Genes can be switched off before birth to prevent cancer, study suggests

Genes that can trigger cancer could be switched off before birth, a study has suggested.

Researchers from Bath University believe they discovered a switch inside a tumour, and it can be ‘turned off‘ hours after fertilisation.

Co-author Professor Tony Perry led the research from the Department of Life Sciences at Bath. He said: “Our work could open a new clinical chapter for the early detection of cancer.”

Experimenting on mice - the team found that gene activity in embryos kicks off within four hours of sperm injection and follows a programme. The genes are not switched on at random but in a pre-set order.

These include ‘oncogenes’ which have the potential to cause cancer - if mutated. Researchers expect these findings to apply to humans.

Prof Perry said: “Many factors responsible for the dawn of gene activity in embryos have long been known to be major oncogenes.”

This is the first time a pre-set order of events has been established in one-cell embryos in any species.

The team made their discovery by combining a state-of-the-art method to inject sperm into eggs with the latest techniques in messenger RNA (mRNA) sequencing.

mRNA is the genetic ‘middleman’ that reads information from genes and delivers it to regions in the cell where proteins - the building blocks of life - are made.

The mRNA strand is produced in eggs before fertilisation but also in embryos when the genome has been switched on.

The researchers were able to differentiate between the two types and to characterise the embryo ‘on’ switch - which was also associated with cancer.

It is inherited from eggs. Applying inhibitors stopped embryos from growing almost immediately.

The researchers targeted a protein called c-Myc - found in over 70 per cent of human cancers. Blocking the cancerous protein helped turn off the switch - potentially preventing future tumours.

The group suggests that c-Myc and other factors are dormant in eggs until they are themselves activated by fertilisation.

This work on mice overlaps with findings published recently by researchers showing gene activity in human embryos also starts at the one-cell stage.