Author(s)
Katherine Kedeshian, BS
Michelle Hong, BS
Larry Hoffman, PhD
Ashley Kita, MD
Affiliation(s)
University of California Los Angeles
Abstract:
Educational Objective: At the conclusion of this presentation, the participants should be able to investigate Schwann cell injury and potential demyelination as a mechanism of cisplatin ototoxicity and to advance a method of screening therapeutic targets for Schwann cell rehabilitation.
Objectives: Cisplatin is known to cause inner ear dysfunction. There is growing evidence that cisplatin induced demyelination of spiral or Scarpa's ganglion neurons may play an additional role in drug induced ototoxicity alongside afferent neuron injury. Through using Schwann cell viability as a proxy of remyelination, there may be an opportunity to reduce ototoxic inner ear damage. This work describes a model for reducing cisplatin induced injury by promoting Schwann cell viability.
Study Design: Using a rat Schwann cell line, RSC96, a cisplatin dose curve was produced to identify the lethal concentration of 50% of the cells (LC50). The antioxidant N-acetyl cysteine (NAC) was then co-dosed at varying concentrations with cisplatin.
Methods: RSC96 cells were seeded at a density of 4,000 cells/well in 96 well plates 24 hours prior to co-treatment with cisplatin and NAC. Cell viability was assessed 48 hours after treatment using the CCK8 assay.
Results: The LC50 dose of cisplatin was determined to be 3.34 -¦M (p=2.2E-16) using a four parameter logistic regression. NAC demonstrated a protective effect when compared to the conditions dosed exclusively with cisplatin on one way ANOVA analysis (p=3.1E-15). When co-dosed with cisplatin NAC concentrations of 100 -¦M and 1000 -¦M showed increased viability compared to cisplatin alone.
Conclusions: Schwann cell injury following cisplatin insult is described in this in vitro model which allows for screening of potentially therapeutic agents. Cisplatin was found to cause injury at physiologic concentrations and NAC was found to improve cell viability and mitigate this injury, thus demonstrating promise as a therapeutic agent to offset cisplatin induced ototoxicity.