Angiotensin II as a factor modulating protein tyrosine kinase activity in two breast cancer lines — MCF-7 and MDA-MB-231

Abstract

Introduction: Angiotensin II (AngII), a peptide that regulates the water-electrolytic balance and blood pressure, is also known to influence cell proliferation. It can either induce cell growth, when binding to angiotensin type-I receptor, or trigger growth inhibition via angiotensin type-II receptor. AngII stimulates proliferation of some normal and tumour cell lines, e.g. pituitary, adrenal glands and breast cancer.
Material and methods: The aim of this study was to evaluate possible AngII effect on the growth of two breast cancer cell lines — hormone-dependent MCF-7 and hormone-independent MDA-MB-231. We measured tyrosine kinase activity as a potential proliferation marker. We also estimated the influence of 17b-oestradiolon AngII-induced changes.
Results: In the MDA-MB-231 line, AngII radically slowed the activity of tyrosine kinases and 17b-oestradiol only at a concentration of 10^–6 M, while it enhanced the effect of angiotensin II at a concentration of 10^–9 M. In MCF-7, Ang II had a strong inhibitory effect in the presence of oestradiol (10^–6 M). Oestradiol alone decreased the activity of examined enzymes in both cell lines. AngII receptor type 1 was found in both studied lines, but type 2 only in MDA-MB-231.
Conclusions: Our results show that AngII can modulate tyrosine kinase activity in breast tumour cell lines.
(Pol J Endocrinol 2011; 62 (2): 151–157)