Understanding Leukemia cell movement gives clues to its resistance to treatment

This is a high-resolution render of unique environments in the bone marrow (blue,
purple and green) as they are invaded and populated by leukemia cells (yellow).
Credit: Edwin Hawkins and Delfim Duarte/Imperial College London

New research is shedding light on how leukaemia cells can survive cancer treatment, suggesting new possibilities for stopping them in their tracks. Leukaemia has one of the highest cancer mortality rates. This is partly because there is a high relapse rate, as some cancer cells can survive the initial treatment. These surviving cells are often resistant to treatment, allowing the cancer to spread and become fatal. These findings were published in Nature.

How these treatment-resistant cells survive initial chemotherapy is not well understood. One popular theory has been that they sit hiding in specific niches within the bone marrow that usually harbour blood stem cells – basic cells that can become all other blood cells.

However, new research in mice, and validated with human samples, has revealed that certain leukaemia cells do not sit and hide. The research was led by a team at Imperial College London with colleagues from the Francis Crick Institute in London and the University of Melbourne in Australia, and is published today in Nature. Instead, to the researchers’ surprise, the cells were scattered throughout the mouse bone marrow both before and after treatment, and they were moving around rapidly.

After treatment, the leukaemia cells that survived were seen moving faster than those before treatment. The researchers suggest that the act of moving itself may help the cells to survive, possibly through short-lived interactions with an array of our own cells.

The team’s investigation into leukaemia cells’ behaviour also revealed that they actively attack bone cells, which are known to support healthy blood production. The researchers believe this insight could help scientists to develop treatments to safeguard production of healthy blood cells in leukaemia patients.

To investigate the working of leukaemia at the cellular level, the team used a technique called intravital microscopy that allows high-resolution fast imaging of live animals. The team used mice with a particularly deadly type of leukaemia called T cell acute leukaemia and tracked the movement of disease cells before and after treatment.

The research was funded by the charities Bloodwise and Cancer Research UK, alongside contributions to buy equipment and recruit team members from the European Research Council, the Human Frontier Science Program, and the European Hematology Association.

Publication: T-cell acute leukaemia exhibits dynamic interactions with bone marrow microenvironments.
DOI: http://dx.doi.org/10.1038/nature19801
Authors: Edwin D. Hawkins et.al.,
Research funding: Bloodwise, Cancer Research UK, European Research Council, Human Frontier Science Program, and European Hematology Association.
Adapted from press release by Imperial College London