Hela cells

HeLa cells, HT29 cells, HCT116 cells, and CT26 cells were obtained from Procell Life Science & Technology Co. Ltd. (Wuhan, China). HeLa cells were cultured in Dulbecco’s modified Eagle’s medium (DMEM) (Procell) with 10% fetal bovine serum (FBS; Gibco) and 1% penicillin-streptomycin (Gibco). HT29 and HCT116 cells were cultured in McCoy’s 5A medium (Procell) with 10% FBS (Gibco) and 1% penicillin-streptomycin (Gibco). CT26 cells were cultured in RPMI 1640 medium (Procell) with 10% FBS (Gibco) and 1% penicillin-streptomycin (Gibco). All the cells were incubated at 37°C with 5% CO₂ for culture and passage unless otherwise stated. As for hypoxic condition, HeLa cells were cultured in a hypoxic incubator at 37°C with 1% O₂ and 5% CO₂.

DNAs utilized in this study were synthesized and HPLC purified by Sangon Biotechnology Co., Ltd. (Shanghai, China). The DNA sequences are listed in Table S1.† The stock solution of each DNA (100 μM) was prepared with TE buffer containing 10 mM Tris–HCl, 1 mM EDTA, and 12.5 mM MgCl₂ (pH 7.4). The 40% acrylamide mix solution, ammonium persulfate (APS), 1,2-bis(dimethylamino)- ethane (TEMED), and DNA ladder were acquired from Sangon Biotechnology Co., Ltd. (Shanghai, China). All the chemicals were of analytical grade and utilized as received without further purification. All oligonucleotides were purchased from Sangon Biotechnology Co., Ltd. (Shanghai, China). All sequencing experiments were performed at Sangon Biotechnology Co., Ltd. (Shanghai, China). DFHBI-1 T (MedChemExpress) and BI were synthesized by our laboratory, SDS-PAGE gel preparation kit, DAPI, and agarose were obtained from Beyotime (Shanghai, China). The HeLa cells (human cervical carcinoma cell line), and CHO cells (Chinese Hamster Ovary) were purchased from Procell, Inc.