Featured Research

from universities, journals, and other organizations

Jumping genes: Tumor microvesicles reveal detailed genetic information

Date:
February 14, 2011
Source:
Massachusetts General Hospital
Summary:
The same research team that first discovered tumor-associated RNA in tiny membrane-enclosed sacs released into the bloodstream by cancer cells has now found that these microvesicles also contain segments of tumor DNA, including retrotransposons -- also called "jumping genes" -- that copy and insert themselves into other areas of the genome.

The Massachusetts General Hospital (MGH) research team that first discovered tumor-associated RNA in tiny membrane-enclosed sacs released into the bloodstream by cancer cells has now found that these microvesicles also contain segments of tumor DNA, including retrotransposons -- also called "jumping genes" -- that copy and insert themselves into other areas of the genome. The investigators' report, which has been published in Nature Communications, is the first to show that microvesicles are involved in transferring retrotransposons between cells.

"Retrotransposons' action of self-copying and reinserting themselves into the genome leads to genetic instability," says Johan Skog, PhD, who led the current study while an investigator in the MGH Neurology Service. "Many researchers have proposed this as a mechanism for genetic diversity and for evolution. Retrotransposons are known to be upregulated in cancer, and discovering them in microvesicles that can be found in all body fluids suggests they could be useful biomarkers to help understand tumor progression and monitor treatment response."

Skog was lead author of a 2008 study that first identified tumor-associated RNA in microvesicles, also called exosomes, released by the deadly adult brain tumor glioblastoma. To further investigate the ability of microvesicles to reflect the genetic status of tumors, in the current study the MGH team analyzed the nucleic acid contents of microvesicles from glioblastomas, from two types of pediatric brain tumors, and from malignant melanomas.

They found that the microvesicles contained tumor DNA as well as RNA and that microvesicles from one of the pediatric tumors studied had elevated levels of both DNA and RNA from the oncogene c-Myc, which correlated with the gene's expression in that tumor. "We showed that amplification of c-Myc was present in microvesicles whenever it was present in the donor cell and that microvesicle analysis can reveal oncogene expression in the original tumor," explains Leonora Balaj of MGH Neurology, the first author of the study.

High levels of retrotransposon-associated RNA sequences were also detected in tumor microvesicles, and the investigators found those microvesicles could transfer their contents into normal cells. "One of the most important functions of tumor-derived microvesicles may be modification of normal cells in the microenvironment to make them more supportive of tumor growth," says study co-author Xandra Breakefield, PhD, MGH Neurology and a professor of Neurology at Harvard Medical School.

Skog is now the director of research for Exosome Diagnostics, the company that licensed the work described in the 2008 paper, and continues to consult with Breakefield's research team. Additional co-authors of the Nature Communications report are Ryan Lessard, MGH Neurology; Lixin Dai, Johns Hopkins School of Medicine; and Yoon-Jae Cho, MD, and Scott Pomeroy, MD, PhD, Children's Hospital Boston. The study was supported by grants from the National Cancer Institute, the Wenner-Gren Foundation, and Stiftelsen Olle Engkvist Byggmastare.


Story Source:

The above story is based on materials provided by Massachusetts General Hospital. Note: Materials may be edited for content and length.


Journal Reference:

  1. Leonora Balaj, Ryan Lessard, Lixin Dai, Yoon-Jae Cho, Scott L. Pomeroy, Xandra O. Breakefield, Johan Skog. Tumour microvesicles contain retrotransposon elements and amplified oncogene sequences. Nature Communications, 2011; 2: 180 DOI: 10.1038/ncomms1180

Cite This Page:

Massachusetts General Hospital. "Jumping genes: Tumor microvesicles reveal detailed genetic information." ScienceDaily. ScienceDaily, 14 February 2011. <www.sciencedaily.com/releases/2011/02/110210141249.htm>.
Massachusetts General Hospital. (2011, February 14). Jumping genes: Tumor microvesicles reveal detailed genetic information. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2011/02/110210141249.htm
Massachusetts General Hospital. "Jumping genes: Tumor microvesicles reveal detailed genetic information." ScienceDaily. www.sciencedaily.com/releases/2011/02/110210141249.htm (accessed July 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
China's Ageing Millions Look Forward to Bleak Future

China's Ageing Millions Look Forward to Bleak Future

AFP (July 24, 2014) China's elderly population is expanding so quickly that children struggle to look after them, pushing them to do something unexpected in Chinese society- move their parents into a nursing home. Duration: 02:07 Video provided by AFP
Powered by NewsLook.com
Hundreds in Virginia Turn out for a Free Clinic to Manage Health

Hundreds in Virginia Turn out for a Free Clinic to Manage Health

AFP (July 24, 2014) America may be the world’s richest country, but in terms of healthcare, the World Health Organisation ranks it 37th - prompting hundreds in Virginia to turn out for a free clinic run by “Remote Area Medical”. Duration 02:40 Video provided by AFP
Powered by NewsLook.com
Idaho Boy Helps Brother With Disabilities Complete Triathlon

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Newsy (July 23, 2014) An 8-year-old boy helped his younger brother, who has a rare genetic condition that's confined him to a wheelchair, finish a triathlon. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins