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:6/30/2017)... Today, American Trucking Associations announced Seeing ... and eye tracking software, became the newest member ... "Artificial intelligence and advanced sensing algorithms ... driver,s attentiveness levels while on the road.  Drivers ... fatigue and prevent potential accidents, which could lead ...
(Date:5/16/2017)... TEANECK, N.J. , May 16, 2017  Veratad ... leading provider of online age and identity verification solutions, ... the K(NO)W Identity Conference 2017, May 15 thru May ... Ronald Regan Building and International Trade Center. ... across the globe and in today,s quickly evolving digital ...
(Date:4/19/2017)... April 19, 2017 The global ... landscape is marked by the presence of several large ... held by five major players - 3M Cogent, NEC ... accounted for nearly 61% of the global military biometric ... in the global military biometrics market boast global presence, ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... CRUZ, Calif. , Oct. 10, 2017 ... grant from the NIH to develop RealSeq®-SC (Single Cell), ... kit for profiling small RNAs (including microRNAs) from single ... Analysis Program highlights the need to accelerate development of ... "New techniques for measuring ...
(Date:10/10/2017)... ... October 10, 2017 , ... The ... prestigious awards honoring scientists who have made outstanding contributions to analytical ... during Pittcon 2018, the world’s leading conference and exposition for laboratory science, which ...
(Date:10/9/2017)... ... ... The award-winning American Farmer television series will feature 3 Bar Biologics in ... 8:30aET on RFD-TV. , With global population estimates nearing ten billion people by ... feed a growing nation. At the same time, many of our valuable resources are ...
(Date:10/9/2017)... ... October 09, 2017 , ... The Giving ... marijuana products targeting the needs of consumers who are incorporating medical marijuana into ... in Phoenix, Arizona. , As operators of two successful Valley dispensaries, The Giving ...
Breaking Biology Technology: