Nek2 (
NIMA-related kinase 2) is involved in cell division and mitotic regulation by centrosome splitting. We previously reported that Nek2 depletion causes growth suppression and cell death in
cholangiocarcinoma and
breast cancer cells. In this report, we examine the effect of a combination treatment using Nek2
siRNA with the cytotoxic chemotherapeutic agent
cisplatin (CDDP) on
colorectal cancer. Nek2 was overexpressed in all
colorectal cancer cell lines examined (HCT-15, DLD-1, Colo205, and Colo320). Nek2
short-interfering RNA (
siRNA) resulted in the inhibition of cell proliferation and the induction of apoptosis in vitro. Nek2
siRNA suppressed
tumor growth compared to control
siRNA in a xenograft mouse model. To investigate the potential utility of Nek2
siRNA for clinical
cancer therapy, we examine the effect of a combination treatment using Nek2
siRNA with CDDP on
colorectal cancer. The combined administration of both Nek2
siRNA and CDDP inhibited cell proliferation and induced apoptotic cell death in vitro. Furthermore, the combined administration of both Nek2
siRNA and CDDP suppressed
tumor growth compared to either the single administration of Nek2
siRNA or the combined administration of control
siRNA and CDDP. Our results suggest that combination treatment using Nek2
siRNA and chemotherapeutic agents may be an effective therapeutic option for
colorectal cancer.