By Kate Vidinsky, UCSF News Office | March 31, 2011
An experimental drug lessens symptoms of a rare form of childhood leukemia and offers significant insight into the cellular development of the disease, according to findings from a new UCSF study. The mouse model research could spearhead the development of new leukemia therapies and paves the way for future clinical trials in humans.
"Although this drug did not produce a cure, it alleviated the symptoms of leukemia as long as the treatment was continued and delayed the development of a more aggressive disease," said senior author Benjamin Braun, MD, PhD, a pediatric cancer specialist at UCSF Benioff Children's Hospital. "Maintaining a clinical remission for as long as we can may help patients who don't have other options, and perhaps will allow us to approach this disease as a chronic, but manageable, condition."
Study results are published in the March 30, 2011, online edition of the journal Science Translational Medicine.
The study focused on a type of leukemia called juvenile myelomonocytic leukemia, or JMML. An aggressive blood cancer usually diagnosed in patients younger than 5, JMML accounts for 1 to 2 percent of all childhood leukemia cases.
The disease develops in the bone marrow and leads to an elevated white blood cell count that interferes with bone marrow's ability to produce healthy red blood cells. The abnormal increase in white blood cells occurs when genetic changes, or mutations, arise in the genes that encode proteins in a cellular signaling network called the Ras pathway. This network, controlled by the Ras protein, is a critical regulator of cell growth and a frequent target of cancerous mutations.
Currently, JMML is curable only through bone marrow transplantation, in which healthy blood stem cells are extracted from a matched donor and intravenously transplanted into the patient. Still, nearly half of patients relapse after undergoing a transplant, and others are not candidates for transplantation because of advanced illness or the lack of a suitable donor, Braun said.