Korean J Dermatol.  2005 Sep;43(9):1186-1191.

Immunohistochemical Study for MAPK Expression in UV Irradiated Melanocytic Nevi

• Park MK
• Choi KC
• Chung BS

Abstract

BACKGROUND
In contrast to the relationship between UV exposure and nonmelanoma skin cancers, molecular evidence for the involvement of UV radiation in melanocytic tumorigenesis is quite limited. Mitogen-activated protein kinase (MAPK) is an important molecule in transducing extracellular signals from the cell surface to the nucleus. The MAPK family includes ERK (extracellular signal- regulated protein kinase), JNK (stress-activated c-Jun N-terminal kinase), and p38 kinases. Various growth factors and cytokines, as well as other signals such as UV light are able to activate MAPK, resulting in a variety of cellular responses including proliferation, differentiation and apoptosis. OBJECTIVE: The purpose of our study was to investigate the effect of UV irradiation on the expression of MAPK in melanocytic nevi. METHOD: Melanocytic nevi from ten healthy volunteers were partially covered, irradiated with a defined UV dose, and excised after 1 week. healthy The irradiated and non-irradiated area were examined separateted by immunohistochemistry using p-ERK, p-JNK, and p-p38 monoclonal antibodies. RESULTS: In the non-irradiated area 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. CONCLUSION: We suggest that a single UV irradiation of melanocytic nevi can stimulate both p-ERK and cytoplasmic p-p38 expression, but not p-JNK.

Keyword

Mitogen-activated protein kinase; ERK; JNK; p38; UVB; Melanocytic nevi

MeSH Terms

Antibodies, Monoclonal
Apoptosis
Carcinogenesis
Cytokines
Cytoplasm
Healthy Volunteers
Humans
Immunohistochemistry
Intercellular Signaling Peptides and Proteins
Nevus
Nevus, Pigmented*
Phosphotransferases
Protein Kinases
Skin Neoplasms
Ultraviolet Rays
Antibodies, Monoclonal
Cytokines
Intercellular Signaling Peptides and Proteins
Phosphotransferases
Protein Kinases