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

Precancerous Condition Clinical Trial

Official title: Transcriptional Profiling of the Epidermal Response to Solar-Simulated Ultraviolet Radiation

Status Completed

Clinical Trial Summary

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.

Clinical Trial Description

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. ;

Study Design

N/A

Related Conditions & MeSH terms

• Non-melanomatous Skin Cancer
• Precancerous Condition
• Precancerous Conditions

• NCT number: NCT00099112
• Study type: Observational
• Source: National Cancer Institute (NCI)
• Status: Completed
• Phase: N/A
• Start date: February 2004