Cutaneous DNA Damage Caused by UV-A Irradiation

Study Overview
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Brief Summary
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The DIMUVA study aims to evaluate the correlation between cutaneous phototype and the nature and quantity of damage caused to cutaneous DNA after exposure to UV-A radiation.

Detailed Description
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Due to their capacity to damage Deoxyribonucleic acid (DNA), Ultra-Violet (UV) radiation is one of the causes of skin cancers. Until recently, the genotoxic effects of UV-A radiation, were poorly identified, in particular their capacity to lead to the dimerization of pyrimidine bases . It is well known that the response to UV-A and UV-B radiations is different depending on the cutaneous phototype. Thus, the aim of this study is to determine the correlation between cutaneous phototype and the quantity and nature (CPD or oxidative lesions) of damage caused to cutaneous DNA after an ex-vivo exposure to UV-A and UV-B radiations.

Official Title
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Damage to DNA Caused by UV-A Irradiation: Photochemical Mechanism and Cutaneous Parameters Involved in the Formation of Cyclobutane Pyrimidine Dimers

Conditions
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Healthy Volunteers

Intervention / Treatment
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* Radiation: UVA and UVB irradiation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male, Between 18 and 35 years old, Healthy volunteers, Cutaneous phototype 2 or 4 according to the Fitzpatrick classification, Affiliation to the French Social Security. Exclusion Criteria: History of photosensibility, Active smoking or stopped since less than one year, Dermatological pathology or treatment contra-indicating cutaneous irradiation and skin biopsies, Any chronic pathology susceptible to interfere with the evaluations related to the protocol, Allergy to local anaesthetics, Volunteers who take drugs and/or food complements acting on oxidative stress in the 8 weeks preceding inclusion, Volunteers who have take paracetamol or aspirin within 7 days prior to the inclusion visit, Subject in exclusion period for another biomedical research study, Subject having exceeded the threshold of annual compensation for biomedical research.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: phototype 2<br>Volunteers with cutaneous phototype 2 | Radiation: UVA and UVB irradiation<br>* 4 cutaneous biopsies for Ex-vivo irradiation Determination of the minimal erythemic dose of UVA and UVB for each volunteer<br>|
| Experimental: phototype 4<br>Volunteers with cutaneous phototype 4 | Radiation: UVA and UVB irradiation<br>* 4 cutaneous biopsies for Ex-vivo irradiation Determination of the minimal erythemic dose of UVA and UVB for each volunteer<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Phototype determination according to the Fitzpatrick classification Number of CPD and oxidative lesions determinated by the analysis of DNA from the skin biopsies after their ex-vivo exposure to UV-A - The CPD / Oxidative lesions ratio |  | Day 0 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of CPD and oxidative lesions determinated by the analysis of DNA from the skin biopsies after their exposure ex-vivo to UV-B. |  | Day 0 | 
| UV-A radiation exposure: Minimal erythemic dose - Number of CPD and oxidative lesions - CPD / oxidative lesions ratio |  | Day x | 
| UV-B radiation exposure: Minimal erythemic dose - Number of CPD and oxidative lesions - CPD/oxidative lesions ratio |  | Day 0 | 
| antioxidant status and quantity of CPD, oxidative lesions after exposure to UV-A and UV-B radiations |  | day 2 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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UV-A irradiation, Cyclobutane-Pyrimidine Dimer, Oxidative lesions, cutaneous phototype, UV-B irradiation, DNA damages