Insulin-like Growth Factor -I Receptor expression and localization in benign and malignant rat mammary tumors

CLAUDIA COCCA; ANDREA RANDI; ALICIA GUTIÉRREZ; MARIEL NÚÑEZ; MÁXIMO CROCI; GABRIELA MARTÍN; GRACIELA CRICCO; VANINA MEDINA; NORA MOHAMAD; ELENA RIVERA; DIANA KLEIMAN; ROSA BERGOC

ANTICANCER RESEARCH

International Institute of Anticancer Research

Lugar: Atenas; Año: 2005 vol. 25 p. 4305 - 4312

0250-7005

The aim of this study was to investigate the expression and localization of the IGF-IR in malign and benign mammary tumors induced in rats by N-nitroso-N-methylurea (NMU) and its correlation with the histopathology and hormonedependence. Also, protein tyrosine kinase activities (PTKs) were analyzed in order to study the activation of the intracellular cascade. Results showed that IGF-IR is present in NMU-tumors (analysed by binding assay and western blot), that a variable content is expressed in tumors that continued growing post-ovariectomy (OVX) of rats, and that is undetectable in tumors that regressed post-OVX. IGF-IR was principally localized (by immunohistochemistry) in epithelial cells of malign tumors and in fibrous cells of benign ones. Also, a significant lower expression in both cytosolic and microsomal PTKs were found in benign tumors in comparison to malign ones. Our results suggest a different expression and role of the IGF-IR in benign and malign tumors.