Hope for children with leukaemia as scientists find new way to 'buy time' for transplants

Scientists have shed new light on how healthy blood cells are disabled in people with leukaemia and how to stop it from happening.



The findings could help 'buy time' for patients who need life-saving transplants, they believe.



The study on mice showed that leukaemia cells lure healthy blood-forming stem cells into their cancerous lairs – and handicap them – using powerful chemical signals.



But jamming the potent signals protects the vital stem cells – allowing them to replenish the blood.

Hope: The findings point towards a new treatment that could buy valuable time for children with leukaemia

If the same system works in humans, this process could help preserve healthy blood cells in people with leukemia, said Dr. Dorothy Sipkins of the University of Chicago Medical Center, whose study appears in the journal Science.

A third of all childhood cancers are leukaemia and about 400 new cases occur each year in the UK.

In prior studies, Sipkins found that leukaemia cells and some solid tumours create specific niches in the bone marrow - where they multiply and spread.

Healthy blood-making cells also gather in special bone marrow niches, where they divide and make vital blood cells.

The healthy blood cells are needed to fight infection, control blood clotting and carry oxygen to the body.



Sipkins wanted to find out what happens when the two worlds collide.

Her team developed a way to image both types of cells in mice with acute lymphoblastic leukemia or ALL, a cancer of the white blood cells that mostly affects children.

‘We saw that the cells that were previously in happy normal homes were actually so attracted by the malignant niches they were migrating into these tumour cell niches,’ Sipkins said.

Her team then studied what happened to the healthy cells in the new environment, and found they were ‘compromised’.

‘Their number declines over time and once they were in the malignant niche they couldn't leave it. They were stuck there,’ she said.



Sipkins believes the cancer overproduces a molecule called a stem cell factor, which entices normal stem cells into the cancer niche.

‘They express it in such a high amount in this malignant niche, the progenitor cells say, “Wow, I'm going to abandon where I am because this smells delicious to me.”’

But when the team blocked the chemical’s release with neutralising antibodies, the blood-making cells went about their normal business.

‘If human stem cells respond in the same way as mouse cells do, it could buy us time to apply other therapies,’ Sipkins said.

This could make bone marrow stem cell transplants an option for more patients, allowing doctors to collect and bank patients' own stem cells for use after high-dose chemotherapy.

Or it could simply keep their immune systems healthy.

Sipkins said there is some evidence that other tumors that spread to the bone, such as breast and lung cancer, may have similar effects.



‘It does give us a lead and that is exciting to us at this stage,’ she said.