NEK9 depletion induces catastrophic mitosis by impairment of mitotic checkpoint control and spindle dynamics

Area of Science:

• Molecular Biology
• Cell Biology
• Cancer Research

Background:

• NEK9 (NIMA-related kinase 9) is implicated in spindle assembly and centrosome separation.
• The therapeutic potential of targeting NEK9 in cancer remains largely unexplored.
• Glioblastoma and kidney cancer are aggressive malignancies with unmet therapeutic needs.

Purpose of the Study:

• To investigate the consequences of NEK9 depletion in glioblastoma and kidney cancer cells.
• To assess the potential of NEK9 as an anti-cancer therapeutic target.
• To elucidate the role of NEK9 in mitotic regulation and checkpoint control.

Main Methods:

• Small interfering RNA (siRNA) was used to deplete NEK9 expression in cancer cell lines (U1242 glioblastoma, Caki2 kidney carcinoma) and a normal cell line (RPE1).
• Live cell imaging was employed to observe cellular behavior during mitosis and cytokinesis.
• Nocodazole was used to induce mitotic arrest to assess the integrity of the mitotic checkpoint.

Main Results:

• NEK9 depletion led to failed cytokinesis in U1242 and Caki2 cells.
• NEK9-depleted Caki2 cells exhibited abnormal mitosis, micronucleation, and subsequent cell death.
• Normal RPE1 cells were resistant to NEK9 knockdown-induced mitotic defects, and NEK9 depletion impaired nocodazole-induced mitotic arrest.

Conclusions:

• NEK9 plays a critical role in maintaining mitotic fidelity and checkpoint control.
• Targeting NEK9 induces mitotic catastrophe through impaired spindle dynamics, cytokinesis, and checkpoint function.
• NEK9 inhibition represents a promising novel anti-cancer strategy.