MAY 09, 2017 10:00 AM PDT

WEBINAR: Querying Cytokine-Signaling Networks in Myeloproliferative Neoplasms

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  • Assistant Professor of Medicine Division of Hematology
      Dr. Stephen Oh is assistant professor of medicine in the Division of Hematology at Washington University School of Medicine. Dr. Oh heads a translational research group focused on the pathogenesis of myeloproliferative neoplasms (MPNs). The laboratory employs a combination of human patient samples and mouse models to study the initiation, development and progression of MPNs. Dr. Oh also conducts clinical research investigating novel targeted therapies for MPN patients. Dr. Oh completed his MD and PhD at Northwestern University Feinberg School of Medicine. He went on to complete a residency, fellowship and postdoctoral fellowship at Stanford University School of Medicine. He joined the faculty at Washington University in 2010.
    • Field Application Scientist Fluidigm Corporation
        Jennifer Frahm is a Houston-based field application scientist for Fluidigm. Jennifer performed her PhD research at North Carolina State University with a focus on method development for ovarian cancer biomarker quantification using high-resolution mass spectrometry. She completed a postdoctoral study at University of North Carolina at Chapel Hill on post-translational regulation in diabetic and obese mice. Tending to cells and mice was enough to persuade her to find a position that maintained a connection with bench science without having to rely on a cell or mouse timeline. She has been training and providing application support ever since.


      DATE: May 9th, 2017
      TIME: 10:00AM PDT, 1:00PM ET

      Myeloproliferative neoplasms including myelofibrosis (MF) are characterized by anemia, splenomegaly, bone marrow fibrosis and inflammatory cytokine production. JAK2 inhibition with ruxolitinib improves symptoms and lowers circulating plasma cytokine levels but does not ameliorate anemia, fibrosis or malignant clonal burden. The goal of this study is to better define the relationship between dysregulated cytokines and downstream signaling in MF and to determine how these pathways can be effectively manipulated for therapeutic benefit.

      To interrogate altered signaling in MF, we have employed mass cytometry, a novel technology that enables the quantitative analysis of more than 40 parameters at the single-cell level. We identified NF-kB pathway hyperactivation distributed across multiple hematopoietic cell populations, including T cells. Plasma TNFα levels were elevated in these subjects, suggesting that excessive production of TNFα may lead to broad activation of NF-κB in a non-cell-autonomous fashion.

      To further elucidate the etiology of systemic NF-κB hyperactivation, we extended our mass cytometry approach to study the cellular distribution of cytokine production in MF. Intracellular levels of several cytokines (including TNFα) were constitutively elevated in MF subjects compared to healthy controls. Supranormal cytokine expression was accentuated by stimulation with PMA/ionomycin or TLR ligands R-848 or Pam3CSK4. PMA/ionomycin increased production of TNFα from MF CD34+ cells and CD33+ immature myeloid cells.

      These findings imply that multiple cell populations in MF overexpress inflammatory cytokines and are hypersensitive to potentiating stimuli. Future experiments will identify signaling effects of multiple elevated cytokines, which may underlie MF features that persist despite JAK2 inhibitor therapy.

      Jennifer Frahm, PhD, of Fluidigm will give a brief overview of mass cytometry, the high-parameter, single-cell analysis technology used by Dr. Oh in his research. 

      Learning Objectives:

      •  Why current treatments for myeloproliferative neoplasms fall short and why additional research is needed
      •  How high-dimensional analysis with mass cytometry can identify signaling pathway abnormalities in  hematopoietic cell subsets in myelofibrosis
      •  How mass cytometry can delineate the cellular sources of aberrant cytokine production in  myelofibrosis




















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