Navigation Links
Treatment resistance in some cancer cells may be reversible
Date:4/1/2010

The ability of cancer cells to resist treatment with either targeted drug therapies or traditional chemotherapy may, in some cases, result from a transient state of reversible drug "tolerance." In a paper that will appear in the journal Cell and is receiving early online release, researchers from the Massachusetts General Hospital (MGH) Cancer Center report finding small populations of drug-tolerant cells from several different types of tumors and identifying aspects of the underlying mechanism.

"While resistance to cancer drugs can result from rare, pre-existing genetic mutations that emerge in response to treatment, accumulating evidence has pointed to additional nongenetic, potentially reversible mechanisms," says Jeffrey Settleman, PhD, of the MGH Cancer Center, who led the study. "In cell lines derived from several different types of cancer we found subpopulations of cells that display a transient ability to tolerate exposure to toxic drugs, which was associated with structural changes in the cells' DNA and points to a therapeutic strategy that could potentially prevent resistance from developing."

When cells within a tumor that had responded to treatment resume uncontrolled growth, drug therapy is usually stopped. But there have been many reports indicating that some tumors can regain sensitivity to the previously ineffective treatment after a "drug holiday." In order to investigate the mechanism underlying that phenomenon, the researchers tested several tumor-derived cell lines against drugs to which the original tumors were known to be sensitive.

In each of the lines they examined, a small number of tumor cells survived exposure to concentrations of drug 100 times greater than levels that killed the vast majority of the cells. But when these drug-tolerant cells were placed in an environment without the drug, their offspring eventually regained sensitivity to the drug.

Further investigation revealed that drug tolerance was associated with changes in gene expression, implicating alterations in chromatin, the chromosome structure consisting of DNA wrapped around a protein scaffolding. The researchers found that a particular chromatin-modifying enzyme was required for the development of tolerance, and while no currently available drug inhibits that protein, agents that block an associated group of enzymes did cause the death of drug-tolerant but not drug-sensitive cells.

"We believe this kind of reversible drug resistance may be a fundamental property of many tumor cell populations," says Settleman. "Determining whether what we see in cell cultures will translate into what happens in patients is essential, and we've already started a clinical trial to see if combining a chromatin-modifying agent with the targeted lung-cancer drug erlotinib [Tarceva] may prevent or delay the development of resistance. We're also using our cell culture models to further explore the underlying mechanisms." Settleman is the Laurel Schwartz Professor of Medicine at Harvard Medical School.


'/>"/>

Contact: Katie Marquedant
kmarquedant@partners.org
617-726-0337
Massachusetts General Hospital
Source:Eurekalert

Related medicine news :

1. Steroids May Be Overrated in Treatment of COPD
2. Experimental stem cell treatment arrests acute lung injury in mice, study shows
3. Entest BioMedical Enters into LOI with Advanced Light Devices to Develop Laser Platform for Stem Cell / Laser COPD Treatment
4. New study shows effectiveness of MEND program in prevention and treatment of pediatric obesity
5. New York City Surgeon Develops All-Natural Treatment for Wrinkles and Scars
6. Novelty lures rats from cocaine-paired settings, hinting at new treatments for recovering addicts
7. Northeast Chiropractic, PC Revolutionizes Pain Management Without Medication, Now Offering New and Unique Blend of Treatments
8. Autism-Supplements.com and Generation Rescue Work Together to Raise Money for Biomedical Autism Treatments
9. Biomarker could help doctors tailor treatment for rheumatoid arthritis
10. St. John Health System Brighton Hospital Signs Letter of Intent to Assist Saudi Arabia in Developing New Addiction Treatment Hospital in Riyadh
11. Jefferson neurosurgeon helps draft new treatment guidelines for brain metastases
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/27/2016)... ... June 27, 2016 , ... ... payment industry today announced its strategic partnership with Connance, a healthcare industry ... The two companies’ proven, proprietary technology combine to provide health systems, hospitals ...
(Date:6/26/2016)... ... June 26, 2016 , ... On June 10-11, 2016, A Forever ... Cereal Festival and World’s Longest Breakfast Table in Battle Creek, MI, where the rehabilitation ... as home to some of the world’s leading providers of cereal and other breakfast ...
(Date:6/26/2016)... ... June 26, 2016 , ... Many women are confused ... endometriosis. These women need a treatment plan to not only alleviate symptoms and ... help for preservation of fertility and ultimately achieving a pregnancy. The specialists at ...
(Date:6/25/2016)... ... 2016 , ... "With 30 hand-drawn hand gesture animations, FCPX users can easily ... of Pixel Film Studios. , ProHand Cartoon’s package transforms over 1,300 hand-drawn pictures ... . Simply select a ProHand generator and drag it above media or text in ...
(Date:6/25/2016)... ... ... On Friday, June 10, Van Mitchell, Secretary of the Maryland Department of Health and ... their exemplary accomplishments in worksite health promotion. , The Wellness at Work Awards took ... the BWI Marriott in Linthicum Heights. iHire was one of 42 businesses to receive ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... Research and Markets has announced the ... to 2022" report to their offering. ... patients with kidney failure, it replaces the function of kidneys ... blood and thus the treatment helps to keep the patient ... Increasing number of ESRD patients & substantial ...
(Date:6/23/2016)... DUBLIN , June 23, 2016 ... "Global MEMS Devices Medical Market Analysis 2016 - Forecast to ... The report contains up to date financial ... reliable analysis. Assessment of major trends with potential impact on ... dive analysis of market segmentation which comprises of sub markets, ...
(Date:6/23/2016)... INDIANAPOLIS , June 23, 2016 If ... Leaders Scholarship is any indication, the future is in ... at www.diabetesscholars.org by the Diabetes Scholars Foundation ... the way of academic and community service excellence. ... since 2012, and continues to advocate for people with ...
Breaking Medicine Technology: