Scientists in the United States have discovered that a chemical signalling system — an important anti-oxidant and cancer prevention pathway long recognized in people and other animals — also plays a role in giving fruit flies a longer lifespan.
The chemical signalling system is one of the ways that the body uses to defend itself from toxic assaults and threats like cigarette smoke, diesel exhaust, and dangerous microbes.
When a gene called KEAP1 senses danger, it unleashes the NRF2 gene that triggers rampant anti-oxidant activity in a cell.
Professor Dirk Bohmann, a geneticist at the University of Rochester Medical Center, now says that a gene called CNC serves like NRF2 in Drosophila, and turns on cellular defences on a broad scale.
The CNC gene is widely known to be involved in determining the development of a fruit fly's head.
"This is one of the main mechanisms the body uses to fight off the things that give you cancer," said Bohmann, who studies fruit flies in an effort ultimately aimed at improving human health.
"This puts cells into an anti-oxidant defence mode. Drug development and testing is very, very expensive and time-consuming. This work should speed the development of new drugs aimed at preventing cancer," he added.
During the study, the researchers engineered fruit flies to glow green, when exposed to ultraviolet light, and when the signalling pathway is functioning. The glow from flies with more active CNC would be brighter than glow more regular flies.
The researchers demonstrated the technology using a compound called oltipraz, which targets the pathway and has been tested in people as a cancer-prevention agent. The flies that ate food with the compound glowed more strongly, demonstrating that the NRF2 pathway was more active in them.
Upon boosting the activity of the pathway, the researchers found that the fruit flies were three times more likely to survive an exposure to a toxin than regular flies. They also suggested that flies with a more active signalling system could live 10 per cent longer than the other flies.
Bohmann says that the presence of this system in fruit flies opens the door to faster, less expensive ways to find compounds that spur natural anti-oxidant activity.
"Turning on our natural anti-oxidants is big business for many companies trying to develop compounds to protect us from cancer and to slow the aging process. The same genetic principles govern many organisms, from flies to rodents to people, and we're hopeful that our tool in fruit flies will speed this work for the benefit of patients," said Bohmann.
This is the first time that the system, long known to be an important anti-oxidant and cancer prevention pathway, has also been shown to play a role in giving an organism a longer lifespan. The link gives new insight into the well-established connection between aging and cancer risk.
The study has been published in the journal Developmental Cell