“These results are very promising, with potential as a part of first-line therapy and also as a treatment for eliminating any remaining cancer cells” Hisham Abdel-Azim MD, co-lead investigator.
At the Children’s Hospital Los Angeles, USA, cancer researchers have shown that select immune cells can be taken from children with leukaemia and multiplied in the laboratory, creating an army of natural killer cells able to be used to destroy leukaemia cells in the child.
Acute lymphoblastic leukemia (ALL) is the most common cancer in children. This disease hinders the development of healthy blood cells, while cancerous blood cells grow and divide uncontrollably. Currently, children with ALL receive chemotherapy for two to three years, putting them at risk of significant side effects including changes in normal development and future fertility.
Looking for an alternative way to treat ALL, investigators have been researching how to use the body’s own immune system to fight cancer more effectively – a technique called immunotherapy.
One part of the immune system is a class of cells called natural killer (NK) cells. The role of these specialized white blood cells is to find and destroy abnormal cells before they turn cancerous.
Using NK cells as immunotherapy presents challenges. If the NK cells are taken from a donor, the patient may reject them. To avoid this problem, the researchers tried taking the patient’s own (autologous) NK cells instead.
“In this study, we used NK cells and ALL cells from the same paediatric patients. We found that autologous natural killer cells will destroy the patient’s leukaemia cells,” says Nora Heisterkamp PhD, one of the lead investigators.
To help the NK cells identify the leukaemia cells as their target, the researchers added a monoclonal antibody – a molecule designed in the laboratory to specifically recognise and attach to a protein on the surface of leukaemia cells. Once coated with this antibody, a leukaemic cell becomes a marked target for NK cells.
According to co-lead investigator on the study, Hisham Abdel-Azim MD, the immunotherapy has the potential to be used both as a part of first-line therapy (the first treatment given after diagnosis), as well as following standard chemotherapy, to help eliminate any remaining cancer cells in the body. “We anticipate additional pre-clinical testing,’ he explains, “and then a clinical trial to evaluate the therapy in children with leukaemia.”
This study was published 19 August 2014 in the journal ‘Leukemia’.
Pictured Leukaemia cell marked for destruction by natural killer cells