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1.
Public Health Res Pract ; 34(2)2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38316050

RESUMO

OBJECTIVES: Skin cancer is highly preventable through primary prevention activities such as avoiding ultraviolet radiation exposure during peak times and regular use of sun protection. General practitioners (GPs) and primary care nurses have key responsibilities in promoting sustained primary prevention behaviour. We aimed to review the evidence on skin cancer primary prevention activities in primary care settings, including evidence on feasibility, effectiveness, barriers and enablers. STUDY TYPE: Rapid review and narrative synthesis. METHODS: We searched published literature from January 2011 to October 2022 in Embase, Medline, PsychInfo, Scopus, Cochrane Central and CINAHL. The search was limited to skin cancer primary prevention activities within primary care settings, for studies or programs conducted in Australia or countries with comparable health systems. Analysis of barriers and enablers was informed by an implementation science framework. RESULTS: A total of 31 peer-reviewed journal articles were included in the review. We identified four main primary prevention activities: education and training programs for GPs; behavioural counselling on prevention; the use of novel risk assessment tools and provision of risk-tailored prevention strategies; and new technologies to support early detection that have accompanying primary prevention advice. Enablers to delivering skin cancer primary prevention in primary care included pairing preventive activities with early detection activities, and access to patient resources and programs that fit with existing workflows and systems. Barriers included unclear requirements for skin cancer prevention counselling, competing demands within the consultation and limited access to primary care services, especially in regional and remote areas. CONCLUSIONS: These findings highlight potential opportunities for improving skin cancer prevention activities in primary care. Ensuring ease of program delivery, integration with early detection and availability of resources such as risk assessment tools are enablers to encourage and increase uptake of primary prevention behaviours in primary care, for both practitioners and patients.


Assuntos
Atenção Primária à Saúde , Prevenção Primária , Neoplasias Cutâneas , Humanos , Neoplasias Cutâneas/prevenção & controle , Prevenção Primária/métodos , Austrália
2.
J Dermatol ; 51(3): 353-364, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38291978

RESUMO

Chronic lymphocytic leukemia (CLL) is a common lymphoid malignancy that is associated with an increased risk of developing cutaneous malignancies. Clinical outcomes for these malignancies, including melanoma and keratinocyte cancers (KC), are worse for patients with CLL. Individuals with CLL develop an immunodeficiency of both the adaptive and innate immune system, which plays a role in the increased prevalence of skin cancers. This review focuses on the complex interplay between genetics, immunity, and pathogens that influence the cellular composition and biology of skin tumors and their microenvironment in CLL patients, and in comparison with other chronic hematological malignancies. It is paramount for dermatologists to be aware of the association between CLL (and chronic hematological malignancies more broadly) and cutaneous malignancies. This is a high-risk population who require regular and vigorous dermatologic follow-up.


Assuntos
Neoplasias Hematológicas , Leucemia Linfocítica Crônica de Células B , Melanoma , Neoplasias Cutâneas , Humanos , Leucemia Linfocítica Crônica de Células B/complicações , Leucemia Linfocítica Crônica de Células B/epidemiologia , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/patologia , Melanoma/epidemiologia , Fatores de Risco , Microambiente Tumoral
3.
Pathology ; 55(6): 743-759, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37573165

