Fig. 5

PELP1 knockdown reduces SETDB1 mediated clonogenic potential and therapy resistance. A Validation of ZR75 and MCF7 model cells expressing SETDB1 with/without PELP1-KD by Western blotting. B Characterization of the effect of PELP1-KD in cells expressing SETDB1 was analyzed by colony formation assays in 10% serum conditions. Quantitation of colonies is presented. C, D ZR75 and MCF7 model cells stably expressing with indicated constructs were cultured in E2 deprived 5% DCC medium, treated with E2 (10^–8 M) or E2 with tamoxifen (2.5 μM) for 5 days and then cells were cultured with regular growth medium for 7 subsequent days. The image and number of colonies for each group was presented. E ZR75 model cells stably expressing SETDB1, PELP1 shRNA or PELP1cyto were cultured in 10% serum. The ability of PELP1cyto to rescue resistance phenotype was analyzed by colony formation assay. F MCF7 cells expressing SETDB1 or PELP1 shRNA were grown in 3D culture condition for 14 days in the presence of E2 (10^–8 M) with or without tamoxifen (10 μM). Representative pictures were presented. Colony sizes were measured with ImageJ software and analyzed using relative ratio to control cells. Scale bar represents 100 μm, n = 6. Data was represented as mean ± SEM. **p < 0.01; ***p < 0.001; ****p < 0.0001