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Francis J. Giles, M.B., M.D., conducted part of the study at CTRC.
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SAN ANTONIO (February 17, 2009) – Scientists studying chronic myeloid leukemia, more commonly known as CML, are one step closer to decoding the “genetic signature” of stem cells in this disease. They’ve identified a marker in a tiny but powerful subset of leukemia cells that could enable scientists to halt cancer cell growth in CML, and perhaps in other forms of cancer.

CTRC’s Dr. Francis Giles was part of research team
Their work is published in the Feb. 23, 2009, edition of the Proceedings of the National Academy of Sciences. Among the authors is Francis J. Giles, M.B., M.D., professor and chief of hematology and medical oncology at The University of Texas Health Science Center at San Antonio. Dr. Giles also is deputy director of the Cancer Therapy & Research Center at the UT Health Science Center, and director of the CTRC’s Institute for Drug Development (IDD).

Stem cell alteration is major factor in cause of CML
About 4,500 new cases of chronic myeloid leukemia were diagnosed in 2006, mostly in adults. The disease, marked by massive growth of white blood cells in the body, results from a change in the DNA of a stem cell in the bone marrow. The stem cells’ altered DNA gives the malignant (cancerous) cells an advantage over normal stem cells in terms of growth and survival. Scientists do not yet understand what produces this change in the DNA, which is not present at birth.

Findings important for patients who do not respond to traditional treatments
“Well over 90 percent of patients with CML improve with the front-line and second-line treatments, imatinib and nilotinib,” says Dr. Giles, a leading developer of nilotinib, approved in 2007 by the Food and Drug Administration. “But if you’re among those who don’t respond or you lose your prior response, this research finding is very important.

Stem cells may be key to eradicating leukemia, Giles says
“We believe stem cells are the obstacle to a cure for leukemia. If we’ve killed nearly all of a patient’s cancer cells, but we haven’t killed the stem cells, we haven’t cured the patient. A marker helps us find the elusive stem cells, quantify them, and follow their behavior in patients. Then we can see how the stem cell behavior differs from that of other more mature cancer cells, and develop stem cell-directed new therapies.”

Dr. Giles says this marker may enable scientists to develop a test that could be given to leukemia patients following treatment to make sure the stem cells have been eliminated. Another potential application is to test drugs under development in San Antonio and elsewhere to change the stem cells’ instructions.

“Perhaps we can tell the stem cells to ignore their previous instructions and get them to change into another type of cancer cell that we know how to kill,” Dr. Giles theorized.

CTRC patients participated in the study
Much of the laboratory work that identified the abnormality was conducted at Moores Cancer Center at the University of California San Diego. Aside from Dr Giles’ role in designing and conducting the research, CTRC patients with CML contributed samples of blood and bone marrow, and the CTRC’s IDD is testing drugs that may alter cancer stem cell function in the leukemias or in solid tumors.

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The Cancer Therapy & Research Center (CTRC) at The University of Texas Health Science Center at San Antonio is one of the nation’s leading academic research and treatment centers, serving more than 4.4 million people in the high-growth corridor of Central and South Texas including Austin, San Antonio, Laredo and the Rio Grande Valley. CTRC is one of a few elite cancer centers in the country to be named a National Cancer Institute (NCI)-designated cancer center, and is one of only three in Texas. A world leader in developing new drugs to treat cancer, The CTRC Institute for Drug Development is internationally recognized for conducting the largest oncology Phase I clinical drug trials program in the world, and participates in the clinical and/or preclinical development of many of the cancer drugs approved by the U.S. Food & Drug Administration. For more information, visit www.ctrc.net.