Elevated expression of Derlin-1 associates with unfavorable survival time of squamous cell carcinoma of the head and neck and promotes its malignance

Derlin-1 is over-expressed to function as an oncoprotein in breast, lung and colon cancers. However, the implications of Derlin-1 involved in squamous cell carcinoma of the head and neck (SCCHN) remain unknown. This study aims to investigate the effects of Derlin-1 expression on SCCHN tissues and cells. The potential mechanism of Derlin-1 regulating SCCHN cell proliferation, apoptosis and metastasis was also indicated in this work. Western blot and immunohistochemistry (IHC) assays showed that Derlin-1 was over-expressed in 114 SCCHN samples and five SCCHN cell lines. We found that the expression of Derlin-1 was positively associated with lymph node metastasis, clinical stage and recurrence in our SCCHN patients' samples. Survival analysis indicated that high expression of Derlin-1 was significantly associated with shorter overall survival (OS) and disease-free survival (DFS). Knock down expression of Derlin-1 in SCCHN cell lines was found to inhibit cell proliferation, metastasis and promote cell apoptosis. Further experiments showed that signals of PI3K/Akt, p53 and Smad2/3 may involve in these processes. In all, Derlin-1 might be a novel prognostic marker of SCCHN patients and plays an oncogenic role in SCCHN cell progression.