Hela cells

HeLa cells were obtained from the China Center for Type Culture Collection (CCTCC) and maintained in Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% FBS, 100 U mL^–1 penicillin and 100 μg mL^–1 streptomycin (GIBCO) at 37 °C under 5% CO₂ atmosphere. The H₂O₂ treatment of HeLa cells was performed according to previous method.24 Briefly, the cells were grown to ∼80% confluence in 25 cm² culture flasks, washed with phosphate-buffered saline (PBS) and then treated with medium including 1000 μM H₂O₂. After incubation for 30 min in a CO₂ incubator, the medium was removed and cells were harvested. Genomic DNA was isolated according to preciously described method with using deferoxamine mesylate as the oxidation inhibitor to protect DNA from excessive oxidation during extraction processing.25 (link) DNA concentration was quantified by NanoDrop 2000c (Thermo Scientific, USA).

Human 293T cells, Jurkat-T cells and HeLa cells were obtained from the China Center for Type Culture Collection and maintained in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum (Invitrogen, Carlsbad, CA), 100 U mL^–1 penicillin, and 100 μg mL^–1 streptomycin. Cells were maintained in a humidified atmosphere with 5% CO₂ at 37 °C. As for the D₃-Met labeling, 30 mg of D₃-Met was added into the l-methionine-free DMEM-KO medium supplemented with 10% fetal bovine serum (Invitrogen, Carlsbad, CA), 100 U mL^–1 penicillin, and 100 μg mL^–1 streptomycin.
A total of 10 pairs of hepatocellular carcinoma (HCC) tissues and matched tumor-adjacent normal tissues were collected from Hubei Cancer Hospital. An approval was granted by the Hubei Cancer Hospital Ethics Committee and the study met the requirements of the declaration of Helsinki. All the experiments were performed in accordance with Hubei Cancer Hospital Ethics Committee's guidelines and regulations.

HeLa cells were obtained from China Center for Type Culture Collection (CCTCC) and maintained at 37°C in a saturating humidity atmosphere containing 5% CO₂. HeLa cells were cultured in DMEM medium (Gibco; C11995500BT) supplemented with 1% penicillin/streptomycin (Gibco; 15140122), and 10% fetal bovine serum (FBS) (Gibco; 26140079).

Human cervical cancer HeLa cells were purchased from the Cell Bank of the Chinese Academy of Sciences, Shanghai, P.R. China. Cells were cultured in DMEM (Thermo Fisher) supplemented with 10% fetal bovine serum (Thermo Fisher) in a 37°C humidified atmosphere of 5% CO₂. Cells were transfected with scramble miR mimic (miR-NC), miR-92a mimic, NC inhibitor, and miR-92a inhibitor, or cotransfected with miR-92a mimic and pcDNA3.1-p21 expression plasmid, using Lipofectamine 2000 (Thermo Fisher) according to the manufacturer’s instruction.

Human embryonic kidney cells (HEK293), human pancreatic duct epithelial cells (HEPD6-C7), and Hela cells were purchased from the Cell Bank of the Chinese Academy of Sciences (Shanghai, China), Otwo Biotech Inc. (Shenzhen, China) and the American Type Culture Collection (U.S.), respectively. Cells were cultured in high-glucose Dulbecco modified Eagle's medium (Gibco, #11965092) or Roswell Park Memorial Institute (RPMI) 1640 Medium (Gibco, #C11875500BT) with 10% fetal bovine serum (Yeasen, #40130ES76) and in a 37°C humid incubator with 5% CO₂.