expression and invasion, its role for immune escape of melanoma cells and the pentose phosphate pathway-derived nicotinamide adenine dinucleotide phosphate (NADPH) as part of a ROS detoxification strategy are discussed.

The protective effect of some Thai plants and their bioactive compounds in UV light-induced skin carcinogenesis

Skin cancer, represents a major public health concern. While the vast majority is non-melanoma skin cancers, melanomas are mostly responsible for mortality. Solar UVB radiation is mutagenic and carcinogenic. It is primarily responsible for both non-melanoma and melanoma skin cancers via excessive production of reactive oxygen species (ROS), which mediate changes in inflammation and immunity, and have been implicated in all three stages of skin cancer development. Due to their regulatory role in numerous functions of cells, signaling pathways are targets for chemoprevention. The current standards in melanoma therapy are targeted and combination therapies, which, albeit prolong survival responses, are still prone to development of drug resistance. To this extent, drugs of natural origin continue to spark great interest. Thailand has a rich biodiversity of indigenous flora, which have traditionally been used to treat a variety of pathologies. The active components in plant extracts that have medicinal properties, termed 'bioactive compounds,' are efficient chemopreventive agents due to their antioxidant, antimutagenic, anticarcinogenic, and carcinogen detoxification properties. Thai plants and their bioactive compounds have shown protective effects on UV light-induced skin cancer in different experimental models. This warrants further in vivo investigations and translation to clinical studies to determine efficacy and safety, for use as lead compounds in targeted/combination therapy or adjuvant therapy with existing regimes. Coupled with a strategy for prevention, this offers a promising outlook for protection against photocarcinogenesis.

MELANOMA IN GOLDEN AND KING WILDEBEESTS ( CONNOCHAETES TAURINUS)

Pigmentation of the skin is a crucial component in the pathogenesis of melanocytic neoplasms and other skin-related tumors, as melanin is known to function in both the absorbance of ultraviolet radiation and as an antioxidant. Very limited information exists regarding the incidence and metastatic potential of neoplastic conditions of the skin in game animals, especially wildebeests, relative to domestic animals. Four cases of cutaneous melanoma in color-variant golden and king wildebeests ( Connochaetes taurinus) (from 2014 to 2015) in South Africa were investigated. Melanoma in these captive animals was characterized using histopathology, transmission electron microscopy, and an immunohistochemistry panel, which consisted of monoclonal antibodies against three melanocytic markers: Melan A, PNL2, and S100. Overall, 2/4 cases (50%) of the melanocytic neoplasms stained strongly positive for all the melanocytic markers, while 4/4 cases (100%) stained positively for at least one of the markers. Cutaneous melanocytic neoplasia has not been reported in wildebeests; the current study suggests that selection of wildebeests for coat color potentially predisposes to this condition.

Incidence of cutaneous malignant melanoma in Iranian provinces and American states matched on ultraviolet radiation exposure: an ecologic study

OBJECTIVES

Ultraviolet radiation (UVR), with UVB and UVA as the relevant components, is a risk factor for melanoma. Complete ascertainment and registration of melanoma in Iran was conducted in five provinces (Ardabil, Golestan, Mazandaran, Gilan and Kerman) during 1996-2000. The aim of our study was to compare population-based incidence data from these provinces with rates in the United States (US) while standardizing ambient UVR.

METHODS

Population-based rates representing all incident cases of melanoma (1996-2000) across the five Iranian provinces were compared to rates of melanoma among white non-Hispanics in the US. Overall age-standardized rates (ASR) for Iran and the US (per 100,000 person-years adjusted to 2000 world population) and standardized rate ratios (SRR) were calculated. We measured erythemally-weighted average solar UVR exposures (with contributions from both UVB and UVA range) of the five Iranian provinces using data from NASA's Total Ozone Mapping Spectrometer and selected five US states (Kentucky, Utah, Texas, Oklahoma, and Hawaii) with matching UVR exposure to each province. Incidence rates of melanoma during 1996-2000 in each Iranian province were compared to rates among white non-Hispanics in its UVR-matched US state.

RESULTS

The overall male and female ASRs of melanoma were 0.60 (95%CI: 0.56-0.64) and 0.46 (95%CI: 0.42-0.49), respectively, for Iran and 22.78 (95%CI: 22.42-23.14) and 16.61 (95%CI: 16.30-16.92) for the US. SRRs of melanoma comparing US to Iran were 37.97 (95%CI: 35.78-40.29) for males and 36.11 (95%CI: 33.69-38.70) for females, indicating significantly higher incidence in the US. ASRs and age-specific rates of melanoma for both genders were significantly lower in each Iranian province compared to its UVR-matched US state.

