Newly found enzymes may play early role in cancer

Dec 24, 2008

Researchers have discovered two enzymes that, when combined, could be involved in the earliest stages of cancer. Manipulating these enzymes genetically might lead to targeted therapies aimed at slowing or preventing the onset of tumors.

"We could conceivably reactivate a completely normal gene in a tumor cell - a gene that could prevent the growth of a tumor if reactivated," says David Jones, Ph.D., professor of oncological sciences at the University of Utah and senior director of early translational research at the university's Huntsman Cancer Institute (HCI).

"We believe this could be one of the earliest processes to go wrong in cancer," he adds. "By manipulating these enzymes, we could possibly prevent or slow the onset of tumors."

The enzymes appear to control an "on-and-off switch" for critical genes that could trigger cancer or numerous other diseases and birth defects. The research is published in the December 26 issue of Cell.

Using zebrafish that share similar genetics to humans, the HCI scientists identified a previously unknown enzyme process that controls the levels of DNA methylation on genes.

"Methylation is a cellular process that is required for healthy cell growth and development, but it can go awry in cancer and diseased cells," says Brad Cairns, Ph.D., HCI investigator and professor of oncological sciences at the University of Utah. "You can think of DNA methylation as an on-and-off switch. Methylation silences or 'shuts off' genes that need to be turned off or are not functioning as they should, whereas the reverse process called demethylation 'turns on' healthy genes and genes needed at critical times in development," he says.

In cancer, this methylation process goes haywire, leading to tumor growth. Genes that should be "turned on" are not and vice versa.

The significance of this research is the discovery of two enzymes involved in DNA demethylation. Defects in DNA methylation balance are strongly associated with the early development of cancer, other diseases and birth defects, and the scientists say their study is the first clear evidence that this enzyme system plays a critical role in maintaining this balance. They also believe it's a process that can be reversed.

Further research will reveal if DNA methylation levels can be manipulated genetically. If so, it could lead to drugs to reactivate particular genes and suppress tumor growth. Remarkably, this system also helps protect the genome from mutations.

"We discovered a pair of enzymes that can remove methylated DNA, but if these enzymes work improperly, they will instead enhance the rate of mutations in methylated DNA and cause cancer progression," says Jones. "The question now is, when they work improperly, can we find ways to shut them off and prevent these mutations?"

The enzymes leading to DNA demethylation involve the coupling of a 5-meC deaminase enzyme, a G:T glycosylase enzyme and Gadd45, which is not an enzyme.

Source: University of Utah

Explore further: Chronic inflammation linked to 'high-grade' prostate cancer

add to favorites email to friend print save as pdf

Related Stories

Researchers show fruit flies have latent bioluminescence

Apr 10, 2014

New research from Stephen C. Miller, PhD, associate professor of biochemistry and molecular pharmacology, shows that fruit flies are secretly harboring the biochemistry needed to glow in the dark—otherwise ...

Ancient buried treasure found in daisy seeds

Mar 31, 2014

(Phys.org) —By tracing the evolutionary origin of a drug-like protein ring found in sunflowers, Australian and US scientists have discovered a diverse, 18-million-year-old group of buried proteins in daisy ...

Recommended for you

Unraveling the 'black ribbon' around lung cancer

Apr 17, 2014

It's not uncommon these days to find a colored ribbon representing a disease. A pink ribbon is well known to signify breast cancer. But what color ribbon does one think of with lung cancer?

User comments : 0

More news stories

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Treating depression in Parkinson's patients

A group of scientists from the University of Kentucky College of Medicine and the Sanders-Brown Center on Aging has found interesting new information in a study on depression and neuropsychological function in Parkinson's ...

Study says we're over the hill at 24

(Medical Xpress)—It's a hard pill to swallow, but if you're over 24 years of age you've already reached your peak in terms of your cognitive motor performance, according to a new Simon Fraser University study.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...