An evolving cellular pathology occurs in dorsal root ganglia, peripheral nerve and spinal cord following intravenous administration of paclitaxel in the rat

• Published in: Brain research 2007-09, Vol.1168, p.46-59
• Main Authors: Peters, Christopher M, Jimenez-Andrade, Juan Miguel, Kuskowski, Michael A, Ghilardi, Joseph R, Mantyh, Patrick W
• Format: Article
• Language: English
• Subjects: Activating Transcription Factor 3 - metabolism; Animals; Antigens, CD - metabolism; Antigens, Differentiation, Myelomonocytic - metabolism; Antineoplastic agents; Antineoplastic Agents, Phytogenic - administration & dosage; Astrocytes - drug effects; Biological and medical sciences; Breast cancer; Cell Size - drug effects; Chemotherapy; Cranial nerves. Spinal roots. Peripheral nerves. Autonomic nervous system. Gustation. Olfaction; Ganglia, Spinal - drug effects; Ganglia, Spinal - pathology; Gene Expression Regulation - drug effects; Glial Fibrillary Acidic Protein - metabolism; Injections, Intraventricular - methods; Macrophages - drug effects; Macrophages - pathology; Male; Medical sciences; Models, Biological; Nervous system (semeiology, syndromes); Neurology; Neuropathic pain; Neurotoxicity; Paclitaxel - administration & dosage; Pharmacology. Drug treatments; Phosphopyruvate Hydratase - metabolism; Rats; Rats, Sprague-Dawley; Sciatic Nerve - drug effects; Sciatic Nerve - pathology; Spinal Cord - drug effects; Spinal Cord - pathology; Statistics, Nonparametric; Taxane; Time Factors; Vincristine
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2007.06.066

Abstract Paclitaxel (Taxol®) is a frontline antineoplastic agent used to treat a variety of solid tumors including breast, ovarian, or lung cancer. The major dose limiting side effect of paclitaxel is a peripheral sensory neuropathy that can last days to a lifetime. To begin to understand the cellular events that contribute to this neuropathy, we examined a marker of cell injury/regeneration (activating transcription factor 3; ATF3), macrophage hyperplasia/hypertrophy; satellite cell hypertrophy in the dorsal root ganglia (DRG) and sciatic nerve as well as astrocyte and microglial activation within the spinal cord at 1, 4, 6 and 10 days following intravenous infusion of therapeutically relevant doses of paclitaxel. At day 1 post-infusion, there was an up-regulation of ATF3 in a subpopulation of large and small DRG neurons and this up-regulation was present through day 10. In contrast, hypertrophy of DRG satellite cells, hypertrophy and hyperplasia of CD68+ macrophages in the DRG and sciatic nerve, ATF3 expression in S100β+ Schwann cells and increased expression of the microglial marker (CD11b) and the astrocyte marker glial fibrillary acidic protein (GFAP) in the spinal cord were not observed until day 6 post-infusion. The present results demonstrate that using the time points and markers examined, DRG neurons show the first sign of injury which is followed days later by other neuropathological changes in the DRG, peripheral nerve and dorsal horn of the spinal cord. Understanding the cellular changes that generate and maintain this neuropathy may allow the development of mechanism-based therapies to attenuate or block this frequently painful and debilitating condition.