CONCLUSION

The markedly lower incidence rates of melanoma in Iranian provinces with similar UVR exposures to US states underscore the need for additional comparative studies to decipher the influence of other extrinsic and intrinsic factors on the risk of this malignancy.

Assessing a portable, real-time display handheld meter with UV-A and UV-B sensors for potential application in personal sun exposure studies

BACKGROUND

Observing accurate real-time measurements of solar ultraviolet radiation (UVR) levels is important since personal excess sun exposure is associated with skin cancers. Handheld measurement devices may be helpful but their accuracy is unknown. We compare a portable, science-grade solar UVR monitoring device against two fixed, science-grade solar UVR instruments.

METHODS

Instruments were (1) a fixed Solar Light 501 UV-B biometer to measure UV-B; (2) a fixed Kipp and Zonen radiometer used to measure UV-A and UV-B; and (3) Goldilux ultraviolet probes which are commercially available portable devices. Two different probes were used, one measured UV-A and the other UV-B radiation. The Goldilux probes were levelled and secured next to the UV-B biometer. Between 10:00 and 14:40 UTC+2, the UV-B biometer was set to record at 10-minute intervals and measurements by the Goldilux probes were manually taken simultaneously. Results were compared for all data and by solar zenith angle (SZA) ranges.

RESULTS

The Goldilux UV-B probe measured UV-B relatively well in its diurnal pattern, however, its readings were ~77% higher than those made by the UV-B biometer. While UV-A measurements from the Goldilux UV-A probe and those from the radiometer were in relatively good agreement in pattern, the radiometer read ~47% higher than the Goldilux UV-A probe. UV-B data from Goldilux UV-B probe had a moderately strong correlation with UV-B biometer data for small SZAs; conversely, for UV-A, the Goldilux UV-A probe had a strong correlation with the UV-A radiometer data for large SZAs.

CONCLUSION

Handheld devices may be useful to provide real-time readings of solar UVR patterns, however, to achieve synchronicity in the magnitude of readings to those made by science-grade fixed instruments, devices may need to be used during certain times of the day and in clear-sky conditions which may not be practical in personal exposure studies.

Identification of epigenetically altered genes and potential gene targets in melanoma using bioinformatic methods

This study aimed to analyze epigenetically and genetically altered genes in melanoma to get a better understanding of the molecular circuitry of melanoma and identify potential gene targets for the treatment of melanoma. The microarray data of GSE31879, including mRNA expression profiles (seven melanoma and four melanocyte samples) and DNA methylation profiles (seven melanoma and five melanocyte samples), were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) and differentially methylated positions (DMPs) were screened using the linear models for microarray data (limma) package in melanoma compared with melanocyte samples. Gene ontology (GO) and pathway enrichment analysis of the DEGs were carried out using the Database for Annotation, Visualization, and Integrated Discovery. Moreover, differentially methylated genes (DMGs) were identified, and a transcriptional regulatory network was constructed using the University of California Santa Cruz genome browser database. A total of 1,215 DEGs (199 upregulated and 1,016 downregulated) and 14,094 DMPs (10,450 upregulated and 3,644 downregulated) were identified in melanoma compared with melanocyte samples. Additionally, the upregulated and downregulated DEGs were significantly associated with different GO terms and pathways, such as pigment cell differentiation, biosynthesis, and metabolism. Furthermore, the transcriptional regulatory network showed that DMGs such as Aristaless-related homeobox (ARX), damage-specific DNA binding protein 2 (DDB2), and myelin basic protein (MBP) had higher node degrees. Our results showed that several methylated genes (ARX, DDB2, and MBP) may be involved in melanoma progression.

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.

Mouse models of UV-induced melanoma: genetics, pathology, and clinical relevance

Melanocytes, a neural crest cell derivative, produce pigment to protect keratinocytes from ultraviolet radiation (UVR). Although melanocytic lesions such as nevi and cutaneous malignant melanomas are known to be associated with sun exposure, the role of UVR in oncogenesis is complex and has yet to be clearly elucidated. UVR appears to have a direct mutational role in inducing or promoting melanoma formation as well as an indirect role through microenvironmental changes. Recent advances in the modeling of human melanoma in animals have built platforms upon which prospective studies can begin to investigate these questions. This review will focus exclusively on genetically engineered mouse models of UVR-induced melanoma. The role that UVR has in mouse models depends on multiple factors, including the waveband, timing, and dose of UVR, as well as the nature of the oncogenic agent(s) driving melanomagenesis in the model. Work in the field has examined the role of neonatal and adult UVR, interactions between UVR and common melanoma oncogenes, the role of sunscreen in preventing melanoma, and the effect of UVR on immune function within the skin. Here we describe relevant mouse models and discuss how these models can best be translated to the study of human skin and cutaneous melanoma.

