Fig. 1.

Experimental modulation of EP300 in cellular models. Expression of EP300 and E-cadherin was determined by immunoblot analyses. a EP300 was downregulated in breast cancer luminal MCF-7 cells by lentiviral expression of two different EP300 hairpins (MCF7-shEP300-1 and MCF7-shEP300-2). Cells expressing the empty pGIPZ vector (MCF7-shev) were used as control. b, a genetic knock-out of EP300 (HCT-KOEP300) is available in colon carcinoma HCT116 cells. This cell line is hemizygous for the EP300 locus and generates a C-terminus truncated EP300 protein [10]—note its lower molecular mass (tEP300, truncated EP300). Paclitaxel-resistant derivatives are indicated with the -TX name extension. c, d EP300 was upregulated in breast cancer basal-like CAL51 and MDA-MB-231 cells with an EP300 expression cassette in pcDNA3.1 (CAL-EP300 and MDA-EP300). In both cases, cells transfected with pcDNA3.1 were used as controls (CAL-ev and MDA-ev). Lamin B was used as a loading control. Representative pictures of three replicates are shown. Immunoblots were quantified and data are shown in the histograms as average ± SD of three blots. All statistical comparisons (*P < 0.05) versus control cells