Targeting p130Cas- and microtubule-dependent MYC regulation sensitizes pancreatic cancer to ERK MAPK inhibition

Cell Rep. 2021 Jun 29;35(13):109291. doi: 10.1016/j.celrep.2021.109291.

Abstract

To identify therapeutic targets for KRAS mutant pancreatic cancer, we conduct a druggable genome small interfering RNA (siRNA) screen and determine that suppression of BCAR1 sensitizes pancreatic cancer cells to ERK inhibition. Integrative analysis of genome-scale CRISPR-Cas9 screens also identify BCAR1 as a top synthetic lethal interactor with mutant KRAS. BCAR1 encodes the SRC substrate p130Cas. We determine that SRC-inhibitor-mediated suppression of p130Cas phosphorylation impairs MYC transcription through a DOCK1-RAC1-β-catenin-dependent mechanism. Additionally, genetic suppression of TUBB3, encoding the βIII-tubulin subunit of microtubules, or pharmacological inhibition of microtubule function decreases levels of MYC protein in a calpain-dependent manner and potently sensitizes pancreatic cancer cells to ERK inhibition. Accordingly, the combination of a dual SRC/tubulin inhibitor with an ERK inhibitor cooperates to reduce MYC protein and synergistically suppress the growth of KRAS mutant pancreatic cancer. Thus, we demonstrate that mechanistically diverse combinations with ERK inhibition suppress MYC to impair pancreatic cancer proliferation.

Keywords: BCAR1; ERK; KRAS; MYC; TUBB3; calpain; microtubules; p130Cas; pancreatic cancer; β-catenin.

Publication types

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

MeSH terms

  • Acetamides / pharmacology
  • Apoptosis / drug effects
  • Apoptosis / genetics
  • Calpain / metabolism
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Proliferation / genetics
  • Crk-Associated Substrate Protein / metabolism*
  • Down-Regulation / drug effects
  • Down-Regulation / genetics
  • Drug Synergism
  • Extracellular Signal-Regulated MAP Kinases / antagonists & inhibitors*
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Gene Expression Regulation, Neoplastic / drug effects
  • Half-Life
  • Humans
  • Microtubules / drug effects
  • Microtubules / metabolism*
  • Morpholines / pharmacology
  • Mutation / genetics
  • Organoids / drug effects
  • Organoids / metabolism
  • Pancreatic Neoplasms / genetics
  • Pancreatic Neoplasms / metabolism*
  • Pancreatic Neoplasms / pathology
  • Protein Kinase Inhibitors / pharmacology*
  • Proto-Oncogene Proteins c-myc / metabolism*
  • Proto-Oncogene Proteins p21(ras) / genetics
  • Pyridines / pharmacology
  • Transcription, Genetic / drug effects
  • Tubulin / metabolism
  • Xenograft Model Antitumor Assays
  • src-Family Kinases / antagonists & inhibitors
  • src-Family Kinases / metabolism

Substances

  • Acetamides
  • Crk-Associated Substrate Protein
  • KRAS protein, human
  • Morpholines
  • Protein Kinase Inhibitors
  • Proto-Oncogene Proteins c-myc
  • Pyridines
  • Tubulin
  • tirbanibulin
  • src-Family Kinases
  • Extracellular Signal-Regulated MAP Kinases
  • Calpain
  • Proto-Oncogene Proteins p21(ras)