Actinic Cheilitis Pre-Treated With DNA Repair Enzyme Cream

It is well known that ultraviolet (UV) light causes sunburn and DNA damage that can lead to skin cancer. Despite preventative measures of sunscreens and other topicals the incidence of skin cancers continues to increase every year. Chronic exposure can lead to development of both basal and squamous cell carcinoma that also is correlated to the risk of melanoma. When epidermal keratinocytes are exposed to UV radiation, they form cyclobutane pyrimidine dimmers (CPDs), 6-pyrimidine-4-pyrimidones (6-4-PPs), and oxygen radicals that alter the structure of nucleotides. When these lesions are not repaired, DNA replication is altered that leads to mutations in p53 and PTCH tumor suppressor gene and ultimately tumor development. It has been discovered that intracellular delivery of bacterial DNA incision repair enzyme T4 endonuclease V DNA repair enzymes can repair sun induced damaged DNA in patients with xeroderma pigmentosum4,. Yarosh et al also showed that T4 endonuclease V DNA repair enzymes are specific to reducing the amount of cyclobutane pyrimidine dimers and were found to lower the rate of new actinic keratoses compared to placebo lotion by 68% with no adverse effects observed. Additionally Yarosh et al also showed that T4N5 liposomes can repair keratinocyte DNA in skin cancer patients. This study will examine if pretreating actinic cheilitis with DNA repair enzyme cream before standard treatments can decrease the need for additional and possibly more aggressive therapies, decrease the surface area of affected areas, and possibly improve skin thickening and texture.