A gemcitabine sensitivity screen identifies a role for NEK9 in the replication stress response

作者：Smith Scott C; Petrova Aleksandra V; Madden Matthew Z; Wang Hongyan; Pan Yunfeng; Warren Matthew D; Hardy Claire W; Liang Dong; Liu Elaine A; Robinson M Hope; Rudra Soumon; Wang Jie; Ehdaivand Shahrzad; Torres Mylin A; Wang Ya; Yu David S^*

来源：Nucleic Acids Research, 2014, 42(18): 11517-11527.

DOI：10.1093/nar/gku840

The Replication Stress Response (RSR) is a signaling network that recognizes challenges to DNA replication and coordinates diverse DNA repair and cellcycle checkpoint pathways. Gemcitabine is a nucleoside analogue that causes cytotoxicity by inducing DNA replication blocks. Using a synthetic lethal screen of a RNAi library of nuclear enzymes to identify genes that when silenced cause gemcitabine sensitization or resistance in human triple-negative breast cancer cells, we identified NIMA (never in mitosis gene A)-related kinase 9 (NEK9) as a key component of the RSR. NEK9 depletion in cells leads to replication stress hypersensitivity, spontaneous accumulation of DNA damage and RPA70 foci, and an impairment in recovery from replication arrest. NEK9 protein levels also increase in response to replication stress. NEK9 complexes with CHK1, and moreover, NEK9 depletion impairs CHK1 autophosphorylation and kinase activity in response to replication stress. Thus, NEK9 is a critical component of the RSR that promotes CHK1 activity, maintaining genome integrity following challenges to DNA replication.

• 出版日期2014-10-13