Zoledronate Inhibits Cancer Cell Proliferation

Cancer cells were seeded at a density of 3000 (HCC827) and 5000 (lung cancer-induced bone metastasis) cells per well in Costar 96 well plates (Fisher Scientific—cat 3882, Canada) with triplicate wells per tested variable in media supplemented with 10% FBS. After 24 h, fresh media with variables were added [vehicle (PBS1x) or zoledronate at concentrations 1, 3 or 10 µM (Sigma—cat SML0223, USA) in low serum-RPMI (1% FBS, 1% PS)]. Experiments were conducted for 7 days with a media change and variable replenishment on day 4. Two metabolic activity-based assays were used to assess proliferation: alamarBlue® (Thermofisher—cat DAL1025, USA) and Vybrant® MTT cell proliferation kit (Thermofisher—cat V13154, USA) as previously described [61 (link)]. For both assays, the plate was read using the Tecan Infinite M200 Pro plate reader (Tecan Trading, AG, Männedorf, Zürich, Switzerland) with the following setting: for alamar (excitation wavelength 540 nm and emission wavelength 585 nm) and MTT (absorbance wavelength of 540 nm). Raw data generated from both assays in excel sheets were after background-normalized and analyzed as ratio of zoledronate-treated values over vehicle-treaded values.