Navigation Links
Common bacteria cause some colon tumors by altering peroxide-producing gene
Date:11/4/2011

Working with lab cultures and mice, Johns Hopkins scientists have found that a strain of the common gut pathogen Bacteroides fragilis causes colon inflammation and increases activity of a gene called spermine oxidase (SMO) in the intestine. The effect is to expose the gut to hydrogen peroxide the caustic, germ-fighting substance found in many medicine cabinets -- and cause DNA damage, contributing to the formation of colon tumors, say the scientists.

"Our data suggest that the SMO gene and its products may be one of the few good targets we have discovered for chemoprevention," says Robert Casero, Ph.D., professor of oncology at the Johns Hopkins Kimmel Cancer Center.

In a study, Casero and his colleagues introduced B. fragilis to two colon cell lines and measured SMO gene activity. In both cell lines, SMO gene activity increased two to four times higher than cells not exposed to the bacteria. The scientists also observed similar increases in enzymes produced by the SMO gene. The scientists successfully prevented DNA damage in these cells by blocking SMO enzyme activity with a compound called MDL 72527.

The Johns Hopkins team also tested their observations in a mouse model, created by Hopkins infectious disease specialist Cynthia Sears, M.D., to develop colon tumors. Mice exposed to the bacteria had similar increases in SMO. Mice treated with MDL 72527 had far fewer tumors and lower levels of colon inflammation than untreated mice. Results of the experiments were published online in the Proceedings of the National Academy of Sciences in August.

Casero says hydrogen peroxide can freely distribute through and into other cells. "It roams around, and can damage the DNA in cells," he says.

Rising levels of hydrogen peroxide and DNA damage in the colon are clear steps to tumor development, says Andrew Goodwin, Ph.D., who spearheaded the studies while performing graduate work in Johns Hopkins' Cellular and Molecular Medicine Program and Casero's laboratory.

B. fragilis strains that secrete a toxin are widely known to cause diarrhea in children and adults, and previous studies, including those at Johns Hopkins, have linked the toxin-producing bacteria to inflammation and colon cancer. Casero and collaborators previously linked the SMO gene to inflammation and cancer of the prostate and stomach.

Using MDL 72527 in humans is not advised, Casero says, because the compound blocks another enzyme in addition to SMO. Investigators hope to develop a drug that targets only the SMO enzyme. Candidates for such prevention strategies may include people with a history of colon polyps, which increases risk for colon cancer, and those with inflammatory bowel disease.


'/>"/>
Contact: Vanessa Wasta
wasta@jhmi.edu
410-614-2916
Johns Hopkins Medical Institutions
Source:Eurekalert

Related medicine news :

1. Mentoring Works Best When Adults, Kids Share Common Interests
2. Vintage leather football helmets often as protective as modern helmets in common, game-like hits
3. Low vitamin D common in spine surgery patients
4. Teen Sexting Common and Linked to Psychological Woes
5. Virginia Commonwealth University findings may help explain high blood pressure in pregnancy
6. Mayo Clinic develops new way to rate severity of colitis, a common cause of diarrhea
7. Compound found in common wart treatment shows promise as leukemia therapy
8. Impact of Canadas Common Drug Review on drug listing
9. Study confirms males and females have at least 1 thing in common: Upregulating X
10. Commonly used 3-drug regimen for idiopathic pulmonary fibrosis found harmful
11. New Guidelines Issued for Common Tremor Disorder
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/23/2019)... ... May 23, 2019 , ... CarePartners announced today that ... Home Care system. Complia Health will provide CarePartners with a cloud-based scalable enterprise ... the operational, clinical, and financial processes for enterprise providers of services including home ...
(Date:5/23/2019)... HOUSTON (PRWEB) , ... May 23, 2019 , ... Mirror ... topped 100. This exciting landmark represents years of dedication to patient satisfaction and top-notch ... commitment to provide a welcoming location where patients can come for exceptional skincare and ...
(Date:5/23/2019)... ... May 23, 2019 , ... ... the esteemed Haute Beauty network. , The Haute Beauty Network, well known for ... leading Face Expert and our newest addition to the Haute Living partnership. , ...
(Date:5/23/2019)... (PRWEB) , ... May 23, 2019 , ... ... the shipment of three (3) Gruenberg Cleanroom Truck-In Ovens to the Medical Industry. ... chamber dimensions of 42” W x 48” D x 72” H. The Gruenberg ...
(Date:5/23/2019)... ... 23, 2019 , ... Hoban Law Group is proud to be partnering with ... is essential to help educate the public about the most sweeping cannabis reform policy ... do so than Times Square,” said Hoban Law Group Founder & President Bob Hoban. ...
Breaking Medicine News(10 mins):
(Date:5/23/2019)... , ... May 23, 2019 , ... NATIONAL OFFICE – ... firm’s new national industry partner (NIP) of the health care practice. Former NIP Eddie ... “I’m honored to be chosen to lead our national health care practice and work ...
(Date:5/23/2019)... ... May 23, 2019 , ... Bergen ... primary-care facilities. “Our philosophy is to provide the highest level of medical care ... managing partner of Bergen Medical Associates. “We offer a therapeutic environment and easy ...
(Date:5/22/2019)... Fla. (PRWEB) , ... May 22, 2019 , ... AdventHealth ... currently serves as CEO for AdventHealth Wesley Chapel, will assume leadership of the hospital ... care services for AdventHealth West Florida Division. She replaces Brian Adams, who is transitioning ...
Breaking Medicine Technology: