Acute myeloid leukemia (AML)
Researchers have discovered that the most common form of acute leukemia which strikes adults, acute myeloid leukemia (AML), prevents chemotherapy from being delivered properly by causing bone marrow to leak blood. This means that, by using drugs developed to treat blood vessel and heart problems in concert with chemotherapy, AML might be much more treatable. In this study, these drugs reversed bone marrow leaks in tissue from mice and humans, and also boosted chemotherapy effects. Since these drugs are already in clinical trials for other applications, the team hopes that they may be approved for use in the treatment of AML patients soon.
“We found that the cancer was damaging the walls of blood vessels responsible for delivering oxygen, nutrients, and chemotherapy. When we used drugs to stop the leaks in mice, we were able to kill the cancer using conventional chemotherapy,” Diana Passaro, Francis Crick Institute researcher and first author of the paper, said in a press release.
The team studied the ways in which AML affects bone marrow by injecting healthy mice with bone marrow from AML patients to create AML mice. They then used intravital microscopy to compare the bone marrow of AML mice with healthy mice and observed pre-loaded fluorescent dyes leaking from the bone marrow blood vessels into the AML mice. Next, they discovered that the cells lining the blood vessels in AML mice were oxygen-starved, which led to increases in nitric oxide (NO), a muscle relaxant. They realized this was probably causing the leaking, and provided NO blockers to the AML mice which slowed leukemia progress and extended remission.