gsk-1070916 and Precursor-T-Cell-Lymphoblastic-Leukemia-Lymphoma

Polo-like kinases (PLKs) and Aurora kinases (AKs) act as key cell cycle regulators in healthy human cells. In cancer, these protein kinases are often overexpressed and dysregulated, thus contributing to uncontrolled cell proliferation and growth. T-cell acute lymphoblastic leukemia (T-ALL) is a heterogeneous malignancy arising in the thymus from T-cell progenitors. Primary chemoresistant and relapsed T-ALL patients have yet a poor outcome, therefore novel therapies, targeting signaling pathways important for leukemic cell proliferation, are required. Here, we demonstrate the potential therapeutic effects of BI6727, MK-5108, and GSK1070916, three selective inhibitors of PLK1, AK-A, and AK-B/C, respectively, in a panel of T-ALL cell lines and primary cells from T-ALL patients. The drugs were both cytostatic and cytotoxic to T-ALL cells by inducing G2/M-phase arrest and apoptosis. The drugs retained part of their pro-apoptotic activity in the presence of MS-5 bone marrow stromal cells. Moreover, we document for the first time that BI6727 perturbed both the PI3K/Akt/mTORC2 and the MEK/ERK/mTORC1 signaling pathways, and that a combination of BI6727 with specific inhibitors of the aforementioned pathways (MK-2206, CCI-779) displayed significantly synergistic cytotoxic effects. Taken together, our findings indicate that PLK1 and AK inhibitors display the potential for being employed in innovative therapeutic strategies for improving T-ALL patient outcome.

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Aurora Kinase A; Aurora Kinase B; Aza Compounds; Cell Cycle Proteins; Cell Proliferation; Cell Survival; Coculture Techniques; Cyclohexanecarboxylic Acids; Dose-Response Relationship, Drug; Drug Design; Drug Synergism; G2 Phase Cell Cycle Checkpoints; Humans; Indoles; Jurkat Cells; Mice; Molecular Targeted Therapy; Polo-Like Kinase 1; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Signal Transduction; Thiazoles; Tumor Cells, Cultured