Targeting Rad51 as a strategy for the treatment of melanoma cells resistant to MAPK pathway inhibition

Cell Death Dis. 2020 Jul 2;11(7):581. doi: 10.1038/s41419-020-2702-y.

Abstract

Rad51 is an essential factor of the homologous recombination DNA repair pathway and therefore plays an important role in maintaining genomic stability. We show that RAD51 and other homologous recombination repair genes are overexpressed in metastatic melanoma cell lines and in melanoma patient samples, which correlates with reduced survival of melanoma patients. In addition, Rad51 expression in melanoma cells was regulated on a transcriptional level by the MAPK signaling pathway with Elk1 as the main downstream transcriptional effector. Most strikingly, melanoma cells which developed resistance towards MAPK inhibitors could be efficiently targeted by Rad51 inhibitors similar to their sensitive counterparts, leading to DNA damage, G2/M arrest and apoptosis. Furthermore, the treatment of MAPK inhibitor resistant cells with Rad51 inhibitors enhances the susceptibility of these cells for MAPK inhibitor treatment in vitro and in vivo. These data indicate that Rad51 plays a critical role in the survival of metastatic melanoma cells and is a promising target for the therapy of melanoma irrespective of its MAPK inhibitor resistance status.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • DNA Damage
  • DNA Repair / drug effects
  • DNA Repair / genetics
  • Drug Resistance, Neoplasm* / drug effects
  • Drug Resistance, Neoplasm* / genetics
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • MAP Kinase Signaling System* / drug effects
  • Melanoma / enzymology*
  • Melanoma / pathology*
  • Mice
  • Models, Biological
  • Molecular Targeted Therapy*
  • Protein Kinase Inhibitors / pharmacology*
  • Rad51 Recombinase / antagonists & inhibitors
  • Rad51 Recombinase / metabolism*
  • ets-Domain Protein Elk-1 / genetics
  • ets-Domain Protein Elk-1 / metabolism

Substances

  • ELK1 protein, human
  • Protein Kinase Inhibitors
  • ets-Domain Protein Elk-1
  • Rad51 Recombinase