Cancer hope in fish research

The blood cells of mammals and the zebra-fish are virtually identical, which scientists believe could help to find a cure for cancer. Photo / Supplied

New Zealand scientists have shown how infections trigger the development of new blood stem cells, a breakthrough that could lead to the development of drugs to treat cancer and infections.

The Auckland University research, published in a top American journal, was conducted by gazing into the transparent embryos of tropical zebra-fish with a powerful microscope. But it is relevant to humans because of similarities at the cellular level.

"Despite mammals and zebra-fish [having] 450 million years of evolutionary separation, the blood cells and the stem cells are virtually identical in their function," Phil Crosier, professor of molecular medicine and pathology and senior author of the report, said yesterday. "What we find in zebra-fish is easily translatable to mammals, to humans."

The genetically altered zebra-fish produce fluorescent proteins of various colours, allowing researchers to see what is happening inside living embryos.

In the Auckland study embryos were given an infection and lead researcher Dr Chris Hall observed that blood stem cells had increased.

All the cells in the blood originate from blood stem cells, which are rare and occur in mammals in the bone marrow.

"When an animal or a person has an infection or an inflammatory response," Professor Crosier said, "it has been speculated for some time that there must be a connection linking back to telling the stem cells what to do.

"During an infection, white cells get used up fighting infection. They have to be replaced in the blood. We know that that triggers the stem cells to make more blood cells.

"But no one has made the connection linking when an animal has an infection ... how that signals back to the blood stem cell compartment. That's what Chris Hall has found.

"We have identified a novel and unexpected mechanism that functions as an important link between infection and stem cell behaviour."

Professor Crosier said that in the longer term this finding, published in Cell Stem Cell, could lead to the development of drugs that mimicked the molecular signalling pathway identified by the research, to boost the production of white blood cells.

"That's pretty important in fighting infection but also in fighting cancer."