Effect of Solar-Simulated Ultraviolet Radiation on Gene Expression in Unprotected and Sunscreen-Protected Skin of Healthy Adults With Fitzpatrick Skin Type II
Condition: Non-melanomatous Skin Cancer; Precancerous Condition
MeSH terms: Precancerous Conditions
Study type: Observational

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.
    

Detailed 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.
    

Intervention name(s): microarray analysis; biopsy; evaluation of cancer risk factors
Intervention type(s): Genetic; Procedure; Procedure
Keywords: basal cell carcinoma of the skin; squamous cell carcinoma of the skin; actinic keratosis