Wild-type KRAS is a novel therapeutic target for melanoma contributing to primary and acquired resistance to BRAF inhibition

Oncogene. 2018 Feb 15;37(7):897-911. doi: 10.1038/onc.2017.391. Epub 2017 Oct 23.

Abstract

Malignant melanoma reveals rapidly increasing incidence and mortality rates worldwide. By now, BRAF inhibition is the standard therapy for advanced melanoma in patients carrying BRAF mutations. However, only approximately 50% of melanoma patients harbor therapeutically attackable BRAF mutations, and overall survival after treatment with BRAF inhibitors is modest. KRAS (Kirsten Rat sarcoma) proteins are acting upstream of BRAF and have a major role in human cancer. Recent approaches awaken the hope to use KRAS inhibition (KRASi) as a clinical tool. In this study, we identified wild-type KRAS as a novel therapeutic target in melanoma. KRASi functions synergistically with BRAF inhibition to reduce melanoma proliferation and to induce apoptosis independently of BRAF mutational status. Moreover, acquired resistance to BRAF inhibitors in melanoma is dependent on dynamic regulation of KRAS expression with subsequent AKT and extracellular-signal regulated kinase activation and can be overcome by KRASi. This suggests KRASi as novel approach in melanoma-alone or in combination with other therapeutic regimes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism*
  • Cell Proliferation
  • Drug Resistance, Neoplasm / genetics*
  • Follow-Up Studies
  • Humans
  • Male
  • Melanoma / drug therapy
  • Melanoma / genetics
  • Melanoma / pathology*
  • Melanoma, Cutaneous Malignant
  • Mice
  • Mice, Nude
  • Mutation*
  • Prognosis
  • Protein Kinase Inhibitors / pharmacology*
  • Proto-Oncogene Proteins B-raf / antagonists & inhibitors*
  • Proto-Oncogene Proteins B-raf / genetics
  • Proto-Oncogene Proteins B-raf / metabolism
  • Proto-Oncogene Proteins p21(ras) / genetics*
  • Signal Transduction
  • Skin Neoplasms / drug therapy
  • Skin Neoplasms / genetics
  • Skin Neoplasms / pathology*
  • Tumor Cells, Cultured
  • Xenograft Model Antitumor Assays

Substances

  • Biomarkers, Tumor
  • KRAS protein, human
  • Protein Kinase Inhibitors
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf
  • Proto-Oncogene Proteins p21(ras)