Medicine and Health Sciences Commons^™

Targeting Tgf-Β During Epithelial-To-Mesenchymal Progression As An Effective Therapy Against Colorectal Cancer, Joyce Fan

Undergraduate Research

Colorectal cancer is one of the most common cancers worldwide. Understanding the mechanisms of colorectal cancer progression is crucial for the development of effective therapeutics. Epithelial-to-mesenchymal transition is a hallmark feature of cancer and is defined as the loss of epithelial cell features, such as apical-basal polarity and high expression of cell adhesion molecules, and the development of mesenchymal features, such as lack of polarity and increased cell mobility. Epithelial-to-mesenchymal is essential for cell migration, proliferation, and tumor growth. Both the TGF-β and SMAD pathway are associated with colorectal cancer progression. TGF-β is crucial to the cellular mechanism of cell …

Variant Characterization Of A Representative Large Pedigree Suggests “Variant Risk Clusters” Convey Varying Predisposition Of Risk To Lynch Syndrome, Mouadh Barbirou, Amanda A. Miller, Amel Mezlini, Balkiss Bouhaouala-Zahar, Peter J. Tonellato

Department of Medical Oncology Faculty Papers

Recently, worldwide incidences of young adult aggressive colorectal cancer (CRC) have rapidly increased. Of these incidences diagnosed as familial Lynch syndrome (LS) CRC, outcomes are extremely poor. In this study, we seek novel familial germline variants from a large pedigree Tunisian family with 12 LS-affected individuals to identify putative germline variants associated with varying risk of LS. Whole-genome sequencing analysis was performed to identify known and novel germline variants shared between affected and non-affected pedigree members. SNPs, indels, and structural variants (SVs) were computationally identified, and their oncological influence was predicted using the Genetic Association of Complex Diseases and Disorders, …

Dynamic Role Of Exosome Micrornas In Cancer Cell Signaling And Their Emerging Role As Noninvasive Biomarkers, Jaya Aseervatham

Department of Neurology Faculty Papers

Exosomes are extracellular vesicles that originate from endosomes and are released by all cells irrespective of their origin or type. They play an important role in cell communication and can act in an autocrine, endocrine, or paracrine fashion. They are 40–150 nm in diameter and have a similar composition to the cell of origin. An exosome released by a particular cell is unique since it carries information about the state of the cell in pathological conditions such as cancer. miRNAs carried by cancer-derived exosomes play a multifaceted role by taking part in cell proliferation, invasion, metastasis, epithelial–mesenchymal transition, angiogenesis, apoptosis, …

Specific Targeting And Labeling Of Colonic Polyps In Cpc-Apc Mice With Mucin 5ac Fluorescent Antibodies: A Model For Detection Of Early Colon Cancer, Michael A. Turner, Kristin E. Cox, Shanglei Liu, Nicholas Neel, Siamak Amirfakhri, Hiroto Nishino, Mojgan Hosseini, Joshua A. Alcantara, Amer Ali Abd El-Hafeez, Thinzar M. Lwin, Kavita Mallya, Joseph R. Pisegna, Satish K. Singh, Pradipta Ghosh, Robert M. Hoffman, Surinder K. Batra, Michael Bouvet

Journal Articles: Biochemistry & Molecular Biology

Poor visualization of polyps can limit colorectal cancer screening. Fluorescent antibodies to mucin5AC (MUC5AC), a glycoprotein upregulated in adenomas and colorectal cancer, could improve screening colonoscopy polyp detection rate. Adenomatous polyposis coli flox mice with a Cdx2-Cre transgene (CPC-APC) develop colonic polyps that contain both dysplastic and malignant tissue. Mice received MUC5AC-IR800 or IRdye800 as a control IV and were sacrificed after 48 h for near-infrared imaging of their colons. A polyp-to-background ratio (PBR) was calculated for each polyp by dividing the mean fluorescence intensity of the polyp by the mean fluorescence intensity of the background tissue. The mean 25 …

The Mucin Family Of Proteins: Candidates As Potential Biomarkers For Colon Cancer, Kristin E. Cox, Shanglei Liu, Thinzar M. Lwin, Robert M. Hoffman, Surinder K. Batra, Michael Bouvet

Journal Articles: Biochemistry & Molecular Biology

Mucins (MUC1-MUC24) are a family of glycoproteins involved in cell signaling and barrier protection. They have been implicated in the progression of numerous malignancies including gastric, pancreatic, ovarian, breast, and lung cancer. Mucins have also been extensively studied with respect to colorectal cancer. They have been found to have diverse expression profiles amongst the normal colon, benign hyperplastic polyps, pre-malignant polyps, and colon cancers. Those expressed in the normal colon include MUC2, MUC3, MUC4, MUC11, MUC12, MUC13, MUC15 (at low levels), and MUC21. Whereas MUC5, MUC6, MUC16, and MUC20 are absent from the normal colon and are expressed in colorectal …

Targeting Gastrointestinal Cancers With Chimeric Antigen Receptor (Car)-T Cell Therapy, Ross E Staudt, Robert D Carlson, Adam E. Snook

Department of Pharmacology and Experimental Therapeutics Faculty Papers

The immune system is capable of remarkably potent and specific efficacy against infectious diseases. For decades, investigators sought to leverage those characteristics to create immune-based therapies (immunotherapy) that might be far more effective and less toxic than conventional chemotherapy and radiation therapy for cancer. Those studies revealed many factors and mechanisms underlying the success or failure of cancer immunotherapy, leading to synthetic biology approaches, including CAR-T cell therapy. In this approach, patient T cells are genetically modified to express a chimeric antigen receptor (CAR) that converts T cells of any specificity into tumor-specific T cells that can be expanded to …

Depletion Of Transmembrane Mucin 4 (Muc4) Alters Intestinal Homeostasis In A Genetically Engineered Mouse Model Of Colorectal Cancer, Ramesh Pothuraju, Priya Pai, Sanjib Chaudhary, Jawed A. Siddiqui, Jesse L. Cox, Sukhwinder Kaur, Satyanarayana Rachagani, Hemant K. Roy, Michael Bouvet, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

Mucins are components of the mucus layer overlying the intestinal epithelial cells, which maintains physiological homeostasis. Altered mucin expression is associated with disease progression. Expression of MUC4 decreases in colorectal cancer (CRC); however, its functional role and implications in the intestinal pathology in CRC are not studied well. Therefore, we generated a genetically engineered Muc4 knockout (Muc4^-/-) CRC mouse model by crossing with Muc4^-/- and Apc^flox/flox mice in the presence of colon-specific inducible Cre. We observed that deficiency of Muc4 results in an increased number of macroscopic tumors in the colon and rectal region and leads …

Cyclin G2, A Novel Target Of Sulindac To Inhibit Cell Cycle Progression In Colorectal Cancer, Hongyou Zhao, Bin Yi, Zhipin Liang, Ches'nique N. Phillips, Hui Yi Lin, Adam I. Riker, Yaguang Xi

School of Medicine Faculty Publications

Sulindac has shown significant clinical benefit in preventing colorectal cancer progression, but its mechanism of action has not been fully elucidated. We have found that sulindac sulfide (SS) is able to inhibit cell cycle progression in human colorectal cancer cells, particularly through G1 arrest. To understand the underlying mechanisms of sulindac inhibitory activity, we have demonstrated that Cyclin G2 up-regulation upon SS treatment can substantially delay cell cycle progression by enhancing the transcriptional activity of FOXO3a in human colorectal tumor cells. MiR-182, an oncogenic microRNA known to inhibit FOXO3a gene expression, is also involved in the suppressive effect of SS …

Potential Use Of Biotherapeutic Bacteria To Target Colorectal Cancer-Associated Taxa, Gareth Lawrence, Maire Begley, Paul D. Cotter, Caitríona M. Guinane