RESUMO

Non-melanocytic skin cancers (NMSCs) account for five times the incidence of all other cancers combined and cost US $6 billion annually. These are the most frequent specimens encountered in community pathology practice in many Western countries. Lack of standardised structured pathology reporting protocols (SPRPs) can result in omission of critical information or miscommunication leading to suboptimal patient management. The lack of standardised data has significant downstream public health implications, including insufficient data for reliable development of prognostic tools and health-economy planning. The Royal College of Pathologists of Australasia has developed an NMSC SPRP. A multidisciplinary expert committee including pathologists, surgeons, dermatologists, and radiation and medical oncologists from high volume cancer centres was convened. A systematic literature review was performed to identify evidence for including elements as mandatory standards or best practice guidelines. The SPRP and accompanying commentary of evidence, definitions and criteria was peer reviewed by external stakeholders. Finally, the protocol was revised following feedback and trialled in multiple centres prior to implementation. Some parameters utilised clinically for determining management and prognosis including tumour depth, lymphovascular invasion or distance to the margins lack high level evidence in NMSC. Dermatologists, surgeons, and radiation oncologists welcomed the SPRP. Pathologists indicated that the variety of NMSC specimens ranging from curettes to radical resections as well as significant differences in the biological behaviour of different tumours covered by the NMSC umbrella made use of a single protocol difficult. The feedback included that using a SPRP for low risk NMSC was neither clinically justified nor compensated adequately by the Australian Medicare Reimbursement Schedule. Following stakeholder feedback, the SPRP implementation was restricted to excision specimens of head and neck NMSC; and low-risk NMSC, such as superficial basal cell carcinoma, were excluded. Implementing NMSC SPRP fulfils an unmet clinical need. Unlike other cancers, NMSCs generate a range of specimen types and are reported in a wide range of pathology practices. Limiting use of SPRP to NMSC at higher risk of progression and providing formatted templates for easy incorporation into laboratory information systems were essential to successful deployment. In the future, further consideration should be given to implementing the SPRP to include all relevant specimens, including non-head and neck and low-risk NMSC specimens.


Assuntos
Carcinoma Basocelular , Neoplasias Cutâneas , Idoso , Humanos , Austrália , Programas Nacionais de Saúde , Neoplasias Cutâneas/patologia , Carcinoma Basocelular/patologia , Risco , Revisões Sistemáticas como Assunto
4.
Ann Dermatol ; 35(4): 243-255, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37550225

RESUMO

The immune system plays a key role in the suppression and progression of basal cell carcinoma (BCC). The primary aetiological factor for BCC development is exposure to ultraviolet radiation (UVR) which, particularly in lighter Fitzpatrick skin types, leads to the accumulation of DNA damage. UVR has roles in the generation of an immunosuppressive environment, facilitating cancer progression. Rates of BCC are elevated in immunosuppressed patients, and BCC may undergo spontaneous immune-mediated regression. Histologic and immunohistochemical profiling of BCCs consistently demonstrates the presence of an immune infiltrate and associated immune proteins. Early studies of immune checkpoint inhibitors reveal promising results in BCC. Therefore, the host immune system and tumor responses to it are important in BCC pathogenesis. Understanding these interactions will be beneficial for disease prognostication and therapeutic decisions.

6.
Ann Dermatol ; 35(2): 91-99, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37041702

RESUMO

Cutaneous squamous cell carcinoma (cSCC) is the most common malignancy in immune-suppressed organ transplant recipients (OTRs). Whilst rates of other malignancies (both cutaneous and non-cutaneous) are elevated in this population, the increase is far less striking. This suggests that cSCC must be a highly immunogenic tumor. The tumor immune microenvironment is altered in cSCC from OTRs. It has reduced anti-tumor properties and instead provides an environment that facilitates tumor growth and survival. Understanding the composition and function of the tumor immune microenvironment in cSCC from OTRs is useful for prognostication and therapeutic decisions.

7.
N Engl J Med ; 388(9): 804-812, 2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36856616

RESUMO

BACKGROUND: Immunosuppressed organ-transplant recipients have an increased incidence of, and mortality from, skin cancer. Nicotinamide (vitamin B3) enhances the repair of ultraviolet (UV) radiation-induced DNA damage, reduces the cutaneous immunosuppressive effects of UV radiation, and reduces the incidence of keratinocyte cancers (including squamous-cell and basal-cell carcinomas) and actinic keratoses among high-risk immunocompetent patients. Whether oral nicotinamide is useful for skin-cancer chemoprevention in organ-transplant recipients is unclear. METHODS: In this phase 3 trial, we randomly assigned, in a 1:1 ratio, organ-transplant recipients who had had at least two keratinocyte cancers in the past 5 years to receive 500 mg of nicotinamide or placebo twice daily for 12 months. Participants were examined for skin lesions by dermatologists at 3-month intervals for 12 months. The primary end point was the number of new keratinocyte cancers during the 12-month intervention period. Secondary end points included the numbers of squamous-cell and basal-cell carcinomas during the 12-month intervention period, the number of actinic keratoses until 6 months after randomization, safety, and quality of life. RESULTS: A total of 158 participants were enrolled, with 79 assigned to the nicotinamide group and 79 to the placebo group. The trial was stopped early owing to poor recruitment. At 12 months, there were 207 new keratinocyte cancers in the nicotinamide group and 210 in the placebo group (rate ratio, 1.0; 95% confidence interval, 0.8 to 1.3; P = 0.96). No significant between-group differences in squamous-cell and basal-cell carcinoma counts, actinic keratosis counts, or quality-of-life scores were observed. Adverse events and changes in blood or urine laboratory variables were similar in the two groups. CONCLUSIONS: In this 12-month, placebo-controlled trial, oral nicotinamide therapy did not lead to lower numbers of keratinocyte cancers or actinic keratoses in immunosuppressed solid-organ transplant recipients. (Funded by the National Health and Medical Research Council; ONTRANS Australian New Zealand Clinical Trials Registry number, ACTRN12617000599370.).


