Activation of tyrosine kinases during induction of mammary gland tumors in GR mice by ovarian hormones

• Published in: Biokhimiia (Moscow, Russia) Vol. 53; no. 4; p. 573
• Main Authors: Mitina, R L, Morozova, T M, Salganik, R I
• Format: Journal Article
• Language: Russian
• Published: Russia (Federation) 01.04.1988
• Subjects: Animals; Enzyme Activation; Estrone - pharmacology; Female; Male; Mammary Neoplasms, Experimental - enzymology; Mammary Neoplasms, Experimental - metabolism; Mammary Neoplasms, Experimental - pathology; Membrane Proteins - metabolism; Mice; Mice, Inbred Strains; Molecular Weight; Neoplasm Transplantation; Phosphorylation; Progesterone - pharmacology; Protein-Tyrosine Kinases - metabolism
• ISSN: 0320-9725

In GR mice, the induction of proliferative processes in mammary tumours with ovarian hormones (estrone and progesterone) is accompanied by the activation of phosphorylation of plasma membrane, cytosolic and nuclear proteins by endogenous protein kinases. The hormones stimulate tyrosine kinases of tumour cells whose activity is as high as 14.9-17.9% of the total phosphorylation in plasma membranes and 9.5-10.4% in cell nuclei. The ovarian hormones stimulate tyrosine kinases of tumour cells which phosphorylate proteins with Mr of 110-230 and 15 kD (plasma membranes), 170, 52 and 13 kD (cytosol) and 32 kD (nuclei) which are resistant to alkaline hydrolysis. Apart from tyrosine kinases, the ovarian hormones also stimulate serine and threonine protein kinases which seems to be due to the activation of protein kinase C and other protein kinases.