Cell growth activity measured by MTT assay on U118 cell line treated with drug combination. (a) U118 GBM cell line was cultured with a range of various concentrations of fluvastatin or celecoxib either alone or in combination. After 48 hours, cell growth was measured by MTT assay, and the concentration of each compound that induced 50% growth inhibition (IC50) was determined. U118 cell line was sensitive to both drugs. Results represent the mean of four independent assays plus standard deviation. (b) After 48 hours, cytotoxicity was measured by MTT assay. Fluvastatin (240 μM) potentiates the action of celecoxib (100 μM) on U87-MG and U118 cells causing massive cell growth inhibition in both cell lines (99%) compared to fluvastin used alone (almost none) or celecoxib used alone (50%). Results represent the mean of four independent assays plus standard deviation.