May 16, 2011Doctors who treat children with the most common form of childhood cancer - acute lymphoblastic leukemia - are often baffled at how sometimes the cancer cells survive their best efforts and the most powerful modern cancer drugs. Now a team of a protein that leukemia cells use to stay alive. at the University of California, San Francisco (UCSF) have uncovered the basis for this drug resistance: BCL6, a protein that leukemia cells use to stay alive. Targeting this protein may be the key to fighting drug-resistant leukemia, a discovery that may make cancer drugs more powerful and help doctors formulate powerful drug cocktails to cure more children of leukemia. "We believe this discovery is of immediate relevance to patient care," said Markus Müschen, MD, PhD, a professor of laboratory medicine at UCSF and the senior author on the study. As described in the journal Nature this week, Mueschen and his colleagues showed that mice with drug-resistant leukemia can be cured of the disease when given conventional cancer drugs in combination with a compound that disables the BCL6 protein. This compound was initially developed by Ari Melnick, a professor of pharmacology at the Weill Cornell College of Medicine in New York and a co-author of the study. A Common Form of Cancer in Children Acute lymphoblastic leukemia is the most common form of cancer in children and accounts for about 23 percent of all cases of cancer in children under the age of 15, according to the National Cancer Institute. In this form of cancer, leukemia cells in the bloodstream and bone marrow continuously multiply, crowding out other, healthy cells. The disease progresses rapidly, and the leukemia cells begin to infiltrate tissues in other parts of the body. Treatment is neither cheap nor easy - but it can be miraculous. It usually involves a long course of drugs that can be physically and emotionally taxing for the children and their parents. Once finished, many enjoy complete remission and are able to live cancer-free, cured of the leukemia.