22 results on '"Ying-Hui Ko"'
Search Results
2. Heme and hemoglobin utilization by Mycobacterium tuberculosis
- Author
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Avishek Mitra, Ying-Hui Ko, Gino Cingolani, and Michael Niederweis
- Subjects
Science - Abstract
Iron is essential for growth of Mycobacterium tuberculosis, but most of the iron in the human body is stored in heme within hemoglobin. Here, Mitra et al. identify two heme uptake mechanisms in M. tuberculosis, one dependent on the inner-membrane Dpp importer and the other dependent on host albumin.
- Published
- 2019
- Full Text
- View/download PDF
3. Learning from Nature: From a Marine Natural Product to Synthetic Cyclooxygenase‐1 Inhibitors by Automated De Novo Design
- Author
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Lukas Friedrich, Gino Cingolani, Ying‐Hui Ko, Mariaclara Iaselli, Morena Miciaccia, Maria Grazia Perrone, Konstantin Neukirch, Veronika Bobinger, Daniel Merk, Robert Klaus Hofstetter, Oliver Werz, Andreas Koeberle, Antonio Scilimati, and Gisbert Schneider
- Subjects
chemoinformatics ,computational chemistry ,drug design ,machine learning ,natural product ,Science - Abstract
Abstract The repertoire of natural products offers tremendous opportunities for chemical biology and drug discovery. Natural product‐inspired synthetic molecules represent an ecologically and economically sustainable alternative to the direct utilization of natural products. De novo design with machine intelligence bridges the gap between the worlds of bioactive natural products and synthetic molecules. On employing the compound Marinopyrrole A from marine Streptomyces as a design template, the algorithm constructs innovative small molecules that can be synthesized in three steps, following the computationally suggested synthesis route. Computational activity prediction reveals cyclooxygenase (COX) as a putative target of both Marinopyrrole A and the de novo designs. The molecular designs are experimentally confirmed as selective COX‐1 inhibitors with nanomolar potency. X‐ray structure analysis reveals the binding of the most selective compound to COX‐1. This molecular design approach provides a blueprint for natural product‐inspired hit and lead identification for drug discovery with machine intelligence.
- Published
- 2021
- Full Text
- View/download PDF
4. Structural basis for nuclear import of hepatitis B virus (HBV) nucleocapsid core.
- Author
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Ruoyu Yang, Ying-Hui Ko, Fenglin Li, Lokareddy, Ravi K., Chun-Feng David Hou, Kim, Christine, Klein, Shelby, Antolínez, Santiago, Marín, Juan F., Pérez-Segura, Carolina, Jarrold, Martin F., Zlotnick, Adam, Hadden-Perilla, Jodi A., and Cingolani, Gino
- Abstract
Nuclear import of the hepatitis B virus (HBV) nucleocapsid is essential for replication that occurs in the nucleus. The ~360-angstrom HBV capsid translocates to the nuclear pore complex (NPC) as an intact particle, hijacking human importins in a reaction stimulated by host kinases. This paper describes the mechanisms of HBV capsid recognition by importins. We found that importin α1 binds a nuclear localization signal (NLS) at the far end of the HBV coat protein Cp183 carboxyl-terminal domain (CTD). This NLS is exposed to the capsid surface through a pore at the icosahedral quasi-sixfold vertex. Phosphorylation at serine-155, serine-162, and serine-170 promotes CTD compaction but does not affect the affinity for importin α1. The binding of 30 importin α1/β1 augments HBV capsid diameter to ~620 angstroms, close to the maximum size trafficable through the NPC. We propose that phosphorylation favors CTD externalization and prompts its compaction at the capsid surface, exposing the NLS to importins. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Recognition of an α-helical hairpin in P22 large terminase by a synthetic antibody fragment
- Author
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Ying-Hui Ko, Nathaniel Hong, Marcin Paduch, Ravi K. Lokareddy, Anthony A. Kossiakoff, Gino Cingolani, Michael Niederweis, and Steven G Doll
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Models, Molecular ,Nuclease ,Endodeoxyribonucleases ,biology ,Chemistry ,Stereochemistry ,Protein subunit ,biology.organism_classification ,Research Papers ,Epitope ,Synthetic antibody ,law.invention ,Bacteriophage ,Immunoglobulin Fab Fragments ,Viral Proteins ,Capsid ,Peptide Library ,Structural Biology ,law ,biology.protein ,Recombinant DNA ,Target protein ,Bacteriophage P22 ,Helix-Turn-Helix Motifs ,Protein Binding - Abstract
The genome-packaging motor of tailed bacteriophages and herpesviruses is a multisubunit protein complex formed by several copies of a large (TerL) and a small (TerS) terminase subunit. The motor assembles transiently at the portal protein vertex of an empty precursor capsid to power the energy-dependent packaging of viral DNA. Both the ATPase and nuclease activities associated with genome packaging reside in TerL. Structural studies of TerL from bacteriophage P22 have been hindered by the conformational flexibility of this enzyme and its susceptibility to proteolysis. Here, an unbiased, synthetic phage-display Fab library was screened and a panel of high-affinity Fabs against P22 TerL were identified. This led to the discovery of a recombinant antibody fragment, Fab4, that binds a 33-amino-acid α-helical hairpin at the N-terminus of TerL with an equilibrium dissociation constant K d of 71.5 nM. A 1.51 Å resolution crystal structure of Fab4 bound to the TerL epitope (TLE) together with a 1.15 Å resolution crystal structure of the unliganded Fab4, which is the highest resolution ever achieved for a Fab, elucidate the principles governing the recognition of this novel helical epitope. TLE adopts two different conformations in the asymmetric unit and buries as much as 1250 Å2 of solvent-accessible surface in Fab4. TLE recognition is primarily mediated by conformational changes in the third complementarity-determining region of the Fab4 heavy chain (CDR H3) that take place upon epitope binding. It is demonstrated that TLE can be introduced genetically at the N-terminus of a target protein, where it retains high-affinity binding to Fab4.
- Published
- 2020
6. Recognition of the TDP-43 nuclear localization signal by importin α1/β
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Steven G. Doll, Hamed Meshkin, Alexander J. Bryer, Fenglin Li, Ying-Hui Ko, Ravi K. Lokareddy, Richard E. Gillilan, Kushol Gupta, Juan R. Perilla, and Gino Cingolani
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Cell Nucleus ,DNA-Binding Proteins ,alpha Karyopherins ,Nuclear Localization Signals ,beta Karyopherins ,General Biochemistry, Genetics and Molecular Biology - Abstract
Cytoplasmic mislocalization of the TAR-DNA binding protein of 43 kDa (TDP-43) leads to large, insoluble aggregates that are a hallmark of amyotrophic lateral sclerosis and frontotemporal dementia. Here, we study how importin α1/β recognizes TDP-43 bipartite nuclear localization signal (NLS). We find that the NLS makes extensive contacts with importin α1, especially at the minor NLS-binding site. NLS binding results in steric clashes with the C terminus of importin α1 that disrupts the TDP-43 N-terminal domain (NTD) dimerization interface. A putative phosphorylation site in the proximity of TDP-43 R83 at the minor NLS site destabilizes binding to importins by reducing the NLS backbone dynamics. Based on these data, we explain the pathogenic role of several post-translational modifications and mutations in the proximity of TDP-43 minor NLS site that are linked to disease and shed light on the chaperone activity of importin α1/β.
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- 2021
7. A periplasmic cinched protein is required for siderophore secretion and virulence of Mycobacterium tuberculosis
- Author
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Lei Zhang, James E. Kent, Meredith Whitaker, David C. Young, Dominik Herrmann, Alexander E. Aleshin, Ying-Hui Ko, Gino Cingolani, Jamil S. Saad, D. Branch Moody, Francesca M. Marassi, Sabine Ehrt, and Michael Niederweis
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Mice ,Multidisciplinary ,Virulence ,Iron ,General Physics and Astronomy ,Animals ,Siderophores ,Tuberculosis ,General Chemistry ,Mycobacterium tuberculosis ,General Biochemistry, Genetics and Molecular Biology - Abstract
Iron is essential for growth of Mycobacterium tuberculosis, the causative agent of tuberculosis. To acquire iron from the host, M. tuberculosis uses the siderophores called mycobactins and carboxymycobactins. Here, we show that the rv0455c gene is essential for M. tuberculosis to grow in low-iron medium and that secretion of both mycobactins and carboxymycobactins is drastically reduced in the rv0455c deletion mutant. Both water-soluble and membrane-anchored Rv0455c are functional in siderophore secretion, supporting an intracellular role. Lack of Rv0455c results in siderophore toxicity, a phenotype observed for other siderophore secretion mutants, and severely impairs replication of M. tuberculosis in mice, demonstrating the importance of Rv0455c and siderophore secretion during disease. The crystal structure of a Rv0455c homolog reveals a novel protein fold consisting of a helical bundle with a ‘cinch’ formed by an essential intramolecular disulfide bond. These findings advance our understanding of the distinct M. tuberculosis siderophore secretion system.
- Published
- 2021
8. Learning from Nature: From a Marine Natural Product to Synthetic Cyclooxygenase-1 Inhibitors by Automated De Novo Design
- Author
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Veronika Bobinger, Morena Miciaccia, Ying-Hui Ko, Mariaclara Iaselli, Gino Cingolani, Robert Klaus Hofstetter, Oliver Werz, Gisbert Schneider, Maria Grazia Perrone, Konstantin Neukirch, Daniel Merk, Antonio Scilimati, Andreas Koeberle, and Lukas Friedrich
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natural product ,Structure analysis ,Computer science ,drug design ,Science ,General Chemical Engineering ,Chemical biology ,General Physics and Astronomy ,Medicine (miscellaneous) ,02 engineering and technology ,Computational biology ,010402 general chemistry ,01 natural sciences ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,chemoinformatics ,chemistry.chemical_compound ,Artificial Intelligence ,Drug Discovery ,Cyclooxygenase Inhibitors ,Pyrroles ,General Materials Science ,Research Articles ,Biological Products ,Natural product ,Drug discovery ,General Engineering ,021001 nanoscience & nanotechnology ,Small molecule ,computational chemistry ,machine learning ,0104 chemical sciences ,Marinopyrrole A ,chemistry ,Cheminformatics ,Identification (biology) ,0210 nano-technology ,Research Article - Abstract
The repertoire of natural products offers tremendous opportunities for chemical biology and drug discovery. Natural product-inspired synthetic molecules represent an ecologically and economically sustainable alternative to the direct utilization of natural products. De novo design with machine intelligence bridges the gap between the worlds of bioactive natural products and synthetic molecules. On employing the compound Marinopyrrole A from marine Streptomyces as a design template, the algorithm constructs innovative small molecules that can be synthesized in three steps, following the computationally suggested synthesis route. Computational activity prediction reveals cyclooxygenase (COX) as a putative target of both Marinopyrrole A and the de novo designs. The molecular designs are experimentally confirmed as selective COX-1 inhibitors with nanomolar potency. X-ray structure analysis reveals the binding of the most selective compound to COX-1. This molecular design approach provides a blueprint for natural product-inspired hit and lead identification for drug discovery with machine intelligence., Advanced Science, 8 (16), ISSN:2198-3844
- Published
- 2021
- Full Text
- View/download PDF
9. Heme and hemoglobin utilization by Mycobacterium tuberculosis
- Author
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Gino Cingolani, Avishek Mitra, Michael Niederweis, and Ying-Hui Ko
- Subjects
0301 basic medicine ,Heme binding ,Science ,Iron ,030106 microbiology ,General Physics and Astronomy ,Heme ,Crystallography, X-Ray ,General Biochemistry, Genetics and Molecular Biology ,Article ,Protein Structure, Secondary ,Mycobacterium tuberculosis ,03 medical and health sciences ,chemistry.chemical_compound ,Hemoglobins ,Protein structure ,Bacterial Proteins ,Albumins ,Metalloproteins ,Inner membrane ,Humans ,lcsh:Science ,Bacterial structural biology ,Antigens, Bacterial ,Multidisciplinary ,biology ,General Chemistry ,biology.organism_classification ,Blood proteins ,3. Good health ,030104 developmental biology ,Biochemistry ,chemistry ,Periplasmic Binding Proteins ,lcsh:Q ,Hemoglobin ,Pathogens ,Bacterial outer membrane ,Protein Binding - Abstract
Iron is essential for growth of Mycobacterium tuberculosis (Mtb), but most iron in the human body is stored in heme within hemoglobin. Here, we demonstrate that the substrate-binding protein DppA of the inner membrane Dpp transporter is required for heme and hemoglobin utilization by Mtb. The 1.27 Å crystal structure of DppA shows a tetrapeptide bound in the protein core and a large solvent-exposed crevice for heme binding. Mutation of arginine 179 in this cleft eliminates heme binding to DppA and prevents heme utilization by Mtb. The outer membrane proteins PPE36 and PPE62 are also required for heme and hemoglobin utilization, indicating that these pathways converge at the cell surface of Mtb. Albumin, the most abundant blood protein, binds heme specifically and bypasses the requirements for PPE36, PPE62 and Dpp. Thus, our study reveals albumin-dependent and -independent heme uptake pathways, highlighting the importance of iron acquisition from heme for Mtb., Iron is essential for growth of Mycobacterium tuberculosis, but most of the iron in the human body is stored in heme within hemoglobin. Here, Mitra et al. identify two heme uptake mechanisms in M. tuberculosis, one dependent on the inner-membrane Dpp importer and the other dependent on host albumin.
- Published
- 2019
10. Oncogenes and inflammation rewire host energy metabolism in the tumor microenvironment
- Author
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Richard G. Pestell, Ruth Birbe, Ubaldo E. Martinez-Outschoorn, Anthony Howell, Alessandro Bombonati, Edmund A. Pribitkin, Madalina Tuluc, Federica Sotgia, Ying-Hui Ko, David Cognetti, Zhao Lin, Michael P. Lisanti, and Joseph Curry
- Subjects
Tumor microenvironment ,Stromal cell ,Oncogene ,Inflammation ,Cell Biology ,Biology ,Cell biology ,Mitochondrial biogenesis ,Downregulation and upregulation ,Cancer cell ,medicine ,Reverse Warburg effect ,medicine.symptom ,Molecular Biology ,Developmental Biology - Abstract
Here, we developed a model system to evaluate the metabolic effects of oncogene(s) on the host microenvironment. A matched set of "normal" and oncogenically transformed epithelial cell lines were co-cultured with human fibroblasts, to determine the "bystander" effects of oncogenes on stromal cells. ROS production and glucose uptake were measured by FACS analysis. In addition, expression of a panel of metabolic protein biomarkers (Caveolin-1, MCT1, and MCT4) was analyzed in parallel. Interestingly, oncogene activation in cancer cells was sufficient to induce the metabolic reprogramming of cancer-associated fibroblasts toward glycolysis, via oxidative stress. Evidence for "metabolic symbiosis" between oxidative cancer cells and glycolytic fibroblasts was provided by MCT1/4 immunostaining. As such, oncogenes drive the establishment of a stromal-epithelial "lactate-shuttle", to fuel the anabolic growth of cancer cells. Similar results were obtained with two divergent oncogenes (RAS and NFκB), indicating that ROS production and inflammation metabolically converge on the tumor stroma, driving glycolysis and upregulation of MCT4. These findings make stromal MCT4 an attractive target for new drug discovery, as MCT4 is a shared endpoint for the metabolic effects of many oncogenic stimuli. Thus, diverse oncogenes stimulate a common metabolic response in the tumor stroma. Conversely, we also show that fibroblasts protect cancer cells against oncogenic stress and senescence by reducing ROS production in tumor cells. Ras-transformed cells were also able to metabolically reprogram normal adjacent epithelia, indicating that cancer cells can use either fibroblasts or epithelial cells as "partners" for metabolic symbiosis. The antioxidant N-acetyl-cysteine (NAC) selectively halted mitochondrial biogenesis in Ras-transformed cells, but not in normal epithelia. NAC also blocked stromal induction of MCT4, indicating that NAC effectively functions as an "MCT4 inhibitor". Taken together, our data provide new strategies for achieving more effective anticancer therapy. We conclude that oncogenes enable cancer cells to behave as selfish "metabolic parasites", like foreign organisms (bacteria, fungi, viruses). Thus, we should consider treating cancer like an infectious disease, with new classes of metabolically targeted "antibiotics" to selectively starve cancer cells. Our results provide new support for the "seed and soil" hypothesis, which was first proposed in 1889 by the English surgeon, Stephen Paget.
- Published
- 2013
11. TP53-inducible Glycolysis and Apoptosis Regulator (TIGAR) Metabolically Reprograms Carcinoma and Stromal Cells in Breast Cancer
- Author
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Àurea Navarro-Sabaté, Erin L. Seifert, Marina Domingo-Vidal, Megan Roche, Patrick Tassone, Diana Whitaker-Menezes, Jaime Caro, Ubaldo E. Martinez-Outschoorn, Claudia Capparelli, Ruth Birbe, Zhao Lin, Ramon Bartrons, Joseph Curry, Madalina Tuluc, Anna Manzano, and Ying-Hui Ko
- Subjects
0301 basic medicine ,Stromal cell ,Phosphofructokinase-2 ,Àcid glutàmic ,Glutamic Acid ,Apoptosis ,Breast Neoplasms ,Biology ,Bioenergetics ,Biochemistry ,Càncer de mama ,03 medical and health sciences ,0302 clinical medicine ,Breast cancer ,Carcinoma ,medicine ,Humans ,Glycolysis ,Lactic Acid ,Molecular Biology ,Tumor microenvironment ,L-Lactate Dehydrogenase ,Catabolism ,Intracellular Signaling Peptides and Proteins ,Cell Biology ,Fibroblasts ,medicine.disease ,TP53-inducible glycolysis and apoptosis regulator ,Molecular biology ,Metabolisme ,Coculture Techniques ,Phosphoric Monoester Hydrolases ,Glutamine ,Isoenzymes ,030104 developmental biology ,Metabolism ,030220 oncology & carcinogenesis ,Cancer research ,MCF-7 Cells ,Female ,Glutamic acid ,Lactate Dehydrogenase 5 ,Tumor Suppressor Protein p53 ,Breast carcinoma ,Apoptosis Regulatory Proteins - Abstract
A subgroup of breast cancers has several metabolic compartments. The mechanisms by which metabolic compartmentalization develop in tumors are poorly characterized. TP53 inducible glycolysis and apoptosis regulator (TIGAR) is a bisphosphatase that reduces glycolysis and is highly expressed in carcinoma cells in the majority of human breast cancers. Hence we set out to determine the effects of TIGAR expression on breast carcinoma and fibroblast glycolytic phenotype and tumor growth. The overexpression of this bisphosphatase in carcinoma cells induces expression of enzymes and transporters involved in the catabolism of lactate and glutamine. Carcinoma cells overexpressing TIGAR have higher oxygen consumption rates and ATP levels when exposed to glutamine, lactate, or the combination of glutamine and lactate. Coculture of TIGAR overexpressing carcinoma cells and fibroblasts compared with control cocultures induce more pronounced glycolytic differences between carcinoma and fibroblast cells. Carcinoma cells overexpressing TIGAR have reduced glucose uptake and lactate production. Conversely, fibroblasts in coculture with TIGAR overexpressing carcinoma cells induce HIF (hypoxia-inducible factor) activation with increased glucose uptake, increased 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3), and lactate dehydrogenase-A expression. We also studied the effect of this enzyme on tumor growth. TIGAR overexpression in carcinoma cells increases tumor growth in vivo with increased proliferation rates. However, a catalytically inactive variant of TIGAR did not induce tumor growth. Therefore, TIGAR expression in breast carcinoma cells promotes metabolic compartmentalization and tumor growth with a mitochondrial metabolic phenotype with lactate and glutamine catabolism. Targeting TIGAR warrants consideration as a potential therapy for breast cancer.
- Published
- 2016
12. Glutamine fuels a vicious cycle of autophagy in the tumor stroma and oxidative mitochondrial metabolism in epithelial cancer cells
- Author
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Zhao Lin, Michael P. Lisanti, Federica Sotgia, Ying-Hui Ko, Neal Flomenberg, Richard G. Pestell, Ubaldo E. Martinez-Outschoorn, and Anthony Howell
- Subjects
Cancer Research ,Programmed cell death ,Stromal cell ,Glutamine ,Caveolin 1 ,Apoptosis ,Cell Communication ,Mitochondrion ,Biology ,Oxidative Phosphorylation ,Downregulation and upregulation ,Cell Line, Tumor ,Neoplasms ,Autophagy ,Tumor Microenvironment ,Humans ,Pharmacology ,Tumor microenvironment ,Intracellular Signaling Peptides and Proteins ,Chloroquine ,Epithelial Cells ,Fibroblasts ,Coculture Techniques ,Phosphoric Monoester Hydrolases ,Mitochondria ,Cell biology ,Tamoxifen ,Oncology ,Cancer cell ,MCF-7 Cells ,Molecular Medicine ,Stromal Cells ,Apoptosis Regulatory Proteins - Abstract
Glutamine metabolism is crucial for cancer cell growth via the generation of intermediate molecules in the tricarboxylic acid (TCA) cycle, antioxidants and ammonia. The goal of the current study was to evaluate the effects of glutamine on metabolism in the breast cancer tumor microenvironment, with a focus on autophagy and cell death in both epithelial and stromal compartments. For this purpose, MCF7 breast cancer cells were cultured alone or co-cultured with non-transformed fibroblasts in media containing high glutamine and low glucose (glutamine +) or under control conditions, with no glutamine and high glucose (glutamine -). Here, we show that MCF7 cells maintained in co-culture with glutamine display increased mitochondrial mass, as compared with control conditions. Importantly, treatment with the autophagy inhibitor chloroquine abolishes the glutamine-induced augmentation of mitochondrial mass. It is known that loss of caveolin-1 (Cav-1) expression in fibroblasts is associated with increased autophagy and an aggressive tumor microenvironment. Here, we show that Cav-1 downregulation which occurs in fibroblasts maintained in co-culture specifically requires glutamine. Interestingly, glutamine increases the expression of autophagy markers in fibroblasts, but decreases expression of autophagy markers in MCF7 cells, indicating that glutamine regulates the autophagy program in a compartment-specific manner. Functionally, glutamine protects MCF7 cells against apoptosis, via the upregulation of the anti-apoptotic and anti-autophagic protein TIGAR. Also, we show that glutamine cooperates with stromal fibroblasts to confer tamoxifen-resistance in MCF7 cancer cells. Finally, we provide evidence that co-culture with fibroblasts (1) promotes glutamine catabolism, and (2) decreases glutamine synthesis in MCF7 cancer cells. Taken together, our findings suggest that autophagic fibroblasts may serve as a key source of energy-rich glutamine to fuel cancer cell mitochondrial activity, driving a vicious cycle of catabolism in the tumor stroma and anabolic tumor cell expansion.
- Published
- 2011
13. Anti-estrogen resistance in breast cancer is induced by the tumor microenvironment and can be overcome by inhibiting mitochondrial function in epithelial cancer cells
- Author
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Neal Flomenberg, Allison F. Goldberg, Ying-Hui Ko, Federica Sotgia, Anthony Howell, Zhao Lin, Chenguang Wang, Michael P. Lisanti, Ubaldo E. Martinez-Outschoorn, Stephanos Pavlides, and Richard G. Pestell
- Subjects
Cancer Research ,Cell ,Estrogen receptor ,Apoptosis ,Ketone Bodies ,Mitochondrion ,Arsenicals ,0302 clinical medicine ,Arsenic Trioxide ,Estrogen Receptor Modulators ,Tumor Microenvironment ,skin and connective tissue diseases ,Fulvestrant ,0303 health sciences ,Estradiol ,Apoptosis Regulator ,Intracellular Signaling Peptides and Proteins ,Oxides ,Metformin ,Mitochondria ,3. Good health ,medicine.anatomical_structure ,Oncology ,030220 oncology & carcinogenesis ,Molecular Medicine ,Female ,Research Paper ,medicine.drug ,medicine.medical_specialty ,Breast Neoplasms ,Poly(ADP-ribose) Polymerase Inhibitors ,Biology ,03 medical and health sciences ,Cell Line, Tumor ,Internal medicine ,medicine ,Humans ,Hypoglycemic Agents ,Lactic Acid ,030304 developmental biology ,Pharmacology ,Tumor microenvironment ,Fibroblasts ,Coculture Techniques ,Phosphoric Monoester Hydrolases ,Tamoxifen ,Endocrinology ,Doxorubicin ,Drug Resistance, Neoplasm ,Cancer cell ,Cancer research ,Apoptosis Regulatory Proteins - Abstract
Here, we show that tamoxifen resistance is induced by cancer-associated fibroblasts (CAFs). Coculture of estrogen receptor positive (ER+) MCF7 cells with fibroblasts induces tamoxifen and fulvestrant resistance with 4.4 and 2.5-fold reductions, respectively, in apoptosis compared with homotypic MCF7 cell cultures. Treatment of MCF7 cells cultured alone with high-energy mitochondrial "fuels" (L-lactate or ketone bodies) is sufficient to confer tamoxifen resistance, mimicking the effects of coculture with fibroblasts. To further demonstrate that epithelial cancer cell mitochondrial activity is the origin of tamoxifen resistance, we employed complementary pharmacological and genetic approaches. First, we studied the effects of two mitochondrial "poisons," namely metformin and arsenic trioxide (ATO), on fibroblast-induced tamoxifen resistance. We show here that treatment with metformin or ATO overcomes fibroblast-induced tamoxifen resistance in MCF7 cells. Treatment with the combination of tamoxifen plus metformin or ATO leads to increases in glucose uptake in MCF7 cells, reflecting metabolic uncoupling between epithelial cancer cells and fibroblasts. In coculture, tamoxifen induces the upregulation of TIGAR (TP53-induced glycolysis and apoptosis regulator), a p53 regulated gene that simultaneously inhibits glycolysis, autophagy and apoptosis and reduces ROS generation, thereby promoting oxidative mitochondrial metabolism. To genetically mimic the effects of coculture, we next recombinantly overexpressed TIGAR in MCF7 cells. Remarkably, TIGAR overexpression protects epithelial cancer cells from tamoxifen-induced apoptosis, providing genetic evidence that increased mitochondrial function confers tamoxifen resistance. Finally, CAFs also protect MCF7 cells against apoptosis induced by other anticancer agents, such as the topoisomerase inhibitor doxorubicin (adriamycin) and the PARP-1 inhibitor ABT-888. These results suggest that the tumor microenvironment may be a general mechanism for conferring drug resistance. In summary, we have discovered that mitochondrial activity in epithelial cancer cells drives tamoxifen resistance in breast cancer and that mitochondrial "poisons" are able to re-sensitize these cancer cells to tamoxifen. In this context, TIGAR may be a key "druggable" target for preventing drug resistance in cancer cells, as it protects cancer cells against the onset of stress-induced mitochondrial dys-function and aerobic glycolysis.
