MET is a potential target for use in combination therapy with EGFR inhibition in triple-negative/basal-like breast cancer

Int J Cancer. 2014 May 15;134(10):2424-36. doi: 10.1002/ijc.28566.

Abstract

MET, a cell surface receptor for hepatocyte growth factor, is involved in the development of triple-negative/basal-like breast cancer (TNBC/BLBC). However, its utility as a therapeutic target in this subtype of breast cancer is poorly understood. To evaluate MET fully as a potential therapeutic target for TNBC/BLBC, we investigated the relationship between MET expression and clinical outcomes of patients with breast cancer and the functional effect of MET inhibition. Using automated immunohistochemistry (Ventana), we analyzed MET expression in 924 breast cancer patients with relevant clinicopathologic parameters. BLBC showed the strongest relationship with MET expression (57.5%, p < 0.001). High expression of MET in breast cancer resulted in poor overall survival (p = 0.001) and disease-free survival (DFS, p = 0.010). MET expression was relatively high in TNBC cell lines, and the silencing of MET via small interfering RNA reduced cell proliferation and migration. We observed reduced TNBC cell viability after treatment with the MET inhibitor PHA-665752. In the most drug-resistant cell line, MDA-MB-468, which showed elevated epidermal growth factor receptor (EGFR) expression, silencing of EGFR resulted in increased sensitivity to PHA-665752 treatment. We confirmed that PHA-665752 synergizes with the EGFR inhibitor erlotinib to decrease the viability of MDA-MB-468 cells. TNBC patients coexpressing MET and EGFR showed significantly worse DFS than that in patients expressing EGFR alone (p = 0.021). Our findings strongly suggest that MET may be a therapeutic target in TNBC and that the combined therapy targeting MET and EGFR may be beneficial for the treatment of TNBC/BLBC patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Cell Movement / genetics
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Cell Survival / genetics
  • ErbB Receptors / antagonists & inhibitors*
  • ErbB Receptors / metabolism
  • Erlotinib Hydrochloride
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Immunoblotting
  • Immunohistochemistry
  • Indoles / pharmacology
  • Kaplan-Meier Estimate
  • Middle Aged
  • Molecular Targeted Therapy / methods*
  • Neoplasms, Basal Cell / drug therapy
  • Neoplasms, Basal Cell / genetics
  • Neoplasms, Basal Cell / metabolism
  • Protein Kinase Inhibitors / pharmacology
  • Proto-Oncogene Proteins c-met / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-met / genetics
  • Proto-Oncogene Proteins c-met / metabolism
  • Quinazolines / pharmacology
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sulfones / pharmacology
  • Triple Negative Breast Neoplasms / drug therapy*
  • Triple Negative Breast Neoplasms / genetics
  • Triple Negative Breast Neoplasms / metabolism

Substances

  • 5-((2,6-dichlorobenzyl)sulfonyl)-3-((3,5-dimethyl-4-((2-(pyrrolidin-1-ylmethyl)pyrrolidin-1-yl)carbonyl)-1H-pyrrol-2-yl)methylene)-1,3-dihydro-2H-indol-2-one
  • Indoles
  • Protein Kinase Inhibitors
  • Quinazolines
  • Sulfones
  • Erlotinib Hydrochloride
  • ErbB Receptors
  • MET protein, human
  • Proto-Oncogene Proteins c-met