37 results on '"Isaac S. Chan"'
Search Results
2. Antibody-drug conjugates in breast cancer: overcoming resistance and boosting immune response
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Hannah L. Chang, Blake Schwettmann, Heather L. McArthur, and Isaac S. Chan
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Medicine - Abstract
Antibody-drug conjugates (ADCs) have emerged as a revolutionary therapeutic class, combining the precise targeting ability of monoclonal antibodies with the potent cytotoxic effects of chemotherapeutics. Notably, ADCs have rapidly advanced in the field of breast cancer treatment. This innovative approach holds promise for strengthening the immune system through antibody-mediated cellular toxicity, tumor-specific immunity, and adaptive immune responses. However, the development of upfront and acquired resistance poses substantial challenges in maximizing the effectiveness of these therapeutics, necessitating a deeper understanding of the underlying mechanisms. These mechanisms of resistance include antigen loss, derangements in ADC internalization and recycling, drug clearance, and alterations in signaling pathways and the payload target. To overcome resistance, ongoing research and development efforts are focused on urgently identifying biomarkers, integrating immune therapy approaches, and designing novel cytotoxic payloads. This Review provides an overview of the mechanisms and clinical effectiveness of ADCs, and explores their unique immune-boosting function, while also highlighting the complex resistance mechanisms and safety challenges that must be addressed. A continued focus on how ADCs impact the tumor microenvironment will help to identify new payloads that can improve patient outcomes.
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- 2023
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3. Improving the odds together: a framework for breast cancer research scientists to include patient advocates in their research
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Hillary Stires, Igor Bado, Thelma Brown, Martha Carlson, Isaac S. Chan, Gloria V. Echeverria, Andrew J. Ewald, Bora Lim, Carla Lloyd, Julia Maues, Steffi Oesterreich, Robert N. Riter, Kelly Shanahan, Alana L. Welm, and Josh Newby
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Including patient advocates in basic cancer research ensures that breast cancer research is intentional, supports effective communication with broader audiences, and directly connects researchers with those who they are striving to help. Despite this utility, many cancer research scientists do not work with patient advocates. To understand barriers to engagement and build a framework for enhanced interactions in the future, we hosted a workshop with patient advocates and researchers who do engage, then discussed findings at an international metastatic breast cancer conference to solicit additional feedback and suggestions. Findings demonstrate that researchers are uncertain about how to initiate and maintain relationships with advocates. We offer actionable steps to support researchers working with patient advocates to improve cancer research and accomplish our collective goal of improving lives of those who have been diagnosed with breast cancer. We hope that this initiative will facilitate such collaborative efforts.
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- 2022
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4. Epigenetically regulated digital signaling defines epithelial innate immunity at the tissue level
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Helen R. Clark, Connor McKenney, Nathan M. Livingston, Ariel Gershman, Seema Sajjan, Isaac S. Chan, Andrew J. Ewald, Winston Timp, Bin Wu, Abhyudai Singh, and Sergi Regot
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Science - Abstract
Fine tuning the immune response in line with the degree of threat is central to recognition of a pathogen versus commensal bacteria. Here the authors implicate a digital all-or-nothing cell response in control of the tissue level immune response.
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- 2021
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5. The changing role of natural killer cells in cancer metastasis
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Isaac S. Chan and Andrew J. Ewald
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Medicine - Abstract
Natural killer (NK) cells are innate immune cells that are critical to the body’s antitumor and antimetastatic defense. As such, novel therapies are being developed to utilize NK cells as part of a next generation of immunotherapies to treat patients with metastatic disease. Therefore, it is essential for us to examine how metastatic cancer cells and NK cells interact with each other throughout the metastatic cascade. In this Review, we highlight the recent body of work that has begun to answer these questions. We explore how the unique biology of cancer cells at each stage of metastasis alters fundamental NK cell biology, including how cancer cells can evade immunosurveillance and co-opt NK cells into cells that promote metastasis. We also discuss the translational potential of this knowledge.
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- 2022
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6. Immunotherapy for Merkel cell carcinoma: a turning point in patient care
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Isaac S. Chan, Shailender Bhatia, Howard L. Kaufman, and Evan J. Lipson
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Merkel Cell carcinoma (MCC) is a rare but aggressive cancer, with an estimated disease-associated mortality as high as 46%. MCC has proven to be an immunologically responsive disease and the advent of immune checkpoint inhibitors has changed the treatment landscape for patients with advanced MCC. In this review, we discuss the rationale for the use of immune checkpoint inhibition, review current single agent therapies tested in and approved for MCC, and discuss emerging immunotherapeutic options for these patients.
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- 2018
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7. Olaparib Use in Patients With Metastatic Breast Cancer Harboring Somatic BRCA1/2 Mutations or Mutations in Non-BRCA1/2, DNA Damage Repair Genes
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Elaine M. Walsh, Neha Mangini, John Fetting, Deborah Armstrong, Isaac S. Chan, Roisin M. Connolly, Katie Fiallos, Jennifer Lehman, Raquel Nunes, Dana Petry, Jeffrey Reynolds, Mirat Shah, Karen L Smith, Kala Visvanathan, Josh Lauring, Ben H Park, Vered Stearns, and Antonio C. Wolff
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BRCA2 Protein ,Cancer Research ,Oncology ,BRCA1 Protein ,Mutation ,Humans ,Phthalazines ,Breast Neoplasms ,Female ,Poly(ADP-ribose) Polymerase Inhibitors ,Piperazines ,DNA Damage ,Retrospective Studies - Abstract
Poly-ADP ribose polymerase (PARP) inhibitors (PARPi) are active in patients with germline BRCA1/2 (gBRCA1/2)-mutated breast cancer, accounting for 5% to 10% of all breast cancers. Another 5% to 10% harbor somatic BRCA1/2 (sBRCA1/2) mutations or mutations in non-BRCA1/2, homologous recombination repair (HRR) genes but until recently, there were no data for the use of PARPi in these patients. This study examines the use of olaparib in patients with metastatic breast cancer harboring sBRCA1/2 or germline or somatic non-BRCA1/2, HRR mutations and demonstrates potential activity of PARPi in this setting.In this retrospective, single institution study, patients who were treated with off-label, off-protocol olaparib for metastatic breast cancer harboring sBRCA1/2 or germline or somatic non-BRCA1/2, HRR mutations were identified. The primary aim was to describe these patients' demographics, tumor characteristics, mutations, safety and tolerability, response rates, progression free survival, PARPi-associated survival and subsequent treatment.Seven patients were treated off-label, off-trial with olaparib for sBRCA1/2-mutated cancers (n = 4) or non-BRCA1/2, HRR-mutated cancers (n = 3). All patients with sBRCA1/2-mutated cancers responded to PARP inhibition; patients with non-BRCA1/2, HRR-mutated cancers did not respond. The median progression free survival in patients with a sBRCA1/2 mutation was 6.5 months (range 5-9 months) vs. 3 months (range 2-4 months) in patients with non-BRCA1/2, HRR mutations.This single institution experience adds to recent larger reports confirming evidence for PARPi therapy in patients with metastatic breast cancer harboring sBRCA1/2 mutations. No activity was observed in patients with either germline or somatic non-BRCA1/2, HRR-mutated cancers.
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- 2022
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8. Supplementary Table 1 from Paracrine Hedgehog Signaling Drives Metabolic Changes in Hepatocellular Carcinoma
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Anna Mae Diehl, Albert S. Baldwin, Steve S. Choi, Thiago A. Pereira, Blair R. Anderson, Wing-Kin Syn, Leandi Krüger, Guanhua Xie, Gamze Karaca, Gregory A. Michelotti, Marzena Swiderska-Syn, Jiuyi Lu, Yuping Chen, Cynthia D. Guy, and Isaac S. Chan
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PDF file - 54K, Related primer sequences
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- 2023
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9. Supplementary Methods , Figure Legends 1-5 from Paracrine Hedgehog Signaling Drives Metabolic Changes in Hepatocellular Carcinoma
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Anna Mae Diehl, Albert S. Baldwin, Steve S. Choi, Thiago A. Pereira, Blair R. Anderson, Wing-Kin Syn, Leandi Krüger, Guanhua Xie, Gamze Karaca, Gregory A. Michelotti, Marzena Swiderska-Syn, Jiuyi Lu, Yuping Chen, Cynthia D. Guy, and Isaac S. Chan
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PDF file - 82K
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- 2023
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10. Supplementary Figures 1-5 from Paracrine Hedgehog Signaling Drives Metabolic Changes in Hepatocellular Carcinoma
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Anna Mae Diehl, Albert S. Baldwin, Steve S. Choi, Thiago A. Pereira, Blair R. Anderson, Wing-Kin Syn, Leandi Krüger, Guanhua Xie, Gamze Karaca, Gregory A. Michelotti, Marzena Swiderska-Syn, Jiuyi Lu, Yuping Chen, Cynthia D. Guy, and Isaac S. Chan
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PDF file - 127K, S1. Panc 10.05 cells do not generate functional Hh ligands. S2. Other malignant hepatoma lines can increase MF Hh and glycolytic activity. S3. Summary of glycolytic metabolism. S4. MF-derived lactate provides energy source for lipogenesis in other malignant hepatoma lines. S5. Schematic of alterations in hepatoma cells due to release of metabolic end products by glycolytic MF
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- 2023
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11. Generating and Imaging Mouse and Human Epithelial Organoids from Normal and Tumor Mammary Tissue Without Passaging
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Isaac S. Chan, Elizabeth H. Chen, Sangeetha M. Reddy, Evanthia T. Roussos-Torres, Yu-An Zhang, Clayton A. Smith, Katherine E. Lake, Megan M. Colonnetta, and Serena L. Cornelius
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Diagnostic Imaging ,General Immunology and Microbiology ,General Chemical Engineering ,General Neuroscience ,General Biochemistry, Genetics and Molecular Biology ,Article ,Organoids ,Mice ,Neoplasms ,Tumor Microenvironment ,Humans ,Animals ,Breast ,Collagen - Abstract
Organoids are a reliable method for modeling organ tissue due to their self-organizing properties and retention of function and architecture after propagation from primary tissue or stem cells. This method of organoid generation forgoes single-cell differentiation through multiple passages and instead uses differential centrifugation to isolate mammary epithelial organoids from mechanically and enzymatically dissociated tissues. This protocol provides a streamlined technique for rapidly producing small and large epithelial organoids from both mouse and human mammary tissue in addition to techniques for organoid embedding in collagen and basement extracellular matrix. Furthermore, instructions for in-gel fixation and immunofluorescent staining are provided for the purpose of visualizing organoid morphology and density. These methodologies are suitable for myriad downstream analyses, such as co-culturing with immune cells and ex vivo metastasis modeling via collagen invasion assay. These analyses serve to better elucidate cell-cell behavior and create a more complete understanding of interactions within the tumor microenvironment.
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- 2022
12. Increasing the field-of-view in oblique plane microscopy via optical tiling
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Bingying Chen, Bo-Jui Chang, Felix Y. Zhou, Stephan Daetwyler, Etai Sapoznik, Benjamin A Nanes, Isabella Terrazas, Gabriel M. Gihana, Lizbeth Perez Castro, Isaac S. Chan, Maralice Conacci-Sorrell, Kevin M. Dean, Alfred Millett-Sikking, Andrew G. York, and Reto Fiolka
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Atomic and Molecular Physics, and Optics ,Article ,Biotechnology - Abstract
Fast volumetric imaging of large fluorescent samples with high-resolution is required for many biological applications. Oblique plane microscopy (OPM) provides high spatiotemporal resolution, but the field of view is typically limited by its optical train and the pixel number of the camera. Mechanically scanning the sample or decreasing the overall magnification of the imaging system can partially address this challenge, albeit by reducing the volumetric imaging speed or spatial resolution, respectively. Here, we introduce a novel dual-axis scan unit for OPM that facilitates rapid and high-resolution volumetric imaging throughout a volume of 800 × 500 × 200 microns. This enables us to perform volumetric imaging of cell monolayers, spheroids and zebrafish embryos with subcellular resolution. Furthermore, we combined this microscope with a multi-perspective projection imaging technique that increases the volumetric interrogation rate to more than 10 Hz. This allows us to rapidly probe a large field of view in a dimensionality reduced format, identify features of interest, and volumetrically image these regions with high spatiotemporal resolution.
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- 2022
13. A comprehensive single-cell breast tumor atlas defines cancer epithelial and immune cell heterogeneity and interactions predicting anti-PD-1 therapy response
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Lily Xu, Kaitlyn Saunders, Hildur Knutsdottir, Kenian Chen, Julia Maués, Christine Hodgdon, Evanthia T. Roussos Torres, Sangeetha M. Reddy, Lin Xu, and Isaac S. Chan
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We present an integrated single-cell RNA-seq resource of the breast tumor microenvironment consisting of 236,363 cells from 119 biopsy samples across 8 publicly available datasets. In this computational study, we first leverage this novel resource to define cancer epithelial cell heterogeneity based on two clinically relevant markers and identify six new and distinct subsets of natural killer cells. We then illustrate how cancer epithelial cell heterogeneity impacts immune cell interactions. We develop T cell InteractPrint, which considers how cancer epithelial cell heterogeneity shifts the predicted strength of T cell interactions. We use InteractPrint to predict response to immune checkpoint inhibition (ICI) in two clinical trials testing immunotherapy in patients with breast cancer. T cell InteractPrint was predictive in both trials (AUC = 0.81 and 0.84), versus PD-L1 expression (AUC = 0.54 and 0.72). This result provides an alternative predictive biomarker to PD-L1 to select patients who should receive ICI.STATEMENT OF SIGNIFICANCEWe developed a novel integrated single-cell atlas of the breast tumor microenvironment to interrogate breast tumor cell heterogeneity and define how heterogenous cancer epithelial cell and immune cell interactions predict response to anti-PD-1 therapy.
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- 2022
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14. Organoid Co-culture Methods to Capture Cancer Cell-Natural Killer Cell Interactions
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Isaac S, Chan and Andrew J, Ewald
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Killer Cells, Natural ,Organoids ,Neoplasms ,Humans ,Coculture Techniques - Abstract
Metastasis is a complex process that has been historically difficult to model in culture. Host immune responses play critical roles in restraining and promoting metastatic tumor cells. Here we describe a method of 3D organotypic co-culture of natural killer cells and tumor organoids to capture interactions between the two cellular populations. These assays can be used to model key aspects of metastatic biology and to screen for the effectiveness of agents that stimulate natural killer cell cytotoxicity.
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- 2022
15. 529 Cancer cells educate natural killer cells to a metastasis promoting cell state
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Elizabeth M. Jaffee, Andrew J. Ewald, Manisha Warrier, Gayathri Ramakrishnan, Juan Carlos Ramirez, Hildur Knutsdottir, Joel S. Bader, Veena Padmanaban, and Isaac S. Chan
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Mammary tumor ,Adoptive cell transfer ,biology ,Cell ,medicine.disease ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,lcsh:RC254-282 ,Metastasis ,Immunosurveillance ,medicine.anatomical_structure ,Cancer cell ,Cancer research ,medicine ,biology.protein ,Antibody ,Ex vivo - Abstract
Background Metastatic disease drives breast cancer mortality. We recently discovered that leading cells at the invasive edge of mammary tumor organoids retain a conserved basal epithelial program defined by their expression of keratin-14 (K14), establishing K14 as a good marker of invasive breast cancer cells. K14-positive invasive cells also exhibit characteristics that make them targets of immunosurveillance by natural killer (NK) cells. While NK cells are key immune mediators in the control of metastasis, our understanding of the specific mechanisms behind this regulation and its eventual evasion by metastatic cells remains incomplete. Methods We have developed a novel preclinical 3D co-culture assay to discover mechanisms behind interactions between K14+ invasive breast cancer cells and NK cells. Combined with in vivo assays of metastasis, we are able to determine how NK cells limit the early stages of metastasis and also how tumor cells can influence key NK cell properties. Results In ex vivo co-culture assays of NK cells isolated from healthy mouse donors and mammary tumor organoids from MMTV-PyMT and C31T mouse models of breast cancer, we demonstrate that NK cells limit the early stages of metastasis. Antibodies to invasive K14+ cells were able to enhance the ability of NK cells to limit colony formation, suggesting antibody-dependent cell mediated cytotoxicity. Surprisingly, when isolated from tumor bearing mice, NK cells did not limit invasion and instead promoted colony formation. The in vivo adoptive transfer of NK cells from healthy donors prevents the progression of early lung metastatic seeds to macrometastases, while the adoptive transfer of cells isolated from tumor bearing donors promotes macrometastatic development. Transcriptomic analysis of reprogrammed NK cells demonstrate they have similar profiles to resting NK cells. This growth promoting phenotype can be reversed with antibodies targeting inhibitory cell surface receptors or the epigenome. Conclusions Our ex vivo and in vivo data demonstrate that healthy donor NK cells can limit metastasis through the directed cytotoxicity against pioneering K14+ invasive cells. However, prolonged exposure to tumors reprogram NK cells from tumor killing to tumor promoting, specifically in promoting the outgrowth of macrometastases. Further, we can neutralize this effect using NK cell specific inhibitory antibodies and epigenetic modifiers. This is the first time inhibitory signaling on NK cells have been linked with a growth promoting phenotype. These data can provide insight into when the use of NK cell directed therapies can be used to treat or prevent clinically relevant metastatic disease.
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- 2020
16. Cancer cells educate natural killer cells to a metastasis-promoting cell state
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Elizabeth M. Jaffee, Joel S. Bader, Matthew Dunworth, Isaac S. Chan, Manisha Warrier, Hildur Knutsdottir, Veena Padmanaban, Juan Carlos Ramirez, Gayathri Ramakrishnan, Hao Zhang, and Andrew J. Ewald
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medicine.medical_treatment ,Immunology ,Cell ,Breast Neoplasms ,Metastasis ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Cell Signaling ,TIGIT ,Cell Line, Tumor ,Report ,medicine ,Animals ,Humans ,Cytotoxic T cell ,Neoplasm Metastasis ,Receptors, Immunologic ,Cancer ,030304 developmental biology ,0303 health sciences ,biology ,fungi ,Migration, Motility ,food and beverages ,Methyltransferases ,Cell Biology ,medicine.disease ,Killer Cells, Natural ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Cancer cell ,MCF-7 Cells ,biology.protein ,Cancer research ,Female ,Antibody ,Adjuvant ,Ex vivo - Abstract
Chan et al. show that natural killer (NK) cells can be reprogrammed by breast cancer cells to promote metastasis. Reprogramming can be blocked by targeting NK cell inhibitory receptors TIGIT or KLRG1 or inhibiting DNA methyltransferases, which suggests new approaches to prevent or treat metastasis., Natural killer (NK) cells have potent antitumor and antimetastatic activity. It is incompletely understood how cancer cells escape NK cell surveillance. Using ex vivo and in vivo models of metastasis, we establish that keratin-14+ breast cancer cells are vulnerable to NK cells. We then discovered that exposure to cancer cells causes NK cells to lose their cytotoxic ability and promote metastatic outgrowth. Gene expression comparisons revealed that healthy NK cells have an active NK cell molecular phenotype, whereas tumor-exposed (teNK) cells resemble resting NK cells. Receptor–ligand analysis between teNK cells and tumor cells revealed multiple potential targets. We next showed that treatment with antibodies targeting TIGIT, antibodies targeting KLRG1, or small-molecule inhibitors of DNA methyltransferases (DMNT) each reduced colony formation. Combinations of DNMT inhibitors with anti-TIGIT or anti-KLRG1 antibodies further reduced metastatic potential. We propose that NK-directed therapies targeting these pathways would be effective in the adjuvant setting to prevent metastatic recurrence.
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- 2020
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17. Epigenetically regulated digital signaling defines epithelial innate immunity at the tissue level
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Ariel Gershman, Isaac S. Chan, Helen R. Clark, Abhyudai Singh, Nathan M. Livingston, Connor McKenney, Andrew J. Ewald, Sergi Regot, Seema Sajjan, Bin Wu, and Winston Timp
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0301 basic medicine ,animal diseases ,Cell ,General Physics and Astronomy ,Epigenesis, Genetic ,Mice ,0302 clinical medicine ,Image Processing, Computer-Assisted ,RNA-Seq ,Receptor ,Promoter Regions, Genetic ,In Situ Hybridization, Fluorescence ,Innate immunity ,Multidisciplinary ,Toll-Like Receptors ,Pattern recognition receptor ,NF-kappa B ,Cell biology ,Organoids ,medicine.anatomical_structure ,Cytokines ,Epigenetics ,Single-Cell Analysis ,Signal Transduction ,Cell signalling ,Pattern recognition receptors ,Cell signaling ,Science ,chemical and pharmacologic phenomena ,Biology ,General Biochemistry, Genetics and Molecular Biology ,Article ,Cell Line ,03 medical and health sciences ,Lipopeptides ,Immune system ,Mammary Glands, Animal ,medicine ,Animals ,Humans ,Innate immune system ,Bacteria ,Epithelial Cells ,General Chemistry ,biochemical phenomena, metabolism, and nutrition ,DNA Methylation ,Immunity, Innate ,Toll-Like Receptor 2 ,TLR2 ,030104 developmental biology ,Gene Expression Regulation ,bacteria ,030217 neurology & neurosurgery ,Flagellin - Abstract
To prevent damage to the host or its commensal microbiota, epithelial tissues must match the intensity of the immune response to the severity of a biological threat. Toll-like receptors allow epithelial cells to identify microbe associated molecular patterns. However, the mechanisms that mitigate biological noise in single cells to ensure quantitatively appropriate responses remain unclear. Here we address this question using single cell and single molecule approaches in mammary epithelial cells and primary organoids. We find that epithelial tissues respond to bacterial microbe associated molecular patterns by activating a subset of cells in an all-or-nothing (i.e. digital) manner. The maximum fraction of responsive cells is regulated by a bimodal epigenetic switch that licenses the TLR2 promoter for transcription across multiple generations. This mechanism confers a flexible memory of inflammatory events as well as unique spatio-temporal control of epithelial tissue-level immune responses. We propose that epigenetic licensing in individual cells allows for long-term, quantitative fine-tuning of population-level responses., Fine tuning the immune response in line with the degree of threat is central to recognition of a pathogen versus commensal bacteria. Here the authors implicate a digital all-or-nothing cell response in control of the tissue level immune response.
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- 2020
18. Abstract 1014: A framework for research scientists to include patient advocates in cancer research
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Hillary Stires, Igor Bado, Thelma Brown, Martha Carlson, Isaac S. Chan, Gloria V. Echeverria, Andrew J. Ewald, Carla Lloyd, Julia Maues, Steffi Oesterreich, Robert N. Riter, Kelly Shanahan, Alana L. Welm, and Josh Newby
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Cancer Research ,Oncology - Abstract
The inclusion of patient advocates in basic cancer research has emerged as a valuable practice to ensure research is intentional, to support effective communication with broader audiences, and to directly connect researchers with those whom they are striving to help. Despite this value, many researchers do not work with patient advocates. To understand why and build a roadmap for more engagement in the future, we hosted a workshop with patient advocates and research scientists then presented findings and discussed further at an international conference. We acknowledged four main barriers: 1) It is not clear to everyone why patient advocates should be included in research, 2) Researchers are worried about saying the wrong thing, 3) Researchers do not know where to meet patient advocates, and 4) Researchers do not know how to include patient advocates in research. We identified best practices from various organizations and opportunities to overcome these barriers in the short- and long-term. This is the first time a multi-stakeholder group has come together to provide ways to support research scientists with overcoming barriers to regularly working with patient advocates. Ultimately, these relationships will improve cancer research and more quickly accomplish our collective goal of improving lives of those who have been diagnosed with cancer. Citation Format: Hillary Stires, Igor Bado, Thelma Brown, Martha Carlson, Isaac S. Chan, Gloria V. Echeverria, Andrew J. Ewald, Carla Lloyd, Julia Maues, Steffi Oesterreich, Robert N. Riter, Kelly Shanahan, Alana L. Welm, Josh Newby. A framework for research scientists to include patient advocates in cancer research [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1014.
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- 2022
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19. Abstract PO039: Cancer cells educate natural killer cells to a metastasis-promoting cell state
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Hildur Knutsdottir, Andrew J. Ewald, Joel S. Bader, Manisha Warrier, Gayathri Ramakrishnan, Elizabeth M. Jaffee, Hao Zhang, Isaac S. Chan, Juan Carlos Ramirez, Matthew Dunworth, and Veena Padmanaban
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Cancer Research ,biology ,business.industry ,medicine.medical_treatment ,Immunology ,Cell ,Cancer ,Immunotherapy ,medicine.disease ,Metastasis ,medicine.anatomical_structure ,TIGIT ,Cancer cell ,medicine ,biology.protein ,Cancer research ,Cytotoxic T cell ,Antibody ,business - Abstract
Natural killer (NK) cells have potent antitumor and antimetastatic activity. It is incompletely understood how cancer cells escape NK cell surveillance. Using ex vivo and in vivo models of metastasis, we establish that keratin-14+ breast cancer cells are vulnerable to NK cells. We then discovered that exposure to cancer cells causes NK cells to lose their cytotoxic ability and promote metastatic outgrowth. Gene expression comparisons revealed that healthy NK cells have an active NK cell molecular phenotype, whereas tumor-exposed (teNK) cells resemble resting NK cells. Receptor–ligand analysis between teNK cells and tumor cells revealed multiple potential targets. We next showed that treatment with antibodies targeting TIGIT, antibodies targeting KLRG1, or small-molecule inhibitors of DNA methyltransferases (DMNT) each reduced colony formation. Combinations of DNMT inhibitors with anti-TIGIT or anti-KLRG1 antibodies further reduced metastatic potential. We propose that NK-directed therapies targeting these pathways would be effective in the adjuvant setting to prevent metastatic recurrence. Citation Format: Isaac S. Chan, Hildur Knútsdóttir, Gayathri Ramakrishnan, Veena Padmanaban, Manisha Warrier, Juan Carlos Ramirez, Matthew Dunworth, Hao Zhang, Elizabeth M. Jaffee, Joel S. Bader, Andrew J. Ewald. Cancer cells educate natural killer cells to a metastasis-promoting cell state [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2020 Oct 19-20. Philadelphia (PA): AACR; Cancer Immunol Res 2021;9(2 Suppl):Abstract nr PO039.
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- 2021
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20. Abstract 3926: Establishment of patient-derived organoids as ex vivo tool to characterize the molecular mechanisms of SCLC chemo-radiation resistance
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Eddie Luidy-Imada, Isaac S. Chan, Hailun Wang, Christine Lam, Andrew J. Ewald, Phuoc T. Tran, Eloise M. Grasset, Christine L. Hann, Francesca A. Carrieri, Luigi Marchionni, and Nick Connis
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Cancer Research ,Oncology ,Chemistry ,Organoid ,Cancer research ,Chemo radiation - Abstract
Small cell lung cancer (SCLC) is the most aggressive form of lung malignancies and accounts for 15-20% of all lung cancers. It has the tendency to metastasize early, thus limited-stage SCLC patients receive systemic chemo-radiotherapy (XRT) treatments. SCLC is exceptionally sensitive to XRT and exhibits high response rates; however, the recurrence rate is almost 100% and patients relapse with tumors that resist further chemotherapy. Clearly, elucidating the mechanisms of chemo-radiation resistance in SCLC will contribute to understanding how SCLC resists further treatments, to develop improved therapies and positively impact patient outcomes. Significant limitations for SCLC therapeutic development have been the lack of germane reliable and tractable model systems. Recent advances in establishing 3D organotypic culture have shown that this model can preserve the majority of pathways, key genes, histology and behavior of in situ tumors. Furthermore, patient-derived organoids (PDO) represent a powerful preclinical model that enable real-time cellular and molecular analysis of patient-derived xenograft (PDX) behavior ex vivo. Here, we present a novel patient-derived cancer organoid model to study the molecular underpinnings of XRT resistance in SCLC. Classic and variant SCLC PDX tumor tissues were isolated from mice and mechanically dissociated. Derived organoids were cultured in basal organoid medium. PDOs have been characterized using the SCLC molecular subtype classification reported in literature. RNA for transcriptomic analyses has been obtained to further characterize gene expression profiles of primary PDXs and PDOs, and to reconstruct gene regulatory network associated with XRT resistance. A SCLC PDX served as in vivo system to characterize the response to chemo-radiation resistance. Briefly, PDX tumor bearing mice were treated with: 1) vehicle control; 2) Cisplatin 5mg/kg on d1 plus Etoposide 8mg/kg on d1-2 (EP); 3) Radiotherapy 3Gy x1 on d3 (RT); and 4) both EP/RT. Whole transcriptome profiling among all treatments arms reveals molecular pathways and biological processes associated with XRT resistance. Also, by comparing our data with two previous SCLC patient cohort studies, we identified ideal candidates for functional analyses. SCLC XRT resistance candidate genes will be tested by either treating PDOs with small molecule inhibitors or by cDNA/shRNA lentiviral infection. To assess changes in chemo-radiation sensitivity, chemo-radiation protocols have been established and immunofluorescence staining for Ki67, γH2AX and cleaved caspase 3 served as markers for proliferation, DNA damage and apoptosis, respectively. Although further in-depth characterization is required, we aim to utilize our novel SCLC PDO model as a tool to identify candidate biomarkers to be used for developing therapy responses and translational research. Citation Format: Francesca A. Carrieri, Nick Connis, Eloise M. Grasset, Isaac S. Chan, Eddie Luidy-Imada, Christine Lam, Hailun Wang, Andrew J. Ewald, Luigi Marchionni, Christine L. Hann, Phuoc T. Tran. Establishment of patient-derived organoids as ex vivo tool to characterize the molecular mechanisms of SCLC chemo-radiation resistance [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3926.
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- 2020
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21. Schistosome-induced cholangiocyte proliferation and osteopontin secretion correlate with fibrosis and portal hypertension in human and murine schistosomiasis mansoni
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Thiago A. Pereira, Isaac S. Chan, Márcia Maria de Souza, Wing-Kin Syn, Vivian Resende, Steve S. Choi, Alba Otoni, Mariana Verdelho Machado, Anna Mae Diehl, Guilherme Vaz de Melo Trindade, Paula Vieira Teixeira Vidigal, Elisângela Trindade Santos, Izabela Voieta, William Evan Secor, Rafal P. Witek, Zilton A. Andrade, José Roberto Lambertucci, Guanhua Xie, and Fausto Edmundo Lima Pereira
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Liver Cirrhosis ,Male ,Pathology ,osteopontin ,Cholangiocyte proliferation ,ductular proliferation ,Mice ,Fibrosis ,Osteopontin ,Cells, Cultured ,biology ,Reverse Transcriptase Polymerase Chain Reaction ,portal hypertension ,General Medicine ,Middle Aged ,Immunohistochemistry ,Original Papers ,S10 ,3. Good health ,Real-time polymerase chain reaction ,Schistosoma ,Female ,Schistosoma mansoni ,Adult ,medicine.medical_specialty ,Adolescent ,Kupffer Cells ,digestive system ,S2 ,Cholangiocyte ,Cell Line ,Host-Parasite Interactions ,Young Adult ,stomatognathic system ,Hypertension, Portal ,Hepatic Stellate Cells ,medicine ,Animals ,Humans ,Cell Proliferation ,Original Paper ,Symmers' fibrosis ,medicine.disease ,biology.organism_classification ,Schistosomiasis mansoni ,Rats ,Antigens, Helminth ,Portal fibrosis ,biology.protein ,Hepatic stellate cell ,Bile Ducts ,cholangiocyte - Abstract
Schistosomal egg antigens induce host bile ductular cells to proliferate and produce osteopontin (OPN), a pro-fibrogenic factor that stimulates hepatic stellate cells to become myofibroblasts. The numbers of OPN-producing bile ductules correlate with fibrogenesis and portal hypertension in humans and mice., Schistosomiasis is a major cause of portal hypertension worldwide. It associates with portal fibrosis that develops during chronic infection. The mechanisms by which the pathogen evokes these host responses remain unclear. We evaluated the hypothesis that schistosome eggs release factors that directly stimulate liver cells to produce osteopontin (OPN), a pro-fibrogenic protein that stimulates hepatic stellate cells to become myofibroblasts. We also investigated the utility of OPN as a biomarker of fibrosis and/or severity of portal hypertension. Cultured cholangiocytes, Kupffer cells and hepatic stellate cells were treated with soluble egg antigen (SEA); OPN production was quantified by quantitative reverse transcriptase polymerase chain reaction (qRTPCR) and ELISA; cell proliferation was assessed by BrdU (5-bromo-2'-deoxyuridine). Mice were infected with Schistosoma mansoni for 6 or 16 weeks to cause early or advanced fibrosis. Liver OPN was evaluated by qRTPCR and immunohistochemistry (IHC) and correlated with liver fibrosis and serum OPN. Livers from patients with schistosomiasis mansoni (early fibrosis n=15; advanced fibrosis n=72) or healthy adults (n=22) were immunostained for OPN and fibrosis markers. Results were correlated with plasma OPN levels and splenic vein pressures. SEA-induced cholangiocyte proliferation and OPN secretion (P
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- 2015
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22. Abstract P3-01-01: A dual role of natural killer cells in breast cancer metastasis
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Veena Padmanaban, Hildur Knútsdoóttir, Andrew J. Ewald, Elizabeth M. Jaffee, Isaac S. Chan, Joel S. Bader, and Gayathri Ramakrishnan
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Cancer Research ,Mammary tumor ,Adoptive cell transfer ,Cell ,Cancer ,Biology ,medicine.disease ,Metastasis ,Immunosurveillance ,medicine.anatomical_structure ,Oncology ,Cancer research ,medicine ,biology.protein ,Antibody ,Ex vivo - Abstract
BACKGROUND: Metastatic disease drives breast cancer mortality. We recently discovered that leading cells at the invasive edge of mammary tumor organoids retain a conserved basal epithelial program defined by their expression of keratin-14 (K14), establishing K14 as a good marker of invasive breast cancer cells. K14-positive invasive cells also exhibit characteristics that make them targets of immunosurveillance by natural killer (NK) cells. While NK cells are key immune mediators in the control of metastasis, our understanding of the specific mechanisms behind this regulation and its eventual evasion by metastatic cells remains incomplete. METHODS: We have developed a novel preclinical 3D co-culture assay to discover mechanisms behind interactions between K14+ invasive breast cancer cells and NK cells. Combined with in vivo assays of metastasis, we are able to determine how NK cells limit the early stages of metastasis and also how tumor cells can influence key NK cell properties. RESULTS: In ex vivo co-culture assays of NK cells isolated from healthy mouse donors and mammary tumor organoids from MMTV-PyMT and C31T mouse models of breast cancer, we demonstrate that NK cells limit the early stages of metastasis, namely invasion and colony formation. Antibodies to invasive K14+ cells were able to enhance the ability of NK cells to limit colony formation, suggesting antibody-dependent cell mediated cytotoxicity. Surprisingly, when isolated from tumor bearing mice, NK cells did not limit invasion and instead promoted colony formation. The in vivo adoptive transfer of NK cells from healthy donors prevents the progression of early lung metastatic seeds to macrometastases, while the adoptive transfer of cells isolated from tumor bearing donors promotes macrometastatic development. This growth promoting phenotype can be neutralized with antibodies targeting inhibitory cell surface receptors. CONCLUSIONS: Our ex vivo and in vivo data demonstrate that healthy donor NK cells can limit metastasis through the directed cytotoxicity against pioneering K14+ invasive cells. However, prolonged exposure to tumors reprogram NK cells from tumor killing to tumor promoting, specifically in promoting the outgrowth of macrometastases. Further, we can neutralize this effect using NK cell specific inhibitory antibodies. This is the first time inhibitory signaling on NK cells have been linked with a growth promoting phenotype. These data can provide insight into when the use of NK cell directed therapies can be used to treat or prevent clinically relevant metastatic disease. Citation Format: Isaac S. Chan, Hildur Knútsdoóttir, Gayathri Ramakrishnan, Veena Padmanaban, Joel S. Bader, Elizabeth M. Jaffee, Andrew J. Ewald. A dual role of natural killer cells in breast cancer metastasis [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-01-01.
