Triple Akt inhibition as a new therapeutic strategy in T-cell acute lymphoblastic leukemia

// Alice Cani 1, * , Carolina Simioni 1, * , Alberto M. Martelli 2 , Giorgio Zauli 3 , Giovanna Tabellini 4 , Simona Ultimo 1 , James A. McCubrey 5 , Silvano Capitani 1, 6 , Luca M. Neri 1 1 Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy 2 Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy 3 Institute for Maternal and Child Health, IRCCS “Burlo Garofolo”, Trieste, Italy 4 Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy 5 Department of Microbiology & Immunology, Brody School of Medicine, East Carolina University, Greenville, NC, USA 6 LTTA Center, University of Ferrara, Ferrara, Italy * These authors have contributed equally to this work Correspondence to: Luca M. Neri, e-mail: luca.neri@unife.it Silvano Capitani, e-mail: silvano.capitani@unife.it Keywords: T-acute lymphoblastic leukemia, Akt, Perifosine, GSK690693, MK-2206 Received: December 22, 2014      Accepted: January 29, 2015      Published: March 02, 2015 ABSTRACT T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplastic disorder in which chemotherapy resistance and refractory relapses occur, with a poorer prognostic outcome. Constitutively active PI3K/Akt/mTOR pathway is a common feature of T-ALL upregulating cell proliferation, survival and drug resistance. This pathway is currently under clinical trials with small molecules inhibitors (SMI). To verify whether a multi-inhibition treatment against Akt protein could enhance the efficacy of individual drug administration and overcome drug resistance as well as to obtain a decrease in single drug concentration, we tested on T-ALL cell lines the effects of combined treatments with three Akt inhibitors with different mode of action, GSK690693, MK-2206 and Perifosine. In cells with hyperactivated Akt, combined administration of the drugs displayed a significant synergistic and cytotoxic effect and affected PI3K/Akt/mTOR pathway at much lower concentration than single drug use. Highest synergistic effect for full inhibition of Akt was also related to the timing of every drug administration. Furthermore the triple treatment had greater efficacy in inducing cell cycle arrest in G 0 /G 1 phase and both apoptosis and autophagy. Targeting Akt as a key protein of PI3K/Akt/mTOR pathway with multiple drugs might represent a new and promising pharmacological strategy for treatment of T-ALL patients.