Medicine and Health Sciences Commons^™

Intestinal Neuropod Cell Gucy2c Regulates Visceral Pain, Joshua R. Barton, Annie K. Londregran, Tyler D. Alexander, Ariana A. Entezari, Shely Bar-Ad, Lan Cheng, Angelo C. Lepore, Adam E. Snook, Manuel Covarrubias, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Visceral pain (VP) is a global problem with complex etiologies and limited therapeutic options. Guanylyl cyclase C (GUCY2C), an intestinal receptor producing cyclic GMP(cGMP), which regulates luminal fluid secretion, has emerged as a therapeutic target for VP. Indeed, FDA-approved GUCY2C agonists ameliorate VP in patients with chronic constipation syndromes, although analgesic mechanisms remain obscure. Here, we revealed that intestinal GUCY2C was selectively enriched in neuropod cells, a type of enteroendocrine cell that synapses with submucosal neurons in mice and humans. GUCY2Chi neuropod cells associated with cocultured dorsal root ganglia neurons and induced hyperexcitability, reducing the rheobase and increasing the resulting …

Human Gucy2c-Targeted Chimeric Antigen Receptor (Car)-Expressing T Cells Eliminate Colorectal Cancer Metastases., Michael S. Magee, Tara S. Abraham, Trevor R. Baybutt, John C. Flickinger, Natalie A. Ridge, Glen P Marszalowicz, Priyanka Prajapati, Adam R. Hersperger, Scott A. Waldman, Adam E. Snook

Department of Pharmacology and Experimental Therapeutics Faculty Papers

One major hurdle to the success of adoptive T-cell therapy is the identification of antigens that permit effective targeting of tumors in the absence of toxicities to essential organs. Previous work has demonstrated that T cells engineered to express chimeric antigen receptors (CAR-T cells) targeting the murine homolog of the colorectal cancer antigen GUCY2C treat established colorectal cancer metastases, without toxicity to the normal GUCY2C-expressing intestinal epithelium, reflecting structural compartmentalization of endogenous GUCY2C to apical membranes comprising the intestinal lumen. Here, we examined the utility of a human-specific, GUCY2C-directed single-chain variable fragment as the basis for a CAR construct targeting …

Gucy2c Signaling Opposes The Acute Radiation-Induced Gi Syndrome., Peng Li, Evan Wuthrick, Jeff A. Rappaport, Crystal Kraft, Jieru E. Lin, Glen Marszalowicz, Adam E. Snook, Tingting Zhan, Terry M. Hyslop, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

High doses of ionizing radiation induce acute damage to epithelial cells of the gastrointestinal (GI) tract, mediating toxicities restricting the therapeutic efficacy of radiation in cancer and morbidity and mortality in nuclear disasters. No approved prophylaxis or therapy exists for these toxicities, in part reflecting an incomplete understanding of mechanisms contributing to the acute radiation-induced GI syndrome (RIGS). Guanylate cyclase C (GUCY2C) and its hormones guanylin and uroguanylin have recently emerged as one paracrine axis defending intestinal mucosal integrity against mutational, chemical, and inflammatory injury. Here, we reveal a role for the GUCY2C paracrine axis in compensatory mechanisms opposing RIGS. …

Intestinal Gucy2c Prevents Tgf-Β Secretion Coordinating Desmoplasia And Hyperproliferation In Colorectal Cancer., Ahmara V Gibbons, Jieru Egeria Lin, Gilbert Won Kim, Glen P Marszalowicz, Peng Li, Brian Arthur Stoecker, Erik S Blomain, Satish Rattan, Adam E. Snook, Stephanie Schulz, Scott A Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Tumorigenesis is a multistep process that reflects intimate reciprocal interactions between epithelia and underlying stroma. However, tumor-initiating mechanisms coordinating transformation of both epithelial and stromal components are not defined. In humans and mice, initiation of colorectal cancer is universally associated with loss of guanylin and uroguanylin, the endogenous ligands for the tumor suppressor guanylyl cyclase C (GUCY2C), disrupting a network of homeostatic mechanisms along the crypt-surface axis. Here, we reveal that silencing GUCY2C in human colon cancer cells increases Akt-dependent TGF-β secretion, activating fibroblasts through TGF-β type I receptors and Smad3 phosphorylation. In turn, activating TGF-β signaling induces fibroblasts to …

Analysis Of The Proteome Of Human Airway Epithelial Secretions., Mehboob Ali, Erik P Lillehoj, Yongsung Park, Yoshiyuki Kyo, K Chul Kim

Department of Pharmacology and Experimental Therapeutics Faculty Papers

BACKGROUND: Airway surface liquid, often referred to as mucus, is a thin layer of fluid covering the luminal surface that plays an important defensive role against foreign particles and chemicals entering the lungs. Airway mucus contains various macromolecules, the most abundant being mucin glycoproteins, which contribute to its defensive function. Airway epithelial cells cultured in vitro secrete mucins and nonmucin proteins from their apical surface that mimics mucus production in vivo. The current study was undertaken to identify the polypeptide constituents of human airway epithelial cell secretions to gain a better understanding of the protein composition of respiratory mucus.

RESULTS: …

Identification Of Thioaptamer Ligand Against E-Selectin: Potential Application For Inflamed Vasculature Targeting., Aman P Mann, Anoma Somasunderam, René Nieves-Alicea, Xin Li, Austin Hu, Anil K Sood, Mauro Ferrari, David G Gorenstein, Takemi Tanaka

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Active targeting of a drug carrier to a specific target site is crucial to provide a safe and efficient delivery of therapeutics and imaging contrast agents. E-selectin expression is induced on the endothelial cell surface of vessels in response to inflammatory stimuli but is absent in the normal vessels. Thus, E-selectin is an attractive molecular target, and high affinity ligands for E-selectin could be powerful tools for the delivery of therapeutics and/or imaging agents to inflamed vessels. In this study, we identified a thiophosphate modified aptamer (thioaptamer, TA) against E-selectin (ESTA-1) by employing a two-step selection strategy: a recombinant protein-based …

Lineage-Specific T-Cell Responses To Cancer Mucosa Antigen Oppose Systemic Metastases Without Mucosal Inflammatory Disease., Adam E. Snook, Peng Li, Benjamin J Stafford, Elizabeth J Faul, Lan Huang, Ruth C Birbe, Alessandro Bombonati, Stephanie Schulz, Matthias J. Schnell, Laurence C. Eisenlohr, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Cancer mucosa antigens are emerging as a new category of self-antigens expressed normally in immunologically privileged mucosal compartments and universally by their derivative tumors. These antigens leverage the established immunologic partitioning of systemic and mucosal compartments, limiting tolerance opposing systemic antitumor efficacy. An unresolved issue surrounding self-antigens as immunotherapeutic targets is autoimmunity following systemic immunization. In the context of cancer mucosa antigens, immune effectors to self-antigens risk amplifying mucosal inflammatory disease promoting carcinogenesis. Here, we examined the relationship between immunotherapy for systemic colon cancer metastases targeting the intestinal cancer mucosa antigen guanylyl cyclase C (GCC) and its effect on inflammatory …

A Study Of Micrornas In Silico And In Vivo: Diagnostic And Therapeutic Applications In Cancer., Scott A Waldman, Andre Terzic

Department of Pharmacology and Experimental Therapeutics Faculty Papers

There is emerging evidence of the production in human tumors of abnormal levels of microRNAs (miRNAs), which have been assigned oncogenic and/or tumor-suppressor functions. While some miRNAs commonly exhibit altered amounts across tumors, more often, different tumor types produce unique patterns of miRNAs, related to their tissue of origin. The role of miRNAs in tumorigenesis underscores their value as mechanism-based therapeutic targets in cancer. Similarly, unique patterns of altered levels of miRNA production provide fingerprints that may serve as molecular biomarkers for tumor diagnosis, classification, prognosis of disease-specific outcomes and prediction of therapeutic responses.

Transgenic Avian-Derived Recombinant Human Interferon-Alpha2b (Avi-005) In Healthy Subjects: An Open-Label, Single-Dose, Controlled Study., T B Patel, E Pequignot, S H Parker, M C Leavitt, H E Greenberg, Walter K. Kraft

Department of Pharmacology and Experimental Therapeutics Faculty Papers

BACKGROUND/AIMS: This study characterized the safety and pharmacological properties of AVI-005, a novel glycosylated recombinant human interferon-alpha2b produced from the egg whites of chickens transfected with human cDNA.

METHODS: 18 healthy volunteers received single subcutaneous rising doses (0.5, 1.66 or 5 million international units, MIU) of AVI-005. A randomized parallel comparator group of 10 subjects received 5 MIU of unglycosylated IFN-alpha2b (Intron A). The pharmacokinetic parameters t1/2, tmax, Cmax, AUC0-24h, Vd, and clearance were compared between AVI-005 and unglycosylated IFN-alpa2b.

RESULTS: At equipotent doses, AVI-005 had a larger AUC0-24h than the control interferon. Pharmacodynamic markers ofneopterin and beta2-microglobulin for the …