Research
Background
Cancer research over the past several decades has produced advances in the diagnosis and treatment of most malignancies. Development of new drugs, enhanced understanding of the principles of radiation, and refinement in surgical technique have led to longer survival rates with less morbidity (side effects) during the treatment of cancer.
Despite these efforts a cure for cancer in a global sense is still far from being realized. What we do know is certain is that the earlier a tumor is detected, the higher the chances of cure. This seems to be the only universally applicable finding in all of cancer research.
To this end a significant amount of our research efforts are applied to investigating ways to detect the presence of malignancy at an early stage. Historically, efforts directed toward early detection of malignancy have involved screening groups of patients thought to be at risk for a particular malignancy, for example smokers being screened for lung cancer. The screening for the most part has involved imaging studies used to detect lesions in the targeted organ. This has proved to be quite costly given the large numbers of patients eligible for screening.
Currently, our interest is to go beyond imaging studies to try to detect "invisible" cancer. We believe that with appropriate resources we may be able to enhance our ability to determine the presence of malignancy with a higher yield and lower cost, ultimately providing patients with a higher chance of cure. Our laboratory currently has several avenues of active and proposed research projects involving the early detection of thoracic malignancies.
Early Detection of Lung Cancer
Circulating biomarkers: Malignant cells are thought to give off or secrete substances that may allow identification of the presence of tumor by measuring these substances in the bloodstream. These substances may be either proteins or abnormal genetic material. They also may be normally occurring substances but at higher levels than in an unaffected subject. Proposed projects in our laboratory include investigating novel proteins in the serum of patients with known lung cancer. We are fortunate to have the ability to do this due to a large tissue bank containing specimens of patients who have been treated for lung cancer here at the University of Colorado. Other methods useful to identifying these novel markers include analysis of cell culture media, which allows the study of compounds secreted by different strains of lung cancer cells, as well as animal models. Sputum Biomarkers: Lung cancer commonly arises from the air passages in the lung called bronchi or bronchioles. Even the smallest of the airways are eventually connected to the outside world. When cells of both normal and malignant airways are shed they may be collected in sputum. We know that it is possible to identify malignant cells by examination of sputum under a microscope and analysis of abnormal genetic material. Currently the identification of malignancy in the airway by examination of the sputum requires a large amount of cells which often means cancer is quite advanced. Our goal is to develop more sensitive methods of detecting these malignant cells in the sputum, hopefully allowing identification of malignant cells with less material and therefore earlier cancer. The use of sputum for early detection of malignancy is uniquely suited to malignancies such as bronchioloalveolar carcinoma which is known to shed copious amounts of cells in the airway.
Early Detection of Esophageal Cancer
The incidence of esophageal adenocarcinoma of the gastroesophageal junction is rapidly rising and is currently the cancer with the fastest increasing incidence in the United States. The rate of rise in the incidence of this tumor has outpaced the second fastest, melanoma, by three times since 1975. Since 1970 its incidence in some populations has increased >800%. Many possible risk factors including obesity and tobacco use have been identified but the one undisputable risk factor is the increased exposure of the esophagus to refluxed gastric juice. One case-control study estimated that patients with long standing severe reflux disease were 43 times more likely to develop adenocarcinoma of the esophagus. These alarming statistics indicate the timely need for study of this critical problem. The development of esophageal cancer is thought to be a multi-step process involving genetic events that result in key abnormalities of cell cycle regulation. This results in formation of pre-cancerous and eventually malignant lesions. It is now generally accepted that esophageal adenocarcinomas develop from a pre-malignant lesion of the esophagus, which is referred to as Barrett's esophagus. Although several molecular mechanisms have been proposed to explain tumor development such as DNA methylation, overexpression of growth factors, and mutations of oncogenes, there is little data to explain the molecular transformation of normal esophageal mucosa to Barrett's metaplasia and subsequently to invasive malignancy. Currently, representative models available to study the development of esophageal adenocarcinoma due to gastroesophageal reflux disease are lacking. We have begun development of an animal model (mouse) of gastroesophageal reflux in our laboratory which includes the incision of the gastroesophageal junction and an anastomosis of the first portion of the duodenum to this area This allows for both acid and bile exposure to the esophageal mucosa. We have already been successful in demonstrating the technical feasibility of this model with radiographic studies illustrating the patency of the anastomosis and the potential for reflux of gastric contents into the esophagus. Histologically the esophageal lining demonstrates dysplastic and hyperproliferative changes as well as thickening of the mucosal lining by routine hematoxylin and eosin (H&E) staining. The successful development of this model will be the first of its kind in the mouse and would allow for several avenues of investigation. This would involve identification of abnormalities in the earliest stages of the metamorphasis to cancer which in turn would allow discovery of more sensitive methods of early detection of esophageal cancer.
Lung Transplantation
Lung transplantation has become a viable method of treatment for several end stage lung diseases. Lung transplantation is limited by the availability of donor organs and the allowable ischemic time, which limits the distance to which organs are harvested. Organ transplants are also subjected to variable levels of dysfunction once the organ is re-perfused with the recipients blood. This condition, termed ischemia-reperfusion injury, places transplanted organs at risk of dysfunction. Our laboratory is actively working to elucidate the mechanisms of this injury as well as a means of potentially protecting the transplanted organs through administration of an exogenous agent. Our work has shown that we can modulate the levels of an intrinsic protective enzyme with administration of this agent. We will hopefully soon be able to apply this to human transplants.
Technical Aspects of Research Capability at the University of Colorado
The Department of Surgery currently has 6,000 sq. ft of laboratory space. This space is equipped with a tissue and cell culture area, organ perfusion systems, a cold room, fume hoods, a microscopy center, NMR rooms and office space. The Halstead Research Laboratory is a fully equipped large animal operating room and is directed by a board certified veterinarian. The said laboratory possesses the equipment to perform a broad range of enzyme-linked assays with a 7 well Hewlett Packard diode-array UV spectrophotometer as well as a 96-well plate reader IBIORAD). Dedicated computers are linked. The difital imaging facility has two deconvoluting wide-field microscopes, (Leica DRM and Zeiss Axioscope) running a software in order to produce quantifiable 3-D confocal images. Each instrument is equipped with a C16-bit cooled camera system under software control. The Department of Surgical Laboratories also contains the instrumentation for many sequencing analyses of genomic DNA for the study of many genetic polymorphisms. The laboratory also has sufficient storage space for samples at -70oC.
In addition we have at our disposal access to the University Research Core Facilities which include:
Gene Expression Core Facility
Instrumentation and facilities for construction and analysis of custom cDNA arrays, as well as hybridization, scanning and analysis of commercial oligonucleotide arrays from Affymetrix.
CU Cancer Center DNA Sequencing and Analysis Core Facility
Automated fluorescent DNA sequencing is available.
Tissue Culture/Monoclonal Antibody Core Facility
A CU Cancer Center core laboratory that provides specialized techniques and equipment to support modern biomedical cancer research in the areas of cell culture of mammalian cell lines, production of monoclonal antibodies and over-expression of recombinant proteins in eukaryotic cell systems.
The UCD Light Microscope Facility consists of a Bio-Rad confocal microscope, Deltavision Digital Deconvolution Microscope and a Zeiss two-photon microscope.
Mass Spectrometry and Proteomics Facility
The goal of the Proteomics Facility is to provide investigators with the capabilities to identify, characterize and quantify the proteins present in tissues, cells and biological fluids. Through the development of advanced methods, the facility aims to assist members with solving difficult or previously intractable problems in biomedical research. Methods for protein and peptide isolation, separations, quantification, identification and bioinformatics analysis, together with expert guidance in study design, are integrated into expertise offered by the facility X-ray
Crystallography Core Facility
The X-ray Crystallography Core Facility is fully equipped for biomolecular crystallization, crystal screening, data collection, data processing, structure-determination and model building.
Laboratory Animal and Transgenic Mouse Core
The Laboratory Animal and Transgenic Mouse Core within the CU Cancer Center provides high-quality, centralized and specialized services for animal experimentation including the generation of transgenic and knock-out mice.
Anschutz Medical Campus
Construction of two new, multi-story research buildings has been completed at the University of Colorado Health Sciences Center Anschutz Medical Campus in Aurora. This has provided significant expansion to our research endeavors. Over the next two years all of our research activities will be transferred to the Anschutz Medical Campus.
