Including Skin Cancer Research Articles

Effects of pH on arsenic mineralogy and stability in Poldice Valley, Cornwall, United Kingdom

Many abandoned mine sites in Cornwall, UK, are characterised by elevated concentrations of arsenic (As), which can cause contamination of surrounding soil and water resources. These sites have important historical value that requires access to be maintained, despite exposure of humans to toxins that may lead to health issues including hyperpigmentation keratosis (including skin cancers) and liver fibrosis. The abandoned mine tailings at Wheal Maid has been assessed for As-bearing mineralogy and stability taking into account the public footpaths made by the local council to areas of potential contamination.To assess the potential risk associated with these mine sites, the As concentration in waters along the tailings dam and Carnon River have been measured and range up to 3.6 ppm, which is 2 orders of magnitude above the WHO guideline value of 0.01 ppm for drinking water. Samples of water, rocks and soils from the mine tailings ponds and the Carnon River were analysed using Inductively Coupled Plasma – Optical Emission Spectrometry (ICP-OES) and Inductively Coupled Plasma – Mass Spectrometry (ICP-MS) to determine the concentration of individual elements in each sample followed by mineral identification using X-Ray Diffraction (XRD). Mineralogical evaluation indicated that the majority of mine tailings consist of clay-rich rocks, with few associated As-bearing minerals. Scorodite (FeAsO4·2H2O) is observed in the mine tailings pond and appears critical to the As distribution and storage in this surface environment. Using the analysed water chemistry, a modified version of PHREEQC is used to calculate the saturation index of scorodite as a function of pH conditions. The strong variation of the solubility of this mineral with pH and oxidation state highlights potential risks for using scorodite for As fixation and storage.

Abstract 178: Desmosome mutations in melanoma promote cellular proliferation and disease progression

Abstract Desmosomes are transmembrane protein complexes that contribute to cell-cell adhesion in the epithelia and other tissues under mechanical stress. Aberrant desmosome expression is often associated with developmental diseases leading to impaired tissue integrity. Recently, similar findings have been reported in cancer; Mutations in desmosomes genes have been observed in various cancer types including skin cancer, head and neck and lung cancer, however mostly epigenetic alterations have been used to associate desmosomes as suppressors of tumor metastasis. Here, we report that desmosomes are frequently mutated in seven cancer types. In melanoma, we find that over 70% of tumors have non-synonymous mutations in desmosomes, and that the desmosome mutational burden is associated with a strong decrease in mRNA expression levels in primary tumor samples (R = -0.23). Differential gene expression analysis and functional characterizations between mutant and wild-type tumors implicates the mutated cells in promoting cell proliferation at early stages of tumorigenesis. These results emerge uniquely from a systems-level analysis integrating multiple proteins in complexes and multiple cell types in heterogeneous tumors. Citation Format: Maayan Baron, Trey Ideker. Desmosome mutations in melanoma promote cellular proliferation and disease progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 178.

Towards gender equity in artificial intelligence and machine learning applications in dermatology.

There has been increased excitement around the use of machine learning (ML) and artificial intelligence (AI) in dermatology for the diagnosis of skin cancers and assessment of other dermatologic conditions. As these technologies continue to expand, it is essential to ensure they do not create or widen sex- and gender-based disparities in care. While desirable bias may result from the explicit inclusion of sex or gender in diagnostic criteria of diseases with gender-based differences, undesirable biases can result from usage of datasets with an underrepresentation of certain groups. We believe that sex and gender differences should be taken into consideration in ML/AI algorithms in dermatology because there are important differences in the epidemiology and clinical presentation of dermatologic conditions including skin cancers, sex-specific cancers, and autoimmune conditions. We present recommendations for ensuring sex and gender equity in the development of ML/AI tools in dermatology to increase desirable bias and avoid undesirable bias.

Selenium (Se) as well as mercury (Hg) may influence the methylation and toxicity of inorganic arsenic, but further research is needed with combination of Inorg-arsenic, Se, and Hg

Selenium (Se) as well as mercury (Hg) may influence the methylation and toxicity of inorganic arsenic, but further research is needed with combination of Inorg-arsenic, Se, and Hg

Investigation of IL-17A Serum Levels in Patients with Nonmelanoma Skin Cancer.