Assuntos
Antineoplásicos , Niacinamida , Neoplasias Cutâneas , Transplantados , Humanos , Austrália , Carcinoma Basocelular/etiologia , Carcinoma Basocelular/prevenção & controle , Carcinoma de Células Escamosas/etiologia , Carcinoma de Células Escamosas/prevenção & controle , Quimioprevenção , Ceratose Actínica/etiologia , Ceratose Actínica/prevenção & controle , Niacinamida/administração & dosagem , Niacinamida/uso terapêutico , Qualidade de Vida , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/prevenção & controle , Hospedeiro Imunocomprometido , Transplante de Órgãos/efeitos adversos , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Raios Ultravioleta/efeitos adversos
8.
Cancer Epidemiol ; 81: 102263, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36174452

RESUMO

BACKGROUND: In Australia, skin cancer awareness campaigns have focused on raising the awareness and consequences of skin cancer and highlighting the importance of utilising sun protection. METHODS: Trends in melanoma incidence and mortality have been explored elsewhere in Australia and this study sought to examine the trends in NSW. Anonymised incidence and mortality data for in situ and invasive melanoma from 1988 to 2014 were obtained from the NSW Cancer Registry. Trends of melanoma incidence and mortality were analysed using segmented regression to allow for changes over time. Birth cohort patterns were assessed using age-period-cohort models. RESULTS: Over the period, incidence of in situ melanoma increased in all age groups although the rates were lowest in those under 40 years of age. Incidence of invasive melanoma was either stable or decreased in people under 60, while it increased in those aged 60 and above, particularly in men. Age-period-cohort analysis revealed decreasing age-specific incidence of invasive melanoma under 40 years of age. Melanoma mortality over the period was stable or decreased in all groups except in men aged 60 or over. Overall, mortality rates generally declined or remained stable particularly in recent years. CONCLUSION: It is encouraging that rates of invasive melanoma are declining in the younger age cohorts - which could be attributed to both primary prevention efforts with individuals protecting their skin as well as early detection through self assessment and clinician performed skin checks. In addition, whilst it is important to monitor the increasing rates of in situ melanoma, the increase is likely due to early detection and treatment of melanoma that could have progressed to invasive melanoma and therefore detection whilst still in situ is an improved outcome. Overall, the results demonstrate the need to continue to improve the understanding of and compliance with primary skin cancer prevention measures in order to reduce population UVR exposure and overall melanoma incidence.

9.
Case Rep Dermatol ; 14(2): 127-131, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35813836

RESUMO

Syringocystadenocarcinoma papilliferum (SCACP) is a rare cutaneous adnexal neoplasm. To the best of our knowledge, fewer than 50 cases have been described in the literature. We describe the first reported case of an SCACP in an immunocompromised patient. We report the development of an SCACP over 3 months in a 77-year-old organ transplant recipient undergoing regular dermatological follow-up. The lesion was excised with clear margins with Mohs micrographic surgery. This lesion's rapid development and small size contrasts with the predominantly slow-growing, larger lesions described in immunocompetent patients. Lastly, this case further highlights the importance of close dermatological follow-up of immunosuppressed patients.

