Phase II Research Projects
Research Theme - Cancer
Investigator: Dr. Mary C. Farach-Carson, UD Biological Sciences
Research Title: Electrospun Collagen Scaffolds for Development of 3-D Cellular Models for Testing Anti-Neoplastic Agents
Abstract: Greater than 90% of cancers, including those from breast and prostate, originate from epithelial cells that line the surfaces of human tissues. This reflects the fact that these surface cells bear the brunt of exposure of living cells to environmental insult including physical and chemical stimuli. As these cells are transformed from normal cells to cancer cells, their properties change. Tumors form from cells that are released from their natural lining (or basement membrane) and form 3-D structures that interact with each other and with the micro-environment of the tissue around the tumor. Cancer cells growing flat on plastic tissue culture as single layers do not reflect many of the properties of whole tumors. This shortcoming limits their ability to serve as perfect models for testing of pharmacologically active compounds, including those that are being tested as anti-cancer drugs (anti-neoplastics). We propose to combine two technologies that have been optimized in our separate laboratories in Biology and Materials Sciences and Engineering to create new 3-D cellular materials possessing properties more similar to those in native tissues surrounding cancers. The goal of this work is to produce an electrospun micro- and nanofibrous scaffold that will support tumor growth in three dimensions. Electrospinning, an offshoot of electrospraying, will be used to spin spider web type fibers on which cells will be grown for characterization and testing of anti-cancer compounds. The fibers produced during the electrospinning process are nanoscale, with diameters ranging from 40 to 2000 nm compared to traditional textile fibers that have diameters from 5-200 µm. The primary advantage of electrospinning is that it uses tiny quantities (50-100 mg) the quantity that might result from a custom sythesis of polymer in solution to form micro- and nanofibers. A second advantage is that additional components, e.g. small molecules, a second polymer, or cell binding factors can be added to the polymer solution and often be incorporated into the fiber during the electrospinning process. For a feasibility study, collagen (type I) was chosen as the matrix material because it is a major constituent of natural fibers and thus can structurally mimic the physical environment of the natural extracellular matrix (ECM). Collage alone ahs been shown to promote cellular recognition and exhibits a high affinity for proteins like those found in cell surface binding and growth factors. We plan to coat the collagen-based scaffolds with small recombinant fragments of the ECVM basement scaffolds. We believe this coating will provide a more natural environment to cancer cells such that they will grow more similarly to human tumors. As such, it will provide a superior way to test how cancer cells respond to pharmacologically active compounds and will provide a superior model for testing potential new anti-cancer drugs in 3-D cell culture.
Investigator: Dr. Deni Galileo, UD Biological Sciences
Mentor: Nicholas Petrelli, M.D. Christiana Care Cancer Center
Research Title: Autocrine stimulation of primary and metastatic brain cancer cells
Abstract: Primary and metastatic brain tumors are insidious and can be lethal within weeks to months, even with current treatments. Unfortunately, the most common primary brain tumors in adults (glioblastomas) are ones with the worst prognosis. Breast cancer metastases to brain also result in poor patient survival of only months. We have developed a new model in which to study these tumors and have uncovered a mechanism that these tumor cells use to be so aggressive. We are able to inject human and rat brain tumor cell lines into the early chicken embryo brain to produce aggressive brain tumors in less than 2 weeks. We have also injected human breast cancer cell lines into embryonic blood vessels to show that they metastasize to the brain in less than 2 weeks. We now use this system to study mechanisms that contribute to the aggressive behavior of these two cancer types. Our laboratory has also developed a sophisticated microscopy system that is capable of recording movies of the migratory behavior of live tumor cells in a dish, and that can precisely measure their minute velocities and directions over time. We have found that a particular molecule (L1) is produced and released by certain brain and breast cancer cell lines to interact with themselves to stimulate their own spread.
Here, we will investigate 1) how L1 is produced and released by brain and breast cancer cells, 2) the mechanism of how L1 stimulates them to become more migratory in simple cell culture, 3) whether or not this mechanism controls their invasive and metastatic behavior in our chicken embryo model, 4) whether or not cancer cells from patient surgical samples use this stimulatory mechanism, and 5) whether or not molecular "nanobombs" can be targeted to tumors in our model to selectively destroy the tumor cells. This project involves collaborative efforts between multiple University of Delaware investigators, the Helen F. Graham Cancer Center, and surgeons at Christiana Hospital.
