Insulin-like growth factor-I receptor expression and localization in benign and malignant rat mammary tumors.

COCCA C; RANDI A; GUTIERREZ A; NÚÑEZ M; CROCI M; MARTÍN G; CRICCO G; MEDINA V; MOHAMAD N; RIVERA E; KLEIMAN D; BERGOC R

ANTICANCER RESEARCH

Birkhauser Verlag

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

0250-7005

The aim of this study was to investigate theexpression and localization of the insulin growth factor type 1receptor (IGF-IR) in malignant and benign mammary tumorsinduced in rats by N-nitroso-N-methylurea (NMU) and itscorrelation with histopathology and hormone dependence. Also,protein tyrosine kinase activities (PTKs) were analyzed in orderto study the activation of the intracellular cascade. The resultsshowed that IGF-IR is present in NMU tumors (analyzed bybinding assay and Western blot), that a variable content isexpressed in tumors that continued growing post-ovariectomy(OVX) of rats, and that it is undetectable in tumors thatregressed post-OVX. IGF-IR was principally localized (byimmunohistochemistry) in the epithelial cells of malignanttumors and in the fibrous cells of benign ones. Also, asignificantly lower expression of both cytosolic and microsomalPTKs were found in benign tumors. Our results suggest adifferent expression and role of IGF-IR in benign andmalignant tumors.