Sphere Formation Assay with UM-HACC-2A Cells

To evaluate the ability of tumor cells to grow in suspension and form spheres, we cultured UM-HACC-2A cells (5 × 10³) in ultra-low attachment round-bottom plates (Corning^® Elplasia^® 96-well Black/Clear Round Bottom Ultra-Low Attachment—Thermo Fisher Scientific, Waltham, MA, USA) [44 (link),45 (link),46 (link)]. Cells were incubated for 3 days to allow spheres to form. Following this, we added the histone modifier drugs identified in the HTS to the plates at a final concentration of 10µM and closely monitored the spheres for 48 h. Images of the spheres were obtained and quantified using Molecular Devices ImageXpress Micro 4.