Featured Research

from universities, journals, and other organizations

Tumor suppressor APC could stop cancer through its effect on actin cytoskeleton

Date:
June 21, 2010
Source:
Rockefeller University Press
Summary:
The APC protein serves as the colon's guardian, keeping tumors at bay. Now researchers reveal a new function for the protein: helping to renovate the cytoskeleton by triggering actin assembly. The result suggests a second way that mutations in APC could lead to cancer.

A new study in the Journal of Cell Biology suggests that APC mutations could promote tumors not just through their effects on Wnt signaling, but also through their impact on the cytoskeleton. This image of a layer of cells highlights the actin structures that formed in one cell after an injection of an APC fragment. The inset reveals that the GFP-tagged fragment latched onto actin.
Credit: Okada, K., et al 2010. J. Cell Biol. doi:10.1083/jcb.201001016

The APC protein serves as the colon's guardian, keeping tumors at bay. Now researchers reveal a new function for the protein: helping to renovate the cytoskeleton by triggering actin assembly. The result suggests a second way that mutations in APC could lead to cancer.

The study appears online on June 21 in the Journal of Cell Biology.

A faulty APC gene occurs in more than 80% of colon cancers and is one of the early "gateway" mutations leading to abnormal growth. Researchers probing APC's anti-cancer powers have focused on how it curbs the activity of beta-catenin, a key link in the Wnt pathway that manages cell division and differentiation. But APC also helps shape the cytoskeleton. The protein latches onto and stabilizes growing microtubule ends and connects to actin filaments, though it was unclear exactly how APC affects actin dynamics.

A team of researchers led by Bruce Goode at Brandeis University found that APC plays matchmaker, corralling actin monomers into a complex that seeds further elongation. But that discovery raised another question. Cells deploy proteins that rein in actin extension. For example, profilin latches onto actin monomers and curbs spontaneous nucleation. And capping protein seals the barbed ends of actin filaments, preventing them from elongating and thus limiting their growth. APC can assemble actin filaments even if profilin is around. But how does it overcome capping protein?

The answer is that APC gets help, collaborating with formins that deter capping protein. The team found that when capping protein and profilin are present, APC or the formin mDia1 alone is a weak nucleator. But combining the two boosts actin assembly nearly fourfold.

APC is the seventh actin nucleator that researchers have identified. "The cellular functions of actin are so pervasive," Goode says. "It's involved in dozens of critical processes, so it makes sense that cells have a large number of factors that promote actin assembly." So far, APC is the only nucleator with direct links to cancer. Goode says that it's plausible that APC mutations could foment tumors not just through their effects on Wnt signaling, but also through their impact on the cytoskeleton, because cancer-causing mutations typically lop off the protein's actin-binding section.


Story Source:

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


Journal Reference:

  1. Kyoko Okada, Francesca Bartolini, Alexandra M. Deaconescu, James B. Moseley, Zvonimir Dogic, Nikolaus Grigorieff, Gregg G. Gundersen, Bruce L. Goode. Adenomatous polyposis coli protein nucleates actin assembly and synergizes with the formin mDia1. Journal of Cell Biology, 2010; DOI: 10.1083/jcb.201001016

Cite This Page:

Rockefeller University Press. "Tumor suppressor APC could stop cancer through its effect on actin cytoskeleton." ScienceDaily. ScienceDaily, 21 June 2010. <www.sciencedaily.com/releases/2010/06/100621121352.htm>.
Rockefeller University Press. (2010, June 21). Tumor suppressor APC could stop cancer through its effect on actin cytoskeleton. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2010/06/100621121352.htm
Rockefeller University Press. "Tumor suppressor APC could stop cancer through its effect on actin cytoskeleton." ScienceDaily. www.sciencedaily.com/releases/2010/06/100621121352.htm (accessed September 21, 2014).

Share This



More Health & Medicine News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Sierra Leone's Nationwide Ebola Curfew Underway

Sierra Leone's Nationwide Ebola Curfew Underway

Newsy (Sep. 20, 2014) Sierra Leone is locked down as aid workers and volunteers look for new cases of Ebola. Video provided by Newsy
Powered by NewsLook.com
Changes Found In Brain After One Dose Of Antidepressants

Changes Found In Brain After One Dose Of Antidepressants

Newsy (Sep. 19, 2014) A study suggest antidepressants can kick in much sooner than previously thought. Video provided by Newsy
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
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