- Published
- 2011
14. Abstract 4024: Understanding the role of mitochondria in the progression from normal fibroblasts to DCIS associated fibroblasts
- Author
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Ubaldo Martinez Outschoorn, Ying-Hui Ko, and Zhao Lin
- Subjects
Cancer Research ,Pathology ,medicine.medical_specialty ,Cell type ,Stromal cell ,Cancer ,Biology ,medicine.disease ,medicine.disease_cause ,Epithelium ,medicine.anatomical_structure ,Breast cancer ,Oncology ,Caveolin 1 ,medicine ,Cancer research ,Cancer-Associated Fibroblasts ,skin and connective tissue diseases ,Carcinogenesis - Abstract
Background and Purpose: Ductal carcinoma in situ (DCIS) is a non-invasive breast cancer which may progress to invasive breast cancer. Many studies have focused on the epithelial cell mechanisms of progression from normal breast tissue to DCIS. However, in this study we want to study mechanisms of progression in cancer associated fibroblasts from normal breast tissue to DCIS. Loss of caveolin 1 (CAV1) in fibroblasts is a marker of reduced mitochondrial membrane potential and is a prognostic biomarker in ductal carcinoma in situ. High mitochondrial membrane potential in epithelial cells is a crucial determinant of carcinogenesis. Methods: In the study we use MCF10DCIS as a model for DCIS. MCF10DCIS.com (MCF10DCIS) is a clonal breast cancer cell line. The MCF10A, non-tumorigenic epithelial cell line, and human immortalized but non-transformed dermal fibroblasts (BJ1) were used study the difference between non-tumorigenic epithelial cells and DCIS and interactions between these two epithelial cells and fibroblasts. In order to study the interaction between epithelial cells and fibroblasts, we set up a coculture model system comprised both epithelial cells and fibroblasts. Immunofluorescence staining and confocal microscopy were used here to visualize the specific protein expression in different cell types. Results: (1) MCF10DCIS cells in coculture with fibroblasts have increased mitotracker red staining while as fibroblasts have decreased mitotracker staining compared to homotypic culture. However, coculture of MCF10A cells with fibroblasts did not change the mitotracker staining in either MCF10A or fibroblasts. (2) Loss of stromal CAV1 protein expression is observed in fibroblasts when fibroblasts are cocultured with MCF10DCIS cells compared to homotypic culture. CAV1 protein expression is unchanged in coculture with MCF10A cells. Conclusion: Previous studies have demonstrated that loss of stromal CAV1 and changes in mitochondrial membrane potential are factors involved in the transition from DCIS to invasive breast cancer. In this study we show that loss of stromal CAV1 and increases in epithelial mitochondrial membrane potential may play a role in the progression to DCIS. Citation Format: Ying-Hui Ko, Zhao Lin, Ubaldo E. Martinez Outschoorn. Understanding the role of mitochondria in the progression from normal fibroblasts to DCIS associated fibroblasts. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4024. doi:10.1158/1538-7445.AM2015-4024
- Published
- 2015
15. Understanding the metabolic basis of drug resistance: therapeutic induction of the Warburg effect kills cancer cells
- Author
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Michael P. Lisanti, Chenguang Wang, Ubaldo E. Martinez-Outschoorn, Anthony Howell, Richard G. Pestell, Neal Flomenberg, Allison F. Goldberg, Zhao Lin, Federica Sotgia, Ying-Hui Ko, and Stephanos Pavlides
- Subjects
Stromal cell ,Antineoplastic Agents, Hormonal ,Dasatinib ,Apoptosis ,Breast Neoplasms ,Biology ,Cell Line ,Cancer stem cell ,Report ,Mitophagy ,medicine ,Humans ,Molecular Biology ,Telomerase ,Cancer ,Cell Biology ,Suicide gene ,Fibroblasts ,medicine.disease ,Warburg effect ,Coculture Techniques ,Tamoxifen ,Thiazoles ,Pyrimidines ,Drug Resistance, Neoplasm ,Cancer cell ,Immunology ,Cancer research ,Cancer-Associated Fibroblasts ,Female ,Glycolysis ,Developmental Biology - Abstract
Previously, we identified a form of epithelial-stromal metabolic coupling, in which cancer cells induce aerobic glycolysis in adjacent stromal fibroblasts, via oxidative stress, driving autophagy and mitophagy. In turn, these cancer-associated fibroblasts provide recycled nutrients to epithelial cancer cells, "fueling" oxidative mitochondrial metabolism and anabolic growth. An additional consequence is that these glycolytic fibroblasts protect cancer cells against apoptosis, by providing a steady nutrient stream of to mitochondria in cancer cells. Here, we investigated whether these interactions might be the basis of tamoxifen-resistance in ER(+) breast cancer cells. We show that MCF7 cells alone are Tamoxifen-sensitive, but become resistant when co-cultured with hTERT-immortalized human fibroblasts. Next, we searched for a drug combination (Tamoxifen + Dasatinib) that could over-come fibroblast-induced