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 …

T-Cell Responses To Immunodominant Listeria Epitopes Limit Vaccine-Directed Responses To The Colorectal Cancer Antigen, Guanylyl Cyclase C, John C. Flickinger, Jagmohan Singh, Yanki Yarman, Robert D Carlson, Joshua Barton, Scott A Waldman, Adam E. Snook

Department of Pharmacology and Experimental Therapeutics Faculty Papers

The Gram-positive bacterium Listeria monocytogenes (Lm) is an emerging platform for cancer immunotherapy. To date, over 30 clinical trials have been initiated testing Lm cancer vaccines across a wide variety of cancers, including lung, cervical, colorectal, and pancreatic. Here, we assessed the immunogenicity of an Lm vaccine against the colorectal tumor antigen GUCY2C (Lm-GUCY2C). Surprisingly, Lm-GUCY2C vaccination did not prime naïve GUCY2C-specific CD8+ T-cell responses towards the dominant H-2Kd-restricted epitope, GUCY2C254-262. However, Lm-GUCY2C produced robust CD8+ T-cell responses towards Lm-derived peptides suggesting that GUCY2C254-262 peptide may be subdominant to Lm-derived peptides. Indeed, incorporating immunogenic Lm peptides into an adenovirus-based GUCY2C …

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 …

Gucy2c Opposes Systemic Genotoxic Tumorigenesis By Regulating Akt-Dependent Intestinal Barrier Integrity, Jieru Egeria Lin, Adam Eugene Snook, Peng Li, Brian Arthur Stoecker, Gilbert Won Kim, Michael Sullivan Magee, Alex Vladimir Mejia Garcia, Michael Anthony Valentino, Terry Hyslop, Stephanie Schulz, Scott Arthur Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

The barrier separating mucosal and systemic compartments comprises epithelial cells, annealed by tight junctions, limiting permeability. GUCY2C recently emerged as an intestinal tumor suppressor coordinating AKT1-dependent crypt-villus homeostasis. Here, the contribution of GUCY2C to barrier integrity opposing colitis and systemic tumorigenesis is defined. Mice deficient in GUCY2C (Gucy2c^−/−) exhibited barrier hyperpermeability associated with reduced junctional proteins. Conversely, activation of GUCY2C in mice reduced barrier permeability associated with increased junctional proteins. Further, silencing GUCY2C exacerbated, while activation reduced, chemical barrier disruption and colitis. Moreover, eliminating GUCY2C amplified, while activation reduced, systemic oxidative DNA damage. This genotoxicity was associated …

Expression Of The Intestinal Biomarkers Guanylyl Cyclase C And Cdx2 In Poorly Differentiated Colorectal Carcinomas., Brody Winn, Rosemarie Tavares, Andres Matoso, Lelia Noble, Jacqueline Fanion, Scott A Waldman, Murray B Resnick

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Guanylyl cyclase C, a receptor for bacterial diarrheagenic enterotoxins, is expressed selectively by intestinal epithelium and is an endogenous downstream target of CDX2. The expression of Guanylyl cyclase C is preserved throughout the adenoma/carcinoma sequence in the colorectum. Detection of Guanylyl cyclase C expression by reverse transcriptase-polymerase chain reaction is currently being validated as a technique to identify occult lymph node metastases in patients with colorectal cancer and for circulating cells in the blood for postoperative surveillance. Although Guanylyl cyclase C is widely expressed by well-differentiated colorectal cancer, its expression in poorly differentiated colorectal cancer has not been evaluated. A …

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 …

Association Of Gucy2c Expression In Lymph Nodes With Time To Recurrence And Disease-Free Survival In Pn0 Colorectal Cancer., Scott A Waldman, Terry Hyslop, Stephanie Schulz, Alan Barkun, Karl Nielsen, Janis Haaf, Christine Bonaccorso, Yanyan Li, David S Weinberg

Department of Pharmacology and Experimental Therapeutics Faculty Papers

CONTEXT: The established relationship between lymph node metastasis and prognosis in colorectal cancer suggests that recurrence in 25% of patients with lymph nodes free of tumor cells by histopathology (pN0) reflects the presence of occult metastases. Guanylyl cyclase 2C (GUCY2C) is a marker expressed by colorectal tumors that could reveal occult metastases in lymph nodes and better estimate recurrence risk.

OBJECTIVE: To examine the association of occult lymph node metastases detected by quantifying GUCY2C messenger RNA, using the reverse transcriptase-polymerase chain reaction, with recurrence and survival in patients with colorectal cancer.

DESIGN, SETTING, AND PARTICIPANTS: Prospective study of 257 patients …

Guanylyl Cyclase C Agonists Regulate Progression Through The Cell Cycle Of Human Colon Carcinoma Cells., Giovanni Mario Pitari, M D Di Guglielmo, J Park, S Schulz, Scott A Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

The effects of Escherichia coli heat-stable enterotoxin (ST) and uroguanylin were examined on the proliferation of T84 and Caco2 human colon carcinoma cells that express guanylyl cyclase C (GC-C) and SW480 human colon carcinoma cells that do not express this receptor. ST or uroguanylin inhibited proliferation of T84 and Caco2 cells, but not SW480 cells, in a concentration-dependent fashion, assessed by quantifying cell number, cell protein, and [(3)H]thymidine incorporation into DNA. These agonists did not inhibit proliferation by induction of apoptosis, assessed by TUNEL (terminal deoxynucleotidyl transferase-mediated dNTP-biotin nick end labeling of DNA fragments) assay and DNA laddering, or necrosis, …