Hec 1a cell line

ECSCs were cultured in serum-free medium, DMEM/F12 (1:1) (Corning, New York, USA) containing 2% B27 Supplement (Gibco, New York, USA), 20 ng/mL EGF (PeproTech, New Jersey, USA), 20 ng/mL bFGF (PeproTech), and 1% penicillin–streptomycin (Invitrogen, Carlsbad, California, USA). Ishikawa cell line (Shanghai huiying, Shanghai, China) and HEC-1A cell line (Genechem, Shanghai, China) were cultured in α-MEM medium (Bioind, Kibbutz Beit Haemek, Israel) and McCoy's 5A medium (Bioind), respectively. The medium contained 10% fetal bovine serum (FBS) (Bioind) and 1% penicillin–streptomycin (Invitrogen). HEK293T cells were cultured in DMEM/high-glucose medium (Corning). The medium contained 10% FBS (Bioind) and 1% penicillin–streptomycin (Invitrogen). All cells were cultured in a humidified incubator at 37° C with 5% CO₂.

Ishikawa cell line (Shanghai Huiying, Shanghai, China) and HEC-1A cell line (Genechem, Shanghai, China) were cultured in α-MEM medium (Bioind, Kibbutz Beit Haemek, Israel) and McCoy’s 5A medium (Bioind), respectively. The medium contained 10% fetal bovine serum (FBS) (Bioind) and 1% penicillin–streptomycin (Invitrogen). All cells were cultured in a humidified incubator at 37 °C with 5% CO₂. BTG1’s overexpression plasmid and knockdown plasmid were purchased from GeneChem (Shanghai, China), and both were transfected with jetPRIME^® in vitro DNA and siRNA Transfection Reagent (PolyPlus-transfection, France) for subsequent experiments. The related sequences can be found in Additional file 2: Table S2.