Tamoxifen-resistance. Importantly, we show that this drug combination acutely induces the Warburg effect (aerobic glycolysis) in MCF7 cancer cells, abruptly cutting off their ability to use their fuel supply, effectively killing these cancer cells. Thus, we believe that the Warburg effect in tumor cells is not the "root cause" of cancer, but rather it may provide the necessary clues to preventing chemo-resistance in cancer cells. Finally, we observed that this drug combination (Tamoxifen + Dasatinib) also had a generalized anti-oxidant effect, on both co-cultured fibroblasts and cancer cells alike, potentially reducing tumor-stroma co-evolution. Our results are consistent with the idea that chemo-resistance may be both a metabolic and stromal phenomenon that can be overcome by targeting mitochondrial function in epithelial cancer cells. Thus, simultaneously targeting both (1) the tumor stroma and (2) the epithelial cancer cells, with combination therapies, may be the most successful approach to anti-cancer therapy. This general strategy of combination therapy for overcoming drug resistance could be applicable to many different types of cancer.
- Published
- 2011
16. $$B_{(s)}$$ B ( s ) to light tensor meson form factors via LCSR in HQEFT with applications to semileptonic decays
- Author
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Ya-Bing Zuo, Chong-Xing Yue, Bo Yu, Ying-Hui Kou, Yan Chen, and Wen Ling
- Subjects
Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract In the present work, the form factors of $$B_{(s)}$$ B ( s ) to light P-wave tensor mesons ( $$a_2(1320)$$ a 2 ( 1320 ) , $$K^*_2(1430)$$ K 2 ∗ ( 1430 ) , $$f_2(1270)$$ f 2 ( 1270 ) , $$f^\prime _2(1525)$$ f 2 ′ ( 1525 ) ) are calculated via the light cone sum rules (LCSR) in the framework of heavy quark effective field theory (HQEFT). Firstly, the expressions of form factors in terms of the light cone distribution amplitudes (DAs) of tensor mesons are derived via the LCSR at the leading order of heavy quark expansion. It is found that the penguin type form factors can be obtained directly from the corresponding semileptonic ones, which is similar to the case of S-wave mesons. Considering the light tensor meson DAs to twist-3, we give the numerical results of form factors systematically. As applications, we investigate the branching ratios, longitudinal polarization fractions and forward-backward asymmetries of relevant semileptonic decays induced by charged current and flavor changing neutral current (FCNC) separately. Our results may be tested by more precise experiments in the future.
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- 2021
- Full Text
- View/download PDF
17. Dietary antioxidants protect hematopoietic cells and improve animal survival after total-body irradiation
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Manunya Nuth, Jenine K. Sanzari, Ying-Hui Ko, Carly M. Sayers, Jeffrey H. Ware, Matthew Baran, James G. Davis, X. Steven Wan, Chris Wambi, and Ann R. Kennedy
- Subjects
Male ,Antioxidant ,Neutrophils ,medicine.medical_treatment ,Biophysics ,Bone Marrow Cells ,Radiation-Protective Agents ,Biology ,Pharmacology ,Antioxidants ,Article ,Transforming Growth Factor beta1 ,Leukocyte Count ,Mice ,White blood cell ,medicine ,Animals ,Radiology, Nuclear Medicine and imaging ,Mice, Inbred ICR ,Radiation ,Vitamin C ,Vitamin E ,Lethal dose ,Total body irradiation ,Hematopoietic Stem Cells ,Peripheral blood ,Diet ,Haematopoiesis ,medicine.anatomical_structure ,Immunology ,Whole-Body Irradiation - Abstract
The purpose of this study was to determine whether a dietary supplement consisting of L-selenomethionine, vitamin C, vitamin E succinate, alpha-lipoic acid and N-acetyl cysteine could improve the survival of mice after total-body irradiation. Antioxidants significantly increased the 30-day survival of mice after exposure to a potentially lethal dose of X rays when given prior to or after animal irradiation. Pretreatment of animals with antioxidants resulted in significantly higher total white blood cell and neutrophil counts in peripheral blood at 4 and 24 h after 1 Gy and 8 Gy. Antioxidants were effective in preventing peripheral lymphopenia only after low-dose irradiation. Antioxidant supplementation was also associated with increased bone marrow cell counts after irradiation. Supplementation with antioxidants was associated with increased Bcl2 and decreased Bax, caspase 9 and TGF-beta1 mRNA expression in the bone marrow after irradiation. Maintenance of the antioxidant diet was associated with improved recovery of the bone marrow after sublethal or potentially lethal irradiation. Taken together, oral supplementation with antioxidants appears to be an effective approach for radioprotection of hematopoietic cells and improvement of animal survival, and modulation of apoptosis is implicated as a mechanism for the radioprotection of the hematopoietic system by antioxidants.
