Involvement of c-Myc-mediated transient receptor potential melastatin 8 expression in oxaliplatin-induced cold allodynia in mice

• Oxaliplatin (OXP) elicited cold allodynia in mice.
• OXP-induced cold allodynia was inhibited by TRPM8 antagonists.
• OXP increased TRPM8 mRNA expression in the dorsal root ganglia.
• OXP increased TRPM8 protein expression in the planter skin.
• c-Myc inhibitor attenuated OXP-induced cold allodynia and TRPM8 mRNA expression.
• OXPmay induce cold allodynia through the increase of TRPM8 in sensory neurons.

BackgroundOxaliplatin, a platinum-based chemotherapeutic agent, induces acute cold allodynia and dysesthesia. Cold-sensitive transient receptor potential channels (TRPM8 and TRPA1) have been implicated as candidates to mediate oxaliplatin-induced cold allodynia and hyperalgesia, but precise roles of these channels remain unclear. In this study, we investigated the role of TRPM8 in oxaliplatin-induced cold allodynia.MethodsOxaliplatin was injected intraperitoneally in mice. Cold allodynia was evaluated by the acetone test. Expression levels of TRPM8 mRNA and protein were measured using reverse transcription-polymerase chain reaction and Western blotting, respectively.ResultsOxaliplatin-induced cold allodynia was alleviated by the TRPM8 blockers N-(2-aminoethyl)-N-[4-(benzyloxy)-3-methoxybenzyl]-N′-(1S)-1-(phenyl) ethyl] urea and TC-I 2014. Oxaliplatin increased the expression levels of TRPM8 mRNA and protein in the dorsal root ganglia and plantar skin, respectively. Prophylactic administration of the c-Myc inhibitor 10058-F4 prevented cold allodynia and the increase of TRPM8 mRNA after oxaliplatin injection.ConclusionThese results suggest that oxaliplatin induces cold allodynia through the increase of c-Myc-mediated TRPM8 expression in primary sensory neurons.