Cyclin E1 and RTK/RAS signaling drive CDK inhibitor resistance via activation of E2F and ETS

Oncotarget. 2015 Jan 20;6(2):696-714. doi: 10.18632/oncotarget.2673.


High-grade serous ovarian cancers (HGSOC) are genomically complex, heterogeneous cancers with a high mortality rate, due to acquired chemoresistance and lack of targeted therapy options. Cyclin-dependent kinase inhibitors (CDKi) target the retinoblastoma (RB) signaling network, and have been successfully incorporated into treatment regimens for breast and other cancers. Here, we have compared mechanisms of response and resistance to three CDKi that target either CDK4/6 or CDK2 and abrogate E2F target gene expression. We identify CCNE1 gain and RB1 loss as mechanisms of resistance to CDK4/6 inhibition, whereas receptor tyrosine kinase (RTK) and RAS signaling is associated with CDK2 inhibitor resistance. Mechanistically, we show that ETS factors are mediators of RTK/RAS signaling that cooperate with E2F in cell cycle progression. Consequently, CDK2 inhibition sensitizes cyclin E1-driven but not RAS-driven ovarian cancer cells to platinum-based chemotherapy. In summary, this study outlines a rational approach for incorporating CDKi into treatment regimens for HGSOC.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cyclin E / metabolism*
  • Cyclin-Dependent Kinases / antagonists & inhibitors
  • Drug Resistance, Neoplasm
  • E2F Transcription Factors / genetics
  • E2F Transcription Factors / metabolism
  • Female
  • Humans
  • Mice
  • Mice, Nude
  • Oncogene Proteins / metabolism*
  • Ovarian Neoplasms / drug therapy*
  • Ovarian Neoplasms / enzymology
  • Ovarian Neoplasms / genetics
  • Ovarian Neoplasms / metabolism*
  • Oxazoles / pharmacology
  • Piperazines / pharmacology
  • Protein Kinase Inhibitors / pharmacology*
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-ets / genetics
  • Proto-Oncogene Proteins c-ets / metabolism*
  • Proto-Oncogene Proteins p21(ras)
  • Pyridines / pharmacology
  • Random Allocation
  • Receptor Protein-Tyrosine Kinases / metabolism*
  • Signal Transduction / drug effects
  • Thiazoles / pharmacology
  • Transcription, Genetic
  • Xenograft Model Antitumor Assays
  • ras Proteins / metabolism*


  • CCNE1 protein, human
  • Cyclin E
  • E2F Transcription Factors
  • KRAS protein, human
  • N-(5-(((5-(1,1-dimethylethyl)-2-oxazolyl)methyl)thio)-2-thiazolyl)-4-piperidinecarboxamide
  • Oncogene Proteins
  • Oxazoles
  • Piperazines
  • Protein Kinase Inhibitors
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-ets
  • Pyridines
  • Thiazoles
  • Receptor Protein-Tyrosine Kinases
  • Cyclin-Dependent Kinases
  • Proto-Oncogene Proteins p21(ras)
  • ras Proteins
  • palbociclib