Major Gene Study Uncovers Secrets of Leukemia
March 13, 2007
MEMPHIS, Mar. 2007 (Source: St. Jude Children’s Research Hospital)— Investigators at St. Jude Children’s Research Hospital have discovered previously unsuspected mutations that contribute to the formation of pediatric acute lymphoblastic leukemia (ALL), the most common cancer in children. The discovery, published in the March 7 online edition of Nature, not only suggests novel methods for treating pediatric ALL, but also provides a roadmap for the identification of unsuspected mutations in adult cancers.
ALL is a tumor in which immature white blood cells that normally develop into immune system cells, called B or T lymphocytes, instead multiply rapidly and overwhelm the normal blood cells the body needs to survive.
The study found that 40 percent of patients with ALL had deletions or mutations in one of three so-called “master genes” that control the normal differentiation of immature progenitor cells into mature B lymphocytes. The mutations identified are likely to directly contribute to a block in normal lymphocyte differentiation, according to James Downing, M.D., scientific director and chair of the pathology department at St. Jude and senior author of the paper. In ALL, the leukemic cells fail to differentiate normally and instead remain blocked at an immature stage of development. Locked in this state, the leukemic cells continue to proliferate, and this continual growth of leukemic cells eventually kills the child.
“The results of our study demonstrate that it is possible to significantly speed the identification of the genetic lesions that are the underlying cause of not only ALL, but also many other cancers, including those affecting adults,” says Downing. “Although the identification of such a high frequency of mutations in this pathway was surprising, it is important to note that the approach used provides a lower limit of the true frequency of these mutations, since not every gene in this pathway could be accurately analyzed using this methodology,” he says.
“If we could design a drug that bypasses the roadblock to differentiation, we could push these cells to become fully mature B lymphocytes,” Downing continues. “And then the body would recognize them as defective B lymphocytes and destroy them.”
About St. Jude Children's Research Hospital
St. Jude Children's Research Hospital is internationally recognized for its pioneering work in finding cures and saving children with cancer and other catastrophic diseases. Founded by late entertainer Danny Thomas and based in Memphis, Tenn., St. Jude freely shares its discoveries with scientific and medical communities around the world. No family ever pays for treatments not covered by insurance, and families without insurance are never asked to pay. St. Jude is financially supported by ALSAC, its fundraising organization. For more information, visit www.stjude.org.
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March 13, 2007
MEMPHIS, Mar. 2007 (Source: St. Jude Children’s Research Hospital)— Investigators at St. Jude Children’s Research Hospital have discovered previously unsuspected mutations that contribute to the formation of pediatric acute lymphoblastic leukemia (ALL), the most common cancer in children. The discovery, published in the March 7 online edition of Nature, not only suggests novel methods for treating pediatric ALL, but also provides a roadmap for the identification of unsuspected mutations in adult cancers.
ALL is a tumor in which immature white blood cells that normally develop into immune system cells, called B or T lymphocytes, instead multiply rapidly and overwhelm the normal blood cells the body needs to survive.
The study found that 40 percent of patients with ALL had deletions or mutations in one of three so-called “master genes” that control the normal differentiation of immature progenitor cells into mature B lymphocytes. The mutations identified are likely to directly contribute to a block in normal lymphocyte differentiation, according to James Downing, M.D., scientific director and chair of the pathology department at St. Jude and senior author of the paper. In ALL, the leukemic cells fail to differentiate normally and instead remain blocked at an immature stage of development. Locked in this state, the leukemic cells continue to proliferate, and this continual growth of leukemic cells eventually kills the child.
“The results of our study demonstrate that it is possible to significantly speed the identification of the genetic lesions that are the underlying cause of not only ALL, but also many other cancers, including those affecting adults,” says Downing. “Although the identification of such a high frequency of mutations in this pathway was surprising, it is important to note that the approach used provides a lower limit of the true frequency of these mutations, since not every gene in this pathway could be accurately analyzed using this methodology,” he says.
“If we could design a drug that bypasses the roadblock to differentiation, we could push these cells to become fully mature B lymphocytes,” Downing continues. “And then the body would recognize them as defective B lymphocytes and destroy them.”
About St. Jude Children's Research Hospital
St. Jude Children's Research Hospital is internationally recognized for its pioneering work in finding cures and saving children with cancer and other catastrophic diseases. Founded by late entertainer Danny Thomas and based in Memphis, Tenn., St. Jude freely shares its discoveries with scientific and medical communities around the world. No family ever pays for treatments not covered by insurance, and families without insurance are never asked to pay. St. Jude is financially supported by ALSAC, its fundraising organization. For more information, visit www.stjude.org.
<< Back