Department of Biological Sciences Publications

The role of the gut microbiome in human health and disease is the focus of much attention. It has been widely agreed upon that our gut bacteria play a role in host immunity, nutrient absorption, digestion, metabolism, and other key drivers of health. Furthermore, certain microbial signatures and specific taxa have also been associated with the development of diseases, such as obesity; inflammatory bowel disease; and, indeed, colorectal cancer (CRC), which is the focus of this review. By extension, such taxa represent potential therapeutic targets. In particular, the emerging human pathogen Fusobacterium nucleatum represents an important agent in CRC development …

Molecular Implications Of Muc5ac-Cd44 Axis In Colorectal Cancer Progression And Chemoresistance, Ramesh Pothuraju, Satyanarayana Rachagani, Shiv Ram Krishn, Sanjib Chaudhary, Rama Krishna Nimmakayala, Jawed A. Siddiqui, Koelina Ganguly, Imayavaramban Lakshmanan, Jesse L. Cox, Kavita Mallya, Sukhwinder Kaur, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND: Differential expression of mucins has been associated with several cancers including colorectal cancer (CRC). In normal physiological conditions, secretory mucin MUC5AC is not expressed in the colonic mucosa, whereas its aberrant expression is observed during development of colon cancer and its precursor lesions. To date, the molecular mechanism of MUC5AC in CRC progression and drug resistance remains obscure.

METHODS: MUC5AC expression was determined in colon tissue microarray by immunohistochemistry. A RNA interference and CRISPR/Cas9-mediated system was used to knockdown/knockout the MUC5AC in CRC cell lines to delineate its role in CRC tumorigenesis using in vitro functional assays and in …

N-Glycosylation-Defective Splice Variants Of Neuropilin-1 Promote Metastasis By Activating Endosomal Signals, Xiuping Huang, Qing Ye, Min Chen, Aimin Li, Wenting Mi, Yuxin Fang, Yekaterina Y. Zaytseva, Kathleen L. O'Connor, Craig W. Vander Kooi, Side Liu, Qing-Bai She

Markey Cancer Center Faculty Publications

Neuropilin-1 (NRP1) is an essential transmembrane receptor with a variety of cellular functions. Here, we identify two human NRP1 splice variants resulting from the skipping of exon 4 and 5, respectively, in colorectal cancer (CRC). Both NRP1 variants exhibit increased endocytosis/recycling activity and decreased levels of degradation, leading to accumulation on endosomes. This increased endocytic trafficking of the two NRP1 variants, upon HGF stimulation, is due to loss of N-glycosylation at the Asn150 or Asn261 site, respectively. Moreover, these NRP1 variants enhance interactions with the Met and β1-integrin receptors, resulting in Met/β1-integrin co-internalization and co-accumulation on endosomes. This provides persistent …

Silencing The Guca2a-Gucy2c Tumor Suppressor Axis In Cin, Serrated, And Msi Colorectal Neoplasia., Babar Bashir, Dante J. Merlino, Jeff A. Rappaport, Esteban Gnass, Juan P. Palazzo, Ying Feng, Eric R R. Fearon, Adam E. Snook, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Colorectal cancers (CRCs) initiate through distinct mutations, including in APC pathway components leading to tubular adenomas (TAs); in BRAF, with epigenetic silencing of CDX2, leading to serrated adenomas (SAs); and in the DNA mismatch repair machinery driving microsatellite instability (MSI). Transformation through the APC pathway involves loss of the hormone GUCA2A that silences the tumor-suppressing receptor GUCY2C. Indeed, oral hormone replacement is an emerging strategy to reactivate GUCY2C and prevent CRC initiation and progression. Moreover, retained expression by tumors arising from TAs has established GUCY2C as a diagnostic and therapeutic target to prevent and treat metastatic CRC. Here, we defined …

