Esta web utiliza cookies. Si continúas navegando consideramos que aceptas su uso.
Más información
Aceptar
I Jornadas Científicas del IMIB-Arrixaca
Acceso Personal
Contacto
Aviso Legal
Inicio
Bienvenida
Comités
Ponencias
Comunicaciones
Programa
Fechas clave
Inscripciones
Selección comunicaciones
Enviar comunicación
Patrocinadores
Sede
Imprimir
NOVEL ROLES OF PI3K/AKT PATHWAY DOWNSTREAM OF MELANOCORTIN 1 RECEPTOR IN MELANOCYTES AND HUMAN MELANOMA CELLS.
Autores:
MARÍA CASTEJÓN GRIÑÁN
,
JULIA SIRÉS CAMPOS
,
MARTA ABRISQUETA GONZÁLEZ
, IDOYA MARÍA MARTÍNEZ VICENTE,
MARÍA CONCEPCIÓN OLIVARES SÁNCHEZ
,
CELIA JIMENEZ-CERVANTES FRIGOLS
,
JOSE CARLOS GARCIA-BORRON MARTINEZ
,
CECILIA MARÍA HERRAIZ SERRANO
,
Grupos de investigación:
[GI/IMIB/C010/2011] Control molecular de la proliferación y diferenciación
Comunicación:
Antecedentes:
Ultraviolet radiation (UVR) is the main etiologic factor for melanoma, since it causes DNA lesions either directly or indirectly, via generation of reactive oxygen species (ROS). Cutaneous pigmentation is the main photoprotective mechanism against UVR-induced DNA damage. Melanocytes also take advantage of other processes to cope with this damage, including the activation of DNA repair mechanisms, antioxidant defenses and survival pathways. These non-pigmentary photoprotective actions, mediated by the melanocortin 1 receptor (MC1R), are thought to rely on activation of the cAMP pathway. We analyzed the signaling pathways downstream of MC1R activation by ?-melanocyte-stimulating hormone (?MSH) responsible for protection against oxidative damage in human melanoma cells (HMCs) and epidermal melanocytes (HEMs) of defined MC1R, NRAS and BRAF genotype.
Métodos:
We carried out the following methods: - Functional MC1R assay: cAMP levels were measured by a commercial ELISA immunoassay. - Labelling of 8-oxo-dG by immunocytochemistry. - Labelling of ?H2AX by immunocytochemistry. - Confocal microscopy of HBL and A375 melanoma cell lines. - Quantitative analysis of 8-oxodG and ?H2AX fluoresence using the software Leica Qwin. - Alkaline Comet Assay of HMCs and HEMs. - Quantitative analysis of comet tail using CASPLAB software. - Electrophoresis and western blotting
Resultados:
1-MC1R signaling decreases oxidative DNA damage in human HBL and A375 melanoma cells. 2-MC1R signaling decreases ?H2AX DNA repair foci in human HBL and A375 melanoma cells. 3-Both cAMP-dependent and independent signaling downstream of MC1R contributes to prevent DNA breaks in HMCs and HEMs. 4-?MSH activates AKT efficiently in cells harboring MC1R variants with reduced or absent cAMP signaling. 5-PI3K/AKT pathway is involved in the protective effect of MC1R.
Conclusiones:
We have demonstrated that pretreatment of HEMs and HMCs with NDP-MSH decreased: H2O2-induced oxidative DNA damage as estimated by staining of 8-oxodG the phosphorylation of histone H2A variant H2AX and the number of DNA repair foci the formation of DNA breaks as estimated by comet assay These responses were mainly cAMP-dependent in HMCs wild-type for MC1R, but not exclusively, since significant protection was afforded by ?MSH under conditions of complete adenylyl cyclase inhibition. Moreover, ?MSH significantly decreased oxidative DNA damage in HMCs and HEMs harboring hypomorphic MC1R allelic variants lacking detectable cAMP signaling, most likely through cAMP-independent PI3K/AKT activation. These results demonstrate occurrence of cAMP-independent protective roles of ?MSH that should be considered for the design of improved photoprotective pharmacological strategies.
Instituto de Investigación Sanitaria Acreditado
Inicio
Grupo de Investigación
Miembros
Proyectos
Colaboraciones
Servicios
Recursos formativos
Producción Científica
Publicaciones
Tesis
Novedades
Noticias
Eventos
Convocatorias
Agenda