SIRT4 expression in laryngeal squamous cell carcinoma.

SIRT4 has been reported to be abnormally expressed in many malignant tumor tissues, but data in laryngeal squamous cell carcinoma (LSCC) is lacking. In the present study, we detected the expression of SIRT4 in 168 pairs of LSCC tissues and adjacent normal tissues using RT-qPCR, immunoblotting and immunohistochemical staining, and analyzed its clinical implication. We found that SIRT4 expression was low in LSCC tissues, and was significantly related to histological grade, T classification, clinical stage, lymph node metastasis and recurrence of LSCC patients. In vitro, knockdown of SIRT4 promoted the proliferation and migration of LSCC cells, while overexpression of SIRT4 inhibits the proliferation and migration of LSCC cells. Moreover, the expression of SIRT4 protein was an independent factor affecting the disease-free survival (DFS) (HR=0.562, 95%CI=0.1290.834) and overall survival rates (OS) (HR=0.628, 95%CI=0.267-0.935) of LSCC patients. The 5-years DFS and OS in LSCC patients with low SIRT4 expression were significantly lower than that in LSCC patients with high SIRT4 expression. In conclusion, SIRT4 was lowly expressed in LSCC patients, which might be related to more aggressive tumor behaviour and a poor prognosis.