Figure 4. Zoledronic acid reduces mammosphere formation in EMT-enriched breast cancer cell models.

Mammosphere-forming efficiency (MSFE) of HMLER^shECad, MDA-MB-231, and SUM-159 cells in the absence or presence of graded concentrations of zoledronic acid was calculated after 7 days and expressed as a percentage (mean ± SD); three technical replicates per n; n = 3 biological replicates. MSFE of vehicle-alone control cells was normalized to one in each model. Re-feeding of mammospheres cultures with zoledronic acid and/or sphere medium was performed on day 4. *p<0.05.