Protection of both auditory hair cells and auditory neurons from cisplatin induced damage.

Cisplatin is an effective anti-neoplastic agent used in the treatment of squamous cell cancer of the head and neck, but with serious side effects. One serious side effect is damage to both the auditory hair cells and the auditory neurons. The damage to the neurons has been shown to be a direct effect and not due to the loss of the neurotrophic support provided by the hair cells. Several neurotrophins have been shown to lessen the extent of cisplatin induced damage of auditory neurons in vitro, but these neurotrophins have had no effect on the extent of damage to the hair cells. D-methionine (D-met) has been demonstrated to provide protection against cisplatin's nephrotoxicity in vivo and ototoxicity in vitro. In this study the combination of brain derived neurotrophic factor (BDNF) with D-met has shown that both auditory neurons and auditory hair cells can be protected from cisplatin induced damage in vitro. These results demonstrate that this type of combination therapy (i.e. a neurotrophin combined with a free radical scavenger) can provide more complete protection for the auditory receptor against cisplatin toxicity than either of these agents alone. Because both BDNF and D-met have been shown to have trophic activity in vitro we proposed that the combination of these agents will also provide effective protection against cisplatin induced ototoxicity and neurotoxicity of the auditory receptor in vivo.