Alisertib (MLN8237)S1133

MLN8237 shows >200-fold higher selectivity for Aurora A than the structurally related Aurora B with an IC50 of 396.5 nM, and does not have any significant activity against 205 other kinases. ^[1] MLN8237 (0.5 μM) treatment inhibits the phosphorylation of Aurora A in MM1.S and OPM1 cells, without affecting the Aurora B mediated histone H3 phosphorylation. MLN8237 significantly inhibits cell proliferation in multiple myeloma (MM) cell lines with IC50 values of 0.003-1.71 μM. MLN8237 displays more potent anti-proliferation activity against primary MM cells and MM cell lines in the presence of BM stroma cells, as well as IL-6 and IGF-1 than against MM cells alone. MLN8237 (0.5 μM) induces 2- to 6-fold increase in G2/M phase in primary MM cells and cell lines, as well as significant apoptosis and senescence, involving the up-regulation of p53, p21 and p27, as well as PARP, caspase 3, and caspase 9 cleavage. In addition, MLN8237 shows strong synergistic anti-MM effect with dexamethasone, as well as additive effect with doxorubicin and bortezomib. ^[2] MLN8237 (0.5 μM) treatment causes the inhibition of colony formation of FLO-1, OE19, and OE33 esophageal adenocarinoma cell lines, and induces a significant increase in the percentage of polyploid cells, and subsequently an increase in the percentage of cells in the sub-G1 phase, which can be further enhanced in combination with cisplatin (2.5 μM), involving the higher induction of TAp73β, PUMA, NOXA, cleaved caspase-3, and cleaved PARP as compared with a single-agent treatment. ^[3]