Picking the point of inhibition: a comparative review of PI3K/AKT/mTOR pathway inhibitors

Mol Cancer Ther. 2014 May;13(5):1021-31. doi: 10.1158/1535-7163.MCT-13-0639. Epub 2014 Apr 18.

Abstract

The frequent activation of the PI3K/AKT/mTOR pathway in cancer, and its crucial role in cell growth and survival, has made it a much desired target for pharmacologic intervention. Following the regulatory approval of the rapamycin analogs everolimus and temsirolimus, recent years have seen an explosion in the number of phosphoinositide 3-kinase (PI3K) pathway inhibitors under clinical investigation. These include: ATP-competitive, dual inhibitors of class I PI3K and mTORC1/2; "pan-PI3K" inhibitors, which inhibit all four isoforms of class I PI3K (α, β, δ, γ); isoform-specific inhibitors of the various PI3K isoforms; allosteric and catalytic inhibitors of AKT; and ATP-competitive inhibitors of mTOR only (and thus mTORC1 and mTORC2). With so many agents in development, clinicians are currently faced with a wide array of clinical trials investigating a multitude of inhibitors with different mechanisms of action, being used both as single agents and in combination with other therapies. Here, we provide a review of the literature, with the aim of differentiating the genomic contexts in which these various types of inhibitors may potentially have superior activity.

Publication types

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

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Humans
  • Isoenzymes
  • Neoplasms / drug therapy
  • Neoplasms / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Kinase Inhibitors / pharmacology*
  • 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*

Substances

  • Antineoplastic Agents
  • Isoenzymes
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Kinase Inhibitors
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases