professor, eppley institute
Department of Biochemistry and Molecular Biology
Department of Pathology and Microbiology
Ph.D. - Wake Forest University, 1982
The general subject of research in my laboratory is pancreatic cancer and other diseases of the pancreas, primarily pancreatitis. We have used modern techniques of molecular biology, biochemistry, cell biology, and immunology to develop a comprehensive program of investigation into the biology of normal and diseased pancreatic ductal epithelial cells.
- Several of the main projects in my laboratory center around the study of a complex mucin-like glycoprotein, MUC1, which is believed to play an important role in the normal function of pancreatic ductal epithelia and in the pathogenesis of pancreatic diseases, such as pancreatic adenocarcinoma. We are using the techniques of molecular and cellular biology to examine the regulation of expression and the mechanisms of post-translational processing of MUC1 in tumor cells and other disease conditions as compared to their normal cell counterparts. These studies also provide a paradigm to study basic aspects of the post-translational process (particularly O-glycosylation). We are developing and characterizing new monoclonal antibodies and tumor vaccine reagents for diagnostic and therapeutic uses that target known tumor associated antigens found on mucins. We are also studying the MUC1 promoter.
- I have received funding by the National Cancer Institute (NCI) as PI of a Biomarker Developmental Laboratory (organ focus Pancreas) within the Early Detection Research Network (EDRN). Biomarker Developmental Laboratories have the responsibility for the development and characterization of new biomarkers or the refinement of existing biomarkers.
The EDRN was created as a foundation for collaborative research on molecular, genetic, and other biological "markers" of human cancers with the goal of creating a multicenter network to discover and coordinate the evaluation of biomarkers for the early detection of common cancers, such as prostate, breast, lung, colorectal, ovarian, and upper aerodigestive tract cancers. These biomarkers could be present in blood, urine, sputum, or tissues and could serve as indicators of early cancer or of risk for impending cancer. Objectives of the EDRN are:
- development and testing of promising biomarkers or technologies
- evaluation of promising, analytically proven biomarkers or technologies
- collaboration among academic and industrial leaders in molecular biology, molecular genetics, clinical oncology, computer science, public health and clinical application for early cancer detection
- collaboration and rapid dissemination of information among awardees
The other components of the EDRN are Biomarker Validation Laboratories, which work to validate the biomarker tests; Clinical and Epidemiologic Centers, which conduct the early phases of clinical and epidemiological research on the application of biomarkers; and the Data Management and Coordinating Center, which provides logistical, informatics, and statistical development and support.
- Other projects in the lab involve the application of different cDNA cloning techniques to identify genes and their encoded proteins that are important to the process of development and differentiation of normal ductal cells in the human pancreas, and which may contribute to the pathogenesis of different diseases.
Specific funded projects.
Mutagenesis Studies on the Post-Translational Processing of MUC1 (NIH R01 CA 57362)
We cloned a cDNA for MUC1 from pancreatic adenocarcinoma cells in the late 1980's. MUC1 is an integral cell surface protein that has mucin-like characteristics and may play a role in cellular adhesion, anti-adhesion, and signal transduction events related to adhesion. The MUC1 protein receives a variety of distinct post-translational modifications (glycosylation, sulfation phosphorylation) in different normal cells and these are altered in tumors and other disease states. We are investigating the nature and biological functions of the different modifications in disease conditions. For example, altered glycoforms of MUC1 may play a role in the ability of tumor cells to metastasize.
Early Diagnosis of Pancreatic Cancer (NIH 5 UO1 CA111294)
The goal of this project is to develop early diagnostic tests for pancreatic cancer. We propose two experimental approaches. One is to improve the utility of the CA19-9 and related tests for pancreatic cancer and other GI cancers by adding to the test a determination of the core protein on which this carbohydrate antigen is detected. This proposal is based upon recent discoveries about the molecular nature of different mucin core proteins that are expressed by different adenocarcinomas, the development of new monoclonal antibodies against these core proteins, and recently obtained knowledge that will enable the development of additional reagents that improve this existing diagnostic test. The second experimental approach is to identify novel proteins that are expressed in the sera and body fluids of patients with premalignant lesions of the pancreas (pancreatic intraepithelial neoplasms - PanIn) by using proteomics techniques. We will employ different highly sensitive and complementary proteomics approaches to identify novel proteins and peptides that appear in serum concomitant with the development of advanced premalignant PanIn lesions. Parallel studies will be performed in newly developed murine systems of PanIn lesions and pancreatic cancer. We will also develop and investigate in vitro cell culture model systems (human and mouse) that represent different stages of PanIn lesions. This information will be used to develop tests (conventional serum or body fluid assays or specialized proteomics assays) that can be widely applied to identify individuals with advanced PanIn lesions, who would become candidates for intensive screening programs, chemoprevention studies, and studies of early intervention. Collaborators on subprojects include Margaret Mandelson and John Potter, of Fred Hutchinson Cancer Research Center, David Tuveson with the University of Pennsylvania, and Randall Brand of Evanston Northwestern Health Care.
