Nek2 siRNA therapy(Nagoya University)

Never in mitosis A (NIMA)-related kinase 2 (NEK2) is a serine/threonine kinase found in the nucleus and cytoplasm throughout the cell cycle. NEK2 is overexpressed in many cancers and is a biomarker of poor prognosis. Factors contributing to NEK2 elevation in cancer cells include oncogenic transcription factors, decreased ubiquitination, DNA methylation, and the circular RNA (circRNA)/long noncoding RNA (lncRNA)-miRNA axis. NEK2 overexpression produces chromosomal instability and aneuploidy, thereby enhancing cancer progression and suppressing antitumor immunity, which highlights the prominence of NEK2 in tumorigenesis and tumor progression. Small-molecule inhibitors targeting NEK2 have demonstrated promising therapeutic potential in vitro and in vivo across various cancer types. This review outlines the regulatory mechanisms of NEK2 expression, emphasizes its functional roles in cancer initiation and progression, and highlights the anticancer properties of NEK2 inhibitors.

Expression of the serine/threonine kinase never in mitosis gene A (NIMA)–related kinase 2 (NEK2) is essential for entry into mitosis via its role in facilitating centrosome separation. Its overactivity can lead to tumorigenesis and drug resistance through the activation of several oncogenic pathways, including AKT. Although the cancer-enabling activities of NEK2 are documented in many malignancies, including correlations with poor survival in myeloma, breast, and non–small cell lung cancer, little is known about the role of NEK2 in lymphoma. Here, in tumors from patients with diffuse large B-cell lymphoma (DLBCL), the most common, aggressive non-Hodgkin lymphoma, we found a high abundance of NEK2 mRNA and protein associated with an inferior overall survival. Using our recently developed NEK2 inhibitor, NBI-961, we discovered that DLBCL cell lines and patient-derived cells exhibit a dependency on NEK2 for their viability. This compromised cell fitness was directly attributable to efficient NEK2 inhibition and proteasomal degradation by NBI-961. In a subset of particularly sensitive DLBCL cells, NBI-961 induced G2/mitosis arrest and apoptosis. In contrast, an existing indirect NEK2 inhibitor, INH154, did not prevent NEK2 autophosphorylation, induce NEK2 proteasomal degradation, or affect cell viability. Global proteomics and phospho-proteomics revealed that NEK2 orchestrates cell-cycle and apoptotic pathways through regulation of both known and new signaling molecules. We show the loss of NEK2-sensitized DLBCL to the chemotherapy agents, doxorubicin and vincristine, and effectively suppressed tumor growth in mice. These studies establish the oncogenic activity of NEK2 in DLBCL and set the foundation for development of anti-NEK2 therapeutic strategies in this frequently refractory and relapse-prone cancer.