Cell Line Characterization and Treatment

All cell lines were purchased from ATCC and maintained as directed except for the 184A1 cells which were a kind gift from Dr Martha Stampfer (University of California) and maintained as previously described [45 (link)]. Cell lines were characterised by isoenzyme/cytochrome c oxidase I (COI) assay and short tandem repeat (STR) analysis by the cell bank. Full details of the HCC-EV/BR and MDA468-EV/BR cell lines are provided in [46 (link)]. 184A1-EV and -BRsh2 cells were generated by stable lentivirus transfection of the 184A1 cells with pll3.7-EV or BRsh2 respectively (a kind gift from Prof. Wicha). Infected cells were selected in the presence of 1μg/μl puromycin. For drug treatments, cells were treated with the relevant concentration of IGF2 inhibitor (Sigma, UK) or Bicalutamide (Sigma, UK) for 72hrs before cell viability was assessed by MTT (Sigma, UK).