Upregulation of ERK phosphorylation in rat dorsal root ganglion neurons contributes to oxaliplatin-induced chronic neuropathic pain

PLoS One. 2019 Nov 25;14(11):e0225586. doi: 10.1371/journal.pone.0225586. eCollection 2019.

Abstract

Oxaliplatin is the first-line chemotherapy for metastatic colorectal cancer. Unlike other platinum anticancer agents, oxaliplatin does not result in significant renal impairment and ototoxicity. Oxaliplatin, however, has been associated with acute and chronic peripheral neuropathies. Despite the awareness of these side-effects, the underlying mechanisms are yet to be clearly established. Therefore, in this study, we aimed to understand the factors involved in the generation of chronic neuropathy elicited by oxaliplatin treatment. We established a rat model of oxaliplatin-induced neuropathic pain (4 mg kg-1 intraperitoneally). The paw withdrawal thresholds were assessed at different time-points after the treatment, and a significant decrease was observed 3 and 4 weeks after oxaliplatin treatment as compared to the vehicle treatment (4.4 ± 1.0 vs. 16.0 ± 4.1 g; P < 0.05 and 4.4 ± 0.7 vs. 14.8 ± 3.1 g; P < 0.05, respectively). We further evaluated the role of different mitogen-activated protein kinases (MAPKs) pathways in the pathophysiology of neuropathic pain. Although the levels of total extracellular signal-regulated kinase (ERK) 1/2 in the dorsal root ganglia (DRG) were not different between oxaliplatin and vehicle treatment groups, phosphorylated ERK (p-ERK) 1/2 was up-regulated up to 4.5-fold in the oxaliplatin group. Administration of ERK inhibitor PD98059 (6 μg day-1 intrathecally) inhibited oxaliplatin-induced ERK phosphorylation and neuropathic pain. Therefore, upregulation of p-ERK by oxaliplatin in rat DRG and inhibition of mechanical allodynia by an ERK inhibitor in the present study may provide a better understanding of intracellular molecular alterations associated with oxaliplatin-induced neuropathic pain and help in the development of potential therapeutics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain-Derived Neurotrophic Factor / metabolism
  • Disease Models, Animal
  • Extracellular Signal-Regulated MAP Kinases / antagonists & inhibitors
  • Extracellular Signal-Regulated MAP Kinases / metabolism*
  • Flavonoids / pharmacology
  • Flavonoids / therapeutic use
  • Ganglia, Spinal / metabolism*
  • Hyperalgesia / prevention & control
  • Male
  • Neuralgia / chemically induced
  • Neuralgia / drug therapy
  • Neuralgia / pathology*
  • Oxaliplatin / toxicity*
  • Phosphorylation / drug effects
  • Rats
  • Rats, Sprague-Dawley
  • Up-Regulation / drug effects*

Substances

  • Brain-Derived Neurotrophic Factor
  • Flavonoids
  • Oxaliplatin
  • Extracellular Signal-Regulated MAP Kinases
  • 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one

Grants and funding

This study was supported by a Grant for Clinical Research from University of Miyazaki Hospital. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.