IQGAP1 silencing suppresses the malignant characteristics of laryngeal squamous cell carcinoma cells.

Laryngeal squamous cell carcinoma (LSCC) has a poor prognosis due to recurrence and metastasis. IQ-domain GTPase-activating protein 1 (IQGAP1), a scaffold protein, plays an important role in tumorigenesis and malignant development. In this study, we aimed to explore the role of IQGAP1 in LSCC. Expression of IQGAP1 in human LSCC specimens was assessed by immunohistochemistry. We also evaluated the roles of IQGAP1 in cell proliferation, migration and invasion and epithelial-to-mesenchymal transition (EMT) in Hep-2 cells. The expression of IQGAP1 protein was significantly up-regulated in LSCC tissues compared with normal laryngeal tissues (p = 0.002). Furthermore, the knockdown of IQGAP1 in Hep-2 cells inhibited cell growth, migration and invasion. Moreover, we found that IQGAP1 silencing reversed EMT. These results show for the first time that IQGAP1 is up-regulated in LSCC tissues and plays an important role in LSCC cell proliferation and invasiveness, which indicates that IQGAP1 could work as an oncogene and may serve as a promising molecular target for treatment of LSCC.