Molecular Studies on the MUC1 Promoter (NIH R01 CA 79580)
MUC1 expression is restricted to ductal epithelial cells and some populations of activated lymphocytes. It is overexpressed by tumors and is expressed by cell types in the pancreas that are the targets of a number of diseases (cancer, cystic fibrosis, pancreatitis). A relatively small fragment of DNA (10kb) conferred accurate expression temporally and spatially in a transgenic mouse strain. Hence, there is interest in defining the elements that direct cell specific expression of MUC1. We are using current in vivo and in vitro methods to investigate the role of elements and DNA structure in regulation of expression of this gene. Collaborators on this project include Ann Harris (Oxford), John Hilkens (Amsterdam), and Jim Maher (Mayo Clinic).
BrevaRex MAB-AR20.5 Preclinical Studies in MUC1 Transgenic Mice Orthotopically Transplanted with PANC 02.MUC1 Pancreatic Cancer Cells Source and identifying number (Unither Pharamaceuticals)
Unither Pharmaceuticals Inc. has developed a monoclonal antibody to MUC1 (BrevaRex® MAb-AR20.5), which it plans to develop for the treatment of pancreatic cancer.
Utilizing the MUC1-transgenic (MUC1-Tg) animal model developed by Dr. Sandra Gendler at the Mayo Clinic in Scottsdale, AZ, and an orthotopic tumor model developed by Dr. Hollingsworth’s team, we propose to assess the ability of MAb-AR20.5 to break tolerance to MUC1 and to influence tumor growth. This model is best suited for pre-clinical studies because the target antigen (MUC1) is a self antigen in this system, as it is in cancer patients. As a consequence, the host, although fully immune competent, is tolerant to MUC1, allows the growth of MUC1-expressing tumors that display similar features of tumor progression and immune regulator pathways as human cancer victims.
We hypothesize that this anti-MUC1 antibody when combined with soluble or cell-bound MUC1 can break humoral and cellular tolerance to MUC1 in this model. This immunity, if optimally induced, can be protective of cancer in a MUC1-transgenic mouse tumor model and ultimately in patients with MUC1-expressing tumors. To test this hypothesis, we propose to immunize MUC1-transgenic mice carrying Panc02.MUC1 orthotopic tumors and test the ability of MAb-AR20.5 to induce MUC1-specific B and T cells and to reject or inhibit tumor growth in this model.
The specific aims of this project are: (1) To assess the release of MUC1 into the serum of MUC1-transgenic mice, transplanted with Panc02.MUC1 tumors into the pancreas as well as subcutaneously into the flank. Mice transplanted s.c. with B16-MUC1 tumor cells will also be assessed. Blood samples are taken at baseline (before tumor transplantation) and at 2, 4, 6, 8, 10 (Panc02.MUC1) or weeks 1, 2, 3, 4 (B16.MUC1); (2) To demonstrate the ability of MAb-AR20.5 to induce MUC1-specific T and B cell responses and to control tumor growth in MUC1-transgenic mice transplanted orthotopically with Panc02.MUC1 tumors; (3) To assess if gemcitabine and 5-FU have an anti-tumor effect in MUC1-transgenic mice transplanted orthotopically with Panc02.MUC1 tumors.
Molecular studies on MUC4 (NIH R01 CA29088)
I am a co-investigator on a project (Principal Investigator Surinder Batra) that is designed to further characterize the sequence, expression patterns and biological function of the MUC4 mucin gene which is overexpressed in cases of pancreatic cancer and is not expressed in adult human pancreas. There is evidence of alternative splicing of the MUC4 mRNA by pancreatic tumor cells as compared to other organ sites.