Articles selected from the June 2007 issue of Molecular & Cellular Proteomics (Vol. 6, No. 6):
- Proteins’ role in coronary heart disease
- Improving colorectal cancer treatment
- Improving the detection and treatment of esophageal cancer
- New and easy way to look at protein interactions
Proteins’ role in coronary heart disease
Scientists provided the first large-scale identification of the proteins involved in coronary heart disease. The information will help to better understand the progression of the disease, improve diagnosis, and detect early pathological signs more efficiently.
Coronary heart disease, which is characterized by abnormal thickening and narrowing of the blood vessels, is the first leading cause of death in the United States. But what happens inside the cells of these blood vessels is not completely understood. One way to figure it out is by identifying the proteins present in blood vessels of heart disease patients, and then comparing them with those present in healthy blood vessels.
David K. Han and colleagues developed a technique called direct tissue proteomics that identified all the proteins expressed in the coronary arteries of heart disease patients. They found about 800 proteins, some of them not previously known to be involved in heart disease. The list of proteins, which is freely available to the scientific community, could help develop more effective therapies against coronary heart disease. The investigators also used another highly sensitive proteomics method to detect important cytokines directly from diseased coronary arteries, an approach that could uncover important biomarkers relevant to other diseases.
Article: “Proteomics Analysis of Human Coronary Atherosclerotic Plaque,” by Carolina Bagnato, Jaykumar Thumar, Viveka Mayya, Sun-Il Hwang, Henry Zebroski, Kevin P. Claffey, Christian Haudenschild, Jimmy K. Eng, Deborah H. Lundgren and David K. Han
MEDIA CONTACT: David K. Han, University of Connecticut School of Medicine, Farmington, Conn.; tel: 860-679-2444; e-mail: han@nso.uchc.edu
Improving colorectal cancer treatment
Researchers have provided new information about a protein responsible for colorectal cancer and the target of a potential drug against this cancer.
Called clusterin, this protein has been linked to the development of tumor cells and resistance to cancer therapy, but how it works is not well understood. Pending questions include how this protein is expressed in normal and cancer cells, how it helps cancer cells escape ionizing radiation and chemotherapy, and which patients will benefit from treatment with a drug targeting clusterin.
Claus Lindbjerg Andersen, Torben Falck Orntoft, and colleagues discovered that clusterin is not expressed in normal cells, while in 25 percent of colorectal tumors, the cancer cells contained clusterin. They also showed that the protein is actually made by the cancer cells themselves. These new findings should help improve current therapies against colorectal cancer, especially for patients with tumors producing clusterin, the scientists concluded.
Article: “Clusterin Expression in Normal Mucosa and Colorectal Cancer,” by Claus Lindbjerg Andersen, Troels Schepeler, Kasper Thorsen, Karin Birkenkamp-Demtroder, Francisco Mansilla, Lauri A. Aaltonen, Søren Laurberg and Torben Falck Orntoft
MEDIA CONTACT: Claus Lindbjerg Andersen, Aarhus University Hospital, Aarhus, Denmark; tel.: +45-89495195; e-mail: cla@ki.au.dk
MEDIA CONTACT: Torben Falck Orntoft, Aarhus University Hospital, Aarhus, Denmark; tel: +45-89495195; e-mail: orntoft@ki.au.dk
Improving the detection and treatment of esophageal cancer
By looking at proteins expressed in esophageal cancer cells, scientists have determined new ways to detect and follow the progression of this type of cancer.
Esophageal cancer is increasing rapidly in Western countries and is currently the seventh leading cause of cancer-related death. But current techniques do not allow doctors to clearly tell patients how their disease will progress and how to best treat it.
David M. Lubman and colleagues developed a technique that identifies proteins in the esophagus. They examined the proteins present in patients with a condition called Barrett metaplasia, whose esophagus’s internal layers contain abnormal cells and who can later develop esophageal cancer.
The technique allowed the scientists to determine proteins that may be used to determine which patients would develop esophageal cancer. Although the technique needs to be further validated, it may have broad potential for identifying tumors, the researchers concluded.
Article: “Comparative Proteomics Analysis of Barrett Metaplasia and Esophageal Adenocarcinoma Using Two-dimensional Liquid Mass Mapping,” by Jia Zhao, Andrew C. Chang, Chen Li, Kerby A. Shedden, Dafydd G. Thomas, David E. Misek, Arun Prasad Manoharan, Thomas J. Giordano, David G. Beer and David M. Lubman
MEDIA CONTACT: David M. Lubman, University of Michigan, Ann Arbor, Mich.; tel: 734-647-8834; e-mail: dmlubman@umich.edu
New and easy way to look at protein interactions
Researchers have devised a new way of looking at proteins that interact with one another inside cells. The new method, which is technically simple and uses commonly available resources, could help scientists studying cellular complexes made up of different proteins.
Inside a cell, proteins constantly interact and work together: proteins modify other proteins, transport one or more proteins, and associate to form new protein complexes with differing cellular functions. Various methods are available to determine how proteins associate with one another, but these methods can be technically demanding and limited by the strength of the interaction or cannot resolve whether the association indeed occurs inside cells.
The new method developed by Cathy L. Miller, Max L. Nibert, and colleagues takes advantage of a strategy used by a virus called mammalian orthoreovirus. When this virus infects a cell, it uses the cellular machinery to synthesize viral proteins that replicate the viral RNA and assemble new viruses. This process occurs in large structures called viral factories made by the virus inside the cell. Previous work had identified an orthoreoviral protein that can form very similar viral factory-like structures (FLS) when expressed on its own in mammalian cells. The scientists used the viral FLS as a platform to visualize the interactions of two to three other proteins at a time in a light microscope.
Article: “Virus-derived Platforms for Visualizing Protein Associations inside Cells,” by Cathy L. Miller, Michelle M. Arnold, Teresa J. Broering, Catherine Eichwald, Jonghwa Kim, Jason B. Dinoso and Max L. Nibert
MEDIA CONTACT: Cathy L. Miller, Iowa State University, Ames, Iowa; tel: 515-297-4797; e-mail: clm@iastate.edu
MEDIA CONTACT: Max L. Nibert, Harvard Medical School, Boston, Mass.; tel: 617-432-4838; e-mail: mnibert@hms.harvard.edu
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Journal
Molecular & Cellular Proteomics