A, MCF7/MTA1 cells transfected with GFP vector or GFP-BRCA1 was assessed by immunofluorescence staining for GFP (green), α-tubulin (Magenta), pericentrin (red) and DAPI stained DNA (blue). MTA1 over expression led to an increase in the number of centrosomes; this phenotype was compromised, however, by the reintroduction of BRCA1, thus implicating BRCA1 repression in the centrosome amplification observed in MTA1-overexpressing cells. B, Bar chart showing quantified results.