A molecular signature for rejuvenation characterizes lesional and non lesional skin following Metvix treatment in Actinic Keratosis patients.. Homo sapiens

Actinic keratoses (AK) are proliferations of pre-neoplastic keratinocytes in the epidermis that are the result of cumulative ultraviolet (UV) radiations from sun exposure. Lesions are commonly found on sites of sun-exposed skin such as the face, balding scalp, and back of the hand. AKs may present on a patient as a few detectable lesions and 5-10% of them are susceptible to transform into SCC. In contrast, Organ Transplant Recipients (OTR) are of increasing risk at developing cancers as a consequence of long-term immunosuppressive therapy. The molecular changes that occur in lesional and perilesional skin of OTR patients 18 weeks following of PDT with topical MAL treatment were investigated to better understand the effect of the therapeutic intervention on the AK lesions. Our data show the complete normalization of the skin biology in the treated areas, i. e restoration of normal proliferation related gene profiles, and correction of aberrantly expressed cancer associated genes. We were also able to uncover a transcriptional signature of a rejuvenation effect induced by MAL-PDT in photodamaged skin opening new avenues in the use of PTD for treating photodamaged skin and field cancerized areas. Overall design: Total of 35 chips. 7 patients : 5 biospies per patient: 1 in healthy skin areas (Buttock) before treatment, 1 in peri-lesional region before treatment, 1 in lesional region before treatment, 1 in perilesional region after 18 weeks of treatment and 1 in lesional region after 18 weeks fo treatment