Effect of Solar-Simulated Ultraviolet Radiation on Gene Expression in Unprotected and Sunscreen-Protected Skin of Healthy Adults With Fitzpatrick Skin Type II

Effect of Solar-Simulated Ultraviolet Radiation on Gene Expression in Unprotected and Sunscreen-Protected Skin of Healthy Adults With Fitzpatrick Skin Type II

RATIONALE: Testing of skin that has been exposed to artificial sunlight may help in understanding the genetic processes involved in the development of skin cancer. PURPOSE: This trial is studying the effect of solar-simulated ultraviolet radiation on skin with or without sunscreen in healthy adults with skin that burns easily after only slight tanning during sun exposure.

OBJECTIVES: Determine the global gene expression profiles in epidermal tissue of healthy fair-skinned adults with Fitzpatrick skin type II after exposure to known doses of solar-simulated ultraviolet radiation (ssUVR) (UVA). Determine the ability of an FDA-standardized sunscreen to alter ssUVR-induced transcription profiles in vivo in these participants. Determine whether the transcriptional profiles of keratinocytes exposed to UVR in cell culture are comparable to the profiles of keratinocytes in skin after similar levels of UVR exposure. OUTLINE: This is a pilot, dose-response study followed by an in vivo transcriptional profiling study in 2 different groups. Pilot study (verification of ultraviolet radiation dose response): Participants are initially exposed to solar-simulated ultraviolet radiation (ssUVR) (UVA) on the back to determine the minimum erythema dose (MED). Between 22-24 hours after exposure, participants undergo shave biopsy from each of the 9 UV exposure sites and 1 unexposed skin site. Group 1 (determination of ssUVR and UVA in vivo transcriptional profiles): On day 1, participants are initially exposed to ssUVR on the back to determine the MED. On day 2, participants are exposed to ssUVR (3 sites) and UVA (3 sites) at the MED on the buttocks. Between 22-24 hours after exposure (day 3), participants undergo shave biopsy from each of the 6 UV exposure sites and 2 unexposed skin sites. Group 2 (determination of sunscreen-protected in vivo transcriptional profiles): On day 1, participants are initially exposed to ssUVR on the back to determine the MED. On day 2, participants are exposed to ssUVR on unprotected skin (3 sites) and sunscreen-protected skin (3 sites) at the MED on the buttocks. Between 22-24 hours after exposure (day 3), participants undergo shave biopsy from each of the 6 UV exposure sites and 2 unexposed skin sites. Biopsies from all participants are analyzed by microarray analysis. One of the unexposed epidermal samples is used for primary keratinocyte culture. PROJECTED ACCRUAL: A total of 6-56 participants (6 for the pilot study and 50 [25 per group] for transcriptional profiling) will be accrued for this study within 2 months.

DISEASE CHARACTERISTICS: Healthy, fair-skinned adults Fitzpatrick skin type II by history and physical exam Skin easily burns, and tans only slightly, after sun exposure Test site for solar-simulated ultraviolet radiation exposure (buttocks) devoid of sunburn, suntan, scars, active dermal lesions, and uneven skin tones Nevi allowed at physician discretion Excess hair must be clipped or shaved No prior nonmelanoma skin cancer, melanoma, or dysplastic nevi PATIENT CHARACTERISTICS: Age 18 to 45 Performance status Not specified Life expectancy Not specified Hematopoietic Not specified Hepatic Not specified Renal Not specified Other No prior malignancy No prior phototoxic, photoallergic, or other abnormal responses to sunlight No prior allergic reaction to sunscreen or lidocaine No underlying disease that is known to cause immunosuppression (e.g., HIV, cancer, or post-organ transplantation) No situation that would preclude study compliance Not pregnant or nursing PRIOR CONCURRENT THERAPY: Biologic therapy Not specified Chemotherapy Not specified Endocrine therapy Not specified Radiotherapy Not specified Surgery Not specified Other More than 6 months since prior topical or systemic medication producing abnormal sunlight responses No concurrent medications with > 1% incidence of sun-related toxic effects No concurrent medications associated with abnormal light response No concurrent immunosuppressants No other concurrent ultraviolet radiation (e.g., sunlight or tanning bed) to the epidermal test site