One of the main problems with chemotherapy for children with brain cancer is that the drugs damage the bone marrow. We are currently running a cancer gene therapy trial to ascertain whether gene therapy could be used to stop this from happening.
If successful, the technique will enable children to receive much higher drug doses than they can currently tolerate – and hopefully have their cancer eradicated.
To do this, the researchers take stem cells out of the bone marrow and insert a new gene into their DNA which allows them to produce a protein which can repair the damage caused by the chemotherapy drugs. Once transferred back to the body, the stem cells are resistant to the side effects of chemotherapy.
The new gene is transferred into the bone marrow stem cells through ‘vector technology.’ Based on viruses, the vectors are manufactured in a specialised cleanroom. This space has its own clean air supply and to enter it researchers must wear sterile blue suits with hoods, masks and big overshoes.
“With the trial nearing completion, the research team has learned some valuable lessons about how to implement a gene therapy strategy to try and improve treatments for patients with brain tumours,” says Dr Belinda Kramer of the Children’s Cancer Research Unit.
“We know these cancers can be sensitive to the drugs if we give more of the chemotherapy, but at the moment we just can’t do it. For children whose’s tumour has relapsed and who can’t ordinarily be given higher doses, this strategy could both reduce chemotherapy side effects and more effectively treat their tumour,” she says.
Led by Dr Geoff McCowage and Dr Belinda Kramer, the team continues to work on refining their strategy, and broadening its possible applications in the treatment of other childhood cancers and other diseases.