Albumin influences the inhibitory effect exerted by celecoxib on cellular viability in WiDR and CAOV3 cancer cell lines

Abstract

6083

Background: Fetal Bovine Serum (FBS) is the most common component used in cell culture medium allowing cells a supply of nutrients for growth. FBS is a complex mix of albumins and growth factors. Nevertheless, the albumin concentration of serum can impair some cytotoxicity experiments linking it with drugs and involving a cellular response. Objetive: Our study examines the cellular viability of two different carcinoma cells lines exposed to celecoxib using 8 different media conditions containing diverse albumin concentrations. Methods: WiDR colon and OVCAR ovarian carcinoma cell lines were obtained from ATCC and maintained in DMEM medium containing 10% FBS, 2mM L-Glutamine, antibiotic-antimycotic solution, and MEM vitamin solution and placed in a humidified atmosphere containing 5% CO₂ at 37°C. After each cell line reached a confluency of 70-80%, 5000 cells/well were seeded on flat bottomed 96 well plates in 100 μl media/per well for 24 hrs in 8 different conditions: DMEM+10% FBS, DMEM+FBS+ITS 100X (insulin-transferrin-selenium), DMEM+ITS 100X, DMEM+Albumin 1% (AlbuMax I (Lipid-Rich Bovine Serum Albumin), DMEM+Albumin 2%, DMEM+Albumin 3%, DMEM+Albumin 4% and DMEM+BSA 10%. A stock solution of COX-2 inhibitor, Celecoxib (Celebrex ®), dissolved in ethanol was prepared at various concentrations (0, 10, 30, 50, 70 and 100 μM) for each different media condition. Each cell line was exposed to celecoxib for 72 Hrs. Cellular proliferation was performed using a Tetrazolium Conversion Assay (Promega Corporation) according to manufacturer’s instructions. Results: A significant decrease in the cell viability compared with controls was observed in both carcinoma cells lines exposed to celecoxib at 50, 70 and 100 μM for 72 hrs with DMEM+FBS10%. When the cells lines were exposed to different concentrations of Celecoxib in DMEM media containing 1, 2, 3, 4 and 10% albumin, the inhibitory effect of celecoxib observed before with DMEM+FBS 10% was absent. In contrast, when the cell lines were exposed to DMEM+ITS without serum, the cells were more sensitive to an inhibitory effect exerted by celecoxib in cellular viability. Conclusions: Our data shows that Celecoxib affects cellular viability in vitro in a dose-dependent manner in two different carcinoma cell lines. However, when we increased the concentration of albumin in culture media, the inhibitory effect in cellular viability exerted by Celecoxib was lost. This observation supports the interaction between Celecoxib and albumin that has been described in in vivo studies indicating that celecoxib is highly protein bound. Our results indicate that the inhibitory effect of celecoxib in cellular viability may be affected by the concentration of albumin in culture media; hence, these data may have implications when cytotoxicity studies are planned.