자외선에 노출된 멜라닌세포성 모반에서 랑게르한스 세포 수와 사이토카인 발현에 관한 연구

Abstract

It is well established that UV-induced DNA damage is involved in the mutation of oncogenes and tumor suppressor genes, and subsequent development of skin cancers. More recently, it is also accepted that UV-induced immunosuppression contributes to the UV related carcinogenesis. Langerhans cells(LC) are thought to play an important role in presentation of tumor antigens for the induction of anti-tumor immunity. Cytokines may have a key role in the UV-induced modulation of the skin immune system. Skin biopsies from 10 melanocytic nevi, taken from partially covered and irradiated part with a defined UV dose, were examined using immunohistological technicque for the quantitative distribution of LC and the expression of cytokines which are related to LC migration and maturation(TNF-α and GM-CSF), Th1 response(IL-12), and Th2 response(IL-10). LC number was increased in non-irradiated neoplastic epithelium compared to control skin. In UV-exposed nevi, LC density decreased significantly but a constant number was still maintained. TNF-α and GM-CSF were predominently expressed in lesional epithelium and some nevus cells 2 days after irradiation. GM-CSF expression was maintained in nevus cells up to day 7 after exposure. IL-10 was expressed in epidermis 2 days after exposure. IL-12 was weakly positive in unexposed lesional epidermis and this IL-12 expression was disappeared by 2 days after exposure but it was reappeared by 7 days after exposure. These findings suggests that LC may have a functional role in immune surveillance against UV-induced carcinogenesis.