For Immediate Release: Jan. 2, 2002
Contact:Bill Schaller617-632-5357[email protected]
News Tips from Dana-Farber Cancer Institute
1. Study Upends Earlier Thinking about Immune Cells' Readiness Against Disease2. Drawing a New Map of Cancer: Gene Chips Help Sort Out Cancer Types3. Researchers to Examine Disparity in Cancer Care Among Minorities
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1. Study Upends Earlier Thinking about Immune Cells' Readiness Against Disease
More vigilant than minutemen, the immune system's T cells form one of the main lines of defense against infection and disease. A recent study by Dana-Farber investigators is reversing scientists' understanding of how the cells are alerted to enemy invaders.
Researchers led by Vassiliki Boussiotis, MD, PhD, found that a signal from a gene called Tob keeps the cells in a dormant, or "quiescent," state. Only when that gene is shut off - when an infection is afoot - do the cells become activated against disease.
"The quiescent state isn't something the cells lapse into, as had been previously thought, but one they must actively maintain," Boussiotis says. The finding has direct implications both for the development of cancer vaccines and of safer techniques of organ transplantation.
Cancer vaccines seek to rouse the immune system to attack cancer cells. Organ transplantation, by contrast, aims to "desensitize" the immune system to foreign tissue so it doesn't launch a biochemical strike against donated organs. Knowing how to switch Tob on and off - thereby putting T cells either to sleep or on high alert - could lead to more potent vaccines and transplantation techniques that don't require patients to take as many anti-rejection drugs.
The study was published in the December 2001 issue of Nature Immunology.
2. Drawing a New Map of Cancer: Gene Chips Help Sort Out Cancer Types
Even under a microscope, cancer cells can baffle the most experienced of pathologists, making it hard to give a patient an accurate diagnosis and prognosis. Now, using "gene chips" to identify abnormal genes in a cancer cell, Dana-Farber scientists and colleagues at the MIT/Whitehead Center for Genome Research are working toward a new classification of cancer based on their abnormal genetic "profile" instead of their outward appearance, or what organ or tissue they arose from.
Not only do they foresee more accurate, quicker diagnoses of cancer based on these profiles: the method should also help doctors target finely-tuned therapies to specific types of cancer, and also help to design new drugs.
A team led by Dana-Farber researcher Sridhar Ramaswamy, MD, obtained genetic profiles of 218 samples of cancers of 14 different types, and showed that those profiles could be used to identify the site of origin unknown tumors. Every cell contains thousands of genes that determine its structure, function and growth. In a cancer cell, some genes are damaged and send erroneous growth signals that send the cell dividing endlessly and forming a tumor. Ramaswamy and his colleagues, including Todd Golub, MD, of Dana-Farber and the MIT/Whitehead center, used electronic "gene chips" to record the unique pattern of activity of the genes in each type of cancer cell. The profiles will be used to create a database, which Ramaswamy likened to a map, of cancer types.
The paper, published in the Dec. 18 issue of the Proceedings of the National Academy of Sciences, reports diagnostic accuracy of 90 percent when testing unknown tumors with gene chips. Ramaswamy says that with further refinement, the technique should be a valuable companion to more traditional diagnostic methods based on how cancer cells looks under a microscope and what tissue or organ it originated in.
Dana-Farber researchers have quickly seized on gene profiling as a new tool for understanding cancer at the fundamental level: several have published papers on the subject in the past few months, and others expect their reports to be published in the months ahead.
3. Researchers to Examine Cancer Care Inequalities
There's evidence that Americans in different ethnic and economic groups don't receive equal care for cancer, but these gaps haven't been well-documented. In a new nationwide study, researchers from Dana-Farber/Harvard Cancer Center will have a major role in looking for such inequalities. The federal government has granted $34 million to seven scientists who will carry-out the study, called CanCORS, for Cancer Care Outcomes Research and Surveillance Consortium over the next five years. Grants were made to two Dana-Farber researchers, David Harrington, PhD, and Jane Weeks, MD, MSc, and to John Ayanian, MD, of the Department of Health Care Policy at Harvard Medical School. The study will enroll about 10,000 patients diagnosed with lung or colorectal cancer at a number of sites around the country.
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