Project description:Doublecortin like kinase 1 (DCLK1) is an understudied kinase that is upregulated in a wide range of cancers, including pancreatic ductal adenocarcinoma (PDAC). However, little is known about its potential as a therapeutic target. We leveraged chemoproteomic profiling and structure-based design to develop the first selective, in vivo-compatible chemical probe of the DCLK1 kinase domain, DCLK1-IN-1. We demonstrate activity of DCLK1-IN-1 against clinically relevant patient-derived PDAC organoid models and use a combination of RNA sequencing, proteomics and phosphoproteomics analysis to reveal that DCLK1 inhibition modulates proteins and pathways associated with cell motility in this context. DCLK1-IN-1 will serve as a versatile tool to investigate DCLK1 biology and establish its role in cancer.
Project description:Doublecortin like kinase 1 (DCLK1) is an understudied kinase that is upregulated in a wide range of cancers, including pancreatic ductal adenocarcinoma (PDAC). However, little is known about its potential as a therapeutic target. We used chemoproteomic profiling and structure-based design to develop a selective, in vivo-compatible chemical probe of the DCLK1 kinase domain, DCLK1-IN-1. We demonstrate activity of DCLK1-IN-1 against clinically relevant patient-derived PDAC organoid models and use a combination of RNA-sequencing, proteomics and phosphoproteomics analysis to reveal that DCLK1 inhibition modulates proteins and pathways associated with cell motility in this context. DCLK1-IN-1 will serve as a versatile tool to investigate DCLK1 biology and establish its role in cancer.
Project description:Doublecortin-like kinase 1 (DCLK1), a microtubule-associated protein kinase, is involved in neurogenesis, and its levels are elevated in various human cancers. Recent studies suggest that DCLK1 may relate to inflammatory responses in the mouse model of colitis. However, cellular pathways engaged by DCLK1, and potential substrates of the kinase remain undefined. To understand how DCLK1 regulates inflammatory responses, we utilized the well-established lipopolysaccharide (LPS)-stimulated macrophages and mouse model. Through a range of macrophage-based and cell-free platforms, we discovered that DCLK1 binds directly with the inhibitor of κB kinase β (IKKβ) and induces IKKβ phosphorylation on Ser177/181 to initiate nuclear factor-κB (NF-κB) pathway. Deficiency in DCLK1, achieved by silencing or through pharmacological inhibition, prevented LPS-induced NF-κB activation and cytokine production in macrophages. We further show that mice with myeloid-specific DCLK1 knockout or DCLK1 inhibitor treatment are protected against LPS-induced acute lung injury and septic death. Our studies report a novel functional role of macrophage DCLK1 as a direct IKKβ regulator in inflammatory signaling and suggest targeted therapy against DCLK1 for inflammatory diseases.
Project description:Exploiting an Asp-Glu “switch” in glycogen synthase kinase 3 to design paralog selective inhibitors for use in acute myeloid leukemia: Genome-wide transcriptional profiles for the GSK3α selective inhibitor BRD0507 and for the GSK3α/β dual inhibitor BRD0320 Glycogen synthase kinase 3 (GSK3), a key regulatory kinase in the WNT pathway, remains a therapeutic target of interest in many diseases. While dual GSK3α/β inhibitors have entered clinical trials, none has successfully translated to clinical application. Mechanism-based toxicities, driven in part by the inhibition of both GSK3 paralogs and subsequent β-catenin stabilization, are a concern in the translation of this target class to cancer therapy, particularly for the treatment of acute myeloid leukemia (AML). Knockdown of GSK3α or GSK3β individually does not increase β-catenin in certain cellular subtypes and offers a conceptual resolution to targeting GSK3: paralog-selective inhibition. However, only inadequate chemical tools exist. The design of selective ATP competitive inhibitors poses a drug discovery challenge due to the high homology (95% identity, 100% similarity) in their ATP binding domains. Taking advantage of an Asp133®Glu196 “switch” in their hinge binding domains, we present a rational design strategy towards the discovery of a paralog selective set of GSK3 inhibitors. These first-in-class GSK3α and GSK3β selective inhibitors provided insights into GSK3 targeting in AML where GSK3α has been identified as a therapeutic target using genetic approaches. Our GSK3α selective compound (BRD0705) inhibits kinase function and does not stabilize β-catenin, mitigating potential neoplastic concerns. BRD0705 induces myeloid differentiation and impairs colony formation in AML cells while no effect is observed on normal hematopoietic cells. Moreover, BRD0705 impairs leukemia initiation and prolongs survival in AML mouse models. These studies validate feasibility of paralog selective GSK3α inhibition offering a promising therapeutic approach in AML.
Project description:Exploiting an Asp-Glu “switch” in glycogen synthase kinase 3 to design paralog selective inhibitors for use in acute myeloid leukemia: Genome-wide transcriptional profile for the GSK3β selective inhibitor BRD3731. Glycogen synthase kinase 3 (GSK3), a key regulatory kinase in the WNT pathway, remains a therapeutic target of interest in many diseases. While dual GSK3α/β inhibitors have entered clinical trials, none has successfully translated to clinical application. Mechanism-based toxicities, driven in part by the inhibition of both GSK3 paralogs and subsequent β-catenin stabilization, are a concern in the translation of this target class to cancer therapy, particularly for the treatment of acute myeloid leukemia (AML). Knockdown of GSK3α or GSK3β individually does not increase β-catenin in certain cellular subtypes and offers a conceptual resolution to targeting GSK3: paralog-selective inhibition. However, only inadequate chemical tools exist. The design of selective ATP competitive inhibitors poses a drug discovery challenge due to the high homology (95% identity, 100% similarity) in their ATP binding domains. Taking advantage of an Asp133®Glu196 “switch” in their hinge binding domains, we present a rational design strategy towards the discovery of a paralog selective set of GSK3 inhibitors. These first-in-class GSK3α and GSK3β selective inhibitors provided insights into GSK3 targeting in AML where GSK3α has been identified as a therapeutic target using genetic approaches. Our GSK3α selective compound (BRD0705) inhibits kinase function and does not stabilize β-catenin, mitigating potential neoplastic concerns. BRD0705 induces myeloid differentiation and impairs colony formation in AML cells while no effect is observed on normal hematopoietic cells. Moreover, BRD0705 impairs leukemia initiation and prolongs survival in AML mouse models. These studies validate feasibility of paralog selective GSK3α inhibition offering a promising therapeutic approach in AML.