Recent findings have highlighted that constitutively active phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling is a common feature of T-cell acute lymphoblastic leukemia (T-ALL), where it upregulates cell proliferation, survival, and drug resistance. These observations lend compelling weight to the application of PI3K/Akt/mTOR inhibitors in the therapy of T-ALL. Here, we have analyzed the therapeutic potential of the novel dual PI3K/mTOR inhibitor NVP-BEZ235, an orally bioavailable imidazoquinoline derivative, which has entered clinical trials for solid tumors, on both T-ALL cell lines and patient samples. NVP-BEZ235 was cytotoxic to a panel of T-ALL cell lines as determined by MTT assays. NVP-BEZ235 treatment resulted in cell cycle arrest and apoptosis. Western blots showed a dose- and time-dependent dephosphorylation of Akt and mTORC1 downstream targets in response to NVP-BEZ235. Remarkably, NVP-BEZ235 targeted the side population of both T-ALL cell lines and patient lymphoblasts, which might correspond to leukemia-initiating cells, and synergized with chemotherapeutic agents (cyclophosphamide, cytarabine, dexamethasone) currently used for treating T-ALL patients. NVP-BEZ235 reduced chemoresistance to vincristine induced in Jurkat cells by coculturing with MS-5 stromal cells, which mimic the bone marrow microenvironment. NVP-BEZ235 was cytotoxic to T-ALL patient lymphoblasts displaying pathway activation, where the drug dephosphorylated eukaryotic initiation factor 4E-binding protein 1, at variance with rapamycin. Taken together, our findings indicate that longitudinal inhibition at two nodes of the PI3K/Akt/mTOR network with NVP-BEZ235, either alone or in combination with chemotherapeutic drugs, may be an efficient treatment of those T-ALLs that have aberrant upregulation of this signaling pathway for their proliferation and survival.
Activity of the novel dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor NVP-BEZ235 against T-cell acute lymphoblastic leukemia.
F. Chiarini,C. Grimaldi,F. Ricci,P. Tazzari,C. Evangelisti,A. Ognibene,M. Battistelli,E. Falcieri,F. Melchionda,A. Pession,Pasquale Paolo Pagliaro,J. McCubrey,A. Martelli
Published 2010 in Cancer Research
ABSTRACT
PUBLICATION RECORD
- Publication year
2010
- Venue
Cancer Research
- Publication date
2010-10-15
- Fields of study
Biology, Medicine
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
- No claims are published for this paper.
CONCEPTS
- No concepts are published for this paper.
REFERENCES
Showing 1-51 of 51 references · Page 1 of 1