Scientists discover genes that slow ageing but also protect against cancer
A person's risk of developing cancer increases with age, but researchers have now found that certain genes are capable both of delaying ageing, and of protecting against cancer.
The findings, published in the journal Nature Genetics, are based on studies involving the roundworm species Caenorhabditis elegans, but are also relevant to humans as many of the genes found in the worm species have counterparts in humans.
The study was conducted by Dr Cynthia Kenyon - the University of California, San Francisco biologist who discovered back in 1993 that a single gene change was able to double C. elegans' lifespan.
This threw into doubt the previous assumption that lifespan was the inevitable result of the body's breakdown and showed that it was in fact regulated by genes and therefore potentially changeable.
The latest study focussed on daf-16, a gene that regulates lifespan and codes for a protein responsible for regulating hundreds of other genes.
The team aimed to identify specific genes that are regulated by daf-16 and that are directly involved in determining lifespan or cancer development.
They identified 29 genes, around half of which promote tumour cell growth and half of which suppress it.
They also discovered that those genes that stimulated tumour growth accelerated ageing, while those that prevented tumour growth slowed down the ageing process and extended lifespan.
Dr Kenyon said that the latest findings are "very exciting" and highlight the evolutionary connection between lifespan and cancer.
"There is a widely held view that any mechanism that slows ageing would probably stimulate tumour growth. But we found many genes that increase lifespan, but slow tumour growth.
"Humans have versions of many of these genes, so this work may lead to treatments that keep us youthful and cancer-free much longer than normal," she suggested.