A Key to Fight Drug-Resistant Leukemia

Photo: Leukemia cells

Left: Drug-resistant leukemia cells
can easily survive drug-treatment
when they are able to produce the
BCL6 protein. Right: The BCL6
protein is inactivated in leukemia
cells, cells become fragile and die;
© M. Müschen, UCSF

“It is something like an emergency mechanism whereby tumor cells try to evade drug-treatment,” said Doktor Markus Müschen, a professor of laboratory medicine at UCSF and the senior author on the study. This discovery may make cancer drugs more powerful and help doctors formulate better drug cocktails to cure more children of leukemia. Müschen 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.

In acute lymphoblastic 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 and 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. Still a large number of children are not cured and ultimately succumb to the disease. In those cases, some of the cancer cells resist the therapy and survive quietly in the body. When the cancer reemerges, it is no longer sensitive to the drugs.

The work started four years ago when the scientists exposed leukemia cells in the petri dish to drugs and then looked at how the expression of 22.000 different genes changed when different cancer cells were given different drugs. “We think that this discovery will directly influence the treatment of drug-resistance in leukemia” said Doktor Hassan Jumaa, a BIOSS-scientist and a co-author on the study.

MEDICA.de; Source: Albert-Ludwigs-Universität Freiburg