NEK2 Promotes the Migration, Invasion, Proliferation and Drug Resistance of ESCC Through the E2F1-IGF2 Pathway

Abstract

Abstract Purpose:Esophageal squamous cell carcinoma(ESCC) is a disease with a high incidence rate and high mortality worldwide. The Never in Mitosis A (NIMA) family member NIMA-related kinase 2 (NEK2) plays an important role in mitosis. However, the role of NEK2 in the pathogenesis of ESCC remains unclear. Patients and methods:The expression and function of NEK2 in TCGA and GEO data sets were analyzed by bioinformatics.We verified the expression of NEK2 in ESCC tissues and cell lines by Western blotting and immunohistochemical methods and further explored the relationship between tumor stage and NEK2 expression. The differences in NEK2 expression and survival in patients with EC were verified by bioinformatics analysis. ESCC cell lines with stable knockdown of NEK2 were established by lentivirus-mediated shRNA delivery. The effects of NEK2 on ESCC cells were analyzed on the cytological level with assays including CCK-8, EdU, cell scratch, Transwell migration and invasion, colony formation, flow cytometry and apoptosis assays. Tumor growth was measured in a mouse xenograft model. Results: We found that NEK2 is highly expressed in ESCC tissues and ESCC cells and that the high expression of NEK2 is associated with poor tumor healing. Knockdown of the NEK2 gene inhibits the migration, proliferation, invasion and cell cycle of ESCC cells. Biologic analysis shows that NEK2 is involved in biological processes such as progression and apoptosis of esophageal cancer, and is related to E2F.Mechanistically, NEK2 knockdown decreases the expression levels of E2F1 and IGF2. NEK2 competes with the transcription factor E2F1 to bind CDC20, resulting in decreased degradation and increased expression of E2F1. There is a positive correlation between E2F1 expression and IGF2 expression; thus, IGF2 expression is also increased, which promotes the expression of thymidylate synthase, further promoting the drug resistance of ESCC cells. Conclusion: NEK2 is highly expressed in ESCC and can promote the migration, proliferation and invasion of ESCC cells. The NEK2-E2F1-IGF2 signaling pathway has great significance for the treatment of ESCC.