자외선에 노출된 멜라닌 색소성 모반의 MAPK계열 발현에 관한 연구

Abstract

Background : In contrast to the relationship between UV exposure and nonmelanoma skin cancers, the molecular evidence for the involvement of UV radiation in the melanocytic tumorigenesis is quite limited. Mitogen-activated protein kinase(MAPK) is an important molecule in transducing extracellular signal from cell surface to the nucleus. MAPK family includes ERK(extracellular signal-regulated protein kinase), JNK(stress-activated c-Jun N-terminal kinase), p38 kinases. Not only various growth factors and cytokines, but also other signals such as UN light are able to activate MAPK, resulting in various cellular responses including proliferation, differentiation and apoptosis. Objective : The purpose of our study was to investigate the effect of UV irradiation on the expressions of MAPK in melanocytic nevi. Methods : Melanocytic nevi from ten healty volunteers were partially covered, irradiated with a defined UV dose, and excised 1 week thereafter. The irradiation and the protected parts were examined separatedly by immunohistochemistry using p-ERK, p-JNK, and p-p38 monoclonal antibody. Results : In the nonirradiated half of melanocytic nevus, p-ERK, p-JNK, and p-p38 were undetectable in nevus cells. After irradiation, p-ERK expression was observed in nevus cells in 7 cases and p-p38 was stained diffusely in the cytoplasm of nevus cells in 6 cases, but there was no immunoreactivity of p-JNK. Conclusions : We suggest that a single UV irradiation of melanocytic nevi can stimulate the p-ERK expression and cytoplasmic p-p38 expression but not p-JNK.