Our body's immune system is designed to attack foreign invaders using a number of specialised immune cells. Some cells are designed to flag up foreign invaders and some cells are specifically needed to 'eat' and destroy unwanted substances. Microglia carry out this action in the brain.
However, Dr Sieger's observation in zebrafish has shown a different type of interaction. Using fluorescent microscopy, the team have produced footage that shows the microglia may actually encourage the tumours to grow.
“Looking at these interactions the microglia appear to be friendly towards the tumour," says Sieger. “We call this 'nursing' as they really help and support the cancer cells develop."
However, the lab produced another piece of footage showing that microglia don't respond in the same way when faced with other tumours. The microglia began breaking down and engulfing cells from a fribrosarcoma tumour, which is not found in the brain.
This new discovery could be used to test experimental drugs for the treatment of brain tumours.
"If we can make a drug that can convert microglia's alliance, then we should be able to see these immune cells attacking tumour cells," says Dr Seiger.
Glioblastomas are the most common and aggressive brain tumour found in adults, and the most difficult type to treat.
So why is it that these immune cells do the opposite of what they're supposed to? Dr Sieger's team are hoping to answer this question by zooming in further on the conversation between these two cells.
Read more about Dr Sieger's research.