Background Role of interleukin 17A (IL-17A) in carcinogenesis and cancer growth is controversial. Although some researches support its antitumor activity, some others suggest that it promotes the growth and development of different types of cancer including skin cancer by activation of STAT3. Although the function of the cytokines such as IL-17A has been extensively studied in various types of cancer, nonmelanoma skin cancer (NMSC) has not received much attention. Therefore, the present study was aimed to investigate the serum levels of IL-17A in NMSC patients. Methods This cross-sectional study was performed on 60 patients with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) as well as 57 age-sex matched healthy individuals as control group. Measurement of IL-17A serum levels in both case and control groups was performed by a commercially reliable sandwich enzyme-linked immunosorbent assay (ELISA) kit. Results In this study, we observed that IL-17A serum levels in NMSC patients were significantly higher than the control group (P < 0.001). Also, both BCC and SCC patients had higher levels of IL-17A in their sera in comparison to the controls (P=0.001 and P < 0.001, respectively). However, there was no significant difference between SCC and BCC patients regarding serum levels of IL-17A. Conclusion According to our results, it can be concluded that IL-17A may play a role in inducing the growth and progression of NMSC and it can be used as a therapeutic target in these patients in future.

Pharmacoepigenomics circuits induced by a novel retinoid-polyamine conjugate in human immortalized keratinocytes.

Retinoids are widely used in diseases spanning from dermatological lesions to cancer, but exhibit severe adverse effects. A novel all-trans-Retinoic Acid (atRA)-spermine conjugate (termed RASP) has shown previously optimal in vitro and in vivo anti-inflammatory and anticancer efficacy, with undetectable teratogenic and toxic side-effects. To get insights, we treated HaCaT cells which resemble human epidermis with IC50 concentration of RASP and analyzed their miRNA expression profile. Gene ontology analysis of their predicted targets indicated dynamic networks involved in cell proliferation, signal transduction and apoptosis. Furthermore, DNA microarrays analysis verified that RASP affects the expression of the same categories of genes. A protein-protein interaction map produced using the most significant common genes, revealed hub genes of nodal functions. We conclude that RASP is a synthetic retinoid derivative with improved properties, which possess the beneficial effects of retinoids without exhibiting side-effects and with potential beneficial effects against skin diseases including skin cancer.

Antioxidant and Antimelanogenic Activities of Kimchi-Derived Limosilactobacillus fermentum JNU532 in B16F10 Melanoma Cells.

Melanin is a natural skin pigment produced by specialized cells called melanocytes via a multistage biochemical pathway known as melanogenesis, involving the oxidation and polymerization of tyrosine. Melanogenesis is initiated upon exposure to ultraviolet (UV) radiation, causing the skin to darken, which protects skin cells from UVB radiation damage. However, the abnormal accumulation of melanin may lead to the development of certain skin diseases, including skin cancer. In this study, the antioxidant and antimelanogenic activities of the cell-free supernatant (CFS) of twenty strains were evaluated. Based on the results of 60% 2,2-diphenyl-1-picrylhydrazyl scavenging activity, 21% 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) scavenging capacity, and a 50% ascorbic acid equivalent ferric reducing antioxidant power value, Limosilactobacillus fermentum JNU532 was selected as the strain with the highest antioxidant potential. No cytotoxicity was observed in cells treated with the CFS of L. fermentum JNU532. Tyrosinase activity was reduced by 16.7% in CFStreated B16F10 cells (but not in the cell-free system), with >23.2% reduction in melanin content upon treatment with the L. fermentum JNU532-derived CFS. The inhibitory effect of the L. fermentum JNU532-derived CFS on B16F10 cell melanogenesis pathways was investigated using quantitative reverse transcription polymerase chain reaction and western blotting. The inhibitory effects of the L. fermentum JNU532-derived CFS were mediated by inhibiting the transcription of TYR, TRP-1, TRP-2, and MITF and the protein expression of TYR, TRP-1, TRP-2, and MITF. Therefore, L. fermentum JNU532 may be considered a potentially useful, natural depigmentation agent.

Recent Updates on the Involvement of PI3K/AKT/mTOR Molecular Cascade in the Pathogenesis of Hyperproliferative Skin Disorders.

PhosphoInositide-3 Kinase (PI3K) represents a family of different classes of kinases which control multiple biological processes in mammalian cells, such as cell growth, proliferation, and survival. Class IA PI3Ks, the main regulators of proliferative signals, consists of a catalytic subunit (α, β, δ) that binds p85 regulatory subunit and mediates activation of AKT and mammalian Target Of Rapamycin (mTOR) pathways and regulation of downstream effectors. Dysregulation of PI3K/AKT/mTOR pathway in skin contributes to several pathological conditions characterized by uncontrolled proliferation, including skin cancers, psoriasis, and atopic dermatitis (AD). Among cutaneous cancers, basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) display PI3K/AKT/mTOR signaling hyperactivation, implicated in hyperproliferation, and tumorigenesis, as well as in resistance to apoptosis. Upregulation of mTOR signaling proteins has also been reported in psoriasis, in association with enhanced proliferation, defective keratinocyte differentiation, senescence-like growth arrest, and resistance to apoptosis, accounting for major parts of the overall disease phenotypes. On the contrary, PI3K/AKT/mTOR role in AD is less characterized, even though recent evidence demonstrates the relevant function for mTOR pathway in the regulation of epidermal barrier formation and stratification. In this review, we provide the most recent updates on the role and function of PI3K/AKT/mTOR molecular axis in the pathogenesis of different hyperproliferative skin disorders, and highlights on the current status of preclinical and clinical studies on PI3K-targeted therapies.

Health Risks Associated With Excessive Exposure to Solar Ultraviolet Radiation Among Outdoor Workers in South Africa: An Overview.

Exposure of outdoor workers to high levels of solar ultraviolet radiation (UVR) poses significant, well-known health risks including skin cancer and eye diseases. In South Africa, little is known about how many workers are potentially overexposed to solar UVR and what the associated impacts on their health might be. In this overview, the geography and solar UVR environment in South Africa are considered, as well as the different outdoor occupational groups likely to be affected by excessive solar UVR exposure. Sunburn, pterygium, cataract, keratinocyte cancers, and melanoma are discussed in the context of outdoor workers. Few studies in South Africa have considered these health issues and the most effective ways to reduce solar UVR exposure for those working outside. Several countries have developed policies and guidelines to support sun safety in the workplace which include training and education, in addition to the provision of personal protective equipment and managerial support. Several gaps in occupational sun protection and workplace sun safety for South Africa are identified. Legislation needs to recognize solar UVR exposure as an occupational health hazard, with sun safety guidelines and training provided for employers and employees.

Natural photoprotectors: A literature review

Ultraviolet (UV) radiation has contributed to the onset of various skin diseases, including skin cancer. Consequently, there are a series of incentives for research and development of innovative photoprotectors that can provide protection against such health problems. With the growing consumer interest in cosmetic products of natural origin, there has been an increase in new proposals such as the replacement of synthetic assets with molecules extracted from medicinal plants that present activity compatible or superior to synthetic products and with lesser environmental impact. Natural photoprotectors are gaining attention within this scenario, and some previous studies have demonstrated their potential for use. A literature review was conducted on the main groups and active principles of plants with photoprotective activity and for this purpose we used national and international scientific articles from the Medline/PubMed, SCIELO, LILACs, Science Direct, Scopus and Google Scholar databases. We mentioned 17 different species of medicinal plants with photoprotective action and their respective active ingredients. The flavonoid group was the most cited and studied in relation to the protective capacity against ultraviolet radiation and its isolated action and synergistic action was highlighted. Studies show that plant extracts from different plant species have a photoprotective action, among which they highlight the rich in antioxidant compounds, such as plants of the species Ginkgo biloba, Psidium guajava, Camellia sinensis and Lippia sp. which stand out for their large amount of polyphenols, especially flavonoids.

The bioactivities of resveratrol and its naturally occurring derivatives on skin.

Resveratrol has been extensively reported as a potential compound to treat some skin disorders, including skin cancer, photoaging, allergy, dermatitis, melanogenesis, and microbial infection. There has been an increasing interest in the discovery of cosmetic application using resveratrol as the active ingredient because of its anti-aging and skin lightening activities. The naturally occurring derivatives of resveratrol also exert a beneficial effect on the skin. There are four groups of resveratrol derivatives, including hydroxylated compounds, methoxylated compounds, glycosides, and oligomers. The major mechanism of resveratrol and its derivatives for attenuating cutaneous neoplasia, photoaging and inflammation, are related with its antioxidative activity to scavenge hydroxyl radical, nitric oxide and superoxide anion. A systematic review was conducted to describe the association between resveratrol-related compounds and their benefits on the skin. Firstly, the chemical classification of resveratrol and its derivatives was introduced. In this review the cases which were treated for different skin conditions by resveratrol and the derivatives were also described. The use of nanocarriers for efficient resveratrol skin delivery is also introduced here. This review summarizes the cutaneous application of resveratrol and the related compounds as observed in the cell-based, animal-based and clinical models. The research data in the present study relates to the management of resveratrol for treating skin disorders and suggesting a way forward to achieve advancement in using it for cosmetic and dermatological purpose.

