Navigation Links
University of Pennsylvania researchers zero in on the tiniest members in the war on cancer
Date:12/13/2007

PHILADELPHIA - Researchers from the University of Pennsylvania and Johns Hopkins University have uncovered another reason why one of the most commonly activated proteins in cancer is so dangerous. As reported in Nature Genetics this week, the Myc protein can stop the production of at least 13 microRNAs, small pieces of nucleic acid that help control which genes are turned on and off.

Furthermore, in several instances, re-introducing repressed miRNAs into Myc-containing cancer cells suppressed tumor growth in mice, raising the possibility that a gene-therapy approach could be an effective therapy for treating certain cancers.

Andrei Thomas-Tikhonenko, an associate professor in the Department of Pathobiology in Penns School of Veterinary Medicine, and a research team led by Joshua Mendell, assistant professor at the McKusick-Nathans Institute of Genetic Medicine at Johns Hopkins, analyzed more than 300 miRNAs in both human and mouse lymphoma cells.

Mendells team had previously found that Myc could turn on one particular group of growth-promoting miRNAs called the miR-17-92 cluster in lymphoma cells. In those cells that had high amounts of Myc protein, the researchers found significant changes in the quantities of at least 13 miRNAs.

"The surprising aspect, considering our miR-17-92 results," Tsung-Cheng Chang and Duonan Yu, lead co-authors on the study, wrote, "is that lots of Myc turns everything off, not on."

When they looked closer at the DNA of the lymphoma cells, the team also found that Myc was directly attaching to the DNA at the miRNA genes.

"This was further evidence that the decrease in miRNA levels was directly due to the action of Myc," says Chang said.

"This study expands our understanding of how Myc acts as such a potent cancer-promoting protein," Mendell said. "We already knew that it can directly regulate thousands of genes. Through its repertoire of miRNAs, Myc likely influences the expression of thousands of additional genes. Activation of Myc therefore profoundly changes the program of genes that are expressed in cancer cells."

"Still, we needed to determine whether any of these Myc-regulated microRNAs played a direct role in cancer," Thomas-Tikhonenko said.

The Penn team individually reintroduced several of the repressed miRNAs into mouse lymphomas that also had high levels of Myc and measured the effect on lymphoma progression in animals. They found that at least five of the miRNAs could stop cancer growth.

"While this result was not entirely surprising, we had no idea that cancer suppression by microRNAs could be so powerful," Thomas-Tikhonenko said.

Mendell also notes that RNA-based therapies have had some success in animal models, and researchers might potentially find a wide range of miRNAs that can stop cancers in their tracks.


'/>"/>

Contact: Jordan Reese
jreese@upenn.edu
215-573-6604
University of Pennsylvania
Source:Eurekalert

Related biology news :

1. A study by the MUHC and McGill University opens a new door to understanding cancer
2. University of Pennsylvania researchers develop formula to gauge risk of disease clusters
3. University of Oregon researcher finds that on waters surface, nitric acid is not so tough
4. Bioengineers at University of Pennsylvania devise nanoscale system to measure cellular forces
5. Binghamton University researchers investigate evolving malaria resistance
6. Antioxidant to retard wrinkles discovered by Hebrew University researcher
7. Society for General Microbiology 161st Meeting, University of Edinburgh
8. Boston University biomedical engineers find chink in bacterias armor
9. KAUST and American University in Cairo to collaborate on research and academic development
10. UNH becomes first university in nation to use landfill gas as primary energy source
11. University of Minnesota study refutes belief that black men have more aggressive prostate cancer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/16/2017)... CeBIT 2017 - Against identity fraud with DERMALOG solutions "Made in ... ... combined in one project, multi-biometric solutions provide a crucial contribution against identity fraud. (PRNewsFoto/Dermalog Identification ... Used combined in one project, multi-biometric solutions provide a ... ...
(Date:3/9/2017)... FRANCISCO and MOUNTAIN VIEW, Calif. ... , "Eating Well Made Simple," and 23andMe , ... help guide better food choices.  Zipongo can now provide ... their food preferences, health goals and biometrics, but also ... certain food choices. Zipongo,s personalized food decision ...
(Date:3/6/2017)... , March 6, 2017 ... sales technology, today announced Predictive Sales Coach TM ... infusing actionable sales intelligence into Salesforce. This unique ... enable their sales organizations with deep knowledge of ... allow for intelligent engagement. Predictive Sales Coach extends ...
Breaking Biology News(10 mins):
(Date:4/27/2017)... , April 27, 2017  Kinexum, a distinguished resource ... today announces the appointment of Thomas C. Seoh ... ("Zan") Fleming, M.D., Kinexum founder, who becomes Executive Chairman ... to Kinexum clients. Thomas Seoh ... the Kinexum mission and lead the firm,s remarkable team ...
(Date:4/26/2017)... ... April 26, 2017 , ... Baltimore ... Bioflash MailGuardtm mail security screening solution at the National Postal Forum 2017 in ... provides a fast, highly accurate, easy to use and low cost threat detection ...
(Date:4/25/2017)... ... April 25, 2017 , ... ... supplier of Common Lisp (CL) development tools, and market leader for Semantic ... key performance enhancements now available within the most effective system for developing and ...
(Date:4/25/2017)... ... , ... Leaders of Quorum Review IRB and Kinetiq , ... this week’s Association of Clinical Research Professionals (ACRP) 2017 Meeting & Expo ... "We are excited to present subject matter expertise on topics that impact the global ...
Breaking Biology Technology: