NEK6 functions as an oncogene to promote the proliferation and metastasis of ovarian cancer.

Background: Ovarian cancer (OC) is a common malignant tumor of the female reproductive organs. The novel serine/threonine kinase NEK6 is highly expressed in various cancers and affects the prognosis of patients. However, the role of NEK6 in OC is still unclear. Methods: In this study, the expression profiles of NEK6 in OC and its roles in the development of OC were investigated. The expression profiles of NEK6 across cancers and OC were explored using bioinformatics analysis, and its expression in OC patients was detected by immunohistochemical (IHC) staining. The correlation between its expression and clinicopathological factors was also analyzed. Furthermore, the NEK6 levels in the tumor tissues of OC patients were detected via RT‒qPCR and Western blotting. Biological functions, including cell growth, migration, invasion and apoptosis, were analyzed using MTT, Transwell and flow cytometry assays, respectively. Results: Bioinformatics analysis revealed that NEK6 was highly expressed in most human cancers, including OC. IHC revealed 67.27% moderate or strong NEK6 staining in tumor tissues, 32.73% (36/110) weak staining, and negative or weak NEK6 staining in normal ovarian tissues, and its high expression was correlated with clinicopathological factors, including histological grade (P=0.008) and metastasis (P=0.006). The Kaplan‒Meier survival curve revealed that OC patients with high expression of NEK6 had poorer overall survival rates (P=0.025). NEK6 was overexpressed in OC tissues and SK-OV-3 and A2780 cells, and when NEK6 was knocked down with siRNAs, cell growth, migration and invasion were inhibited, whereas cell apoptosis was significantly promoted. Conclusion: NEK6 is highly expressed in OC; its overexpression indicates poor prognosis; and NEK6 knockdown leads to inhibited growth, migration and invasion while promoting the apoptosis of OC cells. These findings indicate that NEK6 is a potential oncogene and a poor prognostic factor in OC, suggesting that NEK6 can serve as a new therapeutic candidate for OC and that NEK6 inhibition may be an effective strategy for OC treatment.