- Chen, Yumay;
- Chen, Chi-Fen;
- Chiang, Huai-Chin;
- Pena, Michelle;
- Polci, Rosaria;
- Wei, Randy L;
- Edwards, Robert A;
- Hansel, Donna E;
- Chen, Phang-Lang;
- Riley, Daniel J
Background: NEK1, the first mammalian ortholog of the fungal protein kinase never-in-mitosis A (NIMA), is involved early in the DNA damage sensing/repair pathway. A defect in DNA repair in NEK1-deficient cells is suggested by persistence of DNA double strand breaks after low dose ionizing radiation (IR). NEK1-deficient cells also fail to activate the checkpoint kinases CHK1 and CHK2, and fail to arrest properly at G1/S or G2/M-phase checkpoints after DNA damage. Results: We show here that NEK1-deficient cells suffer major errors in mitotic chromosome segregation and cytokinesis, and become aneuploid. These NEK1-deficient cells transform, acquire the ability to grow in anchorageindependent conditions, and form tumors when injected into syngeneic mice. Genomic instability is also manifest in NEK1 +/- mice, which late in life develop lymphomas with a much higher incidence than wild type littermates. Conclusion: NEK1 is required for the maintenance of genome stability by acting at multiple junctures, including control of chromosome stability.