Epigenetic switch from untransformed to a transformed phenotype
(A) Number of mammosphere formed/1000 seeded transformed (TAM-treated for 36h; mean ± SD) ER-Src cells during 12 serial passages.
(B) Levels of Src-Y419 phosphorylation (ELISA assay; mean ± SD) in untreated, and TAM-treated (36h), and 1st, 2nd, 4th, and 8th generation mammospheres derived from TAM-treated ER-Src cells.
(C) Kinetics of cellular transformation as a function of TAM exposure. ER-Src cells were treated with 1 μM TAM for the indicated times, and then analyzed for cellular transformation (defined by morphological changes) 24, 48 and 72h post TAM treatment.
(D) Phase-contrast images and Src-Y419 phosphorylation levels (ELISA assay; mean ± SD) in ER-Src cells 36 and 120h post TAM treatment. Cells were treated with TAM for 36h and then TAM was removed from the medium.