Navigation Links
Silencing small but mighty cancer inhibitors
Date:12/10/2007

Researchers from Johns Hopkins and the University of Pennsylvania have uncovered another reason why one of the most commonly activated proteins in cancer is in fact 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.

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

A research team led by Joshua Mendell, M.D., Ph.D., assistant professor at the McKusick-Nathans Institute of Genetic Medicine, previously found that Myc could turn on one particular group of growth-promoting miRNAs called the miR-17-92 cluster in lymphoma cells. His team, along with Andrei Thomas-Tikhonenkos lab at the University of Pennsylvania, now took a broader approach and analyzed more than 300 miRNAs in both human and mouse 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, says Tsung-Cheng Chang, lead author on the study, 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.

This study expands our understanding of how Myc acts as such a potent cancer-promoting protein, says Mendell. 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, adds Thomas-Tikhonenko. His team then 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 more than 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, admits Thomas-Tikhonenko. 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: Audrey Huang
audrey@jhmi.edu
410-614-5105
Johns Hopkins Medical Institutions
Source:Eurekalert

Related medicine news :

1. Prophylactic cranial irradiation in small cell lung cancer significantly increases survival
2. American Red Cross and FedEx Announce Collaboration to Help Small Businesses Get Prepared for Disaster
3. iCAD to Present at William Blair & Company Small-Cap Growth Stock Conference
4. Governor Rendell Announces $2.1 Million Investment in Small Transit Vehicles
5. Karen Vigil Named Senior Vice President and Chief Executive Officer, Blue Shield of Californias Individual, Small Group, and Government Business Unit
6. Small Incisions Make Heart Valve Surgery Safer
7. Smaller breast reduction surgeries provide health benefits and should be reimbursed
8. Exponent to Present at the Upcoming Sidoti & Company Investor Forum and William Blair Small-Cap Growth Stock Conference
9. Activate America(R) Brings Together YMCAs Nationwide to Promote Small Steps Toward a Healthier Lifestyle During America on the Move Week With the YMCA, September 22-29, 2007
10. Small Bone Innovations Introduces the Artelon(R) STT Spacer to Increase Treatment Options for Thumb Arthritis
11. Small Army Takes on Cure for Diabetes and New Approach to Ending World Poverty with Addition of Non-Profit Accounts
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/25/2016)... ... June 25, 2016 , ... On Friday, June 10, ... Bronze Wellness at Work award to iHire in recognition of their exemplary accomplishments in ... the 7th annual Maryland Workplace Health & Wellness Symposium at the BWI Marriott in ...
(Date:6/24/2016)... ... ... June 19, 2016 is World Sickle Cell Observance Day. In an effort ... holistic treatments, Serenity Recovery Center of Marne, Michigan, has issued a pain ... Disease (SCD) is a disorder of the red blood cells, which can cause episodes ...
(Date:6/24/2016)... ... 24, 2016 , ... Dr. Amanda Cheng, an orthodontist ... has extensive experience with all areas of orthodontics, including robotic Suresmile technology, ... , Micro-osteoperforation is a revolutionary adjunct to orthodontic treatment. It can be used ...
(Date:6/24/2016)... ... June 24, 2016 , ... EB Medicine ... Making in Emergency Medicine conference in Ponte Vedra Beach, FL. The awards honor ... Emergency Medicine Practice and Pediatric Emergency Medicine Practice. , “With this ...
(Date:6/24/2016)... ... 24, 2016 , ... National recruitment firm Slone Partners is pleased ... and genomics experience, as Vice President of North American Capital Sales at HTG ... leading the sales team in the commercialization of the HTG EdgeSeq system and associated ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... , June 24, 2016  Global Blood ... biopharmaceutical company developing novel therapeutics for the treatment ... today announced the closing of its previously announced ... stock, at the public offering price of $18.75 ... offering were offered by GBT. GBT estimates net ...
(Date:6/24/2016)... June 24, 2016 ... announced the addition of the " Global Markets ... This report focuses ... an updated review, including its applications in various applications. ... market, which includes three main industries: pharmaceutical and biotechnology, ...
(Date:6/24/2016)... , June 24, 2016 The Academy ... of recommendations that would allow biopharmaceutical companies ... with entities that make formulary and coverage decisions, a ... "value" of new medicines. The recommendations address ... not appear on the drug label, a prohibition that ...
Breaking Medicine Technology: