Expression of Integrins, Anchorage Dependent Apoptosis and Invasiveness of Multidrug Resistant Human Breast Carcinoma Cells

Abstract

The aim of the study was to investigate the role of integrins in anchorage dependent apoptosis (anoikis) and in vitro invasion of human breast cancer cell line MCF-7 and its multidrug resistant subline MCF-7Dox. Acquisition of MDR was associated with markedly decreased expression of collagen specific a2ß1 and avß3 integrins, laminin specific a3ß1 and a6ß1 receptors and dramatic up-regulation of fibronectin specific a5ß1 integrin. The MDR subline was substantially more resistant to anoikis than their wild type counterparts. Furthermore, MCF-7Dox cells secreted MMP-9 collagenase and invaded Matrigel. We demonstrate for the first time that stimulation of ß1 integrin signaling strongly sensitizes MCF-7 cells to anoikis.