Downregulation of Survivin by ShRNA Inhibits Invasion and Enhances the Radiosensitivity of Laryngeal Squamous Cell Carcinoma

Radiotherapy is an important treatment modality for laryngeal carcinoma, however, some patients with early stage laryngeal carcinomas showed resistance to radiotherapy. Survivin overexpression is associated with radioresistance of laryngeal squamous cell carcinoma. We speculated that the inhibition of survivin expression might improve the radiosensitivity of laryngeal carcinoma. We assessed the effect of survivin expressions by shRNA on the radiosensitivity of laryngeal squamous cell carcinoma in vitro and in vivo. After transfection of shRNA-targeting survivin, MTS assay showed that the survival rates of radiation groups were reduced with the prolongation of culture time (p < 0.05). In addition, shRNA-targeting survivin abrogated radiation-induced G2 phase arrest and amplified radiation-induced apoptosis. In vivo, shRNA transfection also sensitized tumor xenograft to radiotherapy. Radioresistance of laryngeal squamous cell carcinoma may be associated with increased expression of survivin, and survivin suppression may enhance the radiosensitivity of laryngeal squamous cell carcinoma.