Human Induced Pluripotent Stem Cell Derived Sensory Neurons are Sensitive to the Neurotoxic Effects of Paclitaxel

Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting adverse event associated with treatment with paclitaxel and other chemotherapeutic agents. The prevention and treatment of CIPN are limited by a lack of understanding of the molecular mechanisms underlying this toxicity. In the current study, a human induced pluripotent stem cell–derived sensory neuron (iPSC-SN) model was developed for the study of chemotherapy-induced neurotoxicity. The iPSC-SNs express proteins characteristic of nociceptor, mechanoreceptor and proprioceptor sensory neurons and show Ca 2+ influx in response to capsaicin, α,β-meATP and glutamate. iPSC-SNs are relatively resistant to the cytotoxic effects of paclitaxel, with IC 50 values of 38.1 μM (95% CI: 22.9 – 70.9 μM) for 48 hr exposure and 9.3 μM (95% CI: 5.7 – 16.5 μM) for 72 hr treatment. Paclitaxel causes dose- and time-dependent changes in neurite network complexity detected by βIII-tubulin staining and high content imaging. The IC 50 for paclitaxel reduction of neurite area was 1.4 μ M (95% CI: 0.3 - 16.9 μ M) for 48 hr exposure and 0.6 μ M (95% CI: 0.09 - 9.9 μ M) for 72 hr exposure. Decreased mitochondrial membrane potential, slower movement of mitochondria down the neurites and changes in glutamate-induced neuronal excitability were also observed with paclitaxel exposure. The iPSC-SNs were also sensitive to docetaxel, vincristine and bortezomib. Collectively, these data support the use of iPSC-SNs for detailed mechanistic investigations of genes and pathways implicated in chemotherapy-induced neurotoxicity and the identification of novel therapeutic approaches for its prevention and treatment.