Navigation Links
Digital PCR technology detects brain-tumor-associated mutation in cerebrospinal fluid
Date:7/23/2013

Massachusetts General Hospital (MGH) researchers and their colleagues have used digital versions of a standard molecular biology tool to detect a common tumor-associated mutation in the cerebrospinal fluid (CSF) of patients with brain tumors. In their report being published in the open-access journal Molecular Therapy Nucleic Acids, the investigators describe using advanced forms of the gene-amplification technology polymerase chain reaction (PCR) to analyze bits of RNA carried in membrane-covered sacs called extracellular vesicles for the presence of a tumor-associated mutation in a gene called IDH1.

"Reliable detection of tumor-associated mutations in cerebrospinal fluid with digital PCR would provide a biomarker for monitoring and tracking tumors without invasive neurosurgery," says Xandra Breakefield, PhD, of the MGH Molecular Neurogenetics Unit, corresponding author of the paper. "Knowing the IDH1 mutation status of these tumors could help guide treatment decisions, since a number of companies are developing drugs that specifically target that mutant enzyme."

Both normal and tumor cells regularly release extracellular vesicles, which contain segments of RNA, DNA or proteins and can be found in blood, CSF and other body fluids. A 2008 study from the MGH team was able to identify a relatively large tumor-associated mutation in extracellular vesicles from the blood of brain tumor patients, but most current diagnostic technologies that analyze CSF do not capture molecular or genetic information from central nervous system tumors.

In addition, explains Leonora Balaj, PhD, of MGH Neurology, co-lead author of the current report, "Tumor-specific EVs make up only a small percentage of the total number of EVs found in either blood or cerebrospinal fluid, so finding rare, single-nucleotide mutations in a sample of blood or CSF is very challenging. These digital PCR techniques allow the amplification of such hard-to-find molecules, dramatically improving the ability to identify tumor-specific changes without the need for biopsy."

The current study used two forms of digital PCR BEAMing and Droplet Digital PCR to analyze extracellular vesicles in the blood and CSF of brain tumor patients and healthy controls for the presence of a single-nucleotide IDH1 mutation known to be associated with several types of cancer. Both forms of PCR were able to detect both the presence and abundance of mutant IDH1 in the CSF of 5 of the 8 patients known to have IDH1-mutant tumors. Two of the three mutation-positive tumors that had false negative results were low grade and the third was quite small, suggesting a need for future studies of more samples to determine how the grade and size of the tumors affect the ability to detect mutations. The failure to detect tumor-associated mutations in blood samples with this technology may indicate that CSF is a better source for extracellular vesicles from brain tumors.

The ability to noninvasively determine the genetic makeup of brain tumors could have a significant effect on patient care, explains study co-author Fred Hochberg, MD, MGH Neurology. "The current approach for patients who may have a brain tumor is first to have a brain scan and then a biopsy to determine whether a growth is malignant. Patients may have a second operation to remove the tumor prior to beginning radiation therapy and chemotherapy, but none of these treatments are targeted to the specific molecular nature of the tumor.

"Having this sort of molecular diagnostic assay whether in spinal fluid or blood would allow us to immediately initiate treatment that is personalized for that patient without the need for surgical biopsy," he adds. "For some patients, the treatment could shrink a tumor before surgical removal, for others it may control tumor growth to the point that surgery is not necessary, which in addition to keeping patients from undergoing an unnecessary procedure, could save costs. We still have a long way to go to improve survival of these malignancies, so every improvement we can make is valuable."

Breakefield is a professor of Neurology at Harvard Medical School, where Hochberg is an associate professor and Balaj a research fellow, also in Neurology. Walter Chen, MGH Neurology, is also co-lead author of the Molecular Therapy Nucleic Acid paper. Additional co-authors are Casey Maguire, Li Dan Zhu, and Sarada Sivaraman, MGH Neurology; Linda Liau, Horacio Soto, and Matthew Garrett, University of California, Los Angeles; Michael Samuels and Steven Kotsopoulos, RainDance Technologies; Lori LoGuidice and Johan Skog, Exosome Diagnostics; Clark Chen and Eric Wong, Beth Israel Deaconess Medical Center; and Bob Carter, University of California, San Diego.

