Featured Research

from universities, journals, and other organizations

Study On Chromosome Ends May Aid Cancer Research

Date:
August 4, 2000
Source:
Princeton University
Summary:
A Princeton scientist has discovered a mechanism that cells use to control the length of their chromosome ends, a process that is thought to go awry in cancer. The finding, reported in the August 4 issue of Science by Professor of Molecular Biology Virginia Zakian and colleagues, may provide cancer researchers with clues for designing treatments.

PRINCETON, N.J. -- A Princeton scientist has discovered a mechanism that cells use to control the length of their chromosome ends, a process that is thought to go awry in cancer.

The finding, reported in the August 4 issue of Science by Professor of Molecular Biology Virginia Zakian and colleagues, may provide cancer researchers with clues for designing treatments.

Zakian found a naturally occurring protein that inhibits the activity of another protein, called telomerase, which replicates and lengthens the very ends of chromosomes. The protein, called Pif1p, acts directly on the chromosome ends, called telomeres, to keep the lengthening process in check, Zakian's research group reported.

Researchers have been studying telomerase with great intensity for the past 15 years because it appears to play a central role in the way cells age or become cancerous. Studies have shown that telomerase is present in 90 percent of cancer types, but is absent from most healthy cells. Cancer researchers have thus looked for ways to interfere with telomerase. Zakian's research suggests that mimicking or enhancing the action of Pif1p may be a good way to do so.

Telomerase builds structures called telomeres at the ends of chromosomes, like plastic caps at the ends of shoelaces. In normal conditions, telomeres shorten each time a cell divides, eventually exposing the genetic material and causing the cell to die. In cancer cells, however, telomerase keeps rebuilding the telomere caps, preventing the cell from undergoing its normal aging process.

In 1994, Zakian and collaborator Vincent Schulz reported that Pif1p keeps telomeres from lengthening. It remained unclear, however, how Pif1p accomplished that feat. There are many natural substances that could inhibit telomere lengthening in indirect ways,

Zakian said. The new paper shows that Pif1p acts on the telomerase pathway itself and interacts directly with telomeric DNA, a potentially attractive feature for drug developers.

One interesting aspect of Pif1p is that it is special type of enzyme, a helicase, that unwinds the double strands of DNA. Zakian's research team created a small mutation in the gene that encodes Pif1p so that the protein is produced normally yet lacks this unwinding ability. When telomerase-rich cells carried this mutated gene, Pif1p no longer worked and telomere lengthening progressed unchecked. Zakian believes that Pif1p may work by unzipping a temporary bond that forms between telomerase and the chromosome as telomeres are synthesized.

The experiments were done in baker's yeast cells, but Zakian said that telomere regulation has been so important throughout evolution that human cells employ many of the same mechanisms.

"These are very lowly organisms. This is what we use to bake bread," she said. "However, as we show in this paper, humans have a protein very similar to yeast Pif1p. It would be quite gratifying if it turned out that it also functions in a similar way in humans and could give us insights into human cancer."


Story Source:

The above story is based on materials provided by Princeton University. Note: Materials may be edited for content and length.


Cite This Page:

Princeton University. "Study On Chromosome Ends May Aid Cancer Research." ScienceDaily. ScienceDaily, 4 August 2000. <www.sciencedaily.com/releases/2000/08/000804075602.htm>.
Princeton University. (2000, August 4). Study On Chromosome Ends May Aid Cancer Research. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2000/08/000804075602.htm
Princeton University. "Study On Chromosome Ends May Aid Cancer Research." ScienceDaily. www.sciencedaily.com/releases/2000/08/000804075602.htm (accessed July 22, 2014).

Share This




More Health & Medicine News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins