A2780cis

The human epithelial serous ovarian cancer cell lines A2780 (cisplatin-sensitive) and A2780cis (cisplatin-resistant) were purchased from the European Collection of Cell Cultures (ECACC, UK) and cultured in a humidified atmosphere at 37 °C, 5 % CO₂. They were maintained in RPMI 1640 medium (Sigma, UK) supplemented with 10 % foetal bovine serum (FBS, Lonza, UK), 1 % penicillin/streptomycin mixture (Lonza, UK) and 2 mM Glutamax (Gibco, Biosciences, Ireland). In addition, A2780cis were cultured in 1 μM cisplatin (Hospira, UK) every second passage in accordance with the ECACC guidelines. Cells were regularly checked for signs of bacterial, fungal or mycoplasmal contamination.

The human epithelial ovarian cancer cells A2780 and A2780CIS were purchased from the European Collection of Cell Cultures (ECACC). A2780CP20 cells were kindly gifted by Dr. Anil K. Sood (MD Anderson Cancer Center, Houston, TX) (16 (link)). High-grade serous ovarian cancer (HGSOC) cells OV-90 and OVCAR3 were purchased from ATCC (Chicago, IL). Cisplatin-resistant OV90CIS and OVCAR3CIS were generated by sequential addition of increasing concentrations of cisplatin to the parental cell lines (17 ). The chemosensitivity of the generated cell lines was assessed by dose-response experiments with cisplatin. The IC50 of this panel of cells has been reported (17 ). A2780, A2780CP20, and A2780CIS cells were maintained in RPMI-1640 (HyClone, Logan, UT), and OVCAR3 and OVCAR3CIS were maintained in RPMI-1640 supplemented with 0.01 mg/mL insulin (Sigma-Aldrich, St Louis, MO). OV-90 and OV-90CIS cells were cultivated on a 1:1 (v/v) ratio of M199 media and MCDB 105 media. All media was supplemented with 10% FBS and 1% antibiotics. For experiments, all cells were kept at 37°C and 5% CO₂ atmosphere. Experiments were performed at 60–80% confluency.

The human endometrioid ovarian carcinoma cell line A2780 and its platinum-resistant variant A2780cis were obtained from European Collection of Cell Cultures. The A2780 cell line was cultured in RPMI1640 (ThermoFisher Scientific, Waltham, MA, USA) with 10% fetal bovine serum. The A2780cis cells were continuously cultivated in presence of cisplatin at a concentration of 10 mg/mL. All cells were incubated in a humidified incubator at 37 °C and 5% CO₂. Calcitriol was purchased from Cayman Chemical Company (Michigan, USA). Cells were treated with 0.1% Dimethyl sulfoxide (DMSO) as vehicle or Calcitriol at indicated concentration in RPMI1640 with fetal bovine serum (FBS) (or with cisplatin).