Pharmacology of mangostins and their derivatives: A comprehensive review

Mangosteen (Garcinia mangostana Linn.) is a well-known tropical tree indigenous to Southeast Asia. Its fruit's pericarp abounds with a class of isoprenylated xanthones which are referred as mangostins. Numerous in vitro and in vivo studies have shown that mangostins and their derivatives possess diverse pharmacological activities, such as antibacterial, antifungal, antimalarial, anticarcinogenic, antiatherogenic activities as well as neuroprotective properties in Alzheimer's disease (AD). This review article provides a comprehensive review of the pharmacological activities of mangostins and their derivatives to reveal their promising utilities in the treatment of certain important diseases, mainly focusing on the discussions of the underlying molecular targets/pathways, modes of action, and relevant structure-activity relationships (SARs). Meanwhile, the pharmacokinetics (PK) profile and recent toxicological studies of mangostins are also described for further druggability exploration in the future.

Sunscreen compliance with regional clinical practice guidelines and product labeling standards in New Zealand

INTRODUCTION For general practitioners, practice nurses and community pharmacists in New Zealand, a core duty is to educate patients about sun protection. We aimed to evaluate compliance of locally available sunscreens with regional clinical practice guidelines and sunscreen labelling standards, to assist clinicians in advising consumers on sunscreen selection. METHODS We audited all sunscreens available at two Auckland stores for three New Zealand sunscreen retailers. We then assessed compliance with accepted regional clinical practice guidelines for sun protection from the New Zealand Guidelines Group. We further assessed compliance with regional Australia/New Zealand consumer standards for sunscreen labelling. RESULTS All sunscreens satisfied clinical guidelines for broad-spectrum protection, and 99% of sunscreens met or exceeded clinical guidelines for minimal Sun Protection Factor. Compliance with regional standardized labelling guidelines is voluntary in New Zealand and 27% of audited sunscreens were not fully compliant with SPF labelling standards. DISCUSSION Sunscreens were generally compliant with clinical guidelines for minimal sun protection. However there was substantial noncompliance with regional recommendations for standardized sunscreen labelling. Primary health care clinicians should be aware that this labelling noncompliance may mislead patients into thinking some sunscreens offer more sun protection than they do. Mandatory compliance with the latest regional labelling standards would simplify sunscreen selection by New Zealand consumers. KEYWORDS Sunscreen; Sun Protection Factor; SPF; Skin Neoplasms; Melanoma; Skin Cancer Prevention.

Action spectrum of melanoblast maturation and involvement of the aryl hydrocarbon receptor

The aryl hydrocarbon receptor (AHR) mediates melanocyte activation and skin tanning. We hypothesized that the AHR also mediates melanoblast-to-melanocyte maturation. In a cloned cell line, NCCmelb4, derived from mouse neural crest cells, we investigated AHR expression in melanoblasts stimulated by UV irradiation and AHR agonists. We irradiated the cells with UV, ranging from 280 to 380 nm in 10-nm increments, using a multiwavelength irradiation spectral apparatus. Tyrosinase expression significantly increased with bimodal peaks at 310 and 360 nm. Although melanoblast activation peaked 48 hours after irradiation, the most suitable irradiation interval was 24 hours. AHR expression significantly increased at 360 nm, but not at 310 nm. The AHR agonist, VAF347, and water-soluble tobacco smoke extract induced melanoblast maturation and AHR activation. The culture supernatant derived from the NS47 fibroblast cell line also induced melanoblast maturation and AHR activation. These findings suggest that UV and environmental stimulation of melanoblast-to-melanocyte maturation are enhanced via the AHR pathway.