Split Tolerance Permits Safe Ad5-Gucy2c-Padre Vaccine-Induced T-Cell Responses In Colon Cancer Patients., Adam E. Snook, Trevor R. Baybutt, Bo Xiang, Tara S. Abraham, John C. Flickinger, Terry Hyslop, Tingting Zhan, Walter K. Kraft, Takami Sato, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Background: The colorectal cancer antigen GUCY2C exhibits unique split tolerance, evoking antigen-specific CD8+, but not CD4+, T-cell responses that deliver anti-tumor immunity without autoimmunity in mice. Here, the cancer vaccine Ad5-GUCY2C-PADRE was evaluated in a first-in-man phase I clinical study of patients with early-stage colorectal cancer to assess its safety and immunological efficacy.

Methods: Ten patients with surgically-resected stage I or stage II (pN0) colon cancer received a single intramuscular injection of 1011 viral particles (vp) of Ad5-GUCY2C-PADRE. Safety assessment and immunomonitoring were carried out for 6 months following immunization. This trial employed continual monitoring of both efficacy and toxicity …

The Anti-Cancer Effect Of Retinoic Acid Signaling In Crc Occurs Via Decreased Growth Of Aldh+ Colon Cancer Stem Cells And Increased Differentiation Of Stem Cells, Shirin R. Modarai, Anindita Gupta, Lynn M. Opdenaker, Ryan Kowash, Gabriel Masters, Vignesh Viswanathan, Tao Zhang, Jeremy Z. Fields, Bruce M. Boman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Background: Tumorigenesis is driven by stem cell (SC) overpopulation. BecauseALDH is both a marker for SCs in many tissues and a key enzyme in retinoid acid (RA)signaling, we studied RA signaling in normal and malignant colonic SCs.Hypothesis: RA signaling regulates growth and differentiation of ALDH+ colonicSCs dysregulation of RA signaling contributes to SC overpopulation and colorectalcancer (CRC) development.Methods: We analyzed normal and malignant colonic tissues and CRC cell linesto see if retinoid receptors (RXR &RAR) are exclusively expressed in ALDH+ SCs,and if RA signaling changes during CRC development. We determined whether RAsignaling regulates cancer SC (CSC) proliferation, differentiation, sphere formation,and …

The Guanylate Cyclase C-Cgmp Signaling Axis Opposes Intestinal Epithelial Injury And Neoplasia., Jeffrey A. Rappaport, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Guanylate cyclase C (GUCY2C) is a transmembrane receptor expressed on the luminal aspect of the intestinal epithelium. Its ligands include bacterial heat-stable enterotoxins responsible for traveler's diarrhea, the endogenous peptide hormones uroguanylin and guanylin, and the synthetic agents, linaclotide, plecanatide, and dolcanatide. Ligand-activated GUCY2C catalyzes the synthesis of intracellular cyclic GMP (cGMP), initiating signaling cascades underlying homeostasis of the intestinal epithelium. Mouse models of GUCY2C ablation, and recently, human populations harboring GUCY2C mutations, have revealed the diverse contributions of this signaling axis to epithelial health, including regulating fluid secretion, microbiome composition, intestinal barrier integrity, epithelial renewal, cell cycle progression, responses …

Alcohol Consumption Promotes Colorectal Carcinoma Metastasis Via A Ccl5-Induced And Ampk-Pathway-Mediated Activation Of Autophagy, Haodong Zhao, Danlei Chen, Rui Cao, Shiqing Wang, Dandan Yu, Yakun Liu, Yu Jiang, Mei Xu, Jia Luo, Siying Wang

