Navigation Links
Master Switches Found for Adult Blood Stem Cells

Johns Hopkins Kimmel Cancer Center scientists have found a set of "master switches" that keep adult blood-forming stem cells in their primitive state//. Unlocking the switches' code may one day enable scientists to grow new blood cells for transplant into patients with cancer and other bone marrow disorders.

The scientists located the control switches not at the gene level, but farther down the protein production line in more recently discovered forms of ribonucleic acid, or RNA. MicroRNA molecules, once thought to be cellular junk, are now known to switch off activity of the larger RNA strands which allow assembly of the proteins that let cells grow and function.

"Stem cells are poised to make proteins essential for maturing into blood cells, but microRNAs keep them locked in their place," says cancer researcher Curt Civin, M.D., Ph.D., who led the study. The journal account will appear online the week of February 5 in the early edition of the Proceedings of the National Academy of Sciences.

To halt protein assembly, microRNAs pair up with matching full-length RNA, then fold and twist it, rendering the larger RNA useless. But the RNA pairings are not perfect, and one microRNA can latch on to several hundred RNA strands. "They act like a single circuit breaker to efficiently control hundreds of RNAs," says Civin, the Herman and Walter Samuelson Professor of Cancer Research.

"We're looking for ways to flip these microRNA switches, to control when stem cells grow into new blood cells," says Robert Georgantas, Ph.D., research associate at the Johns Hopkins Kimmel Cancer Center and first and corresponding author of the study.

To identify the key microRNAs, Georgantas sifted through thousands of RNA pieces with a custom-built, computer software program. Its algorithms let the software, fed data from samples of blood and bone marrow from healthy donors, match RNA pairs. The outcome was a core set of 33 microRNAs that match with more than 1,200 of the larger variety RNA already known to be important for stem-cell maturation.

Georgantas and Civin currently are testing whether these pair predictions are valid by using a non-reproducing virus to insert genetic instructions for each of the 33 microRNAs into adult stem cells. They'll then be cultured in Petri dishes. MicroRNA-155 - the first microRNA tested - was predicted to stop stem cells from developing into red and white blood cells.

As expected, stem cells without microRNA-155 matured: they formed approximately 75 red and 150 white blood cell colonies per dish. Stem cells with microRNA-155 matured into far fewer red and white cell colonies - about seven and 30 per dish, respectively.

"Using microRNAs to stall an adult blood stem cell in its early stage could help us grow new ones in test tubes, and perhaps give us more insight into stem-cell maturation for other tissue types," says Civin.

Source-Bio-Bio Technology

Related medicine news :

1. Protein acts as "Master Switch" that cuts off cells Cancer-Growth machinery
2. Master Regulatory Gene of Epithelial Stem Cells Identified
3. Unusual Tumor-Suppressor Gene Switches Off in Lung Cancer
4. Breast Cancer Treatment Switches to more Modern Therapy
5. Fluoride Found Effective in Osteoporosis
6. Implantable Contact Lens Found Safe and Effective
7. Cancer hazard Found With Animal-Based Nutrients
8. Processed Meat, Diabetes connection Found
9. Night Time Aspirin Regimen Found to Reduce Blood Pressure
10. Hydrotherapy Found to be Effective for Patients with Osteoarthritis
11. Hydrotherapy Found to be Effective for Patients with Osteoarthritis
Post Your Comments:

(Date:11/26/2015)... ... November 26, 2015 , ... Somu Sivaramakrishnan announced today ... owner, Somu now offers travelers, value and care based Travel Services, including exclusive ... as well as, cabin upgrades and special amenities such as, shore excursions, discounted ...
(Date:11/26/2015)... , ... November 26, 2015 , ... ... set of retro-fused, self-animating trailer titles with ProTrailer: Vintage. This newly styled ProTrailer ... classically-influenced trailer titles work with any font, giving users limitless opportunities to stylize ...
(Date:11/25/2015)... ... 2015 , ... The holiday season is jam-packed with family ... of attendees is of the utmost importance. Whether you are cooking at home ... recipes a try this holiday season. , Turkey Croquettes ,     Ingredients: ...
(Date:11/25/2015)... ... November 26, 2015 , ... Ministers, senior ... (EU), ANDI Pan African Centres of Excellence, and public R&D institutions, civil societies ... the opening of the 5th African Network for Drugs and Diagnostics Innovation, ANDI, ...
(Date:11/25/2015)... ... November 25, 2015 , ... Dental professionals who would like ... , are invited to attend Dr. Mark Iacobelli’s Advanced Implant Mentoring (AIM) CE course. ... OH. , As the co-founders of Advanced Implant Mentoring (AIM), Dr. Iacobelli and ...
Breaking Medicine News(10 mins):
(Date:11/25/2015)... WILMINGTON, N.C. , Nov. 25, 2015 /PRNewswire/ ... announces the planned investment of at least $15.8 ... in Wilmington, NC . The ... services capacity to meet the growing demands of ... Wilmington site expansion will provide up ...
(Date:11/25/2015)... , Nov. 25, 2015 Allergan plc (NYSE: ... agreement with the New York State ... of the Sherman Act, and other statutes with the Attorney ... February 2014, to cease marketing and selling the now generic ... settlement, Allergan admits no liability, has released its counterclaims against ...
(Date:11/25/2015)... USP 800 applies to all healthcare ... pharmacy technicians, nurses, physicians, physician assistants, home healthcare ... covers all entities which store, prepare, transport, or ... institutions, patient treatment clinics, physicians, practice facilities, and ... --> What is the purpose of USP ...
Breaking Medicine Technology: