Project description:A variety of cancers utilize RAS-regulated signaling pathways to promote oncogenic phenotypes. A widely studied example is pancreatic cancer, where mutant KRAS signaling leads to activation of MEK/ERK kinases and downstream signaling which promotes oncogenic mechanisms, including cell proliferation. Importantly, ERK inhibitors have shown efficacy in some cancer clinical trials. Previously, others have studied the effects of the related kinases TBK1 and IKKε in pancreatic cancer where they have been shown to promote cell survival. Here, we show that RAS/MAPK signaling promotes expression of IKKε through control of protein stability and not through control of RNA levels. RNAseq analysis indicate that TBK1 and IKKε contribute to the expression of a subset of ERK-regulated genes. Potentially related to the effects on IKKε, proteomic analysis reveals that ERK functions to stabilize a relatively large set of proteins independent of RNA regulation. Knockdown of IKKε and TBK1 individually does not affect growth of MIA PaCa-2 pancreatic cancer cells, but dual knockdown significantly inhibits MIA PaCa-2 growth which is mediated through cell death. Concurrent silencing or inhibition of both TBK1 and IKKε also reduces tumor sphere growth in MIA PaCa-2 cells, correlating with a loss of stemness pathways found with RNAseq. The data suggest the importance of regulation of IKKε by ERK in pancreatic cancer cells and of the combined oncogenic activity of TBK1 and IKKε.
Project description:A variety of cancers utilize RAS-regulated signaling pathways to promote oncogenic phenotypes. A widely studied example is pancreatic cancer, where mutant KRAS signaling leads to activation of MEK/ERK kinases and downstream signaling which promotes oncogenic mechanisms, including cell proliferation. Importantly, ERK inhibitors have shown efficacy in some cancer clinical trials. Previously, others have studied the effects of the related kinases TBK1 and IKKε in pancreatic cancer where they have been shown to promote cell survival. Here, we show that RAS/MAPK signaling promotes expression of IKKε through control of protein stability and not through control of RNA levels. RNAseq analysis indicate that TBK1 and IKKε contribute to the expression of a subset of ERK-regulated genes. Potentially related to the effects on IKKε, proteomic analysis reveals that ERK functions to stabilize a relatively large set of proteins independent of RNA regulation. Knockdown of IKKε and TBK1 individually does not affect growth of MIA PaCa-2 pancreatic cancer cells, but dual knockdown significantly inhibits MIA PaCa-2 growth which is mediated through cell death. Concurrent silencing or inhibition of both TBK1 and IKKε also reduces tumor sphere growth in MIA PaCa-2 cells, correlating with a loss of stemness pathways found with RNAseq. The data suggest the importance of regulation of IKKε by ERK in pancreatic cancer cells and of the combined oncogenic activity of TBK1 and IKKε.
Project description:b-cell proliferation induction is one of the most tangible therapeutic strategies to restore b-cell mass. However, this approach has proven challenging due to a remarkable resistance of adult human b-cells to proliferation. Here we aim to unravel the role of a non-canonical IkB kinase TBK1 (TANK-binding kinase 1), which is predominantly expressed in b-cells in mammalian islets, in regulating cell cycle progression. Genetic silencing of TBK1 in INS-1 832/13 rat b-cell line promoted proliferation of b-cells. Proteomic and transcriptome analyses further revealed changes of proteins and genes critical for cell growth and proliferation, including upregulation of ribosomal proteins and cell cycle regulators, upon depletion of TBK1. TBK1 overexpression decreased sensitivity of b-cells to the elevation of cAMP levels and reduced proliferation of b-cells in a manner dependent on the activity of phosphodiesterase 3 (PDE3). Importantly, pharmacological inhibition of TBK1 using (E)3-(3-phenylbenzo[c]isoxazol-5-yl) acrylic acid (PIAA) augmented proliferation and function of rat and human embryonic stem cell (hESC)-derived insulin-producing b-cells under basal conditions. Diabetogenic insults further induced TBK1 expression and accordingly, PIAA protected b-cells against cytokine- and streptozotocin-induced diabetogenic challenges and promoted b-cell replication. Furthermore, PIAA increased proliferation of β-cells in normal and type 2 diabetic human islets with elevation in insulin secretion. Altogether, these data unveil novel and essential function of TBK1 as a key cell-autonomous negative regulator of b-cell replication and presenting PIAA as a valid therapeutic strategy for augmenting proliferation and function of b-cells.
Project description:B-DNA-induced gene expression profile in wild-type, TBK1, IKKi(Ikbke), or TBK1 IKKi doubly deficient embryonic fibroblats; to elucidate how TBK1 and/or IKKi mediates B-DNA-mediated innate immune responses. Experiment Overall Design: Total RNA was extracted from embryonic fibroblats transfected for 4 h with or without poly(dA-dT)-poly(dT-dA), after which cRNA was synthesized. Preparation of cRNA, hybridization and scanning of the microarray were done according to the manufacturer's instructions (Affymetrix). A microarray (MG U74A version 2; Affymetrix) was used with Microarray Suite software (version 5.0; Affymetrix) and GeneSpring software (Silicon Genetics).
Project description:MicroRNA (miRNA) expression profiles for pancreatic endocrine tumors were examined to investigate the miRNA involvement in pancreatic carcinogenesis. miRNA microarray analysis identified statistical unique profiles, which could discriminate pancreatic cancers from noncancerous pancreas tissues.
Project description:Recent studies have demonstrated critical roles for TBK1 in regulation of activity of numerous immune cell types, including T cells, B cells, dendritic cells, and macrophages. To examine the effect of TBK1 inhibition on the tumor immune microenvironment, we performed scRNA-seq on CD45+ cells from B16-OVA tumors from mice treated with anti-PD-1, TBK1i, or anti-PD-1 plus TBK1i, compared to isotype control (IgG).
Project description:The receptor tyrosine kinase AXL promotes tumor progression, metastasis and therapy resistance through the induction of epithelial-mesenchymal transition (EMT). Here, we report that activation of AXL results in TANK-binding kinase 1 (TBK1) phosphorylation, subsequent TBK1-dependent phosphorylation of AKT3 (pAKT3) and nuclear accumulation of pAKT3 and the EMT transcription factor (EMT-TF) Snail. Mechanistically, we show that (i) TBK1 directly binds and phosphorylates AKT3, in an mTORC1 dependent manner. Once activated, AKT3 interacts with Snail and promotes the accumulation of nuclear Snail to drive EMT. Congruently, in human pancreatic ductaladenocarcinoma tissue, nuclear AKT3 co-localizes with Snail and correlates with worse clinical outcome. AKT3 knockout in tumor cells significantly reduced metastatic spread in mice suggesting that selective AKT3 inhibition represents a novel therapeutic avenue for targeting EMT in aggressive cancers.
Project description:The purpose of the dataset is to analyze expression of genes induced by KRAS and regulated by TBK1; The proto-oncogene KRAS is mutated in a wide array of human cancers, most of which are aggressive and respond poorly to standard therapies. Although the identification of specific oncogenes has led to the development of clinically effective, molecularly targeted therapies in some cases, KRAS has remained refractory to this approach. An alternative strategy for targeting KRAS is to identify gene products that, when suppressed or inhibited, result in cell death only in the presence of an oncogenic allele. Here we have used systematic RNA interference (RNAi) to detect synthetic lethal partners of oncogenic KRAS and found that the non-canonical IkB kinase, TBK1, was selectively essential in cells that harbor mutant KRAS. Suppression of TBK1 induced apoptosis specifically in human cancer cell lines that depend on oncogenic KRAS expression. In these cells, TBK1 activated NF- B anti-apoptotic signals involving cREL and BCL-XL that were essential for survival, providing mechanistic insights into this synthetic lethal interaction. These observations identify TBK1 as a potential therapeutic target in KRAS mutant tumors and establish a general approach for the rational identification of co-dependent pathways in cancer. Experiment Overall Design: Knock out of TBK1 in the contect of KRAS activation (mutant) and control (WT)