Abstract:Objective: Our previous study has demonstrated that T lymphoma invasion and metastasis inducing factor 1 (Tiam1) is correlated with the prognosis of laryngeal carcinoma. Hence, we will upregulate the Tiam1 expression in cell lines of laryngeal carcinoma, and observe the effect of Tiam1 upregulation on the proliferation, migration and invasion of laryngeal carcinoma in vitro and in vivo. Methods: The Hep-2 cell line of stable high Tiam1 expression (Hep-2/Tiam1) was successfully obtained. The related experiments were carried out to observe the effects of Tiam1 upregulation on the proliferation, migration and invasion of laryngeal carcinoma cell line Hep-2 in vitro. Then, the metastatic xenograft mouse model of laryngeal carcinoma was obtained. The related experiments were also carried out to observe the effects of Tiam1 upregulation on the proliferation and invasion of Hep-2 in vivo. Results: Compared with the group of Hep-2 and cell line with null vector transfection, MTT assay revealed that there was no significant statistical difference in proliferation among 3 groups (P > 0.05). However, Tiam1 upregulation led to significantly increased migration (P < 0.05) and invasion (P < 0.05) of laryngeal carcinoma Hep-2 cells. The tumor formation rate of laryngeal carcinoma metastatic xenograft mouse model was 100%. There was no significant statistical difference among 3 groups on the tumor volume and tumor weight of xenografted tumors (both P > 0.05). The cervical lymph nodes metastasis rate in the group of Hep-2/Tiam1 was significantly increased (P < 0.05). Conclusion: Upregulation of Tiam1 has no effect on the proliferation of Hep-2 cells in vitro and in vivo, but can increase the migration and invasion of Hep-2 cells in vitro and in vivo, suggestting that Tiam1 contributes to the laryngeal carcinoma progression.