Dulbecco s modified minimal essential medium

Cancer cell lines were cultured in Dulbecco’s modified minimal essential medium (Invitrogen) supplemented with heat-inactivated 10% fetal bovine serum (Invitrogen) and antibiotics. Cells were maintained at 37°C in 5% CO₂. Anticancer drug-resistant cancer cell lines were established as described (Kim et al., 2010 (link)).

VeroE6 and A549 epithelial cell lines were cultured in Dulbecco’s modified minimal essential medium (DMEM) (Invitrogen), supplemented with 100 U/mL penicillin, 100 μg/mL streptomycin and 10% (v/v) fetal calf serum, at 37°C, 5% CO₂. To create 3% (v/v) oxygen tension, cells were cultured in a fully humidified incubator supplied with pure nitrogen gas to reduce oxygen as well as with 5% (v/v) CO₂ at 37 °C (New Brunswick CO₂ incubator Innova). SARS-CoV-2 (isolate 30–287, lineage B1), derived from a positively testing oropharyngeal swab sample of a COVID-19 patient in Alexandroupolis (Greece) [35 (link)], was propagated in VeroE6 cells. Fully confluent cells were infected and four days after inoculation, the supernatant was collected and stored at −80°C for further usage. Titration was carried-out in VeroE6 cells seeded in 96-well plates that were cultured at 37°C for 4 days, and the cytopathic effect (CPE) was monitored using inverted phase contract microscopy. TCID₅₀ was determined based on the method of Reed and Muench [36 (link)].

Cancer cell lines used in this study were cultured in Dulbecco's modified minimal essential medium (Invitrogen) supplemented with heat-inactivated 10% fetal bovine serum (Invitrogen) and antibiotics at 37°C in a humidified incubator with a mixture of 95% air and 5% CO2. Anti-cancer drug-resistant cancer cell lines (SNU387^R and Malme3M^R) were established as described [6 (link)]. Malme3M^R and SNU387^R cell lines were established by stepwise addition of celastrol. Cells surviving drug treatment (attached fraction) were obtained and used throughout this study. Malme3M^R-taxol and SNU387^R-Taxol cell lines were established by stepwise addition of taxol. Human umbilical vein endothelial cells (HUVECs) were isolated from human umbilical cord veins by collagenase treatment and used in passages 3–6. The cells were grown in M199 medium supplemented with 20% fetal bovine serum, 100 units/ml penicillin G, 100 μg/ml streptomycin, 3 ng/ml bFGF (Upstate Biotechnology, Waltham, MA), and 5 units/ml heparin at 37 °C under 5% CO2, 95% air.

Cancer cell lines used in this study were cultured in Dulbecco's modified minimal essential medium (Invitrogen) supplemented with heat-inactivated 10% fetal bovine serum (Invitrogen) and antibiotics at 37°C in a humidified incubator with a mixture of 95% air and 5% CO₂.

HSC-T6, a rat immortalized HSC line, and LX2, an immortalized human HSC line11 (link) were cultured at 37 °C in an atmosphere of 5% CO2 in Dulbecco’s modified Minimal Essential Medium (Gibco BRL Life Technologies, Rockville, MD, USA) containing 10% fetal bovine serum (FBS), 2 mM L-glutamine, and antibiotics (penicillin/streptomycin). Methods were carried out in accordance with the approved guidelines.