Your browser has javascript turned off or blocked. This will lead to some parts of our website to not work properly or at all. Turn on javascript for best performance.

The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Default user image.

Maria Eugenia Cordero Concha

Biomedical analyst

Default user image.

Aberrant activation of the PI3K/mTOR pathway promotes resistance to sorafenib in AML

Author

  • O Lindblad
  • E Cordero
  • A Puissant
  • L. Macaulay
  • A Ramos
  • N N Kabir
  • J Sun
  • J Vallon-Christersson
  • K Haraldsson
  • M T Hemann
  • Åke Borg
  • F Levander
  • K Stegmaier
  • K Pietras
  • L Rönnstrand
  • J U Kazi

Summary, in English

Therapy directed against oncogenic FLT3 has been shown to induce response in patients with acute myeloid leukemia (AML), but these responses are almost always transient. To address the mechanism of FLT3 inhibitor resistance, we generated two resistant AML cell lines by sustained treatment with the FLT3 inhibitor sorafenib. Parental cell lines carry the FLT3-ITD (tandem duplication) mutation and are highly responsive to FLT3 inhibitors, whereas resistant cell lines display resistance to multiple FLT3 inhibitors. Sanger sequencing and protein mass-spectrometry did not identify any acquired mutations in FLT3 in the resistant cells. Moreover, sorafenib treatment effectively blocked FLT3 activation in resistant cells, whereas it was unable to block colony formation or cell survival, suggesting that the resistant cells are no longer FLT3 dependent. Gene expression analysis of sensitive and resistant cell lines, as well as of blasts from patients with sorafenib-resistant AML, suggested an enrichment of the PI3K/mTOR pathway in the resistant phenotype, which was further supported by next-generation sequencing and phospho-specific-antibody array analysis. Furthermore, a selective PI3K/mTOR inhibitor, gedatolisib, efficiently blocked proliferation, colony and tumor formation, and induced apoptosis in resistant cell lines. Gedatolisib significantly extended survival of mice in a sorafenib-resistant AML patient-derived xenograft model. Taken together, our data suggest that aberrant activation of the PI3K/mTOR pathway in FLT3-ITD-dependent AML results in resistance to drugs targeting FLT3.Oncogene advance online publication, 21 March 2016; doi:10.1038/onc.2016.41.

Department/s

  • Division of Translational Cancer Research
  • Stem Cell Center
  • Section V
  • BioCARE: Biomarkers in Cancer Medicine improving Health Care, Education and Innovation
  • Department of Immunotechnology

Publishing year

2016-09-29

Language

English

Pages

5119-5131

Publication/Series

Oncogene

Volume

35

Issue

39

Document type

Journal article

Publisher

Nature Publishing Group

Topic

  • Cell and Molecular Biology

Status

Published

ISBN/ISSN/Other

  • ISSN: 1476-5594