INFLUENCE OF CHRONIC NEUROGENIC PAIN ON DYNAMICS OF ENDOTHELIN-1 LEVEL AND COMPONENTS OF NO-SYSTEM DURING MELANOMA B16/F10 GROWTH

Abstract

Chronic neurogenic pain is a pathogenic factor triggering mechanisms of homeostasis disfunction. As chronic neurogenic pain has been found to affect the biological features of B16/F10 melanoma, the purpose of the study was to determine the levels of endothelin-1 and components of the NO-system in mice during the growth of transplantable B16/F10 melanoma with chronic pain. Methods. The study included 64 female mice. B16/F10 melanoma was transplanted under the skin of the back to animals of the main group 2 weeks after the sciatic nerve ligation. Levels of endothelin-1, NOS-2, NOS-3, L-arginine, citrulline, total nitrite, nitrotyrosine and ADMA were determined by ELISA in the intact skin and in tumor tissues. Results. The dynamics of the studied parameters in tumor growth with and without chronic pain was different. Increased levels of endothelin-1 in the skin and in tumor tissues, stably elevated levels of NO-synthases in the tumor and stably elevated ADMA levels with their decrease by week 3 of the growth were observed in the tumor growth with pain. Conclusions. Chronic pain can contribute to the development of the immune tolerance to tumor antigens in the skin. Conditions are formed that both facilitate the survival of tumor cells and contribute to the further development of melanoma. The dynamics of activity of endothelin-1 and NO systems can promote stimulation of the epithelial-mesenchymal transition, enhance tumor invasion and hemangio- and lymphangiogenesis. Changes in the ADMA inhibitor levels in the tumor growth with chronic pain may indicate a more subtle control of the NO level providing increased melanoma invasiveness.