Aim To clarify the regulation role of cathepsin B( Cat B) in cell proliferation and apoptosis induced by SAHA in ER-positive breast cancer cell line MCF-7. Methods MTT was used to screen the optimal concentration and treatment time of SAHA.The expression levels of related proteins were determined by ELISA,and the morphological changes were observed through time-lapse live cell imaging acquisition. Cell viability and apoptosis assay in MCF-7 cells were assessed by Muse Cell Analyzer with SAHA and /or Cystati...