Investigators: Dr. Murray Johnston, UD Chemistry & Biochemistry
Dr. Robert Mason, Nemours Biomedical Research
Research Title: Proteomic Analysis of Apoptotic Mechanisms in Cancer
Abstract: This project is designed to develop proteomic approaches to determine how protease inhibitors cause apoptosis in neuroblastoma. A bifunctional protease inhibitor has been found to selectively cause apoptotic cell death in neuroblastoma, making it a potentially useful therapeutic agent to treat these tumors. Determining the mechanism by which the inhibitor causes apoptosis is needed to help design better therapies to treat this pediatric cancer. This project brings together state of the art proteomic technologies that are located at academic and clinical sites, both within the Delaware INBRE. A fluorescence-based differential protein expression analysis system located at the Alfred I duPont Hospital for Children will be used to identify proteins that are processed by tumor cell proteases and mass spectrometry facilities in the Department of Chemistry and Biochemistry at the University of Delaware will be used to determine the identity of the differentially expressed proteins. Individual candidate substrates will be validated using time dependent immunological assays. These time dependent studies will define early events in the process that lead to death of these cancer cells. A novel proteomic technology will be developed to increase the speed at which these studies can be performed so that a wider range of candidate substrates can be investigated. The long-term objective of this project is to develop novel therapeutic approaches to treat pediatric cancers. It is anticipated that this project will lead to an enhancement of proteomic facilities in the State of Delaware, providing new avenues of research to discover mechanistic pathways that lead to cancers and identify novel biomarkers to aid diagnosis of disease progression.
Investigators: Dr. Leslie Krueger, Nemours Biomedical Research
Dr. Valerie Sampson, Nemours Biomedical Research
Research Title: Dominance of mTOR Inhibitors in Breast Cancer:
Broad Antineoplastic Effects In Vitro and In Vivo
Abstract: Of the factors that mediate against therapeutic success in breast cancer, two major ones stand out. First, cancer cells are robust. Different growth factors and many unrelated pathways lead to cancerous aggressive and uncontrolled growth. By their very nature, they blunt any internal or external attempts to alter growth. The consequences are tumor progression and tumor resistance to therapy. The first significant hurdle for successful intervention in breast cancer is the inherent heterogeneity of the individual cells composing the tumor. In turn, this diversity ultimately leads to cancer treatment failure and spread of the cancer to organs outside the breast. During the first phase of the INBRE grant, we will investigate mTOR inhibitors that inhibit many of the cancer signals sent from these redundant pathways. The second problem that will be explored is the toxic burden of treatment. While novel multi-drug regimens are clearly required for continued cancer treatment successes, the future will require new methods and novel ways of managing toxicity. In this proposal, we will focus on the therapeutic benefits of modulating of the Akt/PI3K/mTOR pathways for specific gene products either one-by-one or in combination. We will use in vitro cell culture and in vivo animal modeling to assess the nature of inhibiting this pathway on the growth of human breast cancer cells. Akt/PI3K/mTOR signals mediate pathways that regulate growth, anti-apoptotic signaling, homeostasis, neovascularization and overall survival in breast cancer. In other words, these pathways are involved in the initial cancer growth and in sustaining that growth overtime. In vitro and in vivo, mTOR inhibition (rapamycin and its derivatives) reverses oncogene-activated pathways (IGF-II, PDGF, HGF, etc). Additionally, the global gene expression analysis of breast cancer cell lines demonstrates the relatedness of individual breast lesions and underscores the great amount of inter- and intra-tumor heterogeneity. Studies in a breast cancer line that used 12,620 probe sets (Hu95 series, human genome build, Affymetrix Inc) showed hundreds of changes when compared to control gene expression. We will examine the indirect effects of mTOR inhibitors on the surrounding tissue. These effects may severely limit expansion and breast cancer growth. For example, in vivo, tumor expansion depends on the enlargement and stabilization of the microvasculature surrounding the tumor, as well as neovascularization. We will study the effects of these inhibitors on vascularization by down-regulation of hypoxia-induced factor family members and other targets e.g., vascular endothelial growth factor (VEGF). Such efforts have already been successful in treating patients with colorectal cancer using an anti-VEGF drug called bevacizumab. Since different pathways exist for the regulation of tumor neovascularization, RNAi will be used to define the contribution of other pathways to growth and vascularization of breast cancer xenografts in the presence/absence of mTOR inhibitors in situ. Efforts to optimize conditions for the use of broad-based dominant drugs that limit the robust nature of breast cancer and show decreased toxicity provide promise for novel intervention and a better quality of life for breast cancer patients. The integration of our laboratory into the INBRE has provided a multi-institutional framework and an interdisciplinary approach to the treatment of breast cancer.
