Knockdown of Secernin 1 inhibit cell invasion and migration by activating the TGF-β/Smad3 pathway in oral squamous cell carcinomas

Secernin-1 (SCRN1) is a regulator of exocytosis in mast cells. Recently, SCRN1 was reported to be correlated with the prognosis of colorectal cancer and gastric cancer, but its functional effects on oral squamous cell carcinoma (OSCC) remain unclear. Our aim was to explore the expression pattern and the migration and invasion effects of the newly identified SCRN1 in OSCC. Western blotting (WB) was performed to measure SCRN1 expression in human OSCC tissue samples and OSCC cell lines. The effects of SCRN1 on OSCC cell proliferation, invasion and migration were analyzed by cell counting kit-8 and Transwell assays. The expression levels of TGF-β, Smad3 and phosphorylated Smad3 (p-Smad3) were measured by WB. The secretion of matrix metalloproteinase (MMP)-2 and MMP-9 was determined by the enzyme-linked immunosorbent assay. The expression of SCRN1 was significantly elevated in OSCC tissues and cell lines. SCRN1 knockdown reduced the expression of TGF-β and p-Smad3 in OSCC cells. TGF-β stimulation promoted proliferation, invasion and migration and enhanced the expression of p-Smad3 and the secretion of MMP9 in SCRN1-knockdown OSCC cell lines. Our study demonstrated that SCRN1 is upregulated in OSCC. Further analyses demonstrated that SCRN1 promotes the proliferation, invasion and migration of OSCC cells via TGF-β/Smad3 signaling.