10.
Health Educ Behav ; 49(3): 415-423, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34636262

RESUMO

Skin cancers are the most common malignancy in Australia. Regular sunscreen use can reduce the incidence of cutaneous squamous cell carcinomas and actinic keratoses and has been associated with reducing the incidence of basal cell carcinomas and melanomas. However, sunscreen effectiveness is limited by the failure of the population to use it routinely. Interventions that promote the daily application of sunscreen may reduce the morbidity, mortality, and economic burden associated with skin malignancies. We reviewed the literature that examines the effectiveness of interventions to increase routine sunscreen use and found that no one strategy has been shown to be clearly effective in adults and that relatively few studies have aimed to increase routine use in groups at extreme skin cancer risk. Future research should consider how interventions can be best designed and how sunscreen use is measured so that cost-effective, feasible strategies that result in improved sunscreen use in adults can be established.


Assuntos
Carcinoma Basocelular , Carcinoma de Células Escamosas , Neoplasias Cutâneas , Adulto , Carcinoma Basocelular/complicações , Carcinoma Basocelular/tratamento farmacológico , Carcinoma de Células Escamosas/complicações , Carcinoma de Células Escamosas/tratamento farmacológico , Humanos , Incidência , Neoplasias Cutâneas/prevenção & controle , Protetores Solares/uso terapêutico
11.
Photochem Photobiol Sci ; 19(2): 171-179, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31942903

RESUMO

Nicotinamide (NAM), an amide form of vitamin B3, replenishes cellular energy after ultraviolet radiation (UVR) exposure, thereby enhancing DNA repair and reducing UVR's immunosuppressive effects. NAM reduces actinic keratoses and new keratinocyte cancers in high risk individuals, but its effects on melanoma are unknown. Melanomas arising on NAM or placebo within the ONTRAC skin cancer chemoprevention trial (Oral Nicotinamide To Reduce Actinic Cancer) were examined by immunohistochemistry. The effects of NAM (50 µM, 5 mM and 20 mM) on the viability, proliferation and invasiveness of four human melanoma cell lines and on the viability and proliferation of two human melanocyte lines, with and without UV irradiation were also investigated. 50 µM NAM did not affect viability, proliferation or invasion of melanoma or melanocyte cell lines, whereas concentrations too high to be achievable in vivo reduced viability and proliferation. Nicotinamide did not enhance melanoma viability, proliferation or invasiveness in vitro, providing additional confidence in its safety for use in clinical trials in high risk patients. Peritumoral and tumour infiltrating CD4+ and CD8+ lymphocytes were significantly increased in melanomas arising on NAM compared to those arising on placebo. Given the chemopreventive activity of nicotinamide against keratinocyte cancers, its DNA repair enhancing effects in melanocytes and now its potential enhancement of tumour-infiltrating lymphocytes and lack of adverse effects on melanoma cell growth and proliferation, clinical trials of nicotinamide for melanoma chemoprevention are now indicated.


Assuntos
Melanoma/patologia , Niacinamida/farmacologia , Neoplasias Cutâneas/patologia , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Melanoma/tratamento farmacológico , Melanoma/prevenção & controle , Niacinamida/química , Niacinamida/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Raios Ultravioleta
12.
Geriatrics (Basel) ; 4(1)2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30934630

RESUMO

Nicotinamide (vitamin B3) has photoprotective effects and reduces skin cancer incidence in high risk patients. Nicotinamide also improves cognition in animal models. As part of the ONTRAC (Oral Nicotinamide To Reduce Actinic Cancer) phase III placebo-controlled, randomized trial to assess nicotinamide's efficacy in skin cancer prevention, we included clinical neurocognitive function and patient-reported quality of life assessments at baseline and after 12 months of intervention in individuals with previous skin cancer in order to assess any effect of oral nicotinamide (500 mg po twice daily) on cognitive function and quality of life. In our sample of 310 participants who completed neurocognitive function testing at baseline and at 12 months, we were not able to detect any significant effect of oral nicotinamide on cognitive function nor on quality of life. Further studies of nicotinamide's effects on cognition in humans might include individuals with pre-existing mild cognitive impairment, and it may be that higher doses of nicotinamide are required to significantly influence cognitive function compared to doses required to reduce skin cancer.

13.
Exp Dermatol ; 28 Suppl 1: 15-22, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30698874

RESUMO

Nicotinamide is a water-soluble vitamin B3 derivative that has many roles in medicine. This review examines the role of nicotinamide in dermatology and its actions in preventing photoageing and skin cancers in humans. Nicotinamide prevents ultraviolet radiation (UV) from reducing ATP levels and inhibiting glycolysis, thus preventing the UV radiation-induced energy crisis. This enhances DNA repair and reduces UV-induced suppression of immunity. Randomised controlled clinical trials have also shown that nicotinamide reduces transepidermal water loss and the development of new non-melanoma skin cancers in high-risk humans. This review also examines nicotinamide's safety profile.