Investigator: Dr. Balaji Panchapakesan, UD Electrical & Computer Engineering
Mentor: Nicholas Petrelli, M.D. Christiana Care Cancer Center
Research Title: Nanotechnology for Cancer Detection and Therapeutics
Abstract: The past quarter century of outstanding progress in fundamental cancer biology has not translated into even distantly comparable advances in the clinic. Inadequacies exist in the early detection and administration of therapeutic moieties to reach the desired targets selectively. Genomics and proteomics research has elucidated many new biomarkers that have the potential to greatly improve disease diagnosis. The availability of multiple biomarkers is believed to be especially important in diagnosis of complex disease such as cancer for which disease heterogeneity makes tests of single markers, such as prostate specific antigen (PSA) or carcino embryognic antigen (CEA) inadequate. Keeping these inadequacies in mind, this proposal addresses the development of two technologies: (1) label free electrical detection of cancer surface markers in blood serum with single wall carbon nanotube sensor arrays (in vitro nanodetector), (2) development of immunotargeted single wall carbon nanotubes as potent nanobomb agents to selectively destroy cancer cells in culture, (3) evaluation of nanotube toxicity in a chicken embryo model for the development of immunotargeted nanobombs for in vivo applications. If successful, these technologies can make a quantum leap in the detection of markers associated with different stages of disease pathogenesis and facilitate early detection of cancer. Further, developing immunotargeted nanobombs for selectively targeting cancer cells can pave the way for its application in cancer therapeutics. The preliminary studies generated through these proposals will allow the PI to be able to apply for competitive R-01 grants for in vitro detection and in vivo therapeutics applications. This proposal brings in new collaborations with Dr. Deni S. Galileo in the INBRE network (UD Dept. of Biological Sciences) on evaluation of nanotube toxicity for in vivo applications and with the Dr. Nicholas Petrelli of the Helen F. Graham Cancer Center as mentor in this project for eventual translation of both these technologies into the clinic. Finally, this proposal provides opportunities for training graduate and undergraduate students in the area of cancer nanotechnology for detection and therapeutics.
Investigator: Dr. Robert Sikes, UD Biological Sciences
Mentor: Nicholas Petrelli, M.D. Christiana Care Cancer Center
Research Title: Role of IGFBP-2 Fragments in Development of Androgen Insensitive Prostate Cancer
Abstract: Prostate cancer (PCa) is the second most common cause of cancer related deaths in American men. The majority of PCa deaths are associated with the loss of proper response to male hormones (androgens). Initially, PCa requires androgens for support (survival) and growth of the tumor. This is called androgen dependent or androgen sensitive (AS). Initial treatment strategies for advanced PCa reduce androgen levels. Such treatments decrease PCa tumor size by removing androgens that cuts off tumor support. Some tumor cells adapt to the low levels of androgen and do not die. As a consequence, these treatments eventually lead to the development of a PCa whose growth is no longer affected by reductions in androgen levels. These tumors are androgen insensitive (AI). The development of AI-PCa is followed by metastasis (cancer spreading), extreme pain (particularly in bones), bone fracture and death. By understanding the changes that enable AI-PCa to metastasize, we hope to prevent or target this deadly event/stage of the disease. Some changes that occur during the development of AI-PCa are associated with cell-to-cell communication pathways. One such communication pathway involves the insulin-like growth factor (IGF) axis. The IGF axis is involved in the regulation of both normal and diseased cell behavior. IGFBP-2 is one member of the axis implicated in the development of AI-PCa. When androgen levels are reduced, IGFBP-2 levels increase dramatically. In support of our contention that IGFBP-2 is important for PCa metastasis, IGFBP-2 is believed to play a role in the metastasis of several other cancers. However, it is currently unknown if IGFBP-2 plays a similar role in PCa metastasis. We have discovered that IGFBP-2 is proteolyzed (fragmented, or cut) extensively upon androgen treatment in AS-PCa cells but NOT in AI-PCa cells. Thus, in the presence of androgens, androgen insensitive, metastatic PCa cells have much higher levels of intact IGFBP-2 and low levels of IGFBP-2 fragments. We hypothesize that the presence of IGFBP-2 fragments generated by androgen-induced cleavage in these cells prevents the acquisition of cell behavior associated with malignant progression and the development of AI-PCa. We propose that the restoration of the ability of AI-PCa cells to properly cut IGFBP-2 in response to androgens may have the effect of inhibiting PCa metastasis. We propose to (1) identify the regions of IGFBP-2 that are cleaved in response to androgen treatment and (2) examine in a PCa cell culture system the biological implications associated with cleaved (pieces) IGFBP-2 on human PCa cell lines. These pilot studies could eventually offer a new therapeutic treatment for preventing the malignant progression leading to AI-PCa by supplementing patients with either the protease required to cleave IGFBP-2 or by treating patients directly with the IGFBP-2 fragment found to inhibit aggressive PCa growth and spreading. There is also the possibility of IGFBP-2 serum fragments being used as a biomarker to stratify patients for risk of progression.