Pharmacology and Nutritional Sciences Faculty Publications

There is a definite relationship between alcohol consumption and colorectal cancer (CRC) development. We investigated effect of alcohol consumption on CRC patients’ progression and prognosis by utilizing epidemiological data and found patients with alcohol consumption increased risks of tumor-node-metastasis (TNM), organ metastasis and poorer prognosis. Because their tumor tissues displayed increased expression of C-C chemokine ligand 5 (CCL5), we hypothesized CCL5 might participate in cancer progression in such patients. Ethanol increased the secretion of CCL5 in two CRC cell lines, HT29 and DLD-1. Treatment with CCL5 directly increased migratory ability of these cells, whereas neutralization or knockdown of CCL5 can …

Preclinical Evaluation Of Novel Fatty Acid Synthase Inhibitors In Primary Colorectal Cancer Cells And A Patient-Derived Xenograft Model Of Colorectal Cancer, Yekaterina Y. Zaytseva, Piotr G. Rychahou, Anh-Thu Le, Timothy L. Scott, Robert M. Flight, Ji Tae Kim, Jennifer Harris, Jinpeng Liu, Chi Wang, Andrew J. Morris, Theru A. Sivakumaran, Teresa Fan, Hunter Moseley, Tianyan Gao, Eun Young Lee, Heidi L. Weiss, Timothy S. Heuer, George Kemble, B. Mark Evers

Toxicology and Cancer Biology Faculty Publications

Fatty Acid Synthase (FASN), a key enzyme of de novo lipogenesis, is upregulated in many cancers including colorectal cancer (CRC); increased FASN expression is associated with poor prognosis. Potent FASN inhibitors (TVBs) developed by 3-V Biosciences demonstrate anti-tumor activity in vitro and in vivo and a favorable tolerability profile in a Phase I clinical trial.

However, CRC characteristics associated with responsiveness to FASN inhibition are not fully understood. We evaluated the effect of TVB-3664 on tumor growth in nine CRC patient-derived xenografts (PDXs) and investigated molecular and metabolic changes associated with CRC responsiveness to FASN inhibition.

CRC cells and PDXs …

The Heat-Stable Enterotoxin Receptor, Guanylyl Cyclase C, As A Pharmacological Target In Colorectal Cancer Immunotherapy: A Bench-To-Bedside Current Report., Trevor R. Baybutt, Allison A. Aka, Adam E. Snook

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Cancer immunotherapy is becoming a routine treatment modality in the oncology clinic, in spite of the fact that it is a relatively nascent field. The challenge in developing effective immunotherapeutics is the identification of target molecules that promote anti-tumor efficacy across the patient population while sparing healthy tissue from damaging autoimmunity. The intestinally restricted receptor guanylyl cyclase C (GUCY2C) is a target that has been investigated for the treatment of colorectal cancer and numerous animal, and clinical studies have demonstrated both efficacy and safety. Here, we describe the current state of GUCY2C-directed cancer immunotherapy and the future directions of this …

Guanylate Cyclase C As A Target For Prevention, Detection, And Therapy In Colorectal Cancer., Allison A. Aka, Jeff A. Rappaport, Amanda M. Pattison, Takami Sato, Adam E. Snook, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

INTRODUCTION: Colorectal cancer remains the second leading cause of cancer death in the United States, and new strategies to prevent, detect, and treat the disease are needed. The receptor, guanylate cyclase C (GUCY2C), a tumor suppressor expressed by the intestinal epithelium, has emerged as a promising target. Areas covered: This review outlines the role of GUCY2C in tumorigenesis, and steps to translate GUCY2C-targeting schemes to the clinic. Endogenous GUCY2C-activating ligands disappear early in tumorigenesis, silencing its signaling axis and enabling transformation. Pre-clinical models support GUCY2C ligand supplementation as a novel disease prevention paradigm. With the recent FDA approval of the …

Co-Targeting Of Cyclooxygenase-2 And Foxm1 Is A Viable Strategy In Inducing Anticancer Effects In Colorectal Cancer Cells, Maqbool Ahmed, Azhar Hussain, Abdul K. Siraj, Shahab Uddin, Nasser Al-Sanea, Fouad Al-Dayel, Mohammed Al-Assiri, Shaham Beg, Khawla S. Al-Kuraya

