Springer Nature [academic journals on nature.com], Leukemia, 4(28), p. 739-748, 2013
DOI: 10.1038/leu.2013.226
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B-precursor acute lymphoblastic leukemia (B-pre ALL) is a malignant disorder characterized by the abnormal proliferation of B-cell progenitors. The prognosis of B-pre ALL has improved in pediatric patients, but the outcome is much less successful in adults. Constitutive activation of the PI3K/Akt/mTOR network is a feature of B-pre ALL, where it strongly influences cell growth and survival. RAD001, a selective mTORC1 inhibitor, has been shown to be cytotoxic against many types of cancer, including hematological malignancies. To investigate if mTORC1 could represent a target in the therapy of B-pre ALL, we treated cell lines and adult patient primary cells with RAD001. We documented that RAD001 decreased cell viability, induced cell cycle arrest in G0/G1 phase and caused apoptosis in B-pre ALL cell lines. Autophagy was also induced, that was important for the RAD001 cytotoxic effect, as down-regulation of Beclin-1 reduced drug cytotoxicity. RAD001 strongly synergized with the novel allosteric Akt inhibitor MK-2206, in both cell lines and patient samples. Similar results were obtained with the combination CCI-779 plus GSK 690693. These findings point out that mTORC1 inhibitors, either as a single-agent or in combination with Akt inhibitors, could represent a potential therapeutic innovative strategy in B-pre ALL.Leukemia accepted article preview online, 29 July 2013. doi:10.1038/leu.2013.226.