Nek6 mediates human cancer cell transformation and is a potential cancer therapeutic target.

We investigated the role of Nek6, a member of the NIMA-related serine/threonine kinase family, in tumorigenesis. Transcript, protein, and kinase activity levels of Nek6 were highly elevated in the malignant tumors and human cancer cell lines compared with normal tissue and fibroblast cells. Expression of exogenous wild-type Nek6 increased anchorage-independent growth of a variety of human cancer cell lines, whereas overexpression of the kinase-dead Nek6 and RNAi knockdown of endogenous Nek6 suppressed cancer cell transformation and induced apoptosis. Additionally, in in vivo xenograft nude mouse model, knockdown of Nek6 in HeLa cells resulted in reduction of tumor size relative to control siRNA tumors. Most importantly, knocking down endogenous Nek6 levels or exogenous expression of the kinase-dead form did not inhibit cell proliferation, nor did it induce apoptosis in normal fibroblast cells. Taken together, our data indicate a pivotal role for Nek6 in tumorigenesis and establish Nek6 as a potential target for treatment of a variety of human cancers.