Navigation Links
Fugitive cancer cells can be blocked by stopping blood cells that aid them
Date:3/6/2008

Cancer cells get a helping hand from platelets, specialized blood cells involved in clotting. Platelets shelter and feed tumor cells that stray into the bloodstream, making it easier for cancer to spread, or metastasize. Research at Washington University School of Medicine in St. Louis suggests that inactivating platelets could slow down or prevent metastasis.

In advance online publication in the Journal of Cellular Biochemistry, the scientists report that a combination of two platelet inhibitors reduced the number and size of breast cancer or melanoma tumors that grew in the bones of laboratory mice.

One of the drugs was aspirin, a widely used inhibitor of platelet clotting. The other was an experimental drug, APT102, which also prevents platelet clotting, but by a different mechanism. Both drugs were needed to reduce bone tumors.

"Past research has shown that tumor cells activate platelets and that mice with defective platelets have significantly fewer metastases," says Katherine Weilbaecher, M.D., assistant professor of medicine and of cell biology and physiology. "We also know that platelets have several traits that can aid tumor cells, and we are working to break up that potentially lethal partnership."

Metastasis of cancer cells to sites away from the main tumor can cause pain and other symptoms and greatly increases the likelihood a patient will die of the disease. In fact, more than 90 percent of cancer deaths are the result of metastasis, which is difficult to control with current therapies.

Cancer cells that leave the primary tumor and circulate in the bloodstream can readily take advantage of platelets they encounter. The circulating tumor cells secrete factors that make platelets stick together, creating a shield of platelets that protects cancer cells from immune attack. In addition, platelets release growth factors that help tumor cells survive, and platelets' capacity to stick to particular sites enables companion tumor cells to settle in and proliferate in new areas.

Weilbaecher, an oncologist with the Siteman Cancer Center at Washington University School of Medicine and Barnes-Jewish Hospital, and colleagues, including zge Ulukan, a predoctoral trainee in molecular genetics, and Mark Eagleton, a research technician, tested the effect of aspirin and APT102 in mice that received an injection of either melanoma or breast cancer cells.

The cancer cells establish themselves in bones in as little as two days and proliferate to produce large bone tumors in less than two weeks. But the researchers found the bone tumors were smaller and fewer in mice that got a dose of aspirin and APT102 before inoculation with cancer cells and additional treatments twice a day for two days after that.

"We only had a small amount of APT102 to test, so in this set of experiments, we gave only a few doses of the drugs to the mice," Ulukan explains. "At this point, we don't know if additional treatment would have further reduced the tumor burden, but it's clear that reducing platelet function had a positive result in this model of metastatic cancer."

By themselves neither aspirin nor APT102 lessened the amount and size of bone tumors in the mice, possibly because cancer cells can activate platelets in several different ways, making a dual approach more effective, according to Weilbaecher.

"Aspirin prevents platelets from making thromboxane, a substance that facilitates clotting," Weilbaecher says. "APT102 is an especially interesting drug because it gets rid of a compound called ADP, which tumor cells release and which stimulates platelets to clump. So APT102 prevents platelet activation in response to tumor cells."

APT102 is produced by APT Therapeutics Inc., a St. Louis-based biopharmaceutical company. The company donated the drug but did not fund the research project. Co-authors Soon Seog Jeong and Ridong Chen are employees of APT Therapeutics and provided expertise about the bioactivity and dosing of APT102.

The researchers noted that the drug combination would likely be well tolerated because it did not cause excessive bleeding in the mice, as might be expected from platelet inhibitors. The research group plans to continue to study the process of metastasis and the role played by platelets.

In collaboration with Michael Naughton, M.D., assistant professor of medicine, Weilbaecher is also involved in a clinical trial of women with advanced breast cancer to test aspirin and Plavix, another antiplatelet drug, to see if the drug combination affects the number of tumor cells that circulate in the blood. The trial is open only to breast cancer patients undergoing treatment at the Siteman Cancer Center.


'/>"/>

Contact: Gwen Ericson
ericsong@wustl.edu
314-286-0141
Washington University School of Medicine
Source:Eurekalert

Related medicine news :

1. Colonoscopy Used to Identify and Remove Flat Colon Lesions: Flat Colon Lesions More Common and More Likely to Be Cancer According to JAMA Study
2. MultiVu Video Feed: New National Colorectal Cancer Screening Guidelines Issued by the American Cancer Society
3. Sharing Miracles Television Program to Feature Mountain Climber and Cancer Survivor Sean Swarner
4. ASGE Re-Launches Colon Cancer Awareness Web Site www.Screen4coloncancer.Org for National Colorectal Cancer Awareness Month
5. Cell recycling protects tumor cells from anti-cancer therapy
6. Drugs like aspirin could reduce breast cancer and help existing sufferers
7. Beverly Hills Executive Competes as a Rodeo Cowboy to Fund Cancer Research
8. Estrogen Levels in Blood Predict Breast Cancers Return
9. New guidelines update recommendations on colorectal cancer screening
10. Patrick Swayzes Diagnosis With Pancreatic Cancer: a Statement From the Pancreatic Cancer Action Network
11. New Guidelines Update Recommendations on Colorectal Cancer Screening
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/2/2016)... ... May 02, 2016 , ... It has just been announced ... for five events throughout the month of May. , Uldrich is the author of ... outlets. He also frequently appears on the Science Channel’s FutureScape and Discovery Channel’s Inside ...
(Date:5/2/2016)... (PRWEB) , ... May 02, 2016 , ... ... Issue 1 of Patient Experience Journal (PXJ), an international, open access, peer-reviewed ... With almost half the issue representing international (non-US) based authors, the third volume ...
(Date:5/2/2016)... ... 02, 2016 , ... Beanfields, PBC, makers of Beanfields Bean ... students at University of Colorado in Boulder to create new advertising campaigns. , ... the School of Journalism, who selected Beanfields as the brand on which to ...
(Date:5/2/2016)... ... 2016 , ... Amica Life Insurance Company has unveiled ... various life stages. , The site launched on April 1, and it has ... to the times when life insurance matters most. , “Through our research, we ...
(Date:5/2/2016)... ... 2016 , ... The National Resident Matching Program® (NRMP®) has ... Match”), the system through which U.S. and international medical school students and graduates ... placed in the 2016 Match, and 29,572 were filled when the matching algorithm ...
Breaking Medicine News(10 mins):
(Date:4/28/2016)... -- TapImmune,Inc. (TPIV), a clinical-stage immune-oncology ... immunotherapeutics and vaccines for the treatment of cancer & metastatic ... Annual Growth Capital Expo to be held on May ... Palace in Las Vegas, Nevada.  The Company presentation will ... by Dr. John N. Bonfiglio a TapImmune ...
(Date:4/27/2016)... 2016 Im ... Zürich gab Strekin AG den Start einer ... Erhaltung des Resthörvermögens von Patienten, denen ein ... umfassende Phase-II-Doppelblindstudie mit Placebo-Kontrollgruppe werden momentan Patienten ... während der Operation direkt ins Mittelohr verabreicht. ...
(Date:4/27/2016)... -- Elekta today announced that its leading-edge ... focal point of seven scientific presentations at ESTRO 35, ... & Oncology, taking place April 29 - May 3. ... and a high-field MRI scanner with sophisticated software that ... in real time. The MR-linac is designed to improve ...
Breaking Medicine Technology: