Mechanisms of skin aging induced by EGFR inhibitors.

Overview

BACKGROUND: The mechanisms of skin aging have not been completely elucidated. Anecdotal data suggests that EGFR inhibition accelerates aging-like skin changes. OBJECTIVE: The objective of the study was to evaluate the clinical characteristics and investigate the cellular and molecular mechanisms underlying skin changes associated with the use of EFGRIs. PATIENTS AND METHODS: Patients during prolonged treatment with EGFRIs (>3 months) were analyzed for aging-like skin changes. Baseline EGFR expression was compared in young (<25 years old) vs. old (> 65 years old) skin. In addition, the regulation of extracellular matrix, senescence-associated genes, and cell cycle status was measured in primary human keratinocytes treated with erlotinib in vitro. RESULTS: There were progressive signs of skin aging, including xerosis cutis, atrophy, rhytide formation, and/or actinic purpura in 12 patients. Keratinocytes treated with erlotinib in vitro showed a significant down-modulation of hyaluronan synthases (HAS2 and HAS3), whereas senescence-associated genes (p21, p53, IL-6, maspin) were upregulated, along with a G1 cell cycle arrest and stronger SA β-Gal activity. There was significantly decreased baseline expression in EGFR density in aged skin, when compared to young controls. CONCLUSIONS: EGFR inhibition results in molecular alterations in keratinocytes that may contribute to the observed skin aging of patients treated with respective targeted agents.