The Slow Cycling Phenotype: A Growing Problem for Treatment Resistance in Melanoma

Mol Cancer Ther. 2017 Jun;16(6):1002-1009. doi: 10.1158/1535-7163.MCT-16-0535.


Treatment resistance in metastatic melanoma is a longstanding issue. Current targeted therapy regimes in melanoma largely target the proliferating cancer population, leaving slow-cycling cancer cells undamaged. Consequently, slow-cycling cells are enriched upon drug therapy and can remain in the body for years until acquiring proliferative potential that triggers cancer relapse. Here we overview the molecular mechanisms of slow-cycling cells that underlie treatment resistance in melanoma. Three main areas of molecular reprogramming are discussed that mediate slow cycling and treatment resistance. First, a low microphthalmia-associated transcription factor (MITF) dedifferentiated state activates various signaling pathways. This includes WNT5A, EGFR, as well as other signaling activators, such as AXL and NF-κB. Second, the chromatin-remodeling factor Jumonji/ARID domain-containing protein 1B (JARID1B, KDM5B) orchestrates and maintains slow cycling and treatment resistance in a small subpopulation of melanoma cells. Finally, a shift in metabolic state toward oxidative phosphorylation has been demonstrated to regulate treatment resistance in slow-cycling cells. Elucidation of the underlying processes of slow cycling and its utilization by melanoma cells may reveal new vulnerable characteristics as therapeutic targets. Moreover, combining current therapies with targeting slow-cycling subpopulations of melanoma cells may allow for more durable and greater treatment responses. Mol Cancer Ther; 16(6); 1002-9. ©2017 AACR.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology
  • Antineoplastic Agents / therapeutic use*
  • Biomarkers, Tumor
  • Cell Cycle / drug effects*
  • Cell Cycle / genetics
  • Chromatin Assembly and Disassembly / drug effects
  • Chromatin Assembly and Disassembly / genetics
  • Drug Resistance, Neoplasm* / drug effects
  • Drug Resistance, Neoplasm* / genetics
  • Energy Metabolism / drug effects
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Melanoma / drug therapy*
  • Melanoma / genetics
  • Melanoma / metabolism
  • Melanoma / pathology
  • Microphthalmia-Associated Transcription Factor / metabolism
  • Molecular Targeted Therapy
  • Neoplasm Metastasis
  • Oxidative Phosphorylation / drug effects
  • Phenotype
  • Signal Transduction / drug effects


  • Antineoplastic Agents
  • Biomarkers, Tumor
  • Microphthalmia-Associated Transcription Factor