Abstract
The mechanisms of how Never in Mitosis (NIMA) Related Kinase 2 (NEK2) coordinates altered signaling to malignant gastric cancer (GC) transformation remain unclear. Overexpression of NEK2 and KDM5B were observed in GC cell lines with high sensitivity to NEK2 inhibitors. Here we investigated the biological behaviors of NEK2 and the possible mechanisms of regulative effects of NEK2 on KDM5B in GC cell lines both in vitro and in vivo. The results showed that NEK2 and KDM5B were highly expressed in most of the 10 GC cell lines. NEK2 knockdown in MGC-803 cells led to suppression of cell proliferation and migration in vitro and tumor growth in vivo, while NEK2 overexpression in BGC-823 cells exhibited the reverse biological effect. When NEK2 was inhibited by NEK2 inhibitors or shNEK2, cellular KDM5B level decreased and H3K4me3 level increased, while overexpression of NEK2 resulted in enhanced KDM5B expression and decreased H3K4me3 level. Though direct interaction between NEK2 and KDM5B was excluded, NEK2 could regulate KDM5B/H3K4me3 expression through β-catenin/Myc both in vitro and in vivo, which was double confirmed by c-myc and KDM5B inhibitor experiments. Taken together, our study showed that NEK2 was highly expressed in GC cell lines and related to promoting cell proliferation, migration and tumor growth. A NEK2/β-catenin/Myc/KDM5B/H3K4me3 signaling pathway may contribute to the important carcinogenic role of NEK2-mediated malignant behaviors in GC.