Development of a High-Throughput Assay for Identifying Inhibitors of TBK1 and IKKε

IKKε and TBK1 are noncanonical IKK family members which regulate inflammatory signaling pathways and also play important roles in oncogenesis. However, few inhibitors of these kinases have been identified. While the substrate specificity of IKKε has recently been described, the substrate specificity of TBK1 is unknown, hindering the development of high-throughput screening technologies for inhibitor identification. Here, we describe the optimal substrate phosphorylation motif for TBK1, and show that it is identical to the phosphorylation motif previously described for IKKε. This information enabled the design of an optimal TBK1/IKKε substrate peptide amenable to high-throughput screening and we assayed a 6,006 compound library that included 4,727 kinase-focused compounds to discover in vitro inhibitors of TBK1 and IKKε. 227 compounds in this library inhibited TBK1 at a concentration of 10 µM, while 57 compounds inhibited IKKε. Together, these data describe a new high-throughput screening assay which will facilitate the discovery of small molecule TBK1/IKKε inhibitors possessing therapeutic potential for both inflammatory diseases and cancer

Cell-State-Specific Metabolic Dependency in Hematopoiesis and Leukemogenesis

The balance between oxidative and non-oxidative glucose metabolism is essential for a number of pathophysiological processes. By deleting enzymes that affect aerobic glycolysis with different potencies, we examine how modulating glucose metabolism specifically affects hematopoietic and leukemic cell populations. We find that deficiency in the M2 pyruvate kinase isoform (PKM2) reduces levels of metabolic intermediates important for biosynthesis and impairs progenitor function without perturbing hematopoietic stem cells (HSC), whereas lactate dehydrogenase-A (LDHA) deletion significantly inhibits the function of both HSC and progenitors during hematopoiesis. In contrast, leukemia initiation by transforming alleles putatively affecting either HSC or progenitors is inhibited in the absence of either PKM2 or LDHA, indicating that the cell state-specific responses to metabolic manipulation in hematopoiesis do not apply to the setting of leukemia. This finding suggests that fine-tuning the level of glycolysis may be therapeutically explored for treating leukemia while preserving HSC function.National Institutes of Health (U.S.) (Grants P30CA147882 and R01CA168653)Smith Family FoundationBurroughs Wellcome FundVirginia and D.K. Ludwig Fund for Cancer ResearchDamon Runyon Cancer Research Foundatio

2-Oxo-N-aryl-1,2,3,4-tetrahydroquinoline-6-sulfonamides as activators of the tumor cell specific M2 isoform of pyruvate kinase

Compared to normal differentiated cells, cancer cells have altered metabolic regulation to support biosynthesis and the expression of the M2 isozyme of pyruvate kinase (PKM2) plays an important role in this anabolic metabolism. While the M1 isoform is a highly active enzyme, the alternatively spliced M2 variant is considerably less active and expressed in tumors. While the exact mechanism by which decreased pyruvate kinase activity contributes to anabolic metabolism remains unclear, it is hypothesized that activation of PKM2 to levels seen with PKM1 may promote a metabolic program that is not conducive to cell proliferation. Here we report the third chemotype in a series of PKM2 activators based on the 2-oxo-N-aryl-1,2,3,4-tetrahydroquinoline-6-sulfonamide scaffold. The synthesis, structure activity relationships, selectivity and notable physiochemical properties are described.National Human Genome Research Institute (U.S.) (Molecular Libraries Initiative of the NIH Roadmap for Medical Research

Hope in dirt: report of the Fort Apache Workshop on Forensic Sedimentology Applications to Cultural Property Crime, 15—19 October 2018

A 2018 workshop on the White Mountain Apache Tribe lands in Arizona examined ways to enhance investigations into cultural property crime (CPC) through applications of rapidly evolving methods from archaeological science. CPC (also looting, graverobbing) refers to unauthorized damage, removal, or trafficking in materials possessing blends of communal, aesthetic, and scientific values. The Fort Apache workshop integrated four generally partitioned domains of CPC expertise: (1) theories of perpetrators’ motivations and methods; (2) recommended practice in sustaining public and community opposition to CPC; (3) tactics and strategies for documenting, investigating, and prosecuting CPC; and (4) forensic sedimentology—uses of biophysical sciences to link sediments from implicated persons and objects to crime scenes. Forensic sedimentology served as the touchstone for dialogues among experts in criminology, archaeological sciences, law enforcement, and heritage stewardship. Field visits to CPC crime scenes and workshop deliberations identified pathways toward integrating CPC theory and practice with forensic sedimentology’s potent battery of analytic methods

A co-clinical approach identifies mechanisms and potential therapies for androgen deprivation resistance in prostate cancer

Here we report an integrated analysis that leverages data from treatment of genetic mouse models of prostate cancer along with clinical data from patients to elucidate new mechanisms of castration resistance. We show that castration counteracts tumor progression in a Pten-loss driven mouse model of prostate cancer through the induction of apoptosis and proliferation block. Conversely, this response is bypassed upon deletion of either Trp53 or Lrf together with Pten, leading to the development of castration resistant prostate cancer (CRPC). Mechanistically, the integrated acquisition of data from mouse models and patients identifies the expression patterns of XAF1-XIAP/SRD5A1 as a predictive and actionable signature for CRPC. Importantly, we show that combined inhibition of XIAP, SRD5A1, and AR pathways overcomes castration resistance. Thus, our co-clinical approach facilitates stratification of patients and the development of tailored and innovative therapeutic treatments

Pyruvate kinase M2 activators promote tetramer formation and suppress tumorigenesis

