Knockdown of WT1 expression in MCF7TAM cells using the shRNA method down-regulates expression levels of EGFR, HER2 and ER-α, and has no effect on TAM resistance. (A). Western blot analysis of the lysates from the parental MCF7 cells (MCF7), MCF7TAM cells transfected with the empty expression vector (MCF7TAM/V) and clonal cell lines from MCF7TAM cells transfected with WT1 shRNA expression vectors (MCF7TAM/WTSh-1, -5 and -6). (B). Cells were seeded at 1×104 cells per 60mm dishes, incubated in medium containing ethanol (Vehicle), or indicated concentrations of TAM and counted in 12 days. Column: means of three independent experiments; bars, SE.