Navigation Links
Brain Tumor Drug May Help Spur Cancer's Return
Date:3/5/2009

But insights into how that happens may lead to ways around it, researchers say,,,,

THURSDAY, March 5 (HealthDay News) -- Temozolomide, a standard treatment for brain cancer, may boost the aggressiveness of surviving cancer cells, making tumor recurrence more likely, a new study suggests.

The research team, from Memorial Sloan-Kettering Cancer Center in New York City, have identified cells in brain tumors called gliomas that have stem cell-like qualities and are able to survive chemotherapy with the help of a particular protein. These surviving cells become drug-resistant, and may be the reason treatment for brain cancer is usually unsuccessful.

"Stem-like cells are found in brain tumors, and the mutations that occur in high-grade tumors promote the stem cell character of tumor cells," explained lead researcher Dr. Eric Holland, director of Sloan-Kettering's Brain Tumor Center. "Furthermore, the standard therapy for brain tumors -- although beneficial against many of the tumor cells -- actually promotes stem cell character in the cells that survive."

The report is published in the March 6 issue of Cell Stem Cell.

According to the American Cancer Society, nearly 22,000 Americans were diagnosed with a malignant tumor of the brain or spinal cord in 2008, and more than 13,000 died from these cancers. Brain tumors also gained prominence this past year after Sen. Ted Kennedy (D-Mass.) was diagnosed with a particularly aggressive type of cancer known as a malignant glioma.

For the new study, Holland's team looked at the role of the protein ABCG2, which is associated with resistance to drugs in brain cancer cells. This protein transports drugs across the cell's membrane, which would otherwise shield the tumor cell from chemotherapy drugs, Holland explained.

The researchers isolated cells from mice and human cancer brain tumors called glioblastomas. Some of these cells appeared to have the ability to renew themselves and resist chemotherapy, the team found, and ABCG2 appears to be a marker for these resistant cells.

Holland's group also identified how the protein helps tumor cells expel chemotherapy drugs.

"Current treatment for gliomas works for a while and then usually fails," Holland said. "These findings might be partly the reason for that. There is more than one cell type in these tumors, and they respond differently to the therapy we treat people with."

For example, the chemotherapy drug temozolomide -- which is the standard treatment for gliomas -- actually increased the number of drug-resistant cells. Because temozolomide doesn't target ABCG2, it may render surviving cells more resistant to treatments that do target the ABCG2 protein, Holland theorized.

"Life is complicated; brain tumors are complicated, too," he said.

Dr. Ronald Benveniste is an assistant professor of neurosurgery at the University of Miami School of Medicine. He believes the study has a real upside because it points to new, longer-lasting brain cancer treatments.

"Clinically, what we see with patients with glioblastoma is that after surgery, radiation and chemotherapy with temozolomide, they live longer and a subset of them will actually live a year, two years or even longer. And then pretty much 100 percent of the patients relapse and no one knows why," Benveniste said.

This study identifies the mechanism by which this happens, he said. "When you treat mice with temozolomide they develop recurrent diseases even quicker, so temozolomide make the cells that survive act in a more aggressive manner," Benveniste said.

"In the future, relapse after treatment with temozolomide could be prevented by inhibiting these pathways," he speculated. "This could open doors to treatment. This is exciting stuff."

More information

For more information on brain tumors, visit the U.S. National Library of Medicine .



SOURCES: Eric Holland, M.D., Ph.D., director, Brain Tumor Center, Memorial Sloan-Kettering Cancer Center, New York City; Ronald Benveniste, M.D., assistant professor, neurosurgery, University of Miami School of Medicine; March 6, 2009, Cell Stem Cell


'/>"/>
Copyright©2009 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. Brain tumor treatment may increase number of cancer stem-like cells
2. European Commission and United States Food and Drug Administration (FDA) Both Approve New Options for Patients With Certain Primary Brain Tumors
3. Now Hear This: Brain Fitness Exercises Improve Listening
4. Nearly 1.4 Million Sustain Traumatic Brain Injuries Each Year
5. National Council on Disability Says More Needs to be Done for Service Members and Veterans With Post Traumatic Stress Disorder and Traumatic Brain Injury
6. Brain Adapts to Age-Related Eye Disease
7. UCI scientists to study brain region linked to autism, schizophrenia
8. Schizophrenia linked to signaling problems in new brain study
9. ProteoTech Receives Funding From The Michael J. Fox Foundation for Parkinsons Disease Research to Develop Tools for Imaging Alpha-Synuclein Aggregation in Living Parkinsons Brain
10. Sex is in the brain, says new research from Stanford
11. Smith & Nephew Orthopaedics and BrainLAB Announce Exclusive Computer-Assisted Surgery Development Agreement
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Brain Tumor Drug May Help Spur Cancer's Return
(Date:5/6/2016)... , ... May 06, 2016 , ... Canadian author Mark Black is a ... Life From the Heart" around the world … with the help of his publisher Strategic ... 24, Mark Black lay in a hospital bed waiting for a miracle: He needed a ...
(Date:5/6/2016)... ... May 06, 2016 , ... Yisrayl Hawkins, Pastor and Overseer at The House of Yahweh, ... he has found in the Bible about helping to stop cancer. Yisrayl says there are ... his hope that the health and science industries will pay close attention and take action. ...
(Date:5/6/2016)... ... May 06, 2016 , ... ... David Konur, CEO of Cardiovascular Institute of the South announced today that Dr. ... a live case of an Intravascular Ultrasound Guided Coronary Atherectomy. , ...
(Date:5/5/2016)... ... May 05, 2016 , ... While the practice and profession ... the impact our aging population has on communities and resources. Aging Life Care plays ... and face age-related challenges. , Aging Life Care is a holistic, client-centered approach ...
(Date:5/5/2016)... ... May 05, 2016 , ... The U.S. Food and ... e-cigarette manufacturers to submit their products through an arduous federal approval process. The ... that entered the market since February 15, 2007. That would essentially ban 99 ...
Breaking Medicine News(10 mins):
(Date:5/6/2016)... , May 6, 2016 ... Molecular Imaging and its Application to Drug Development Including ... Alacrita , the life sciences consulting firm, today ... PhD, as an Associate Partner in its ... Colin G Miller, PhD, in the firm,s Medical Imaging ...
(Date:5/5/2016)... 2016  Endo International plc (NASDAQ: ... Brian Lortie , President, U.S. Branded Pharmaceuticals, has ... the appointment of a successor. Mr. Lortie joined ... business with responsibility for all strategic, commercial and ... portfolio development, commercial operations, managed markets, manufacturing, supply ...
(Date:5/5/2016)... Grand Cayman , May 5, 2016 Progra ... successful trial of Oxitec , s mosquito ... Aedes aegypti by 96 % ... (MRCU) announced a new plan to fight wild Aedes aegypti, the ... these diseases on the island of Grand Cayman .  MRCU, ...
Breaking Medicine Technology: