Tiam1 regulates proliferation, invasion, and differentiation in neuroblastoma through the Tiam1/Rac1 signaling pathway.

Neuroblastoma is the most common extracranial solid tumor in children. The purpose of the present study is to detect the prognostic role and potential therapeutic efficacy of the T lymphoma invasion and metastasis 1 (Tiam1) in neuroblastoma. The overexpression of Tiam1 protein is frequently observed in neuroblastoma. Tiam1 expression is closely associated with adverse prognosis of neuroblastoma and risk group classification. Knockdown of TIAM1 by lentivirus expressing short hairpin RNA against TIAM1 (sh-TIAM1) inhibited the proliferation, invasion and cell-cycle progression, and promoted apoptosis of the neuroblastoma cell lines SH-SY5Y and SK-N-AS. Additionally, downregulation of the differentiation-related protein expression and decreased Rac1 expression was observed in the sh-TIAM1-transfected SH-SY5Y cells. In vivo, nude mice bearing TIAM1 knockdown SH-SY5Y cells showed improved overall survival and tumor growth suppression. The results demonstrate that inhibition of Tiam1 expression is a potential strategy for targeted therapy in neuroblastoma.