New Drug Shows Promise In Reversing Leukemia
A particularly difficult to treat form of leukemia is based on changes in the DNA to cause massive destruction in white blood cells, according to a study at Children’s Hospital Boston and Dana-Farber Cancer Institute. The research team in partnership with a biotechnology company showed that a new drug has the ability to stop these changes, even to stop cancer growth. The drug is one of the first that targets a vulnerability caused by a genetic rearrangement in leukemia gene (MLL).
Researchers knew for some time the cause of MLL leukemia (alterations in DNA structure and proteins associated with it, and not in the genetic code itself). These epigenetic changes start promoting cancer genes that ultimately leads to leukemia. The most important thing is that researchers have shown that they can reverse the process.
Although childhood leukemia is a cancer with very good therapeutic results, those cancers caused by mutations in the MLL gene have devastating consequences. It was found that a portion o on chromosome 11, where the gene MLL can be normally found, breaks and sticks with parts of other chromosomes to form new proteins. These new proteins alter the normal function of MLL protein that leads to cancer. These arrangements in the MLL gene can be observed in about 10% of all children and adults diagnosed with myeloid leukemia or acute lymphoblastic leukemia and who, in many cases do not have a good response to conventional cancer treatment. Normally the rate of successful treatment of childhood leukemia is about 75-90%. Leukemia caused by rearrangement of the MLL gene has a therapy success rate of 50%. Scientists must now find new methods for treating these patients.
The culprit behind the changes in the MLL gene is an enzyme called Dot1l. The researchers injected the mice with leukemia cells that lacked Dot1l, and the mice remained healthy, unlike the mice that were injected with cells with active Dot1l enzyme. Further studies revealed a small molecule called EPZ004777, which has the power to inhibit the Dot1l enzyme. Mice with leukemia treated with EPZ004777 survived longer.
This discovery could revolutionize the oncology field, as researchers announced that enzymes like Dot1l are very active in many types of cancers.