Use of Nanoparticles in Delivery of Nucleic Acids for Melanoma Treatment.

Melanoma accounts for 4% of all skin cancer malignancies, with only 14% of diagnosed patients surviving for more than 5 years after diagnosis. Until now, there is no clear understanding of the detailed molecular contributors of melanoma pathogenesis. Accordingly, more research is needed to understand melanoma development and prognosis.All the treatment approaches that are currently applied have several significant limitations that prevent effective use in melanoma. One major limitation in the treatment of cancer is the acquisition of multidrug resistance (MDR). The MDR results in significant treatment failure and poor clinical outcomes in several cancers, including skin cancer. Treatment of melanoma is especially retarded by MDR. Despite the current advances in targeted and immune-mediated therapy, treatment arms of melanoma are severely limited and stand as a significant clinical challenge. Further, the poor pharmacokinetic profile of currently used chemotherapeutic agents is another reason for treatment failure. Therefore, more research is needed to develop novel drugs and carrier tools for more effective and targeted treatment.Nucleic acid therapy is based on nucleic acids or chemical compounds that are closely related, such as antisense oligonucleotides, aptamers, and small-interfering RNAs that are usually used in situations when a specific gene implicated in a disorder is deemed a therapeutically beneficial target for inhibition. However, the proper application for nucleic acid therapies is hampered by the development of an effective delivery system that can maintain their stability in the systemic circulation and enhance their uptake by the target cells. In this chapter, the prognosis of the different types of melanoma along with the currently used medications is highlighted, and the different types of nucleic acids along with the currently available nanoparticle systems for delivering these nucleic acids into melanoma cells are discussed. We also discuss recently conducted research on the use of different types of nanoparticles for nucleic acid delivery into melanoma cells and highlight the most significant outcomes.

The utilisation of Himalayan Nettle (Girardinia diversifolia) plant for development of UV protective textiles: A new perspective of a traditionally used plant

The Himalayan nettle ( Girardinia diversifolia) plant has been traditionally used to make various fibre-based products such as sack, rope etc. but with this fast-moving technological era, new developments and researches are required to meet the demand of present so that it could also be made commercially viable. Presently UV radiation causes various skin problems including skin cancer. The present study explores the fabric properties of woven fabrics made of Himalayan nettle ( Girardinia diversifolia ) fibre for new end uses to protect the skin from harmful UV radiation. Nettle Yarn was procured from Kraftloom Overseas Private Limited, Dehradun. Twill and crepe weave fabric were prepared using handloom at Kumaon woollens, Haldwani. Physical properties and Ultraviolet Protection Factor (UPF) of the developed woven fabric were studied at textile testing lab of G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand. Based on results it was found that properties of nettle woven fabric like thickness, weight, thread count and cover factor affected the UPF of the nettle fabric. It was also found that ultraviolet protection properties of nettle woven fabric could be enhanced through weave variation. Ultraviolet protection properties of fabric made of nettle fibre were explored and reported for the first time which could be utilised for different UV protection products such as curtains, blinds and jackets. Further natural dyeing of developed fabric was also done in another part of the study to maximise the UV protective properties of the fabric.

14188 Wearable UV/HEV light sensor and smartphone application for personal monitoring and personalized recommendations

Prolonged exposure even to suberythemal UV doses has many associated risk factors, including skin cancer and photo-aging. Recent studies also indicate that high-energy visible light (HEV) induces oxidative stress in the skin which is ultimately linked to visible signs such as pigmentation and aging. Personalized monitoring of UV/HEV radiation is necessary for recommendations of personal sun-safe behaviors. Here, we demonstrate a wireless, battery-free, miniature, wearable UV/HEV sensor that can be mounted on t-shirt, sunglasses, wristband, shoes or necklace.

Erythroid differentiation regulator 1 promotes wound healing by inducing the production of C‑C motif chemokine ligand2 via the activation of MAP kinases invitro and invivo.