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- 2020
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23. Paracrine Hedgehog Signaling Drives Metabolic Changes in Hepatocellular Carcinoma
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Thiago A. Pereira, Yuping Chen, Albert S. Baldwin, Wing-Kin Syn, Jiuyi Lu, Guanhua Xie, Blair R. Anderson, Gregory A. Michelotti, Cynthia D. Guy, Gamze Karaca, Anna Mae Diehl, Isaac S. Chan, Leandi Krüger, Marzena Swiderska-Syn, and Steve S. Choi
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Cancer Research ,Pathology ,medicine.medical_specialty ,Carcinoma, Hepatocellular ,Paracrine Communication ,Biology ,Article ,Mice ,Paracrine signalling ,Non-alcoholic Fatty Liver Disease ,medicine ,Carcinoma ,Animals ,Humans ,Hedgehog Proteins ,Lactic Acid ,Myofibroblasts ,Hedgehog ,Cells, Cultured ,Mice, Knockout ,Lipogenesis ,Liver Neoplasms ,Hep G2 Cells ,medicine.disease ,digestive system diseases ,Hedgehog signaling pathway ,Fatty Liver ,Oncology ,Hepatocellular carcinoma ,Cancer research ,Energy source ,Glycolysis ,Myofibroblast - Abstract
Hepatocellular carcinoma (HCC) typically develops in cirrhosis, a condition characterized by Hedgehog (Hh) pathway activation and accumulation of Hh-responsive myofibroblasts. Although Hh signaling generally regulates stromal–epithelial interactions that support epithelial viability, the role of Hh-dependent myofibroblasts in hepatocarcinogenesis is unknown. Here, we used human HCC samples, a mouse HCC model, and hepatoma cell/myofibroblast cocultures to examine the hypothesis that Hh signaling modulates myofibroblasts' metabolism to generate fuels for neighboring malignant hepatocytes. The results identify a novel paracrine mechanism whereby malignant hepatocytes produce Hh ligands to stimulate glycolysis in neighboring myofibroblasts, resulting in release of myofibroblast-derived lactate that the malignant hepatocytes use as an energy source. This discovery reveals new diagnostic and therapeutic targets that might be exploited to improve the outcomes of cirrhotic patients with HCCs. Cancer Res; 72(24); 6344–50. ©2012 AACR.
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- 2012
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24. An Acquired Factor X Inhibitor: The Importance of Understanding Coagulation
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F. Joy Ogunsile and Isaac S. Chan
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Male ,business.industry ,General Medicine ,Middle Aged ,030204 cardiovascular system & hematology ,Bioinformatics ,medicine.disease ,Acquired Factor X Deficiency ,03 medical and health sciences ,0302 clinical medicine ,Coagulation ,030220 oncology & carcinogenesis ,Factor X inhibitor ,Coagulopathy ,Humans ,Medicine ,Blood Coagulation Tests ,business ,Blood Coagulation ,Factor X Deficiency ,Blood coagulation test - Published
- 2017
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25. Delayed Diagnosis of Disseminated Cryptococcosis with Associated Meningoencephalitis in an Immunocompetent Septuagenarian Host
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Isaac S. Chan, Rani Chudasama, and Adam Burrows
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Antifungal Agents ,Delayed Diagnosis ,020205 medical informatics ,02 engineering and technology ,Delayed diagnosis ,Risk Assessment ,03 medical and health sciences ,0302 clinical medicine ,Meningoencephalitis ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Humans ,030212 general & internal medicine ,Aged ,Host (biology) ,business.industry ,Headache ,Cryptococcosis ,General Medicine ,medicine.disease ,Treatment Outcome ,Disseminated cryptococcosis ,Immunology ,Cryptococcus neoformans ,Disease Progression ,Female ,business ,Fungemia ,Immunocompetence ,Follow-Up Studies - Published
- 2017
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26. Alterations of pulmonary vascular afterload in exercise‐induced pre‐ and post‐capillary pulmonary hypertension
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Elizabeth Karvasarski, Robert F. Bentley, Tayler A. Buchan, Felipe H. Valle, Stephen P. Wright, Isaac S. Chang, John T. Granton, and Susanna Mak
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exercise ,hemodynamics ,pulmonary hypertension ,resistance‐compliance time ,Physiology ,QP1-981 - Abstract
Abstract Exercise imposes increased pulmonary vascular afterload based on rises in pulmonary artery (PA) wedge pressure, declines in PA compliance, and resistance‐compliance time. In health, afterload stress stabilizes during steady‐state exercise. Our objective was to examine alterations of these exercise‐associated stresses in states of pre‐ and post‐capillary pulmonary hypertension (PH). PA hemodynamics were evaluated at rest, 2 and 7 min of steady‐state exercise at moderate intensity in patients who exhibited Pre‐capillary (n = 22) and post‐capillary PH (n = 22). Patients with normal exercise hemodynamics (NOR‐HD) (n = 32) were also studied. During exercise in all groups, PA wedge pressure increased at 2 min, with no further change at 7 min. In post‐capillary PH and NOR‐HD, increases in PA diastolic pressure and diastolic pressure gradient remained stable at 2 and 7 min of exercise, while in pre‐capillary PH, both continued to increase at 7 min. The behavior of the diastolic pressure gradient was linearly related to the duration of resistance‐compliance time at rest (r2 = 0.843) and exercise (r2 = 0.760). Exercise resistance‐compliance time was longer in pre‐capillary PH associated with larger increases in diastolic pressure gradient. Conversely, resistance‐compliance time was shortest in post‐capillary PH compared to pre‐capillary PH and NOR‐HD and associated with limited increases in exercise diastolic pressure gradient. During steady‐state, modest‐intensity exercise‐specific patterns of pulmonary vascular afterload responses were observed in pre‐ and post‐capillary PH relative to NOR‐HD. Longer resistance‐compliance time related to greater increases in PA diastolic pressure and diastolic pressure gradients in pre‐capillary PH, while shorter resistance‐compliance time appeared to limit these increases in post‐capillary PH.
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- 2023
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27. Alcohol Activates the Hedgehog Pathway and Induces Related Procarcinogenic Processes in the Alcohol-Preferring Rat Model of Hepatocarcinogenesis
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Steve S. Choi, C. Max Schmidt, Isaac S. Chan, Gregory A. Michelotti, Abigail Wank, Cynthia D. Guy, Anna Mae Diehl, Marzena Swiderska-Syn, Michele T. Yip-Schneider, Gamze Karaca, Thiago A. Pereira, Vishnu Kadiyala, and Mariana Verdelho Machado
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medicine.medical_specialty ,Pathology ,Epithelial-Mesenchymal Transition ,Carcinogenesis ,Medicine (miscellaneous) ,Biology ,Toxicology ,medicine.disease_cause ,Article ,Random Allocation ,chemistry.chemical_compound ,Liver Neoplasms, Experimental ,Internal medicine ,medicine ,Animals ,Hedgehog Proteins ,Reverse Warburg effect ,Hedgehog ,Ethanol ,Liver cell ,Central Nervous System Depressants ,medicine.disease ,Liver regeneration ,Hedgehog signaling pathway ,Rats ,Psychiatry and Mental health ,Endocrinology ,Liver ,chemistry ,Liver cancer - Abstract
Alcohol consumption promotes hepatocellular carcinoma (HCC). The responsible mechanisms are not well understood. Hepatocarcinogenesis increases with age and is enhanced by factors that impose a demand for liver regeneration. Because alcohol is hepatotoxic, habitual alcohol ingestion evokes a recurrent demand for hepatic regeneration. The alcohol-preferring (P) rat model mimics the level of alcohol consumption by humans who habitually abuse alcohol. Previously, we showed that habitual heavy alcohol ingestion amplified age-related hepatocarcinogenesis in P rats, with over 80% of alcohol-consuming P rats developing HCCs after 18 months of alcohol exposure, compared with only 5% of water-drinking controls.Herein, we used quantitative real-time PCR and quantitative immunocytochemistry to compare liver tissues from alcohol-consuming P rats and water-fed P rat controls after 6, 12, or 18 months of drinking. We aimed to identify potential mechanisms that might underlie the differences in liver cancer formation and hypothesized that chronic alcohol ingestion would activate Hedgehog (HH), a regenerative signaling pathway that is overactivated in HCC.Chronic alcohol ingestion amplified age-related degenerative changes in hepatocytes, but did not cause appreciable liver inflammation or fibrosis even after 18 months of heavy drinking. HH signaling was also enhanced by alcohol exposure, as evidenced by increased levels of mRNAs encoding HH ligands, HH-regulated transcription factors, and HH target genes. Immunocytochemistry confirmed increased alcohol-related accumulation of HH ligand-producing cells and HH-responsive target cells. HH-related regenerative responses were also induced in alcohol-exposed rats. Three of these processes (i.e., deregulated progenitor expansion, the reverse Warburg effect, and epithelial-to-mesenchymal transitions) are known to promote cancer growth in other tissues.Alcohol-related changes in Hedgehog signaling and resultant deregulation of liver cell replacement might promote hepatocarcinogenesis.
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- 2014
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28. NKT associated Hedgehog and Osteopontin drive fibrogenesis in nonalcoholic fatty liver disease
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Kolade M. Agboola, Steve S. Choi, Thiago A. Pereira, Marzena Swiderska, Gamze Karaca, Cynthia D. Guy, Anna Mae Diehl, Paul C. Kuo, Wing-Kin Syn, Guanhua Xie, Evaggelia Liaskou, Manal F. Abdelmalek, Herbert Pang, Isaac S. Chan, Zhiyong Mi, George Philips, Gregory A. Michelotti, and Yuping Chen
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medicine.medical_specialty ,Enzyme-Linked Immunosorbent Assay ,Biology ,Lymphocyte Activation ,Article ,Mice ,Immune system ,Downregulation and upregulation ,stomatognathic system ,Fibrosis ,Non-alcoholic Fatty Liver Disease ,Internal medicine ,medicine ,Hepatic Stellate Cells ,Animals ,Humans ,Hedgehog Proteins ,Osteopontin ,Fatty liver ,Gastroenterology ,hemic and immune systems ,medicine.disease ,Natural killer T cell ,Immunohistochemistry ,Fatty Liver ,Endocrinology ,Liver ,biology.protein ,Hepatic stellate cell ,Disease Progression ,Natural Killer T-Cells ,Steatohepatitis ,Signal Transduction - Abstract
Objective Immune responses are important in dictating non-alcoholic steatohepatitis (NASH) outcome. We previously reported that upregulation of hedgehog (Hh) and osteopontin (OPN) occurs in NASH, that Hh-regulated accumulation of natural killer T (NKT) cells promotes hepatic stellate cell (HSC) activation, and that cirrhotic livers harbour large numbers of NKT cells. Design The hypothesis that activated NKT cells drive fibrogenesis during NASH was evaluated by assessing if NKT depletion protects against NASH fibrosis; identifying the NKT-associated fibrogenic factors; and correlating plasma levels of the NKT cell-associated factor OPN with fibrosis severity in mice and humans. Results When fed methionine-choline-deficient (MCD) diets for 8 weeks, wild type (WT) mice exhibited Hh pathway activation, enhanced OPN expression, and NASH-fibrosis. Ja18‒/‒ and CD1d‒/‒ mice which lack NKT cells had significantly attenuated Hh and OPN expression and dramatically less fibrosis. Liver mononuclear cells (LMNCs) from MCD diet fed WT mice contained activated NKT cells, generated Hh and OPN, and stimulated HSCs to become myofibroblasts; neutralising these factors abrogated the fibrogenic actions of WT LMNCs. LMNCs from NKT-cell-deficient mice were deficient in fibrogenic factors, failing to activate collagen gene expression in HSCs. Human NASH livers with advanced fibrosis contained more OPN and Hh protein than those with early fibrosis. Plasma levels of OPN mirrored hepatic OPN expression and correlated with fibrosis severity. Conclusion Hepatic NKT cells drive production of OPN and Hh ligands that promote fibrogenesis during NASH. Associated increases in plasma levels of OPN may provide a biomarker of NASH fibrosis.
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- 2012
29. Hedgehog signalling regulates liver sinusoidal endothelial cell capillarisation
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Anna Mae Diehl, Steve S. Choi, Marzena Swiderska, Isaac S. Chan, Gregory A. Michelotti, Yuping Chen, Gamze Karaca, Wing-Kin Syn, and Guanhua Xie
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Liver cytology ,Transgene ,Blotting, Western ,Mice, Transgenic ,Biology ,Article ,Rats, Sprague-Dawley ,Mice ,Downregulation and upregulation ,Cell Movement ,Animals ,Hedgehog Proteins ,RNA, Messenger ,Receptor ,Hedgehog ,Cells, Cultured ,Gene knockdown ,Reverse Transcriptase Polymerase Chain Reaction ,Liver Diseases ,Gastroenterology ,Endothelial Cells ,Molecular biology ,Immunohistochemistry ,Rats ,Mice, Inbred C57BL ,Gene Expression Regulation ,Liver ,Chronic Disease ,Microscopy, Electron, Scanning ,Signal transduction ,Smoothened ,Capillary Action ,Signal Transduction - Abstract
Objective Vascular remodelling during liver damage involves loss of healthy liver sinusoidal endothelial cell (LSEC) phenotype via capillarisation. Hedgehog (Hh) signalling regulates vascular development and increases during liver injury. This study therefore examined its role in capillarisation. Design Primary LSEC were cultured for 5 days to induce capillarisation. Pharmacological, antibody-mediated and genetic approaches were used to manipulate Hh signalling. Effects on mRNA and protein expression of Hh-regulated genes and capillarisation markers were evaluated by quantitative reverse transcription PCR and immunoblot. Changes in LSEC function were assessed by migration and tube forming assay, and gain/loss of fenestrae was examined by electron microscopy. Mice with acute or chronic liver injury were treated with Hh inhibitors; effects on capillarisation were assessed by immunohistochemistry. Results Freshly isolated LSEC expressed Hh ligands, Hh receptors and Hh ligand antagonist Hhip. Capillarisation was accompanied by repression of Hhip and increased expression of Hh-regulated genes. Treatment with Hh agonist further induced expression of Hh ligands and Hh-regulated genes, and upregulated capillarisation-associated genes; whereas Hh signalling antagonist or Hh ligand neutralising antibody each repressed expression of Hh target genes and capillarisation markers. LSEC isolated from Smo loxP/loxP transgenic mice that had been infected with adenovirus expressing Cre-recombinase to delete Smoothened showed over 75% knockdown of Smoothened. During culture, Smoothened-deficient LSEC had inhibited Hh signalling, less induction of capillarisation-associated genes and retention of fenestrae. In mice with injured livers, inhibiting Hh signalling prevented capillarisation. Conclusions LSEC produce and respond to Hh ligands, and use Hh signalling to regulate complex phenotypic changes that occur during capillarisation.
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- 2012
30. Macrophage-derived Hedgehog ligands promotes fibrogenic and angiogenic responses in human schistosomiasis mansoni
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Marzena Swiderska, William Evan Secor, Rafal P. Witek, Izabela Voieta, Steve S. Choi, Jiuyi Lu, Anna Mae Diehl, Wing-Kin Syn, Carlos Antunes, Fausto L. Pereira, Kirsten B. Amaral, Thiago A. Pereira, José Roberto Lambertucci, Isaac S. Chan, and Guanhua Xie
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Patched ,Adult ,Liver Cirrhosis ,Male ,Kupffer Cells ,Biopsy ,Schistosomiasis ,Biology ,Ligands ,Real-Time Polymerase Chain Reaction ,Transfection ,Severity of Illness Index ,Cell Line ,Mice ,Young Adult ,Fibrosis ,Genes, Reporter ,medicine ,Macrophage ,Animals ,Humans ,Hedgehog Proteins ,Myofibroblasts ,Hedgehog ,Ultrasonography ,Tube formation ,Hepatology ,Neovascularization, Pathologic ,CD68 ,Macrophages ,Endothelial Cells ,Schistosoma mansoni ,Macrophage Activation ,Middle Aged ,medicine.disease ,Immunohistochemistry ,Hedgehog signaling pathway ,Schistosomiasis mansoni ,Rats ,Liver ,Immunology ,Cancer research ,Female ,Signal Transduction - Abstract
Background: Schistosomiasis mansoni is a major cause of portal fibrosis and portal hypertension. The Hedgehog pathway regulates fibrogenic repair in some types of liver injury. Aims: Determine if Hedgehog pathway activation occurs during fibrosis progression in schistosomiasis and to determine if macrophage-related mechanisms are involved. Methods: Immunohistochemistry was used to characterize the cells that generate and respond to Hedgehog ligands in 28 liver biopsies from patients with different grades of schistosomiasis fibrosis staged by ultrasound. Cultured macrophages (RAW264.7 and primary rat Kupffer cells) and primary rat liver sinusoidal endothelial cells (LSEC) were treated with schistosome egg antigen (SEA) and evaluated using qRT-PCR. Inhibition of the Hedgehog pathway was used to investigate its role in alternative activation of macrophages (M2) and vascular tube formation. Results: Patients with schistosomiasis expressed more ligands (Shh and Ihh) and target genes (Patched and Gli2) than healthy individuals. Activated LSEC and myofibroblasts were Hedgehog responsive [Gli2 (+)] and accumulated in parallel with fibrosis stage (P < 0.05). Double IHC for Ihh/CD68 showed that Ihh(+) cells were macrophages. In vitro studies demonstrated that SEA-stimulated macrophages to express Ihh and Shh mRNA (P < 0.05). Conditioned media from such macrophages induced luciferase production by Shh-LightII cells (P < 0.001) and Hedgehog inhibitors blocked this effect (P < 0.001). SEA-treated macrophages also up-regulated their own expression of M2 markers, and Hh pathway inhibitors abrogated this response (P < 0.01). Inhibition of the Hedgehog pathway in LSEC blocked SEA-induced migration and tube formation. Conclusion: SEA stimulates liver macrophages to produce Hh ligands, which promote alternative activation of macrophages, fibrogenesis and vascular remodelling in schistosomiasis.