Assuntos
Niacinamida/efeitos adversos , Niacinamida/uso terapêutico , Envelhecimento da Pele/efeitos dos fármacos , Neoplasias Cutâneas/prevenção & controle , Trifosfato de Adenosina/metabolismo , Animais , Anti-Inflamatórios , Quimioprevenção , Dano ao DNA , Reparo do DNA , Dermatologia/métodos , Feminino , Trato Gastrointestinal/efeitos dos fármacos , Glicólise , Humanos , Inflamação , Ceratose Actínica/metabolismo , Falência Renal Crônica/complicações , Fígado/efeitos dos fármacos , Leite Humano/efeitos dos fármacos , Segurança do Paciente , Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Envelhecimento da Pele/efeitos da radiação , Raios Ultravioleta , Complexo Vitamínico B/farmacologia
15.
Photodermatol Photoimmunol Photomed ; 34(1): 5-12, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28681504

RESUMO

Ultraviolet radiation (UVR) causes DNA damage in melanocytes by producing photolesions such as cyclobutane pyrimidine dimers and 8-oxo-7-hydrodeoxyguanosine. The production of reactive oxygen species by UVR also induces inflammatory cytokines that, together with the inherent immunosuppressive properties of UVR, propagate carcinogenesis. Nicotinamide (Vitamin B3 ) enhances DNA repair, modulates the inflammatory environment produced by UVR, and reduces UV-induced immunosuppression. As nicotinamide reduces the incidence of actinic keratoses and nonmelanoma skin cancers in high-risk individuals and enhances repair of DNA damage in melanocytes, it is a promising agent for the chemoprevention of melanoma in high-risk populations.


Assuntos
Carcinoma Basocelular/prevenção & controle , Carcinoma de Células Escamosas/prevenção & controle , Melanoma/prevenção & controle , Niacinamida/uso terapêutico , Neoplasias Cutâneas/prevenção & controle , Complexo Vitamínico B/uso terapêutico , Animais , Reparo do DNA/efeitos dos fármacos , Humanos , Imunomodulação/efeitos dos fármacos , Niacinamida/farmacologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Complexo Vitamínico B/farmacologia
16.
Australas J Dermatol ; 58(3): 174-180, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28321860

RESUMO

Nicotinamide (vitamin B3 ) has a range of photoprotective effects in vitro and in vivo; it enhances DNA repair, reduces UV radiation-induced suppression of skin immune responses, modulates inflammatory cytokine production and skin barrier function and restores cellular energy levels after UV exposure. Pharmacological doses of nicotinamide have been shown to reduce actinic keratoses and nonmelanoma skin cancer incidence in high-risk individuals, making this a nontoxic and accessible option for skin cancer chemoprevention in this population.


Assuntos
Carcinoma Basocelular/prevenção & controle , Carcinoma de Células Escamosas/prevenção & controle , Melanoma/prevenção & controle , Niacinamida/uso terapêutico , Neoplasias Cutâneas/prevenção & controle , Complexo Vitamínico B/uso terapêutico , Reparo do DNA/efeitos dos fármacos , Humanos , Tolerância Imunológica/efeitos dos fármacos , Tolerância Imunológica/efeitos da radiação , Ceratose Actínica/tratamento farmacológico , Niacinamida/farmacologia , Transplante de Órgãos , Raios Ultravioleta/efeitos adversos , Complexo Vitamínico B/farmacologia
19.
N Engl J Med ; 373(17): 1618-26, 2015 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-26488693