The erythroid differentiation regulator 1 (Erdr1) protein has been studied for its role in various inflammatory skin diseases, including skin cancer, actinic keratosis and psoriasis. However, the therapeutic effects of Erdr1 on wound repair and its underlying mechanisms remain unknown. The present study aimed to investigate the effects of Erdr1 on wound healing in vitro and in vivo. The results demonstrated that treatment with recombinant Erdr1 enhanced wound healing in vivo and in vitro. In addition, Erdr1 increased the proliferation and migration of human dermal fibroblasts (HDFs). Notably, Erdr1 significantly induced the production of the chemoattractant C-C motif chemokine ligand 2 (CCL2) and recruited immune cells involved in wound healing. Treatment with recombinant Erdr1 induced the activation of the ERK1/1, p38 and JNK1/2 mitogen-activated protein (MAP) kinases. Treatment with specific inhibitors for MAP kinase inhibitors markedly suppressed cell proliferation and migration, and inhibited the production of CCL2 in HDFs. Furthermore, the inhibition of CCL2 with a neutralizing antibody significantly suppressed the recombinant Erdr1-induced proliferation and migration of HDFs. The wound healing activity of Erdr1 was comparable to that of epidermal growth factor. Taken together, these results demonstrated that Erdr1 promoted the proliferation and migration of HDFs and exhibited potent wound healing properties mediated by CCL2. Therefore, the results of the present study suggested that Erdr1 may be a potential therapeutic target for promoting wound healing.

Antioxidant and Photoprotective Metabolites of Bunodophoron melanocarpum, A Lichen from the Andean Páramo

Background: Oxidative stress caused by exposure to ultraviolet radiation has been associated with dermal problems, including skin cancer. In this study, we determined the photoprotective and antioxidant activity of isolated metabolites from the lichen Bunodophoron melanocarpum (Sphaerophoraceae) to find new sunscreens prototypes. Methods: The constituents of B. melanocarpum were isolated by phytochemical methods and their structures were determined by spectroscopy (IR, 1D and 2D NMR). Antioxidant activity was measured by scavenging DPPH free radicals (EC50), ferric reducing power (FRP), and inhibition of lipid peroxidation (% ILP). The photoprotective capacity against ultraviolet(UVA and UVB) radiations was determined in vitro by calculating their sun protection factor(SPF), critical wavelength and UVA ratio and these values were compared against commercial sunscreens. The lipophilicity and possible skin penetration to the lipid-rich stratum corneum of the isolates, was determined by calculating their octanol/water partition coefficients (Log P) and Gibbs free energy of transfer (ΔtG0 ). Results: Sphaerophorin (1), everninic acid (2), sphaerophorol carboxylic acid (3) and friedelin(4) were isolated from B. melanocarpum. Orsellinic acid-type compounds 1 and 3 are dual agents with antioxidant capacity as free radical scavengers (EC50= 0.0857 and 0.1828 mol compound /mol DPPH•, respectively) and photoprotective properties particularly against UVB radiation(SPF 25.78 ± 0.53 and 22.00 ± 1.03, respectively). In addition, they had lipophilicity (Log P 7.07 ±0.64 and 4.03 ± 0.32, respectively) and ΔtG0 (-40.32 ± 3.67 and -22.97 ± 1.82 kJmol-1, respectively)suitable to act on the skin. Conclusion: Sphaerophorin (1) and sphaerophorol carboxylic acid (3) are dual agents with antioxidant and UVB photoprotective properties and are also lipophilic substances that spontaneously would diffuse across the skin.

Feasibility Study of a Smartphone Application for Detecting Skin Cancers in People With Albinism.

PURPOSEAlbinism affects some facets of the eye’s function and coloration, as well as hair and skin color. The prevalence of albinism is estimated to be one in 2,000-5,000 people in sub-Saharan Africa and one in 270 in Tanzania. People in Tanzania with albinism experience sociocultural and economic disparities. Because of stigma related to albinism, they present to hospitals with advanced disease, including skin cancers. Mobile health (mHealth) can help to bridge some of the gaps in detection and treatment of skin cancers affecting this population.METHODSWe assessed the feasibility of using a mobile application (app) for detection of skin cancers among people with albinism. The study was approved by the Ocean Road Cancer Institute institutional review board. Data, including pictures of the lesions, were collected using a mobile smartphone and submitted to expert reviewers. Expert reviewers’ diagnosis options were benign, malignant, or unevaluable.RESULTSA total of 77 lesions from different body locations of 69 participants were captured by the NgoziYangu mobile app. Sixty-two lesions (81%) were considered malignant via the app and referred for biopsy and histologic diagnosis. Of those referred, 55 lesions (89%) were biopsied, and 47 lesions (85%) were confirmed as skin malignancies, whereas eight (15%) were benign.CONCLUSIONWith an increasing Internet coverage in Africa, there is potential for smartphone apps to improve health care delivery channels. It is important that mobile apps like NgoziYangu be explored to reduce diagnostic delay and improve the accuracy of detection of skin cancer, especially in stigmatized groups.