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- 2012
31. Personalized medicine: progress and promise
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Isaac S. Chan and Geoffrey S. Ginsburg
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medicine.medical_specialty ,Knowledge management ,business.industry ,Computer science ,Genome, Human ,Comparative effectiveness research ,MEDLINE ,Translational medicine ,Precision medicine ,Clinical decision support system ,Pharmacogenetics ,Health care ,Genetics ,medicine ,Humans ,Disease ,Genetic Predisposition to Disease ,Personalized medicine ,Preventive Medicine ,Precision Medicine ,business ,Molecular Biology ,Genetics (clinical) ,Preventive healthcare - Abstract
Personalized medicine is a broad and rapidly advancing field of health care that is informed by each person's unique clinical, genetic, genomic, and environmental information. Personalized medicine depends on multidisciplinary health care teams and integrated technologies (e.g., clinical decision support) to utilize our molecular understanding of disease in order to optimize preventive health care strategies. Human genome information now allows providers to create optimized care plans at every stage of a disease, shifting the focus from reactive to preventive health care. The further integration of personalized medicine into the clinical workflow requires overcoming several barriers in education, accessibility, regulation, and reimbursement. This review focuses on providing a comprehensive understanding of personalized medicine, from scientific discovery at the laboratory bench to integration of these novel ways of understanding human biology at the bedside.
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- 2011
32. Hedgehog Controls Hepatic Stellate Cell Fate by Regulating Metabolism
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Steve S. Choi, Anna Mae Diehl, Yuping Chen, Francesca Garibaldi, Claude A. Piantadosi, Isaac S. Chan, Marzena Swiderska-Syn, Cynthia A. Moylan, Gregory A. Michelotti, Gamze Karaca, Guanhua Xie, Richard T. Premont, and Hagir B. Suliman
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Liver Cirrhosis ,Male ,medicine.medical_specialty ,Time Factors ,Pyruvate Kinase ,Mitochondrion ,Biology ,Article ,Mice ,Internal medicine ,Hepatic Stellate Cells ,medicine ,Animals ,Humans ,Hedgehog Proteins ,Lactic Acid ,RNA, Messenger ,Myofibroblasts ,Carbon Tetrachloride ,Ligation ,Hedgehog ,Cells, Cultured ,Hepatology ,Gene Expression Profiling ,Transdifferentiation ,Gastroenterology ,Hypoxia-Inducible Factor 1, alpha Subunit ,Actins ,Hedgehog signaling pathway ,Mitochondria ,Rats ,Cell biology ,Mice, Inbred C57BL ,Endocrinology ,Gene Expression Regulation ,Cell Transdifferentiation ,Hepatic stellate cell ,Bile Ducts ,Signal transduction ,Smoothened ,Glycolysis ,Myofibroblast ,Signal Transduction - Abstract
Background & Aims The pathogenesis of cirrhosis, a disabling outcome of defective liver repair, involves deregulated accumulation of myofibroblasts derived from quiescent hepatic stellate cells (HSCs), but the mechanisms that control transdifferentiation of HSCs are poorly understood. We investigated whether the Hedgehog (Hh) pathway controls the fate of HSCs by regulating metabolism. Methods Microarray, quantitative polymerase chain reaction, and immunoblot analyses were used to identify metabolic genes that were differentially expressed in quiescent vs myofibroblast HSCs. Glycolysis and lactate production were disrupted in HSCs to determine if metabolism influenced transdifferentiation. Hh signaling and hypoxia-inducible factor 1α (HIF1α) activity were altered to identify factors that alter glycolytic activity. Changes in expression of genes that regulate glycolysis were quantified and localized in biopsy samples from patients with cirrhosis and liver samples from mice following administration of CCl 4 or bile duct ligation. Mice were given systemic inhibitors of Hh to determine if they affect glycolytic activity of the hepatic stroma; Hh signaling was also conditionally disrupted in myofibroblasts to determine the effects of glycolytic activity. Results Transdifferentiation of cultured, quiescent HSCs into myofibroblasts induced glycolysis and caused lactate accumulation. Increased expression of genes that regulate glycolysis required Hh signaling and involved induction of HIF1α. Inhibitors of Hh signaling, HIF1α, glycolysis, or lactate accumulation converted myofibroblasts to quiescent HSCs. In diseased livers of animals and patients, numbers of glycolytic stromal cells were associated with the severity of fibrosis. Conditional disruption of Hh signaling in myofibroblasts reduced numbers of glycolytic myofibroblasts and liver fibrosis in mice; similar effects were observed following administration of pharmacologic inhibitors of Hh. Conclusions Hedgehog signaling controls the fate of HSCs by regulating metabolism. These findings might be applied to diagnosis and treatment of patients with cirrhosis.
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- 2012
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33. Su1587 Hedgehog Inhibition Regulates the Stromal Microenvironment in Hepatocellular Carcinoma via Suppression of the Warburg Effect
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Cynthia D. Guy, Yuping Chen, Marzena Swiderska, Steve S. Choi, Gregory A. Michelotti, Anna Mae Diehl, Gamze Karaca, Guanhua Xie, and Isaac S. Chan
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Stromal cell ,Hepatology ,Chemistry ,Hepatocellular carcinoma ,Gastroenterology ,Cancer research ,medicine ,medicine.disease ,Warburg effect ,Hedgehog - Published
- 2012
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34. Hedgehog Signaling Antagonist Promotes Regression of Both Liver Fibrosis and Hepatocellular Carcinoma in a Murine Model of Primary Liver Cancer
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Sebastian Feuerlein, Youngmi Jung, Christopher D. Lascola, Cynthia A. Moylan, Elmar M. Merkle, George Philips, Gamze Karaca, Talaignair N. Venkatraman, Gregory A. Michelotti, Rafal P. Witek, Fatima A. Rangwala, Marzena Swiderska, Cynthia D. Guy, Anna Mae Diehl, Steve S. Choi, Wing-Kin Syn, Vanessa T. Schroder, and Isaac S. Chan
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Liver Cirrhosis ,Pathology ,Mouse ,Pyridines ,lcsh:Medicine ,Cell Count ,Mice ,0302 clinical medicine ,Recurrence ,Fibrosis ,Molecular Cell Biology ,Gastrointestinal Cancers ,Anilides ,Osteopontin ,lcsh:Science ,Liver injury ,0303 health sciences ,Multidisciplinary ,Stem Cells ,Liver Diseases ,Liver Neoplasms ,Animal Models ,Signaling in Selected Disciplines ,Magnetic Resonance Imaging ,Hedgehog signaling pathway ,Tumor Burden ,3. Good health ,Gene Expression Regulation, Neoplastic ,Hyaluronan Receptors ,Cirrhosis ,Oncology ,030220 oncology & carcinogenesis ,Hepatocellular carcinoma ,Medicine ,Immunohistochemistry ,Oncology Agents ,Genetic Engineering ,Signal Transduction ,Research Article ,Biotechnology ,medicine.medical_specialty ,ATP Binding Cassette Transporter, Subfamily B ,Carcinoma, Hepatocellular ,Gastroenterology and Hepatology ,Biology ,03 medical and health sciences ,Model Organisms ,Gastrointestinal Tumors ,medicine ,Animals ,Hedgehog Proteins ,Progenitor cell ,Hedgehog ,030304 developmental biology ,Oncogenic Signaling ,lcsh:R ,Cancers and Neoplasms ,Hepatocellular Carcinoma ,Molecular Development ,medicine.disease ,Signaling ,Disease Models, Animal ,biology.protein ,lcsh:Q ,Transgenics ,Developmental Biology - Abstract
Objective: Chronic fibrosing liver injury is a major risk factor for hepatocarcinogenesis in humans. Mice with targeted deletion of Mdr2 (the murine ortholog of MDR3) develop chronic fibrosing liver injury. Hepatocellular carcinoma (HCC) emerges spontaneously in such mice by 50–60 weeks of age, providing a model of fibrosis-associated hepatocarcinogenesis. We used Mdr2 2/2 mice to investigate the hypothesis that activation of the hedgehog (Hh) signaling pathway promotes development of both liver fibrosis and HCC. Methods: Hepatic injury and fibrosis, Hh pathway activation, and liver progenitor populations were compared in Mdr2 2/2 mice and age-matched wild type controls. A dose finding experiment with the Hh signaling antagonist GDC-0449 was performed to optimize Hh pathway inhibition. Mice were then treated with GDC-0449 or vehicle for 9 days, and effects on liver fibrosis and tumor burden were assessed by immunohistochemistry, qRT-PCR, Western blot, and magnetic resonanceimaging. Results: Unlike controls, Mdr2 2/2 mice consistently expressed Hh ligands and progressively accumulated Hh-responsive liver myofibroblasts and progenitors with age. Treatment of aged Mdr2-deficient mice with GDC-0449 significantly inhibited hepatic Hh activity, decreased liver myofibroblasts and progenitors, reduced liver fibrosis, promoted regression of intrahepatic HCCs, and decreased the number of metastatic HCC without increasing mortality. Conclusions: Hh pathway activation promotes liver fibrosis and hepatocarcinogenesis, and inhibiting Hh signaling safely reverses both processes even when fibrosis and HCC are advanced.
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- 2011
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35. Age- and Sex-Specific Genomic Profiles in Non–Small Cell Lung Cancer
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Wisut Lamlertthon, Jeffrey Crawford, William T. Barry, Isaac S. Chan, Chaitanya R. Acharya, William Mostertz, Kelli S. Walters, Marvaretta Stevenson, Joseph R. Nevins, and Anil Potti
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Adult ,Male ,Oncology ,medicine.medical_specialty ,Lung Neoplasms ,Microarray ,Context (language use) ,Cohort Studies ,Sex Factors ,Carcinoma, Non-Small-Cell Lung ,Internal medicine ,medicine ,Humans ,Neoplasm Invasiveness ,Stage (cooking) ,Lung cancer ,Aged ,Retrospective Studies ,Aged, 80 and over ,business.industry ,Gene Expression Profiling ,Respiratory disease ,Age Factors ,Cancer ,Oncogenes ,General Medicine ,Middle Aged ,Prognosis ,medicine.disease ,Survival Analysis ,Gene expression profiling ,Cohort ,Immunology ,Female ,business - Abstract
Gene expression profiling may be useful in examining differences underlying age- and sex-specific outcomes in non-small cell lung cancer (NSCLC).To describe clinically relevant differences in the underlying biology of NSCLC based on patient age and sex.Retrospective analysis of 787 patients with predominantly early stage NSCLC performed at Duke University, Durham, North Carolina, from July 2008 to June 2009. Lung tumor samples with corresponding microarray and clinical data were used. All patients were divided into subgroups based on age (70 vsor = 70 years old) or sex. Gene expression signatures representing oncogenic pathway activation and tumor biology/microenvironment status were applied to these samples to obtain patterns of activation/deregulation.Patterns of oncogenic and molecular signaling pathway activation that are reproducible and correlate with 5-year recurrence-free patient survival.Low- and high-risk patient clusters/cohorts were identified with the longest and shortest 5-year recurrence-free survival, respectively, within the age and sex NSCLC subgroups. These cohorts of NSCLC demonstrate similar patterns of pathway activation. In patients younger than 70 years, high-risk patients, with the shortest recurrence-free survival, demonstrated increased activation of the Src (25% vs 6%; P.001) and tumor necrosis factor (76% vs 42%; P.001) pathways compared with low-risk patients. High-risk patients aged 70 years or older demonstrated increased activation of the wound healing (40% vs 24%; P = .02) and invasiveness (64% vs 20%; P.001) pathways compared with low-risk patients. In women, high-risk patients demonstrated increased activation of the invasiveness (99% vs 2%; P.001) and STAT3 (72% vs 35%; P.001) pathways while high-risk men demonstrated increased activation of the STAT3 (87% vs 18%; P.001), tumor necrosis factor (90% vs 46%; P.001), EGFR (13% vs 2%; P = .003), and wound healing (50% vs 22%; P.001) pathways. Multivariate analyses confirmed the independent clinical relevance of the pathway-based subphenotypes in women (hazard ratio [HR], 2.02; 95% confidence interval [CI], 1.34-3.03; P.001) and patients younger than 70 years (HR, 1.83; 95% CI, 1.24-2.71; P = .003). All observations were reproducible in split sample analyses.Among a cohort of patients with NSCLC, subgroups defined by oncogenic pathway activation profiles were associated with recurrence-free survival. These findings require validation in independent patient data sets.
- Published
- 2010
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36. Hedgehog Signaling Antagonist Promotes Regression of Both Liver Fibrosis and Hepatocellular Carcinoma in a Murine Model of Primary Liver Cancer.
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Philips, George M., Isaac S. Chan, Swiderska, Marzena, Schroder, Vanessa T., Guy, Cynthia, Karaca, Gamze F., Moylan, Cynthia, Venkatraman, Talaignair, Feuerlein, Sebastian, Syn, Wing-Kin, Jung, Youngmi, Witek, Rafal P., Choi, Steve, Michelotti, Gregory A., Rangwala, Fatima, Merkle, Elmar, Lascola, Christopher, and Diehl, Anna Mae
- Subjects
CANCER risk factors ,LIVER cancer ,HEDGEHOG signaling proteins ,PROMOTERS (Genetics) ,REGRESSION analysis ,FIBROSIS ,LABORATORY mice ,LIVER injuries ,CARCINOGENESIS ,MYOFIBROBLASTS - Abstract
Objective: Chronic fibrosing liver injury is a major risk factor for hepatocarcinogenesis in humans. Mice with targeted deletion of Mdr2 (the murine ortholog of MDR3) develop chronic fibrosing liver injury. Hepatocellular carcinoma (HCC) emerges spontaneously in such mice by 50-60 weeks of age, providing a model of fibrosis-associated hepatocarcinogenesis. We used Mdr2
-/- mice to investigate the hypothesis that activation of the hedgehog (Hh) signaling pathway promotes development of both liver fibrosis and HCC. Methods: Hepatic injury and fibrosis, Hh pathway activation, and liver progenitor populations were compared in Mdr2-/- mice and age-matched wild type controls. A dose finding experiment with the Hh signaling antagonist GDC-0449 was performed to optimize Hh pathway inhibition. Mice were then treated with GDC-0449 or vehicle for 9 days, and effects on liver fibrosis and tumor burden were assessed by immunohistochemistry, qRT-PCR, Western blot, and magnetic resonance imaging. Results: Unlike controls, Mdr2-/- mice consistently expressed Hh ligands and progressively accumulated Hh-responsive liver myofibroblasts and progenitors with age. Treatment of aged Mdr2-deficient mice with GDC-0449 significantly inhibited hepatic Hh activity, decreased liver myofibroblasts and progenitors, reduced liver fibrosis, promoted regression of intrahepatic HCCs, and decreased the number of metastatic HCC without increasing mortality. Conclusions: Hh pathway activation promotes liver fibrosis and hepatocarcinogenesis, and inhibiting Hh signaling safely reverses both processes even when fibrosis and HCC are advanced. [ABSTRACT FROM AUTHOR]- Published
- 2011
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37. Unobtrusive Detection of Simulated Orthostatic Hypotension and Supine Hypertension Using Ballistocardiogram and Electrocardiogram of Healthy Adults
- Author
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Isaac S. Chang, Narges Armanfard, Abdul Q. Javaid, Jennifer Boger, and Alex Mihailidis
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Orthostatic hypotension ,supine hypertension ,RJ-interval ,ballistocardiogram ,electrocardiogram ,systolic blood pressure ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Medical technology ,R855-855.5 - Abstract
Effective management of neurogenic orthostatic hypotension and supine hypertension (SH-OH) due autonomic failure requires a frequent and timely adjustment of medication throughout the day to maintain the blood pressure (BP) within the normal range, i.e., an accurate depiction of BP is a key prerequisite of effective management. One of the emerging technologies that provide one's circadian and long-term physiological status with increased usability is unobtrusive zero-effort monitoring. In this paper, a zero-effort device, a floor tile, was used to develop an unobtrusive BP monitoring technique. Namely, RJ-interval, the time between the J-peak of a ballistocardiogram and the R-peak of an electrocardiogram, was used to develop a classifier that can detect changes in systolic BP (SBP) induced by the Valsalva maneuver on healthy adults (i.e., a simulated SH-OH). A t-test was used to show statistical differences between the mean RJ-intervals of decreased SBP, baseline, and increased SBP. Following the t-test, a classifier that detected a change in SBP was developed based on a naïve Bayes classifier (NBC). The t-test showed a clear statistical difference between the mean RJ-intervals of the increased SBP, baseline, and decreased SBP. The NBC-based classifier was able to detect increased SBP with 89.3% true positive rate (TPR), 100% true negative rate (TNR), and 94% accuracy and detect decreased SBP with 92.3% TPR, 100% TNR, and 95% accuracy. The analysis showed strong potential in using the developed classifier to assist monitoring of people with SH-OH; the algorithm may be used clinically to detect a long-term trend of symptoms of SH-OH.
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- 2018
- Full Text
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