Featured Research

from universities, journals, and other organizations

Accomplice in breast cancer discovered

Date:
August 18, 2010
Source:
George Washington University Medical Center
Summary:
Scientists have discovered an accomplice in breast cancer -- a master control switch with the power to set off a cascade of reactions orchestrated by a cancer-causing gene (or oncogene) named Wnt1.

Scientists have discovered an accomplice in breast cancer -- a master control switch with the power to set off a cascade of reactions orchestrated by a cancer-causing gene (or oncogene) named Wnt1. This executive molecule and its modus operandi are reported in back-to-back papers featured on the cover of the August 15 issue of Cancer Research.

"These papers are about the regulation of a Wnt oncogene," explains lead author Rakesh Kumar, Ph.D., professor and the Catharine Birch & William McCormick Chair of the department of biochemistry and molecular biology at The George Washington University School of Medicine and Health Sciences. Now, Kumar and his team describe how a master switch sparks a type of Wnt signaling in breast cancer. Moreover, this master control switch may help explain why increased levels of a protein called MTA1 (metastasis-associated protein 1) are oncogenic in certain types of breast cancer.

Like many molecular pathways underlying cancer, Wnt pathways govern normal processes like embryonic development and the communication between cells in healthy people. For reasons little understood, however, certain types of Wnt proteins sometimes go awry, sending off cascades of signals that turn normal cells into cancerous ones. Researchers often find evidence of Wnt pathway activation when they analyze what genes are turned on in tumors. Although Wnt has been connected with breast cancer for nearly 30 years, however, the signals (other than mutations) that trigger it remain largely unknown.

Kumar and his team have implicated MTA1 and a shorter variation of the protein, MTA1s, in Wnt1 (a type of Wnt) pathway activation. MTA1 belongs to the MTA family of genes, which help a range of cancers progress in a variety of ways. Before this study, researchers knew that MTA1 levels were higher than normal in breast, ovarian, prostate, colorectal, gastric, liver tumors, and more. But they still didn't know everything about what MTA's were doing there.

In the current studies, funded by a grant from the National Cancer Institute, Kumar's team finds that MTA1 expression triggers cancer-causing signals from Wnt1 in human breast cancer cells. This Wnt1 signaling cascade leads to tumors, they demonstrate, by showing that 8.8 percent of mice bearing artificially elevated levels of MTA1s grew tumors in their mammary glands.

To get down to the details, Kumar and his fellow researchers show that MTA1 and MTA1s activate the cancer-causing pathway by reducing the levels of a protein known as Six3. This protein is known to inhibit Wnt1 in brain cells, but in their study involving breast cancer cells, it inhibited Wnt1 in a rather non-intuitive way. Six3 normally puts the brakes on Wnt signaling, and so when MTA1 obstructed Six3, Wnt1 signals let loose. In addition, the team found that MTA1s also promoted Wnt signaling directly and through another known Wnt-related pathway -- namely ERK-mediated GSK3.

Because inflammation may drive MTA1, and since inflammation is believed to drive certain forms of cancer, Kumar's work suggests one possible reason for why worsening cancer progression has been correlated with other inflammation-inducers. "We've raised the next level question," says Kumar, "and now we're going back into the lab to ask if this pathway plays a role in inflammation-related cancer."


Story Source:

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


Journal Reference:

  1. M. Kumar, M. Yigit, G. Dai, A. Moore, Z. Medarova. Image-Guided Breast Tumor Therapy Using a siRNA Nanodrug. Cancer Research, 2010; DOI: 10.1158/0008-5472.CAN-10-2070

Cite This Page:

George Washington University Medical Center. "Accomplice in breast cancer discovered." ScienceDaily. ScienceDaily, 18 August 2010. <www.sciencedaily.com/releases/2010/08/100817161108.htm>.
George Washington University Medical Center. (2010, August 18). Accomplice in breast cancer discovered. ScienceDaily. Retrieved September 3, 2014 from www.sciencedaily.com/releases/2010/08/100817161108.htm
George Washington University Medical Center. "Accomplice in breast cancer discovered." ScienceDaily. www.sciencedaily.com/releases/2010/08/100817161108.htm (accessed September 3, 2014).

Share This



More Health & Medicine News

Wednesday, September 3, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Snack Attack: Study Says Action Movies Make You Snack More

Snack Attack: Study Says Action Movies Make You Snack More

Newsy (Sep. 2, 2014) You're more likely to gain weight while watching action flicks than you are watching other types of programming, says a new study published in JAMA. Video provided by Newsy
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Doctors Fear They're Losing Battle Against Ebola

Doctors Fear They're Losing Battle Against Ebola

AP (Sep. 2, 2014) As a third American missionary is confirmed to have contracted Ebola in Liberia, doctors on the ground in West Africa fear they're losing the battle against the outbreak. (Sept. 2) Video provided by AP
Powered by NewsLook.com
Tech Giants Bet on 3D Headsets for Gaming, Healthcare

Tech Giants Bet on 3D Headsets for Gaming, Healthcare

AFP (Sep. 2, 2014) When Facebook acquired the virtual reality hardware developer Oculus VR in March for $2 billion, CEO Mark Zuckerberg hailed the firm's technology as "a new communication platform." Duration: 02:24 Video provided by AFP
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