Cancer cells engage in a metabolic program to enhance biosynthesis and support cell proliferation. The regulatory properties of pyruvate kinase M2 (PKM2) influence altered glucose metabolism in cancer. PKM2 interaction with phosphotyrosine-containing proteins inhibits enzyme activity and increases availability of glycolytic metabolites to support cell proliferation. This suggests that high pyruvate kinase activity may suppress tumor growth. We show that expression of PKM1, the pyruvate kinase isoform with high constitutive activity, or exposure to published small molecule PKM2 activators inhibit growth of xenograft tumors. Structural studies reveal that small molecule activators bind PKM2 at the subunit interaction interface, a site distinct from that of the endogenous activator fructose-1,6-bisphosphate (FBP). However, unlike FBP, binding of activators to PKM2 promotes a constitutively active enzyme state that is resistant to inhibition by tyrosine-phosphorylated proteins. These data support the notion that small molecule activation of PKM2 can interfere with anabolic metabolism

Metabolic and Functional Genomic Studies Identify Deoxythymidylate Kinase as a Target in LKB1-Mutant Lung Cancer

The LKB1/STK11 tumor suppressor encodes a serine/threonine kinase which coordinates cell growth, polarity, motility, and metabolism. In non-small cell lung cancer, LKB1 is somatically inactivated in 25-30% of cases, often concurrently with activating KRAS mutation. Here, we employed an integrative approach to define novel therapeutic targets in KRAS-driven LKB1 mutant lung cancers. High-throughput RNAi screens in lung cancer cell lines from genetically engineered mouse models driven by activated KRAS with or without coincident Lkb1 deletion led to the identification of Dtymk, encoding deoxythymidylate kinase which catalyzes dTTP biosynthesis, as synthetically lethal with Lkb1 deficiency in mouse and human lung cancer lines. Global metabolite profiling demonstrated that Lkb1-null cells had striking decreases in multiple nucleotide metabolites as compared to the Lkb1-wt cells. Thus, LKB1 mutant lung cancers have deficits in nucleotide metabolism conferring hypersensitivity to DTYMK inhibition, suggesting that DTYMK is a potential therapeutic target in this aggressive subset of tumors

Vascular Endothelial Growth Factor Induces Branching Morphogenesis/Tubulogenesis in Renal Epithelial Cells in a Neuropilin-Dependent Fashion

Vascular endothelial growth factor (VEGF) is well characterized for its role in endothelial cell differentiation and vascular tube formation. Alternate splicing of the VEGF gene in mice results in various VEGF-A isoforms, including VEGF-121 and VEGF-165. VEGF-165 is the most abundant isoform in the kidney and has been implicated in glomerulogenesis. However, its role in the tubular epithelium is not known. We demonstrate that VEGF-165 but not VEGF-121 induces single-cell branching morphogenesis and multicellular tubulogenesis in mouse renal tubular epithelial cells and that these morphogenic effects require activation of the phosphatidylinositol 3-kinase (PI 3-K) and, to a lesser degree, the extracellular signal-regulated kinase and protein kinase C signaling pathways. Further, VEGF-165-stimulated sheet migration is dependent only on PI 3-K signaling. These morphogenic effects of VEGF-165 require activation of both VEGF receptor 2 (VEGFR-2) and neuropilin-1 (Nrp-1), since neutralizing antibodies to either of these receptors or the addition of semaphorin 3A (which blocks VEGF-165 binding to Nrp-1) prevents the morphogenic response and the phosphorylation of VEGFR-2 along with the downstream signaling. We thus conclude that in addition to endothelial vasculogenesis, VEGF can induce renal epithelial cell morphogenesis in a Nrp-1-dependent fashion

Cytomorphology and diagnostic pitfalls of sebaceous and nonsebaceous salivary gland lymphadenoma: A multi‐institutional study

BackgroundSalivary gland lymphadenoma (LAD) is a rare benign neoplasm comprising sebaceous (SLAD) and nonsebaceous (NSLAD) types. Despite established histologic criteria, limited data on cytomorphology, tumor heterogeneity, and overlap with other entities make the diagnosis of LAD by fine needle aspiration (FNA) challenging. We describe a multi‐institutional cohort of 14 LADs with cytology, clinical, radiologic, and histopathologic data.MethodsOur cohort included nine SLAD and five NSLAD with corresponding histopathology. Mean patient age and M:F ratio were 60.4 years (range 45‐86 years) and 1:2 for SLADs and 57.4 years (range 42‐80 years) and 1:1.5 for NSLADs, respectively. One NSLAD patient had a germline predisposition for Cowden syndrome. Glass slides and whole slide images of air‐dried Diff‐Quik (DQ), alcohol‐stained Papanicolaou smears (Pap) and cellblocks were reviewed for key cytomorphologic findings.ResultsFNAs from SLAD and NSLADs demonstrated vacuolated and basaloid epithelial clusters within a lymphoid background. Vacuolated cells from SLAD showed sebaceous cells with microvesicular cytoplasm indenting a central nucleus. Vacuolated cells from NSLAD were columnar with eccentric nuclei, corresponding to abluminal glandular cells. SLADs were classified using the Milan System for Reporting Salivary Gland Cytopathology as nondiagnostic (11.1%), nonneoplastic (44.4%), atypia of uncertain significance (AUS) (22.2%), and salivary gland neoplasm of uncertain malignant potential (SUMP) (22.2%). NSLADs were classified as AUS (40%), SUMP (40%) and Benign Neoplasm (20%).ConclusionAlthough rare, knowing the cytologic features of salivary LAD is important to avoid diagnostic pitfalls. Vacuolated cells can be prominent in both SLAD and NSLAD aspirates. Diagnostic issues arise from insufficient sampling of all tumor components leading to marked variation in diagnostic classification of LAD.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163841/1/dc24602_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163841/2/dc24602.pd