Terahertz Plasmonic Technology

The terahertz (THz) technology has found applications ranging from astronomical science and earth observation to compact radars, non-destructive testing, chemical analysis, explosive detection, moisture content determination, coating thickness control, film uniformity determination, structural integrity testing wireless covert communications, medical applications (including skin cancer detection), imaging, and concealed weapons detection. Beyond 5G Wi-Fi and Internet of Things (IoT) are the expected killer applications of the THz technology. Plasmonic TeraFETs such as Si CMOS with feature sizes down to 3 nm could enable a dramatic expansion of all these applications. At the FET channel sizes below 100 nm, the physics of the electron transport changes from the collision dominated to the ballistic or quasi-ballistic transport. In the ballistic regime, the electron inertia and the waves of the electron density (plasma waves) determine the high frequency response that extends into the THz range of frequencies. The rectification and instabilities of the plasma waves support a new generation of THz and sub-THz plasmonic devices. The plasmonic electronics technology has a potential become a dominant THz electronics sensing technology when the plasmonic THz sources join the compact, efficient, and fast plasmonic TeraFET THz detectors already demonstrated and being commercialized.

Solar ultraviolet-induced DNA damage response: Melanocytes story in transformation to environmental melanomagenesis.

Exposure to sunlight is both beneficial, as it heats the planet to a comfortable temperature, and potentially harmful, since sunlight contains ultraviolet radiation (UVR), which is deemed detrimental for living organisms. Earth's ozone layer plays a vital role in blocking most of the extremely dangerous UVC; however, low frequency/energy UVR (i.e., UVB and UVA) seeps through in minute amount and reaches the Earth's surface. Both UVB and UVA are physiologically responsible for a plethora of skin ailments, including skin cancers. The UVR is readily absorbed by the genomic DNA of skin cells, causing DNA bond distortion and UV-induced DNA damage. As a defense mechanism, the DNA damage response (DDR) signaling in skin cells activates nucleotide excision repair (NER), which is responsible for the removal of UVR-induced DNA photolesions and helps maintain the genomic integrity of the cells. Failure of proper NER function leads to mutagenesis and development of skin cancers. One of the deadliest form of skin cancers is melanoma which originates upon the genetic transformation of melanocytes, melanin producing skin cells. NER is a well-studied DNA repair system in the whole skin, as a tissue, but not much is known about it in melanocytes. Therefore, this review encapsulates NER in melanocytes, with a specific focus on its functional regulators and their cross talks due to skin heterogeneity and divulging the potential knowledge gap in the field.

Regulation of ultraviolet radiation-induced cutaneous DNA damage by type I interferons

Abstract Type I interferons (IFNs) are cytokines, that are important regulators of immune responses and are downregulated in human cancers, including skin cancer. Solar ultraviolet (UV) radiation is a proven environmental carcinogen, and exposure to solar radiation contributes to the high prevalence of skin cancer. The carcinogenic effects of UV light can be attributed to the formation of cyclobutane pyrimidine dimers (CPD) and errors in repair and replication of DNA. It is believed that type I IFNs reduce cellular proliferation and allow DNA repair in various diseases. Interferon receptor 1 (IFNAR1) is critical for signaling of type I IFNs. We hypothesized that type I IFNs (IFNα/β) will repair UVB induced DNA damage in mice. To test our hypothesis, shaved mice lacking IFNAR1 and wild type mice on a C57BL/6 background were irradiated with single dose of UVB radiation (100 mJ/cm2). Skin samples were examined for CPD by immunofluorescence and ELISA. We found that mice lacking IFNAR1 had more CPD as evident by ELISA and histology. In order to determine the cell type, which produces type I IFNs in skin after UVB exposure, single cell suspensions were prepared from irradiated skin samples and stained for type I IFNs using flow cytometry. We found that type I IFNs were produced by inflammatory monocytes (CD45+CD11b+Ly6C+). We also found that DNA repair gene XPA was downregulated in the mice lacking IFNAR1. In conclusion, our studies show that mice lacking the IFNAR1 had decreased repair of UVB induced CPD in the skin. Our ongoing studies will elucidate whether type I IFNs regulate development of UVB induced skin tumors.