- Published
- 2007
18. TP53-inducible Glycolysis and Apoptosis Regulator (TIGAR) Metabolically Reprograms Carcinoma and Stromal Cells in Breast Cancer.
- Author
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Ying-Hui Ko, Domingo-Vidal, Marina, Roche, Megan, Zhao Lin, Whitaker-Menezes, Diana, Seifert, Erin, Capparelli, Claudia, Tuluc, Madalina, Birbe, Ruth C., Tassone, Patrick, Curry, Joseph M., Navarro-Sabaté, Àurea, Manzano, Anna, Bartrons, Ramon, Caro, Jaime, and Martinez-Outschoorn, Ubaldo
- Subjects
- *
P53 protein , *GLYCOLYSIS , *APOPTOSIS , *BREAST cancer , *STROMAL cells , *CELL compartmentation - Abstract
A subgroup of breast cancers has several metabolic compartments. The mechanisms by which metabolic compartmentalization develop in tumors are poorly characterized. TP53 inducible glycolysis and apoptosis regulator (TIGAR) is a bisphosphatase that reduces glycolysis and is highly expressed in carcinoma cells in the majority of human breast cancers. Hence we set out to determine the effects of TIGAR expression on breast carcinoma and fibroblast glycolytic phenotype and tumor growth. The overexpression of this bisphosphatase in carcinoma cells induces expression of enzymes and transporters involved in the catabolism of lactate and glutamine. Carcinoma cells overexpressing TIGAR have higher oxygen consumption rates and ATP levels when exposed to glutamine, lactate, or the combination of glutamine and lactate. Coculture of TIGAR overexpressing carcinoma cells and fibroblasts compared with control cocultures induce more pronounced glycolytic differences between carcinoma and fibroblast cells. Carcinoma cells overexpressing TIGAR have reduced glucose uptake and lactate production. Conversely, fibroblasts in coculture with TIGAR overexpressing carcinoma cells induce HIF (hypoxia-inducible factor) activation with increased glucose uptake, increased 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3), and lactate dehydrogenase-A expression. We also studied the effect of this enzyme on tumor growth. TIGAR overexpression in carcinoma cells increases tumor growth in vivo with increased proliferation rates. However, a catalytically inactive variant of TIGAR did not induce tumor growth. Therefore, TIGAR expression in breast carcinoma cells promotes metabolic compartmentalization and tumor growth with a mitochondrial metabolic phenotype with lactate and glutamine catabolism. Targeting TIGAR warrants consideration as a potential therapy for breast cancer. [ABSTRACT FROM AUTHOR]
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- 2016
- Full Text
- View/download PDF
19. Oncogenes and inflammation rewire host energy metabolism in the tumor microenvironment.
- Author
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Martinez-Outschoorn, Ubaldo E., Curry, Joseph M., Ying-Hui Ko, Zhao Lin, Tuluc, Madalina, Cognetti, David, Birbe, Ruth C., Pribitkin, Edmund, Bombonati, Alessandro, Pestell, Richard G., Howell, Anthony, Sotgia, Federica, and Lisanti, Michael P.
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- 2013
- Full Text
- View/download PDF
20. Glutamine fuels a vicious cycle of autophagy in the tumor stroma and oxidative mitochondrial metabolism in epithelial cancer cells.
- Author
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Ying-Hui Ko, Zhao Lin, Flomenberg, Neal, Pestell, Richard G., Howell, Anthony, Sotgia, Federica, Lisanti, Michael P., and Martinez-Outschoorn, Ubaldo E.
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- 2011
- Full Text
- View/download PDF
21. Anti-estrogen resistance in breast cancer is induced by the tumor microenvironment and can be overcome by inhibiting mitochondrial function in epithelial cancer cells.
- Author
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Martinez-Outschoorn, Ubaldo E., Goldberg, Allison, Zhao Lin, Ying-Hui Ko, Flomenberg, Neal, Wang, Chenguang, Pavlides, Stephanos, Pestell, Richard G., Howell, Anthony, Sotgia, Federica, and Lisanti, Michael P.
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- 2011
- Full Text
- View/download PDF
22. Understanding the metabolic basis of drug resistance.
- Author
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Martinez-Outschoorn, Ubaldo E., Zhao Lin, Ying-Hui Ko, Goldberg, Allison F., Flomenberg, Neal, Wang, Chenguang, Pavlides, Stephanos, Pestell, Richard G., Howell, Anthony, Sotgia, Federica, and Lisanti, Michael P.
- Published
- 2011
- Full Text
- View/download PDF
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