The insulin growth factor system on mammary tumorigenesis.

GUTIERREZ A; SAMBUCO L; ALVAREZ L; COCCA C; NÚÑEZ M; CROCI M; MARTIN G; CRICCO G; RIVERA E; KLEINMAN D; BERGOC R

Pinamar Argentina

Congreso; 10th Congress-Panamerican Association for Biochemistry and Molecular Biology XLI Reunión Anual de la Sociedad Argentina de Investigación Bioquímica Biología Molecular XX Reunión anual de la Sociedad Argentina de Neuroquímica; 2005

Sociedad Argentina de Investigación Bioquímica Biología Molecular

Insulin growth factors (IGFs) are important mediators in the growth, development, differentiation and survival of normal and transformed gland mammary tissue. The aim of this study was to investigate the expression and localization of the insulin growth factor-type 1 receptor (IGF-IR) and insulin receptor (IR) during the mammary carcinogenesis induced in rats by N-Nitroso-N-methylurea (NMU). NMU was injected to 50, 80 and 110 days old rats. Samples of mammary tissue were collected at days 55, 85 and 115, and binding assay (conventional technique), immunohisto- chemical analysis (monoclonal antibody) and Western blot (monoclonal antibody) were performed. On day 55, neither IGF-IR nor IR were expressed. On day 85, low expression of both receptors were detected in NMU-rats. On day 115, a significantly higher expression of both receptors vs. normal glands were revealed. Our results suggests that both IGF-IR and IR, components of the IGF system, have an important role in the promotion/progression phase in the experimental model tested. poster