Inhibition of PI3K suppresses propagation of drug-tolerant cancer cell subpopulations enriched by 5-fluorouracil

Sci Rep. 2017 May 23;7(1):2262. doi: 10.1038/s41598-017-02548-9.

Abstract

Drug-tolerant cancer cell subpopulations are responsible for relapse after chemotherapy. By continuously exposing the gastric cancer cell line MKN45 to 5-FU for >100 passages, we established a 5-fluorouracil (5-FU)-tolerant line, MKN45/5FU. Orthotopic xenografts of MKN45/5FU cells in the stomach of nude mice revealed that these cells had a high potential to metastasize to sites such as the liver. Levels of phosphorylated phosphatidylinositide 3-kinase (PI3K) increased both in 5-FU-tolerant subpopulations according to the 5-FU dose, and in gastric submucosal orthotopic xenografts of MKN45/5FU cells. Sequential administration of 5-FU and a PI3K inhibitor, GDC-0941, targeted the downstream ribosomal S6 kinase phosphorylation to significantly suppress 5-FU-tolerant subpopulations and tumor propagation of orthotopic MKN45/5FU xenografts. These results suggest that administration of 5-FU followed by GDC-0941 may suppress disease relapse after 5-FU-based gastric cancer chemotherapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antimetabolites, Antineoplastic / pharmacology*
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Class I Phosphatidylinositol 3-Kinases / antagonists & inhibitors
  • Class I Phosphatidylinositol 3-Kinases / genetics
  • Class I Phosphatidylinositol 3-Kinases / metabolism
  • Codon
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Drug Resistance, Neoplasm / drug effects*
  • Drug Resistance, Neoplasm / genetics
  • Fluorouracil / pharmacology*
  • Genetic Variation
  • Heterografts
  • Humans
  • Mice
  • Neoplasms / genetics
  • Neoplasms / metabolism
  • Neoplasms / pathology
  • Phenotype
  • Phosphatidylinositol 3-Kinases / genetics
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoinositide-3 Kinase Inhibitors*
  • Phosphorylation
  • Proteome
  • Proteomics / methods
  • Ribosomal Protein S6 Kinases, 90-kDa / metabolism
  • Signal Transduction

Substances

  • Antimetabolites, Antineoplastic
  • Codon
  • Phosphoinositide-3 Kinase Inhibitors
  • Proteome
  • Class I Phosphatidylinositol 3-Kinases
  • PIK3CA protein, human
  • Ribosomal Protein S6 Kinases, 90-kDa
  • Fluorouracil