RAF1 amplification: an exemplar of MAPK pathway activation in urothelial carcinoma

J Clin Invest. 2021 Nov 15;131(22):e154095. doi: 10.1172/JCI154095.

Abstract

Despite recent therapeutic gains in the treatment of advanced bladder cancer, the overall survival in patients with metastatic disease remains poor and further therapeutic discovery is needed. Advanced bladder cancer is a molecularly heterogeneous disease, and the identification of driver genetic alterations has led to effective targeted therapeutic agents, such as fibroblast growth factor receptor (FGFR) inhibitors. In this issue of the JCI, Bekele et al. identify a subtype of muscle-invasive bladder cancer (MIBC) that harbors RAF1 amplification. The authors showed that RAF1 inhibition, with pan-RAF inhibitors, and the combination of RAF1 inhibition with MEK inhibition were efficacious in preclinical models harboring RAF1 amplifications as well as in tumors with HRAS and NRAS mutations. This study highlights RAF1 amplification as a driver event in bladder cancer and establishes the central role of the MAPK pathway in bladder tumorigenesis.

Publication types

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

MeSH terms

  • Antineoplastic Agents* / therapeutic use
  • Carcinoma, Transitional Cell* / drug therapy
  • Carcinoma, Transitional Cell* / genetics
  • Humans
  • Mutation
  • Receptors, Fibroblast Growth Factor / genetics
  • Urinary Bladder Neoplasms* / drug therapy
  • Urinary Bladder Neoplasms* / genetics

Substances

  • Antineoplastic Agents
  • Receptors, Fibroblast Growth Factor