The expression and clinical significance of an Epithelial-Mesenchymal Transition inducer, SNAI1, in head and neck carcinoma.

ABSTRACT

BACKGROUND: SNAI1 is an epithelial-mesenchymal transition (EMT) inducer, which has been indicated to play a role in the progression of cancers. We aimed to evaluate the expression and prognostic roles of SNAI1 in head and neck carcinoma (HNC). METHODS: The study involved two major phases. In the in silico phase, the SNAI1 expression and its association with clinical features as well as its prognostic values were assessed; then, the target genes of SNAI1 were predicted and the relationship between SNAI1 expression and immune cell infiltration was evaluated. In the validation phase, a cohort of a tissue microarray (47 cases) and a cohort of HNC patients (68 cases) were enrolled. SNAI1 was detected by using an immunochemistry assay. RESULTS: The in silico analysis showed that overexpression of SNAI1 in HNC tissues may be correlated with metastatic lymph node numbers and may predict poor outcomes. Six genes, including CREB3L1, MITF, KLF9, RARA, KLF7, and ETV1, were predicted to be the target genes of SNAI1. The expression of SNAI1 was negatively correlated with tumor purity of HNC, while it was positively correlated with the infiltration of diverse immune cells, such as B cells and macrophages. In the validation phase, the relationships of SNAI1 expression with lymph node metastasis and poor prognosis were verified. CONCLUSION: Overexpression of SNAI1 might promote lymph node metastasis through complex molecular mechanisms and act as a prognostic indicator in HNC. SNAI1 expression may have a correlation with immune cell infiltrates. Future studies are needed to address these points.