Inhibition of nuclear factor kappa-B signaling reduces growth in medulloblastoma in vivo

Abstract Background Medulloblastoma is a highly malignant pediatric brain tumor that requires surgery, whole brain and spine irradiation, and intense chemotherapy for treatment. A more sophisticated understanding of the pathophysiology of medulloblastoma is needed to successfully reduce the intensity of treatment and improve outcomes. Nuclear factor kappa-B (NFκB) is a signaling pathway that controls transcriptional activation of genes important for tight regulation of many cellular processes and is aberrantly expressed in many types of cancer. Methods To test the importance of NFκB to medulloblastoma cell growth, the effects of multiple drugs that inhibit NFκB, pyrrolidine dithiocarbamate, diethyldithiocarbamate, sulfasalazine, curcumin and bortezomib, were studied in medulloblastoma cell lines compared to a malignant glioma cell line and normal neurons. Expression of endogenous NFκB was investigated in cultured cells, xenograft flank tumors, and primary human tumor samples. A dominant negative construct for the endogenous inhibitor of NFκB, IκB, was prepared from medulloblastoma cell lines and flank tumors were established to allow specific pathway inhibition. Results We report high constitutive activity of the canonical NFκB pathway, as seen by Western analysis of the NFκB subunit p65, in medulloblastoma tumors compared to normal brain. The p65 subunit of NFκB is extremely highly expressed in xenograft tumors from human medulloblastoma cell lines; though, conversely, the same cells in culture have minimal expression without specific stimulation. We demonstrate that pharmacological inhibition of NFκB in cell lines halts proliferation and leads to apoptosis. We show by immunohistochemical stain that phosphorylated p65 is found in the majority of primary tumor cells examined. Finally, expression of a dominant negative form of the endogenous inhibitor of NFκB, dnIκB, resulted in poor xenograft tumor growth, with average tumor volumes 40% smaller than controls. Conclusions These data collectively demonstrate that NFκB signaling is important for medulloblastoma tumor growth, and that inhibition can reduce tumor size and viability in vivo. We discuss the implications of NFκB signaling on the approach to managing patients with medulloblastoma in order to improve clinical outcomes.</p

Diseases of the nervous system /

The study of the brain continues to expand at a rapid pace providing fascinating insights into the basic mechanisms underlying nervous system illnesses. New tools, ranging from genome sequencing to non-invasive imaging, and research fueled by public and private investment in biomedical research has been transformative in our understanding of nervous system diseases and has led to an explosion of published primary research articles. Diseases of the Nervous System summarizes the current state of basic and clinical knowledge for the most common neurological and neuropsychiatric conditions. In a systematic progression, each chapter covers either a single disease or a group of related disorders ranging from static insults to primary and secondary progressive neurodegenerative diseases, neurodevelopmental illnesses, illnesses resulting from nervous system infection and neuropsychiatric conditions. Chapters follow a common format and are stand-alone units, each covering disease history, clinical presentation, disease mechanisms and treatment protocols. Dr. Sontheimer also includes two chapters which discuss common concepts shared among the disorders and how new findings are being translated from the bench to the bedside. In a final chapter, he explains the most commonly used neuroscience jargon. The chapters address controversial issues in current day neuroscience research including translational research, drug discovery, ethical issues, and the promises of personalized medicine. This book provides an introduction for course adoption and an introductory tutorial for students, scholars, researchers and medical professionals interested in learning the state of the art concerning our understanding and treatment of diseases of the nervous system.Print version record.The study of the brain continues to expand at a rapid pace providing fascinating insights into the basic mechanisms underlying nervous system illnesses. New tools, ranging from genome sequencing to non-invasive imaging, and research fueled by public and private investment in biomedical research has been transformative in our understanding of nervous system diseases and has led to an explosion of published primary research articles. Diseases of the Nervous System summarizes the current state of basic and clinical knowledge for the most common neurological and neuropsychiatric conditions. In a systematic progression, each chapter covers either a single disease or a group of related disorders ranging from static insults to primary and secondary progressive neurodegenerative diseases, neurodevelopmental illnesses, illnesses resulting from nervous system infection and neuropsychiatric conditions. Chapters follow a common format and are stand-alone units, each covering disease history, clinical presentation, disease mechanisms and treatment protocols. Dr. Sontheimer also includes two chapters which discuss common concepts shared among the disorders and how new findings are being translated from the bench to the bedside. In a final chapter, he explains the most commonly used neuroscience jargon. The chapters address controversial issues in current day neuroscience research including translational research, drug discovery, ethical issues, and the promises of personalized medicine. This book provides an introduction for course adoption and an introductory tutorial for students, scholars, researchers and medical professionals interested in learning the state of the art concerning our understanding and treatment of diseases of the nervous system.Includes bibliographical references and index.Static nervous system diseases -- Progressive neurodegenerative diseases -- Secondary progressive neurodegenerative diseases -- Developmental neurological conditions -- Neuropsychiatric illnesses -- Common concepts in neurological and neuropsychiatric illnesses -- Bench-to-bedside translation -- Neuroscience jargon.Elsevie