Dueling for dual inhibition: Means to enhance effectiveness of PI3K/Akt/mTOR inhibitors in AML

Blood Rev. 2018 May;32(3):235-248. doi: 10.1016/j.blre.2017.11.006. Epub 2017 Dec 2.

Abstract

The phosphatidylinositol 3-kinase/protein kinase B (Akt)/mechanistic target of rapamycin (PI3K/Akt/mTOR) pathway is amplified in 60-80% of patients with acute myelogenous leukemia (AML). Since this complex pathway is crucial to cell functions such as growth, proliferation, and survival, inhibition of this pathway would be postulated to inhibit leukemia initiation and propagation. Inhibition of the mTORC1 pathway has met with limited success in AML due to multiple resistance mechanisms including direct insensitivity of the mTORC1 complex, feedback activation of the PI3k/Akt signaling network, insulin growth factor-1 (IGF-1) activation of PI3K, and others. This review explores the role of mTOR inhibition in AML, mechanisms of resistance, and means to improve outcomes through use of dual mTORC1/2 inhibitors or dual TORC/PI3K inhibitors. How these inhibitors interface with currently available therapies in AML will require additional preclinical experiments and conduct of well-designed clinical trials.

Keywords: AML; Akt; Dual inhibitors; PI3K; Rapalogs; Resistance mechanisms; mTOR.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Antineoplastic Agents / pharmacology
  • Antineoplastic Agents / therapeutic use*
  • Biomarkers
  • Clinical Trials as Topic
  • Drug Hypersensitivity
  • Drug Resistance, Neoplasm
  • Humans
  • Leukemia, Myeloid, Acute / drug therapy*
  • Leukemia, Myeloid, Acute / metabolism
  • Mechanistic Target of Rapamycin Complex 1 / antagonists & inhibitors
  • Mechanistic Target of Rapamycin Complex 2 / antagonists & inhibitors
  • Molecular Targeted Therapy
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoinositide-3 Kinase Inhibitors*
  • Protein Kinase Inhibitors / pharmacology
  • Protein Kinase Inhibitors / therapeutic use*
  • Proto-Oncogene Proteins c-akt / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction / drug effects
  • TOR Serine-Threonine Kinases / antagonists & inhibitors*
  • TOR Serine-Threonine Kinases / metabolism
  • Treatment Outcome

Substances

  • Antineoplastic Agents
  • Biomarkers
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Kinase Inhibitors
  • Mechanistic Target of Rapamycin Complex 1
  • Mechanistic Target of Rapamycin Complex 2
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases