Featured Research

from universities, journals, and other organizations

Suppressing activity of common intestinal bacteria reduces tumor growth

Date:
May 10, 2010
Source:
University of California - San Diego
Summary:
Common intestinal bacteria appear to promote tumor growths in genetically susceptible mice, but tumorigenesis can be suppressed if the mice are exposed to an inhibiting protein enzyme, researchers has discovered. The research could portend an eventual new form of treatment for people with familial adenomatous polyposis or FAP, an inherited condition in which numerous initially benign polyps form in the large intestine, eventually transforming into malignant colon cancer.

A team of University of California, San Diego School of Medicine researchers has discovered that common intestinal bacteria appear to promote tumor growths in genetically susceptible mice, but that tumorigenesis can be suppressed if the mice are exposed to an inhibiting protein enzyme.

Related Articles


The research, said lead author Eyal Raz, MD, a professor of medicine at UC San Diego, could portend an eventual new form of treatment for people with familial adenomatous polyposis or FAP, an inherited condition in which numerous initially benign polyps form in the large intestine, eventually transforming into malignant colon cancer.

The research appears online May 9 in the journal Nature Medicine.

Raz, with colleagues at the UC San Diego School of Medicine and Wonkwang University in the Republic of Korea, looked at interactions between the vast numbers of bacteria typically found in the gastrointestinal tract and the tract's mucosal lining. Ordinarily, the bacteria and tract establish a kind of homeostasis. "In a normal host, these bacteria actually serve important roles, such as supporting cell production," said Raz. "But in susceptible hosts, the presence of these bacteria turns out to be detrimental."

Specifically, Raz and his co-authors found that mice with an engineered mutation that closely mimics FAP in humans leaves the mice notably vulnerable to inflammatory factors produced by ordinary bacterial activity. The constant inflammation enhances expression of an oncogene called c-Myc. Very quickly, the mice develop numerous tumors in their intestines and typically do not survive past six months of age.

In humans, FAP can be equally devastating. It is a genetic condition in which patients at a young age begin to develop hundreds to thousands of polyps in their intestine. By age 35, 95 percent of individuals with FAP have polyps. The polyps start out benign, but ultimately become malignant without treatment. Current treatment essentially consists of prophylactic surgery -- removal of the polyps before they turn cancerous.

"Right now, people with FAP don't have many options," said Raz. "They develop the cancer relatively early in life and the only treatment is surgery, often a total colectomy -- the removal of the entire colon. And that still doesn't preclude the possibility of developing tumors elsewhere in the body."

That's why the second part of the study was especially encouraging, Raz said. When researchers administered a protein enzyme called extracellular signal-related kinase or ERK, it appeared to suppress intestinal turmorigenesis in the mice, causing cancer proteins to degrade more rapidly and increasing the survival time of the mice. If the inhibiting enzyme, which is currently undergoing clinical trials elsewhere, proves to be safe and effective, researchers say it eventually could provide FAP patients with another option other than surgery.

"This is a clear case of nature and nurture in molecular biology," said Raz. "Nature is the host, who in some cases is going to be genetically predisposed to develop certain diseases. Nurture is the environment, which in this case is bacterial activity and its effects. The mechanism for what's happening here with these mice and tumor growth is very clear. We know what we want and need to do."

Co-authors of the paper include Li-Li Hu, Jose Gonzalez-Navajas, Carol Shen, Jonathan Brick, Scott Herdman, Maripat Corr and Jongdae Lee, all from UCSD's Department of Medicine, plus Nissi Varki of the Department of Pathology at UCSD and Sung Hee Lee and Geom Seog Seo at Wonkwang University in Korea. The work was supported with grants from the National Institutes of Health.


Story Source:

The above story is based on materials provided by University of California - San Diego. Note: Materials may be edited for content and length.


Journal Reference:

  1. Sung Hee Lee, Li-Li Hu, Jose Gonzalez-Navajas, Geom Seog Seo, Carol Shen, Jonathan Brick, Scott Herdman, Nissi Varki, Maripat Corr, Jongdae Lee, Eyal Raz. ERK activation drives intestinal tumorigenesis in Apcmin/+ mice. Nature Medicine, 2010; DOI: 10.1038/nm.2143

Cite This Page:

University of California - San Diego. "Suppressing activity of common intestinal bacteria reduces tumor growth." ScienceDaily. ScienceDaily, 10 May 2010. <www.sciencedaily.com/releases/2010/05/100509144652.htm>.
University of California - San Diego. (2010, May 10). Suppressing activity of common intestinal bacteria reduces tumor growth. ScienceDaily. Retrieved March 26, 2015 from www.sciencedaily.com/releases/2010/05/100509144652.htm
University of California - San Diego. "Suppressing activity of common intestinal bacteria reduces tumor growth." ScienceDaily. www.sciencedaily.com/releases/2010/05/100509144652.htm (accessed March 26, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, March 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Jockey Motion Tracking Reveals Racing Prowess

Jockey Motion Tracking Reveals Racing Prowess

Reuters - Innovations Video Online (Mar. 26, 2015) Using motion tracking technology, researchers from the Royal Veterinary College (RVC) are trying to establish an optimum horse riding style to train junior jockeys, as well as enhance safety, health and well-being of both racehorses and jockeys. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Botswana Talks to End Illegal Wildlife Trade

Botswana Talks to End Illegal Wildlife Trade

AFP (Mar. 25, 2015) Experts are gathering in Botswana to try to end the illegal wildlife trade that is decimating populations of elephants, rhinos and other threatened species. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Elephants Help Keep 18-Wheeler From Toppling Over

Elephants Help Keep 18-Wheeler From Toppling Over

Newsy (Mar. 25, 2015) The Natchitoches Parish Sheriff&apos;s Office discovered two elephants keeping a tractor-trailer that had gotten stuck in some mud upright on a highway. Video provided by Newsy
Powered by NewsLook.com
Baby 'pet' Orangutan Rescued from Chicken Cage Takes First Steps

Baby 'pet' Orangutan Rescued from Chicken Cage Takes First Steps

Reuters - Light News Video Online (Mar. 25, 2015) Buti, a baby orangutan who was left malnourished in a chicken cage before his rescue, takes his first steps after months of painful physical therapy. Mana Rabiee reports. Video provided by Reuters
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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