Suppressing activity of common intestinal bacteria reduces tumor growth

May 09, 2010

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.

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 .

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 and the tract's mucosal lining. Ordinarily, the bacteria and tract establish a kind of . "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 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 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 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 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."

Explore further: SLNB doesn't up survival in melanoma arising in head, neck

Related Stories

Protein found to be key in protecting the gut from infection

Feb 17, 2010

A signaling protein that is key in orchestrating the body's overall immune response has an important localized role in fighting bacterial infection and inflammation in the intestinal tract, according to a study by UC San ...

Recommended for you

Putting the brakes on cancer

Dec 19, 2014

A study led by the University of Dundee, in collaboration with researchers at our University, has uncovered an important role played by a tumour suppressor gene, helping scientists to better understand how ...

Peanut component linked to cancer spread

Dec 19, 2014

Scientists at the University of Liverpool have found that a component of peanuts could encourage the spread and survival of cancer cells in the body.

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

KBK
2 / 5 (4) May 09, 2010
At least a few hundred people (killed, garroted, burned to death, blown up, discredited, etc) who are not allowed to produce anything that gets into mainstream science have been saying, for nearly ~100 YEARS~, that cancers are all of bacterial and/or viral origin.

So finding that a given item or methodology involving the curtailing of fungi or bacteria will somehow limit tumors comes to no surprise to those of us who live with our eyes open.

At this time, cancer/medicine is a trillion dollar business. Some people kill others for money and power. It's called war, business, militarization, and politics. The same kind of low empathy animalistic people get into medicine, too, you know. For the very same reasons.

Do you think that common sense working cures can stop that Juggernaut?
blazingspark
1 / 5 (1) May 10, 2010
At least a few hundred people (killed, garroted, burned to death, blown up, discredited, etc) who are not allowed to produce anything that gets into mainstream science have been saying, for nearly ~100 YEARS~, that cancers are all of bacterial and/or viral origin.

So finding that a given item or methodology involving the curtailing of fungi or bacteria will somehow limit tumors comes to no surprise to those of us who live with our eyes open.

At this time, cancer/medicine is a trillion dollar business. Some people kill others for money and power. It's called war, business, militarization, and politics. The same kind of low empathy animalistic people get into medicine, too, you know. For the very same reasons.

Do you think that common sense working cures can stop that Juggernaut?


So you think you have the cure for cancer now? cmon.. be honest now!
satcat
1 / 5 (1) May 10, 2010

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.