RESUMO

BACKGROUND: Nonmelanoma skin cancers, such as basal-cell carcinoma and squamous-cell carcinoma, are common cancers that are caused principally by ultraviolet (UV) radiation. Nicotinamide (vitamin B3) has been shown to have protective effects against damage caused by UV radiation and to reduce the rate of new premalignant actinic keratoses. METHODS: In this phase 3, double-blind, randomized, controlled trial, we randomly assigned, in a 1:1 ratio, 386 participants who had had at least two nonmelanoma skin cancers in the previous 5 years to receive 500 mg of nicotinamide twice daily or placebo for 12 months. Participants were evaluated by dermatologists at 3-month intervals for 18 months. The primary end point was the number of new nonmelanoma skin cancers (i.e., basal-cell carcinomas plus squamous-cell carcinomas) during the 12-month intervention period. Secondary end points included the number of new squamous-cell carcinomas and basal-cell carcinomas and the number of actinic keratoses during the 12-month intervention period, the number of nonmelanoma skin cancers in the 6-month postintervention period, and the safety of nicotinamide. RESULTS: At 12 months, the rate of new nonmelanoma skin cancers was lower by 23% (95% confidence interval [CI], 4 to 38) in the nicotinamide group than in the placebo group (P=0.02). Similar differences were found between the nicotinamide group and the placebo group with respect to new basal-cell carcinomas (20% [95% CI, -6 to 39] lower rate with nicotinamide, P=0.12) and new squamous-cell carcinomas (30% [95% CI, 0 to 51] lower rate, P=0.05). The number of actinic keratoses was 11% lower in the nicotinamide group than in the placebo group at 3 months (P=0.01), 14% lower at 6 months (P<0.001), 20% lower at 9 months (P<0.001), and 13% lower at 12 months (P=0.001). No noteworthy between-group differences were found with respect to the number or types of adverse events during the 12-month intervention period, and there was no evidence of benefit after nicotinamide was discontinued. CONCLUSIONS: Oral nicotinamide was safe and effective in reducing the rates of new nonmelanoma skin cancers and actinic keratoses in high-risk patients. (Funded by the National Health and Medical Research Council; ONTRAC Australian New Zealand Clinical Trials Registry number, ACTRN12612000625875.).


Assuntos
Carcinoma Basocelular/prevenção & controle , Carcinoma de Células Escamosas/prevenção & controle , Ceratose Actínica/prevenção & controle , Niacinamida/uso terapêutico , Neoplasias Cutâneas/prevenção & controle , Complexo Vitamínico B/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Basocelular/epidemiologia , Carcinoma de Células Escamosas/epidemiologia , Método Duplo-Cego , Feminino , Humanos , Ceratose Actínica/epidemiologia , Masculino , Pessoa de Meia-Idade , Niacinamida/efeitos adversos , Prevenção Secundária , Neoplasias Cutâneas/epidemiologia , Complexo Vitamínico B/efeitos adversos
20.
PLoS One ; 10(2): e0117491, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25658450

RESUMO

Arsenic-induced skin cancer is a significant global health burden. In areas with arsenic contamination of water sources, such as China, Pakistan, Myanmar, Cambodia and especially Bangladesh and West Bengal, large populations are at risk of arsenic-induced skin cancer. Arsenic acts as a co-carcinogen with ultraviolet (UV) radiation and affects DNA damage and repair. Nicotinamide (vitamin B3) reduces premalignant keratoses in sun-damaged skin, likely by prevention of UV-induced cellular energy depletion and enhancement of DNA repair. We investigated whether nicotinamide modifies DNA repair following exposure to UV radiation and sodium arsenite. HaCaT keratinocytes and ex vivo human skin were exposed to 2µM sodium arsenite and low dose (2J/cm2) solar-simulated UV, with and without nicotinamide supplementation. DNA photolesions in the form of 8-oxo-7,8-dihydro-2'-deoxyguanosine and cyclobutane pyrimidine dimers were detected by immunofluorescence. Arsenic exposure significantly increased levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine in irradiated cells. Nicotinamide reduced both types of photolesions in HaCaT keratinocytes and in ex vivo human skin, likely by enhancing DNA repair. These results demonstrate a reduction of two different photolesions over time in two different models in UV and arsenic exposed cells. Nicotinamide is a nontoxic, inexpensive agent with potential for chemoprevention of arsenic induced skin cancer.


Assuntos
Arsenitos/farmacologia , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Queratinócitos/efeitos dos fármacos , Niacinamida/farmacologia , Pele/efeitos dos fármacos , Compostos de Sódio/farmacologia , Raios Ultravioleta , Linhagem Celular , Dano ao DNA/efeitos da radiação , Humanos , Queratinócitos/efeitos da radiação , Pele/efeitos da radiação , Cicatrização/efeitos dos fármacos
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