Abstract 4880: A high-throughput siRNA screen identifies Nucleoside Diphosphate Kinase (NME3) as a novel host regulator of NF-êB signaling in response to Salmonella-induced activation of TLR-5

Abstract

Abstract Bacterial flagellin is a potent activator of NF-êB signaling, inflammation and host innate immunity. In comparison to TNFá, perhaps the most studied NF-êB-inducing ligand, flagellin elicits an overlapping, yet unique downstream transcriptional response by host cells. In contrast to the pro-oncogenic functions of TNFá, recent data indicate that flagellin may represent a novel anti-tumor ligand that acts through TLR5 and the NF-êB pathway to induce host immunity and to aid in the clearance of tumor xenografts. To begin to characterize the molecular basis for the anti-tumor effect of flagellin and to identify downstream innate signaling components of NF-êB that are responsible for the pro-inflammatory program necessary for these anti-tumor effects, we employed a high throughput screen. Utilizing HCT116 colon carcinoma cells expressing a dynamic NF-êB bioluminescent reporter and Salmonella typhimurium expressing flagellin, we performed a live cell screen of a siRNA library targeting 691 known and predicted human kinases to identify novel modulators of flagellin-induced NF-êB activation. This screen uncovered nucleoside diphosphate kinase (NME3) as a previously unrecognized, positive regulator of NF-êB signaling in response to flagellin. Targeted knockdown and overexpression assays confirmed the regulatory contribution of NME3. Furthermore, Kaplan-Meier survival analysis for breast, lung and ovarian cancer patients showed that high level expression of NME3 correlated with increased overall survival. Together, these data identify a novel pro-inflammatory role for NME3 in NF-êB signaling that may potentially be exploited to optimize cancer immunotherapy. Citation Format: Caleb Gonzalez, Kelly Flentie, Brandon Kocher, Jayne Jayne Marasa, David Piwnica-Worms. A high-throughput siRNA screen identifies Nucleoside Diphosphate Kinase (NME3) as a novel host regulator of NF-êB signaling in response to Salmonella-induced activation of TLR-5. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4880.