Treatment with anti-TNF alpha protects against the neuropathy induced by the proteasome inhibitor bortezomib in a mouse model.

Bortezomib (BTZ), a proteasome inhibitor, is an effective anti-neoplastic drug used in the treatment of multiple myeloma and mantle cell lymphoma. However, it can induce a reversible peripheral neuropathy that may lead to treatment discontinuation. The mechanism through which BTZ exerts toxic effects in peripheral neurons is not clear. Release of proinflammatory cytokines after nerve damage can induce neurodegeneration, but the effects of BTZ on cytokine expression in neurons are unknown, although BTZ modulates the expression of cytokines, such as TNF-α and IL-6, in tumor cells. The aim of this study was to evaluate the expression and the role of these cytokines on the course of BTZ induced neuropathy in mice. IL-6, TNF-α, TGF-β1 and IL-1β were up-regulated in dorsal root ganglia but TNF-α and IL-6 increased faster and higher. Then, we studied the potential neuroprotective effect of selective antibodies anti-TNF-α and anti-IL-6 on the evolution of the neuropathy. Treatment with anti-TNF-α but not with anti-IL-6 significantly prevented the decrease of sensory nerve action potentials amplitude and the loss of myelinated and unmyelinated fibers. We conclude that monoclonal antibodies directed against TNF-α may be a suitable neuroprotective therapy against the neurotoxicity induced by BTZ.