From foe to friend: can leukaemia cells be reprogrammed to fight cancer?
We were interested to see reports from the US recently suggesting scientists may have found a way to transform leukaemia cells into harmless immune cells that could be used to fight the cancer.
In the study, the leukaemia cells were genetically reprogrammed to mature into immune cells known as macrophages that can engulf and digest the cancer cells, suggesting a new therapeutic strategy for this disease.
This was a chance discovery by a team from the Stanford University School of Medicine working with an aggressive form of leukaemia called acute lymphoblastic leukaemia (ALL).
The discovery was made when the researchers were trying to keep leukaemia cells from a patient alive in a petri dish for further studies.
“We were throwing everything at them to help them survive,” senior author of the paper and assistant professor of medicine, Ravi Majeti, said.
The team noticed that some of the leukaemia cells were changing shape and size into what looked like macrophages but it wasn’t until they recalled the results of previous studies in mice that they could identify what was causing this change. The mice studies had shown that leukaemia cells could be forced to become macrophages when exposed to certain proteins.
Further experiments at Stanford replicated the results from the mice studies in human cancer cells.
Majeti and his colleagues believe that not only can the cancer cells be neutralised when transformed into macrophages, but they may actually assist in fighting the cancer.
“Because the macrophage cells came from the cancer cells, they will already carry with them the chemical signals that will identify the cancer cells, making an immune attack against the cancer more likely.”
The next step is to find a drug that can trigger the same reaction and serve as the basis for a new therapy.
“There are a number of treatments already available that kill leukaemia cells by inducing differentiation. This means, that the immature leukaemia cells are forced to become mature blood cells and as a result of this, these cells are eliminated from the body. For example, we commonly use a drug called All trans retinoic acid (ATRA) to treat patients with acute promyelocytic leukaemia.
“This paper is important because it tells us that leukaemia cells retain the ability to mature and this raises the possibility of using a number of drugs that might differentiate leukaemia cells in patients. However, one of the difficulties of this approach is that the investigators had to take the leukaemia cells out of the body before they could treat them.
“Obviously, this is not something we can do in patients so we will have to think of other ways to differentiate cells that can be delivered to patients directly.”
The results were published in the Proceedings of the National Academy of Sciences.