Centre for Regenerative Medicine & Stem Cell Research

Background: Cross-talk between deregulated signaling pathways in cancer cells causes uncontrolled growth and proliferation. These cancers cells become more aggressive and quickly develop resistance to therapy. Therefore targeting of these deregulated pathways simultaneously can result in efficient cell death of cancer cells. In this study we investigated co-expression of Cox-2 and FoxM1 in a cohort of colorectal carcinoma (CRC) samples and also examined whether inhibition of Cox-2 and FoxM1 simultaneously can lead to inhibition of cell viability and induction of apoptosis in colorectal cancer cell lines and in vivo xenograf
Methods: Protein expression of Cox-2 and FoxM1 was determined …

Molecular Staging Of Node Negative Patients With Colorectal Cancer., Terry Hyslop, Scott A Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Metastatic disease is the principle cause of death from colorectal cancer. In that context, the most significant indicator of overall survival and therapeutic response to adjuvant chemotherapy is the presence of metastatic tumor cells in regional lymph nodes. Although histopathologic analysis of lymph nodes is central to all colorectal cancer staging paradigms, its prognostic and predictive value is limited. Indeed, about 30% of patients with histopathology-negative lymph nodes (pN0) die from metastatic disease, reflected by microscopic lymph node metastases that are overlooked by standard techniques. These unrecognized tumor cells are especially important when considering racial disparities in outcomes in colorectal …

Phosphorylation Of Vasodilator-Stimulated Phosphoprotein Ser239 Suppresses Filopodia And Invadopodia In Colon Cancer., David S Zuzga, Joshua Pelta-Heller, Peng Li, Alessandro Bombonati, Scott A Waldman, Giovanni Mario Pitari

Department of Pharmacology and Experimental Therapeutics Faculty Papers

In colorectal cancer, the antitumorigenic guanylyl cyclase C (GCC) signalome is defective reflecting ligand deprivation from downregulation of endogenous hormone expression. Although the proximal intracellular mediators of that signal transduction system, including cyclic guanosine monophosphate (cGMP) and cGMP-dependent protein kinase (PKG), are well characterized, the functional significance of its distal effectors remain vague. Dysregulation of ligand-dependent GCC signaling through vasodilator-stimulated phosphoprotein (VASP), an actin-binding protein implicated in membrane protrusion dynamics, drastically reduced cGMP-dependent VASP phosphorylation levels in colorectal tumors from patients. Restoration of cGMP-dependent VASP phosphorylation by GCC agonists suppressed the number and length of locomotory (filopodia) and invasive (invadopodia) …

Molecular Staging Individualizing Cancer Management, Alex Mejia, Stephanie Schulz, Terry Hyslop, David S. Weinberg, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Although the most important prognostic and predictive marker in colorectal cancer is tumor cells in lymph nodes, ∼30% of patients who are node-negative die from occult metastases. Molecular staging employing specific markers and sensitive detection technologies has emerged as a powerful platform to assess prognosis in node-negative colon cancer. Integrating molecular staging into algorithms that individualize patient management will require validation and the definition of relationships between occult tumor cells, prognosis, and responses to chemotherapy. J. Surg. Oncol. 2012; 105:468-474. © 2012 Wiley Periodicals, Inc.

Copyright © 2012 Wiley Periodicals, Inc.

