Functional imaging of cysteine proteases in cancer and inflammation using novel activity-based probes
Abstract/Contents
- Abstract
- Cysteine proteases use a catalytic thiol to cleave amide bonds of protein substrates. This activity serves as an important regulatory mechanism for diverse cellular processes necessary for normal physiology. Dysregulated protease activity is a hallmark of numerous diseases, including atherosclerosis, arthritis, stroke, macular degeneration, neurodegenerative disorders, inflammatory diseases, and cancer. In the last decades, the field of activity-based proteomics has produced a number of tools for dissecting protease function. In the introductory chapter, I will discuss the current state of the field and describe the two main classes of probes for cysteine proteases: substrate-based and activity-based probes. I will then describe my own contribution to the field, which includes the design and characterization of several new and improved activity-based probes. We have applied these probes to optical imaging and biochemical characterization of three families of cysteine proteases: caspases, cathepsins and legumain. In particular, I have used these tools to aid in understanding the regulation of complex signaling pathways associated with cancer and inflammation. Caspases are key mediators of a programmed form of cell death called apoptosis. One of the key features of tumor cells is their ability to evade apoptosis, and therefore, a major therapeutic goal is to reactivate latent death pathways. We have developed fluorescent activity-based probes to image the induction of caspase activity in tumors in response to chemotherapy. In addition to non-invasive optical imaging, we have utilized these new probes to assess the kinetics of caspase activation in response to various death stimuli and identified a unique activation mechanism for the caspase-6 enzyme. Another emerging hallmark of cancer is infiltration of stromal-derived immune cells into the tumor, resulting in an inflammatory microenvironment. Crosstalk between tumor and immune cells can lead to enhanced proliferation, angiogenesis, and metastasis of tumor cells. The cysteine proteases legumain and cathepsins have been shown to play critical roles within the tumor microenvironment. I have developed new tools for optical imaging of their proteolytic activity in several cancer models as well as inflammation associated with pancreatitis. In the future, these new probes will have great value in further dissecting the roles of cysteine proteases in basic biology and disease. Since legumain and cathepsins are used as biomarkers for cancer, the ability to detect their proteolytic activity has much diagnostic and prognostic value in both pre-clinical and clinical settings. Furthermore, these new agents will be integral in validating these enzymes, particularly legumain, as drug targets.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2012 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Edgington, Laura Elizabeth |
|---|---|
| Associated with | Stanford University, Cancer Biology Program. |
| Primary advisor | Bogyo, Matthew, 1971- |
| Thesis advisor | Bogyo, Matthew, 1971- |
| Thesis advisor | Giaccia, Amato J |
| Thesis advisor | Sage, Julien |
| Thesis advisor | Sweet-Cordero, Eric |
| Advisor | Giaccia, Amato J |
| Advisor | Sage, Julien |
| Advisor | Sweet-Cordero, Eric |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Laura Elizabeth Edgington. |
|---|---|
| Note | Submitted to the Cancer Biology Program. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2012. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2012 by Laura Elizabeth Edgington
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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