Kinase Assay: PI3K biochemical assay (ATP depletion assay); BKM120 is dissolved in DMSO and directly distributed into a black 384-well plate at 1.25 μL per well. To start the reaction, 25 μL of 10 nM PI3 kinase and 5 μg/mL 1-α-phosphatidylinositol (PI) in assay buffer (10 mM Tris pH 7.5, 5 mM MgCl2, 20 mM NaCl, 1 mM DTT and 0.05% CHAPS) are added into each well followed by 25 μL of 2 μM ATP in assay buffer. The reaction is performed until approx 50% of the ATP is depleted and then stopped by the addition of 25 μL of KinaseGlo solution. The stopped reaction is incubated for 5 minutes and the remaining ATP is then detected via luminescence.

Cell Assay: A2780 cells are cultured in DMEM supplemented with 10% FBS, L-glutamine, sodium pyruvate, and antibiotics. Cells are plated in the same medium at a density of 103 cells per well, 100 μL per well into black-walled-clear-bottom plates and incubated for 3-5 hours. BKM120 supplied in DMSO (20 mM) is diluted. The diluted BKM120 solution (2 μL), is then added to cell medium (500 μL) cell medium (concentration from 0-6.6 μM). Equal volumes of this solution (100 μL) are added to the cells in 96 well plates and incubated at 37 °C for 3 days and developed using Cell Titer Glo. Inhibition of cell proliferation is determined by luminescence read using Trilux.

BKM120 is not sensitive to Class III and Class IV PI3K's or PI4K. NVP-BKM120 shows great antiproliferation activity to PI3K deregulated cell lines including A2780, U87MG, MCF7 and DU145 with GI50 of 0.1-0.7 NM. BKM120 induces multiple myeloma cells (ARP1, ARK, MM.1S, MM1.R and U266) apoptosis, which results in increased G1-phase cells and decreased S-phase cells. BKM120 induced CD138+ primary MM cell apoptosis and has significant lower cytotoxicity toward CD138– stromal cells. BKM120 exposure could cause upregulation of BimS and downregulation of XIAP. BKM120 demonstrates antiproliferative activity in human gastric cancer cell lines by decreasing mTOR downstream signaling. BKM120 could increase either p-ERK or p-STAT3 in KRAS mutant gastric cancer cells. Combination with STAT3 blockade, BKM120 shows a synergism in cells harboring mutated KRAS by inducing apoptosis, but not in KRAS wild-type cells. A recent study shows that BKM120 shows differential forms of cell death on the basis of p53 status of the cells with p53 wild-type cells undergoing apoptotic cell death and p53 mutant/deleted cells having a mitotic catastrophe cell death. BKM120 mediates mitotic catastrophe mainly through Aurora B kinase.

[1] Burger MT, et al. ACS Med Chem Lett, 2011, 2 (10), 774–779.; [2] Zheng Y, et al. J Mol Med (Berl), 2011 Dec 30.