KLF14 inhibits EMT in esophageal cancer cells through inhibition of the MISP-Wnt/β-catenin signaling axis.
BACKGROUND AND OBJECTIVES Esophageal squamous cell carcinoma (ESCC) dominates esophageal malignancies, and metastasis largely accounts for its dismal prognosis. Epithelial-mesenchymal transition (EMT) is a core driver of tumor metastasis. Mitotic spindle positioning protein (MISP) correlates strongly with EMT, yet its function in ESCC EMT remains uncharacterized. This study explored the role of MISP in ESCC EMT and its molecular regulatory mechanisms. METHODS An in vivo human ESCC cell-derived xenograft model was established by injecting ECA109 cells into the left dorsal flank of nude mice. Cell proliferation was assessed using CCK-8 and colony formation assays, while migration and invasion were evaluated via Transwell assays. The expression of key genes and proteins was analyzed by RT‒qPCR, Western blotting, and immunohistochemistry (IHC). The interaction between KLF14 and MISP was validated through chromatin immunoprecipitation (ChIP) and dual-luciferase reporter gene assays. RESULTS We found that MISP was highly expressed in ESCC samples and that its knockdown significantly suppressed the proliferation, colony formation, migration, and invasion of human ESCC cell lines (KYSE30 and ECA109) while concurrently inhibiting EMT progression (as evidenced by the upregulation of E-cadherin expression and downregulation of N-cadherin/vimentin expression). Furthermore, KLF14 bound to the MISP promoter, was downregulated in ESCC cells, and correlated negatively with MISP levels. Overexpression of KLF14 inhibited tumor growth in nude mouse xenografts and reduced MISP expression and EMT in KYSE30 and ECA109 cells. Additionally, KLF14 overexpression or MISP knockdown in these cells suppressed the expression of Wnt/β-catenin signaling-related proteins (Wnt3a, β-catenin, c-Myc, and cyclin D1). Notably, the EMT phenotype could be partially rescued by either MISP overexpression in KLF14-overexpressing cells or LiCl (a Wnt pathway activator) treatment in MISP-knockdown cells. CONCLUSION Our study demonstrates that KLF14 can inhibit ESCC EMT at least partially via downregulating MISP expression to block downstream Wnt/β-catenin signaling. These findings mechanistically elucidate the role of MISP in promoting ESCC EMT and suggest MISP as a potential therapeutic target for related malignancies.