Ultraviolet a Radiation and The Need for Protection

Erythema is a readily visible, often painful, natural phenomenon indicative of prolonged cutaneous exposure to ultraviolet (UV) radiation in the UVB range. As a result, early sunscreens were designed to provide adequate protection from UVB radiation. However, the continuous rise in the melanoma incidence rate alludes to the existence of an established photocarcinogen from which we are not well protected. Recently, scientists have been evaluating the photodamaging effects caused by wavelengths other than UVB. They have presented evidence that suggests that UVA exposure poses a greater hazard than previously acknowledged. For this reason, more emphasis must be placed on the development of broad-spectrum sunscreens providing adequate UVA and UVB protection. Additionally, regular sunscreen application must be advocated, proactive sun-protective practices must be implemented, and greater public awareness of the harmful effects of UVA and UVB radiation must be improved on, with the hope of decreasing the rate of cutaneous malignant melanoma.

“Mata de tristeza!”: representações sociais de pessoas com vitiligo atendidas na Farmácia Universitária da Universidade Federal do Rio de Janeiro, Brasil

Vitiligo é caracterizado por manchas brancas na pele. Na dispensação do metoxisaleno utilizado para tratá-lo, na Farmácia Universitária/UFRJ, os portadores relatavam mal-estares devido à terapia e à doença. A busca pela compreensão da experiência do adoecer conduziu este estudo que adota perspectiva teórico-metodológica socioantropológica. A apreensão da visão de mundo dos sujeitos foi captada em entrevistas entre usuários da FU/UFRJ. A partir do diagnóstico, os sujeitos consideram o vitiligo “um castigo”, sentem-se alvo de “chacotas”, “preconceito”, “discriminações”. A experiência da doença impõe rever seus conceitos e filiação religiosa. O fato de o vitiligo não ser concebido como doença grave estabelece um não-lugar para o sofrimento dos portadores. Aspectos simbólicos, emocionais e socioculturais que circunscrevem a doença devem ser considerados para melhorar a atenção à saúde e vida desses sujeitos. Os profissionais de saúde precisam concebê-los para além de suas “manchas”.

Pea aphid Acyrthosiphon pisum sequesters plant-derived secondary metabolite L-DOPA for wound healing and UVA resistance

Herbivores can ingest and store plant-synthesized toxic compounds in their bodies, and sequester those compounds for their own benefits. The broad bean, Vicia faba L., contains a high quantity of L-DOPA (L-3,4-dihydroxyphenylalanine), which is toxic to many insects. However, the pea aphid, Acyrthosiphon pisum, can feed on V. faba normally, whereas many other aphid species could not. In this study, we investigated how A. pisum utilizes plant-derived L-DOPA for their own benefit. L-DOPA concentrations in V. faba and A. pisum were analyzed to prove L-DOPA sequestration. L-DOPA toxicity was bioassayed using an artificial diet containing high concentrations of L-DOPA. We found that A. pisum could effectively adapt and store L-DOPA, transmit it from one generation to the next. We also found that L-DOPA sequestration verity differed in different morphs of A. pisum. After analyzing the melanization efficiency in wounds, mortality and deformity of the aphids at different concentrations of L-DOPA under ultraviolet radiation (UVA 365.0 nm for 30 min), we found that A. pisum could enhance L-DOPA assimilation for wound healing and UVA-radiation protection. Therefore, we conclude that A. pisum could acquire L-DOPA and use it to prevent UVA damage. This study reveals a successful co-evolution between A. pisum and V. faba.

Education versus regulation: The case for regulating the indoor tanning industry

We examine marketing strategies for indoor tanning services that often target young adult females. Evidence of the addictive nature of indoor tanning suggests that young adults may be vulnerable to the promotion of indoor tanning and as a result deserve greater protection from the marketing of these services. As public awareness of the rising numbers of skin cancers linked to indoor tanning grows, we believe that the public will support increased regulation of this industry.

Benzophenone 1 induced photogenotoxicity and apoptosis via release of cytochrome c and Smac/DIABLO at environmental UV radiation

Solar UV radiation is main factor of photocarcinogenesis, photoageing, and phototoxicity; thus, protection from UV radiation is major concern. Sunscreens containing UV filters are suggested as sun safe practices, but safety of UV filters remains in controversies. Benzophenone-1 (BP1) is commonly used in sunscreens as UV blocker. We assessed the photogenotoxicity and apoptotic parameters in human keratinocytes (HaCaT cells) by western blot, immunocytochemistry, flowcytometry, comet assay and TEM imaging. Our results exposed that BP1 photosensitized and generated intracellular ROS (2.02 folds) under sunlight/UVR. Decrease in cell viability was recorded as 80.06%, 60.98% and 56.24% under sunlight, UVA and UVB, respectively. Genotoxic potential of BP1 was confirmed through photomicronuclei and CPDs formation. BP1 enhanced lipid peroxidation and leakage of LDH enzyme (61.7%). Apoptotic cells were detected by AnnexinV/PI staining and sub G1 population of cell cycle. BP1 induced up regulation of apoptotic proteins Bax/Bcl2 ratio, Apaf-1, cytochrome c, Smac/DIABLO and cleaved caspase 3 was noticed. Down regulation of pro caspase 3 was inhibited by Z-VAD-fmk (inhibitor of caspase). Thus, study established the involvement of BP1 in photogenotoxicity and apoptosis via release of cytochrome c and Smac/DIABLO. These findings suggest sunscreen user to avoid BP1 in cosmetics preparation for its topical application.

