Featured Research

from universities, journals, and other organizations

Gene Packaging Tells Story Of Cancer Development

Date:
December 12, 2008
Source:
Johns Hopkins Medical Institutions
Summary:
To decipher how cancer develops, researchers must take a closer look at the packaging, a new study suggests.

To decipher how cancer develops, Johns Hopkins Kimmel Cancer Center investigators say researchers must take a closer look at the packaging.

Specifically, their findings in the December 2, 2008, issue of PLoS Biology point to the three dimensional chromatin packaging around genes formed by tight, rosette-like loops of Polycomb group proteins (PcG). The chromatin packaging, a complex combination of DNA and proteins that compress DNA to fit inside cells, provides a repressive hub that keeps genes in a low expression state.

"We think the polycomb proteins combine with abnormal DNA methylation of genes to deactivate tumor suppressor genes and lock cancer cells in a primitive state," says Stephen B. Baylin, M.D., Virginia and D.K. Ludwig Professor of Oncology and senior author.

Prior to this discovery, investigators studying cancer genes, looked at gene silencing as a linear process across the DNA, as if genes were flat, one dimensional objects. Research did not take into account the way genes are packaged.

To better understand the role of the PcG packaging, the team compared embryonic cells to adult colon cancer cells. The gene studied in the embryonic cells was packaged by PcG proteins, in a low expression state, and had no DNA methylation. When the gene received signals for cells to mature, the PcG loops were disrupted and the gene was highly expressed. However, when the same gene was abnormally DNA methylated, as is the case in adult, mature colon cancer cells, the PcG packaging loops were tighter and there was no gene expression. "These tight loops touch and interact with many gene sites folding it into a structure that shuts off tumor suppressor genes," says Baylin. However, when the researchers removed DNA methylation from the cancer cells, the loops loosened somewhat, back to the state of an embryonic cell, and some gene expression was restored.

DNA methylation is a normal cellular process, but when it goes awry and genes are improperly methylated, it can shut down important tumor suppressing cell functions.

Demethylating agents, drugs that target and remove abnormal DNA methylation from genes, have been introduced as potential new cancer therapies. For these therapies to be fully effective, Baylin says, researchers may also need to look for agents that disrupt PcG loops.

Working with Baylin on this research were Vijay K. Tiwari, Kelly M. McGarvey, Julien D. F. Licchesi, Joyce E. Ohm, James G. Herman, and Dirk Schόbeler.

The research was funded by the National Institutes of Environmental Health Sciences, the National Institutes of Health, and the Novartis Research Foundation.

 


Story Source:

The above story is based on materials provided by Johns Hopkins Medical Institutions. Note: Materials may be edited for content and length.


Cite This Page:

Johns Hopkins Medical Institutions. "Gene Packaging Tells Story Of Cancer Development." ScienceDaily. ScienceDaily, 12 December 2008. <www.sciencedaily.com/releases/2008/12/081204183243.htm>.
Johns Hopkins Medical Institutions. (2008, December 12). Gene Packaging Tells Story Of Cancer Development. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2008/12/081204183243.htm
Johns Hopkins Medical Institutions. "Gene Packaging Tells Story Of Cancer Development." ScienceDaily. www.sciencedaily.com/releases/2008/12/081204183243.htm (accessed April 23, 2014).

Share This



More Health & Medicine News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Pharma Braces for M&A Wave

Big Pharma Braces for M&A Wave

Reuters - Business Video Online (Apr. 22, 2014) — Big pharma on the move as Novartis boss, Joe Jimenez, tells Reuters about plans to transform his company via an asset exchange with GSK, and Astra Zeneca shares surge on speculation that Pfizer is looking for a takeover. Joanna Partridge reports. Video provided by Reuters
Powered by NewsLook.com
Study Says Most Crime Not Linked To Mental Illness

Study Says Most Crime Not Linked To Mental Illness

Newsy (Apr. 22, 2014) — A new study finds most crimes committed by people with mental illness are not caused by symptoms of their illness or disorder. Video provided by Newsy
Powered by NewsLook.com
Hagel Gets Preview of New High-Tech Projects

Hagel Gets Preview of New High-Tech Projects

AP (Apr. 22, 2014) — Defense Secretary Chuck Hagel is given hands-on demonstrations Tuesday of some of the newest research from DARPA _ the military's Defense Advanced Research Projects Agency program. (April 22) Video provided by AP
Powered by NewsLook.com
How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) — NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. Video provided by Newsy
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