The MGH has applied for a patent on the use of BEAMing PCR to analyze RNA from extracellular vesicles. The technology used to isolate tumor-associated molecules from extracellular vesicles, originally developed at the MGH, has been licensed to Exosome Diagnostics. RainDance Technologies markets the Droplet Digital PCR used in this study. Support for the study includes National Institutes of Health grants CA069246, CA141226, CA156009 and CA141150 and grants from the Brain Tumor Funders' Collaborative and the American Brain Tumor Association.


'/>"/>

Contact: Sue McGreevey
smcgreevey@partners.org
617-724-2764
Massachusetts General Hospital
Source:Eurekalert

Related medicine news :

1. Global Digital Pathology Market to Reach $336.6 Million by 2017 at a CAGR of 12% - New Report by MarketsandMarkets
2. South Charlotte Dentistry Goes Digital with Crowns and Restorations - Now Available in a Single Visit
3. Digital Revolution in the Sales Field: How Tablets Have Become an Essential Enterprise Tool — New Ebook by Intellectsoft
4. DPA Webinar “Real-World Examples of Practical Consultative/Collaborative Digital Pathology Programs” Recording Now Available
5. APAC Will Lead Digital Oil Field Market by 2022 in Oil & Gas Industry Says a Research Report at ReportsnReports.coms
6. Rijuven Debuts CardioSleeve, an FDA Cleared Stethoscope Attachment with 3-Lead ECG and Digital Auscultation that Wirelessly Connects to Mobile Devices
7. Digital Health Funding, Sensors, DNA, Big Data, and Reimbursement Hot Topics at Living in Digital Times' Digital Health Summer Summit
8. Digital X-Ray Market is estimated to reach up to $4.82 Billion by 2018, growing at a CAGR of 4.5% from 2013 to 2018 - New Report by MarketsandMarkets
9. 2013 BioProcess Theater Presentations Now Available on the BioProcess International Digital Media Website
10. Tabor Communications Further Strengthens its Digital Marketing Strategy
11. Visiopharm Partners with LRI Imaging and Inter Instrument AS for the Deployment of Digital Pathology Across Scandinavia
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:8/18/2017)... Raton, Fl (PRWEB) , ... August 18, 2017 ... ... largest network of highly trained practitioners specializing in bioidentical hormone replacement therapy and ... associated with hormone imbalance and conditions of aging, such as menopause, andropause, thyroid ...
(Date:8/18/2017)... ... August 18, 2017 , ... “Our Mountains to Climb: A Journey ... couple that grew stronger together through the faith they shared to overcome struggles in ... the creation of published author, Barbara J. Corcoran, a retired teacher and happily married ...
(Date:8/18/2017)... New York, New York (PRWEB) , ... August ... ... the world’s leading manufacturers and marketers of high-quality anti-aging skincare solutions, ... Prache Antiaging Serum. These new products are an affordable, yet effective alternative to ...
(Date:8/17/2017)... ... August 17, 2017 , ... Riccobene ... new location in Goldsboro, NC to its family of practices. Residents of Goldsboro ... trademark starting August 15, 2017. , Riccobene Associates Family Dentistry, founded by ...
(Date:8/17/2017)... ... August 17, 2017 , ... ... of three years for its residential drug and alcohol detox program. This accreditation ... organization and shows the organization’s substantial conformance to the CARF standards. , Behavioral ...
Breaking Medicine News(10 mins):
(Date:8/7/2017)... , Aug. 7, 2017  Endo International plc (NASDAQ: ... agreements to resolve virtually all known U.S. mesh product ... to resolve the known remaining U.S. claims at reasonable ... beginning in the fourth quarter of 2017 and continuing ... its second quarter 2017 results, the Company intends to ...
(Date:8/3/2017)...  Opioid addiction and other drugs of abuse, blood ... threatening outcomes, were problems taken on directly as laboratory ... support them, met this week. This according to Kalorama ... of abuse, procalcitonin and acute kidney injury were key ... meeting in San Diego, CA. ...
(Date:8/2/2017)... -- Life Flight Network and PeaceHealth Oregon Network announced they renewed ... operational efficiency for patients at hospitals in Eugene ... Grove , and Florence, Oregon , ... Network work collaboratively to move patients who require the highest ... sensitive emergency exists. ...
Breaking Medicine Technology: