Chidamide

The HMCLs ARP-1 and U266 were generously provided by Dr. Qing Yi (Center for Hematologic Malignancy, Research Institute, Houston Methodist, Houston, TX, USA), and RPMI-8226 and MM1.S were purchased from the National Collection of Authenticated Cell Cultures (Beijing, China). All cell lines were cultured in RPMI-1640 medium containing 10% fetal bovine serum (FBS, Biological Industries, Israel) at 37 °C under 5% CO₂ atmosphere.
With the approval of the Ethics Committee of the First Affiliated Hospital of Zhejiang University School of Medicine and informed consents obtained from MM patients, we fetched bone marrow samples for the experimental study only. Primary MM cells were sorted by CD138 microbeads(STEM CELL Technologies, Canada), and then cultured in RPMI-1640 medium containing 20% FBS at 37 °C under 5% CO₂ atmosphere.
Chidamide and venetoclax were purchased from Med Chem Express (New Jersey, USA).

Chidamide was purchased from Med Chem Express (USA), dissolved in Dimethyl sulfoxide (DMSO) at the recommended concentration according to the instructions, and stored at − 80 °C. For vitro experiments, Chidamide was administered to cells at the indicated concentration, and the cells were centrifuged and replaced with fresh medium containing the corresponding concentrations of Chidamide every 3 days, while the control group was treated with DMSO at an equal volume. For tumor/T cells pretreatment, Chidamide was administered to cells at a indicated concentration, DMSO vehicle control was administered to control-treated cells at an equal volume. Prior to co-culture, Chidamide- and DMSO- treated cells were washed three times in sterile PBS. For all in vivo experiments, Chidamide was diluted in DMSO, PEG300, Tween80 and saline in turn and orally administered at 3 mg/kg (30 µg/20 g mouse). For control-treated groups, an equal volume of DMSO was diluted and administered in the same manner.