SIRT1 takes down tumors

April 13, 2009
SIRT1 takes down tumors

Enlarge

Cells that make c-Myc proliferate in culture (left), but not when SIRT1 is present (right). Credit: Yuan, J., et al. 2009. J. Cell Biol. doi:10.1083/jcb.200809167.

Yuan et al. have identified another anti-cancer effect of the "longevity" protein SIRT1. By speeding the destruction of the tumor promoter c-Myc, SIRT1 curbs cell division. The study will be published online April 13 and will appear in the April 20 print issue of the Journal of Cell Biology.

The yeast and equivalents of SIRT1 are fountains of youth that stretch . Whether SIRT1 slows aging in mammals isn't certain, but it's beneficial in other ways. The protein tunes up metabolism, reducing blood levels of glucose and insulin, and might forestall neurodegenerative illnesses such as Alzheimer's disease and ALS. Given its pro-life credentials, you might expect SIRT1 to inhibit cancer. And several studies suggest that it does. But other work indicates that the protein aids tumors. For example, SIRT1 chops off acetyl groups, which can inactivate the tumor suppressor p53.

Yuan et al. determined SIRT1's effect on the transcription factor c-Myc, whose expression surges in many breast, colon, and liver cancers. The two proteins are tangled in a regulatory loop, the team found. c-Myc latched onto SIRT1's promoter, spurring cells to manufacture more SIRT1. In turn, SIRT1 detached acetyl groups from c-Myc, hastening its breakdown. To test SIRT1's effects on , the researchers implanted expressing c-Myc into nude mice that lack immune defenses. Boosting production of SIRT1 blocked tumor formation.

How deacetylation of c-Myc sparks its destruction is still a mystery. The researchers say that the results don't necessarily conflict with studies suggesting that SIRT1 is pro-tumor. Whether SIRT1 promotes or prevents cancer probably depends on the situation.

More information: Yuan, J., et al. 2009. J. Cell Biol. doi:10.1083/jcb.200809167. (www.jcb.org)

Source: Rockefeller University (news : web)

4.6 /5 (5 votes)  

Rank 4.6 /5 (5 votes)
Relevant PhysicsForums posts
  • Factors affecting beet root cell membrane
    created11 hours ago
  • Stem cell question.
    createdFeb 10, 2012
  • Protease cleavage
    createdFeb 10, 2012
  • Pertubance in a model
    createdFeb 10, 2012
  • Cancer drugs and Alzheimer's, Oh my!
    createdFeb 09, 2012
  • Squishing cells
    createdFeb 09, 2012
  • More from Physics Forums - Biology

More news stories

A mitosis mystery solved: How chromosomes align perfectly in a dividing cell

Although the process of mitotic cell division has been studied intensely for more than 50 years, Whitehead Institute researchers have only now solved the mystery of how cells correctly align their chromosomes during symmetric ...

Biology / Cell & Microbiology

created 7 hours ago | popularity 4.5 / 5 (12) | comments 0 | with audio podcast

Researchers find extensive RNA editing in human transcriptome

In a new study published online in Nature Biotechnology, researchers from BGI, the world's largest genomics organization, reported the evidence of extensive RNA editing in a human cell line by analysis of RNA-seq data, demons ...

Biology / Biotechnology

created 7 hours ago | popularity 5 / 5 (4) | comments 0 | with audio podcast

The proteins ensuring genome protection

Researchers from the University of Geneva (UNIGE), Switzerland, have discovered the crucial role of two proteins in developing a cell 'anti-enzyme shield'. This protection system, which operates at the level of molecular ...

Biology / Cell & Microbiology

created 7 hours ago | popularity 5 / 5 (3) | comments 0 | with audio podcast

Entire genome of extinct human decoded from fossil

(PhysOrg.com) -- In 2010, Svante Pääbo and his colleagues presented a draft version of the genome from a small fragment of a human finger bone discovered in Denisova Cave in southern Siberia. The ...

Biology / Biotechnology

created Feb 07, 2012 | popularity 4.7 / 5 (60) | comments 51 | with audio podcast

Why are there so few fish in the Earth's oceans?

(PhysOrg.com) -- A Stony Brook University researcher has found that, contrary to popular belief, there are not plenty of fish in the sea.

Biology / Plants & Animals

created Feb 08, 2012 | popularity 4.2 / 5 (18) | comments 27 | with audio podcast


Scientists discover molecular secrets of 2,000-year-old Chinese herbal remedy

For roughly two thousand years, Chinese herbalists have treated Malaria using a root extract, commonly known as Chang Shan, from a type of hydrangea that grows in Tibet and Nepal. More recent studies suggest that halofuginone, ...

New method to examine batteries -- MRI from the inside

There is an ever-increasing need for advanced batteries for portable electronics, such as phones, cameras, and music players, but also to power electric vehicles and to facilitate the distribution and storage of energy derived ...

Google might launch Drive for cloud storage soon

(PhysOrg.com) -- Google's next big move, according to the Wall Street Journal, is a cloud storage service called Drive. Hardly first to the plate, Google is simply catching up to introducing its cloud reposi ...

Lab study raises questions over nano-particle impact

Tests involving chickens have raised questions about the impact on health from engineered nano-particles, the ultra-fine grains commonly used in drugs and processed foods, scientists said on Sunday.

Overeating may double risk of memory loss

New research suggests that consuming between 2,100 and 6,000 calories per day may double the risk of memory loss, or mild cognitive impairment (MCI), among people age 70 and older. The study was released today and will be ...

Starve a virus, feed a cure? Findings show how some cells protect themselves against HIV

A protein that protects some of our immune cells from the most common and virulent form of HIV works by starving the virus of the molecular building blocks that it needs to replicate, according to research published online ...