Loss of ARID1A expression sensitizes cancer cells to PI3K- and AKT-inhibition

Oncotarget. 2014 Jul 30;5(14):5295-303. doi: 10.18632/oncotarget.2092.

Abstract

ARID1A mutations are observed in various tumors, including ovarian clear cell (OCCC) and endometrioid carcinomas, endometrial, and breast carcinomas. They commonly result in loss of ARID1A-protein expression and frequently co-occur with PI3K/AKT-pathway activating mechanisms. The aim of this study was to test the hypothesis as to whether PI3K/AKT-pathway activation is a critical mechanism in ARID1A-mutated tumors and if consequently ARID1A-deficient tumors show increased sensitivity to treatment with PI3K- and AKT-inhibitors. Upon ARID1A knockdown, MCF7 breast cancer cells and primary MRC5 cells exhibited a significantly increased sensitivity towards the AKT-inhibitors MK-2206 and perifosine, as well as the PI3K-inhibitor buparlisib. Knockdown of ARID1A in MCF7 led to an increase of pAKT-Ser473. AKT-inhibition with MK-2206 led to increased apoptosis and to a decrease of pS6K in ARID1A-depleted MCF7 cells but not in the controls. In five OCCC cell lines ARID1A-deficiency correlated with increased pAKT-Ser473 levels and with sensitivity towards treatment with the AKT-inhibitor MK-2206. In conclusion, ARID1A-deficient cancer cells demonstrate an increased sensitivity to treatment with small molecule inhibitors of the PI3K/AKT-pathway. These findings suggest a specific requirement of the PI3K/AKT pathway in ARID1A-deficient tumors and reveal a synthetic lethal interaction between loss of ARID1A expression and inhibition of the PI3K/AKT pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminopyridines / pharmacology
  • Apoptosis / drug effects
  • Apoptosis / physiology
  • Breast Neoplasms / enzymology
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Breast Neoplasms / therapy
  • DNA-Binding Proteins
  • Female
  • Gene Knockdown Techniques
  • Heterocyclic Compounds, 3-Ring / pharmacology
  • Humans
  • MCF-7 Cells
  • Morpholines / pharmacology
  • Nuclear Proteins / biosynthesis
  • Nuclear Proteins / deficiency*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoinositide-3 Kinase Inhibitors*
  • Phosphorylation
  • Phosphorylcholine / analogs & derivatives
  • Phosphorylcholine / pharmacology
  • Protein Kinase Inhibitors / pharmacology*
  • Proto-Oncogene Proteins c-akt / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism
  • RNA, Small Interfering / administration & dosage
  • RNA, Small Interfering / genetics
  • Ribosomal Protein S6 Kinases, 70-kDa / metabolism
  • Signal Transduction
  • Transcription Factors / biosynthesis
  • Transcription Factors / deficiency*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transfection

Substances

  • ARID1A protein, human
  • Aminopyridines
  • DNA-Binding Proteins
  • Heterocyclic Compounds, 3-Ring
  • MK 2206
  • Morpholines
  • NVP-BKM120
  • Nuclear Proteins
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Kinase Inhibitors
  • RNA, Small Interfering
  • Transcription Factors
  • Phosphorylcholine
  • perifosine
  • Proto-Oncogene Proteins c-akt
  • Ribosomal Protein S6 Kinases, 70-kDa