Figure 1 : PCI-24781 is a more potent inhibitor of cell viability than other HDAC inhibitors and synergizes with bortezomib.

(a) IC50 values of HDAC Inhibitors (PCI-24781, SAHA, valproic acid and sodium butyrate) were established in four NB cell lines.Cells were treated with increasing
drug concentrations for 48 hrs followed by cell viability assay.
(b) IC50 value of bortezomib was established in four NB cell lines. Cell lines were treated with Bortezomib for 48 hrs, with increasing concentrations followed by
cell viability assay.
(c) Isobologram showing that the combination of PCI-24781 plus bortezomib is synergistic for the LA1-55n cell line. Points express mean survival after treatment
with one or both drugs. Survival is expressed by the points’ color, ranging from 100% survival (red) through 50% (black) to 0% (green). Contours represent the
predictions obtained by fitting the model to data. Contour lines are colored according to percent survival, the curvature reflects synergism.

Saulnier Sholler et al.Journal of Cancer Therapeutics and Research  2013 2:21DOI : 10.7243/2049-7962-2-21