IGF-1 Gene Therapy: Future Strategy for Management of Laryngeal Paralysis

Current surgical strategies for the treatment of laryngeal paralysis are limited by the muscle atrophy associated with denervation. Moreover, attempts at reinnervation have not affected significant change in surgical outcome. To address this clinical problem, we have developed a rat laryngeal paralysis model to study novel gene transfer strategies. A muscle specific non-viral vector containing the α-actin promoter and hIGF-I gene formulated with polyvinyl polymers injected into denervated adult rat thyroarytenoid muscle has been shown to produce significant increase in muscle fiber diameter, significant decrease in motor endplate length and significant increase in percentage of endplates with nerve contact. Applied to laryngeal paralysis, hIGF-I gene therapy provides opportunity for augmentation of surgical treatment modalities by prevention or reversal of muscle atrophy, enhanced nerve sprouting and reinnervation. If proven effective, gene therapy may be applied clinically to fine-tune current surgical procedures or even eliminate the need for surgical intervention.