Contrary to what was previously believed, the immune system’s cancer-killing T cells are more effective in a tumour’s anoxic environment when they have access to growth factor VEGF-A. A study published in Cancer Cell shows how the T cells not only survive in this oxygen-depleted micro-environment with the help of transcription factor HIF-1a but also become more effective at killing cancer cells inside it.
 
“We observed that the T cells detect oxygen, and by adapting to a limited amount of oxygen they can enter anoxic tumours, survive within them and then effectively kill them,” says Professor Randall Johnson, who is a member of CRUK Cambridge Centre Cell and Molecular Biology programme.

The research team from Cambridge, Stockholm, Lund and San Diego also used mouse models to try to knock out VEGF-A (a growth factor that makes blood vessels grow and one of HIF’s target genes) from their T cells.

“Doing this, we found that the tumours grew and that the formation of new blood vessels changed,” explains Professor Johnson. “This is interesting because it was previously thought that tumours starve when you reduce VEGF-A. Our research shows that things are more complex than this. I hope that our discovery will lead to better tumour therapy that maximises the effect of the T cells.”
 
More information is available on the CRUK Cambridge Centre website.