A Conserved Tissue-Specific Homeodomain-Less Isoform Of Meis1 Is Downregulated In Colorectal Cancer., Richard C Crist, Jacquelyn J Roth, Scott A Waldman, Arthur M Buchberg

Department of Microbiology and Immunology Faculty Papers

Colorectal cancer is one of the most common cancers in developed nations and is the result of both environmental and genetic factors. Many of the genetic lesions observed in colorectal cancer alter expression of homeobox genes, which encode homeodomain transcription factors. The MEIS1 homeobox gene is known to be involved in several hematological malignancies and solid tumors and recent evidence suggests that expression of the MEIS1 transcript is altered in colorectal cancer. Despite this potential connection, little is known about the role of the gene in the intestines. We probed murine gastrointestinal tissue samples with an N-terminal Meis1 antibody, revealing …

Chronic Diseases: The Emerging Pandemic., Andre Terzic, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

According to the 2011 World Health Organization Global Status Report, of the 57 million annual global deaths – a staggering 36 million or over 63% are due to chronic diseases.¹ Four noncommunicable diseases - namely cardiovascular, cancer, diabetes, and chronic respiratory diseases - emerge as the leading cause of mortality in the world, accounting respectively for 17, 7.6, 4.2, and 1.3 million deaths based on the latest available global epidemiology data. By 2020, global deaths due to chronic diseases are projected to worsen by at least 15 to 20%. It is estimated that the four major noncommunicable diseases will …

Molecular Staging Estimates Occult Tumor Burden In Colorectal Cancer, Alex Mejia, Stephanie Schulz, Terry Hyslop, David S. Weinberg, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Tumor cells in regional lymph nodes are a key prognostic marker of survival and predictive marker of response to adjuvant chemotherapy in colorectal cancer. However, clinicopathologic techniques to detect lymph node metastases remain imperfect, and ~30% of patients with lymph nodes negative by histology (pN0) develop recurrent disease, reflecting occult metastases that escape detection. These observations underscore an unmet clinical need for accurate approaches to identify occult nodal metastases in colorectal cancer patients. GUCY2C is a receptor whose expression normally is restricted to intestinal epithelial cells, but is universally over-expressed by colorectal cancer cells. A prospective, multicenter, blinded clinical trial …

Enterotoxin Preconditioning Restores Calcium-Sensing Receptor-Mediated Cytostasis In Colon Cancer Cells, Giovanni Mario Pitari, Jieru E. Lin, Fawad J. Shah, Wilhelm J. Lubbe, David Zuzga, Peng Li, Stephanie Schulz, Scott A Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Guanylyl cyclase C (GCC), the receptor for diarrheagenic bacterial heat-stable enterotoxins (STs), inhibits colorectal cancer cell proliferation by co-opting Ca(2+) as the intracellular messenger. Similarly, extracellular Ca(2+) (Ca(2+)(o)) opposes proliferation and induces terminal differentiation in intestinal epithelial cells. In that context, human colon cancer cells develop a phenotype characterized by insensitivity to cytostasis imposed by Ca(2+)(o). Here, preconditioning with ST, mediated by GCC signaling through cyclic nucleotide-gated channels, restored Ca(2+)(o)-dependent cytostasis, reflecting posttranscriptional regulation of calcium-sensing receptors (CaRs). ST-induced GCC signaling deployed CaRs to the surface of human colon cancer cells, whereas elimination of GCC signaling in mice nearly abolished …

Immune Response To The Carcinoembryonic Antigen In Patients Treated With An Anti-Idiotype Antibody Vaccine, Kenneth A. Foon, Mala Chakraborty, William J. John, Amanda Sherratt, Heinz Köhler, Malaya Bhattacharya-Chatterjee

Markey Cancer Center Faculty Publications

We have generated an IgG1 murine monoclonal anti-idiotype antibody (Ab2) designated 3H1, which mimics a specific epitope on the carcinoembryonic antigen (CEA). Patients with CEA positive tumors are immunologically "tolerant" to CEA. We used 3H1 as a surrogate for CEA for vaccine therapy of 12 patients with advanced colorectal cancer. Each of the patients received a minimum of four intracutaneous injections of aluminum hydroxide precipitated 3H1 at either 1, 2, or 4 mg dosage per injection. 9 of 12 patients demonstrated anti-anti-idiotypic (Ab3) response to 3H1. All nine patients generated specific anti-CEA antibody demonstrated by reactivity with radiolabeled purified CEA; …