TP53 and breast adenocarcinoma: In this study, we used cell lines derived from the human breast adenocarcinoma MCF-7 containing either wild type (wt)-p53 or a dominant-negative variant of the p53 gene (previously shown to be resistant to microtubule-targeted drugs, Galmarini et al, 2001), as a model to investigate the possible relation between p53 expression, dynamics and composition of microtubules and drug resistance.