Cell proliferation assay and colony formation assay

Cells were seeded into 96-well plates (5000 cells/well), incubated overnight and then treated with or without Tamoxifen for 1, 2, 3, 4 and 5 days. 10 μL of cell counting kit-8 (CCK-8) reagent (Yeasen, Shanghai, China) was added to each well, and plates were incubated for 4 h at 37 °C in accordance with the CCK-8 kit protocol. Optical density (OD) values were measured at 450 nm using a plate reader (Thermo Scientific Multiskan GO, Finland). For colony formation assay, a single-cell suspension was seeded into 6-well plates and grown for 4 days in the presence of 7 μM tamoxifen, fixed with 4% paraformaldehyde, and stained with crystal violet for subsequent colony counting analysis.