Antibodies against p21

Human oral squamous cancer cell lines, HSC2 and HSC3, were obtained from Hokkaido University (Hokkaido, Japan). HSC2 and HSC3 cells were maintained in Dulbecco’s modified Eagle’s medium (DMEM) (Thermo Scientific, USA) containing 10% heat-inactivated fetal bovine serum, and penicillin-streptomycin (100 U/ml)(Thermo Scientific) at 37°C with 5% CO₂ in a humidified atmosphere. DPT was purchased from Sigma-Aldrich (USA) and SC79 was purchased from MedChemExpress. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) was purchased from Duchefa (Netherlands). Antibodies specific to PARP, p-PI3K, p-AKT, AKT, p-p38 MAPK, cleaved caspase-3, Bax, Bak, Bik, and Bim were purchased from Cell Signaling Technology (USA). Antibodies against p21, Mcl-1, GAPDH, and β-actin were obtained from Santa Cruz Biotechnology (USA). Antibodies against PI3K and p38 MAPK were obtained from ABclonal Biotech Co. Ltd. (USA).

Baicalin was purchased from Sigma with a purity >99.0%, which was dissolved in dimethyl sulfoxide (DMSO). Antibodies against p21, p27, HIF-1α and β-actin were purchased from Santa Cruz Biotechnology Inc. (Santa Cruz, CA, USA). Rabbit polyclonal antibodies to AKT and phosphor-AKT were from Cell Signaling Technology, Inc. (Beverly, MA, USA). The bromodeoxyuridine (BrdU) proliferation assay kit was purchased from Roche (Mannheim, Germany). Enhanced chemiluminescence (ECL) reagents were from Amersham International (Amersham, UK). All other reagents were from common commercial sources.