Molecular markers of the risk of development of skin cancer in psoriasis patients receiving a phototherapy

State Research Center of Dermatovenereology and Cosmetology, Ministry of Healthcare of the Russian Federation Korolenko str., 3, bldg 6, Moscow, 107076, Russia Goal. To study potential molecular and genetic markers of an increased risk of development of malignant skin melanomas on the basis of the assessment of nucleotide replacements of genes in the excision system of DNA repair in psoriasis patients receiving a phototherapy. Materials and methods. Biological blood samples taken from 47 psoriasis patients, 24 patients with malignant skin melanomas and 20 healthy subjects. The following methods were used in the study: clinical, molecular and biological (DNA extraction, amplification, PcR, sequencing). Results. The study revealed molecular markers of an increased risk of development of malignant skin melanomas in psoriasis patients: CC genotype of the XPD gene at the 35931 locus (p = 0.00001); TC genotype of the XPF gene at the 27945 locus (p = 0.0067). It also revealed a molecular marker of an increased risk of development of malignant skin melanomas in healthy people: CC genotype of the XPD gene at the 35931 locus (p = 0.0042).

Role of the pro-survival molecule Bfl-1 in melanoma

Bfl-1 is a pro-survival Bcl-2 family member overexpressed in a subset of chemoresistant tumours, including melanoma. Here, we characterised the expression and regulation of Bfl-1 in normal and malignant melanocytes and determined its role in protecting these cells from chemotherapy-induced apoptosis. Bfl-1 was mitochondrially resident in both resting and apoptotic cells and experienced regulation by the proteasome and NFκB pathways. siRNA-mediated knockdown enhanced sensitivity towards various relevant drug treatments, with forced overexpression of Bfl-1 protective. These findings identify Bfl-1 as a contributor towards therapeutic resistance in melanoma cells and support the use of NFκB inhibitors alongside current treatment strategies.

Oxidatively generated damage to cellular DNA by UVB and UVA radiation

This review article focuses on a critical survey of the main available information on the UVB and UVA oxidative reactions to cellular DNA as the result of direct interactions of UV photons, photosensitized pathways and biochemical responses including inflammation and bystander effects. UVA radiation appears to be much more efficient than UVB in inducing oxidatively generated damage to the bases and 2-deoxyribose moieties of DNA in isolated cells and skin. The UVA-induced generation of 8-oxo-7,8-dihydroguanine is mostly rationalized in terms of selective guanine oxidation by singlet oxygen generated through type II photosensitization mechanism. In addition, hydroxyl radical whose formation may be accounted for by metal-catalyzed Haber-Weiss reactions subsequent to the initial generation of superoxide anion radical contributes in a minor way to the DNA degradation. This leads to the formation of both oxidized purine and pyrimidine bases together with DNA single-strand breaks at the exclusion, however, of direct double-strand breaks. No evidence has been provided so far for the implication of delayed oxidative degradation pathways of cellular DNA. In that respect putative characteristic UVA-induced DNA damage could include single and more complex lesions arising from one-electron oxidation of the guanine base together with aldehyde adducts to amino-substituted nucleobases.

Do suncreens protect us?

Sunlight stimulates a multitude of important biological effects on skin, causing, amongst other pathological changes, photocarcinogenesis. Sunscreens are designed to provide protection against these harmful properties of ultraviolet radiation, and public health campaigns have been employed to encourage their use. Despite this, there has been a continued rise in the incidence and mortality of the most harmful skin cancer, malignant melanoma. This review article therefore looks at the role of ultraviolet radiation in causing skin cancer; summarizes the available evidence on both the beneficial and harmful effects of sunscreen use; and concludes with practical advice on how we might advise our patients to best protect themselves from photocarcinogenesis.