The insulin receptor on normal and diabetic mammary rat tumorigenesis. Resumen publicado en Biocell: 32 (Suppl),65. CBP09. 2008.

GUTIÉRREZ A, SAMBUCO L, CROCI M, MARTÍN G, NÚÑEZ M, RIVERA E, RANDI A, BERGOC R

Villa Carlos Paz, Córdoba, Argentina.

Congreso; XLIV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2008

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Several studies report that insulin hormone and its receptor (IR)may be associated to an increased risk for a number ofmalignancies. We demonstrated that N-Nitroso-N-methylurea(NMU) induced mammary adenocarcinomas in normal rats andmore differentiated lesions in diabetic ones. The aim of the presentstudy was to investigate the expression and localization of IR inmammary tissue during the carcinogenic process as well inmammary tumors, in both diabetic and non diabetic rats.Carcinomas were induced in animals by NMU injection to 50, 80and 110 days old rats. Diabetes was induced by streptozotocinadministration at 36 h of animals life. Breast tissue specimens wereprocessed at 60, 90 and 120 days, as well as samples fromdeveloped tumors. Immunohistochemical analysis and Westernblot were performed. Receptor expression was markedly increasedin NMU-mammary glands (+++) vs normal ones (-/+). In diabeticrats IR expression was similar to normal glands (+), whilst indiabetic NMU-injected animals the expression was scarce (+/++).All tumors developed in non-diabetic rats presented highundifferentiated grade, cribriform pattern and marked IRexpression (++++); tumors developed in diabetic animals showeddifferentiated pattern, low malignant grade and slight IRexpression (+/++). Results suggest a correlation between IRexpression and degree of differentiation on mammary tumors.