Navigation Links
Powerful technique for multiplying adult stem cells may aid therapies

Adult stem cells may be free of the ethical concerns that hamper embryonic stem cell research, but they still pose formidable scientific challenges. Chief among these is the doggedness with which adult stem cells differentiate into mature tissue the moment they're isolated from the body. This makes it nearly impossible for researchers to multiply them in the laboratory. And because adult stem cells are so rare, that makes it difficult to use them for treating disease.

Now, researchers in the lab of Whitehead Institute Member and MIT professor of biology Harvey Lodish have discovered a way to multiply an adult stem cell 30-fold, an expansion that offers tremendous promise for treatments such as bone marrow transplants and perhaps even gene therapy.

"A 30-fold increase is ten times higher than anyone's achieved before," says Lodish, senior author on the paper, which will be published January 22 online in Nature Medicine.

Unlike embryonic stem cells, adult stem cells are generally tissue-specific, each one destined to develop into several kinds of cells. Chengcheng Zhang, a postdoctoral researcher in the Lodish lab, was determined to develop a way to multiply adult stem cells once they've been isolated from tissue. Achieving this goal required some intricate laboratory sleuthing.

Zhang began by studying adult hematopoietic--blood cell forming--stem cells. Offspring of some of these cells develop into all of the red and white blood cells, while others form the immune system. Using fetal tissue from mice as the source of these cells, Zhang discovered a population of cells that were not stem cells, yet appeared to interact with stem cells, preserving and allowing them to multiply in the fetal environment. When he isolated the stem cells in the lab and cultured them in a dish by themselves, they died. When he mixed them with these newly discovered cells, they thrived. But how did these new cells manage to sustain the stem cells so dramatically?

Zhang used a microarray platform to search for genes that were active in these newly discovered cells, but not active in similar neighboring cells. Some such genes, he reasoned, might encode secreted proteins that sustained stem cells. Eventually, he located a number of such genes.

In the fall of 2003 and early 2005, Zhang reported in the journal Blood how one of these genes codes for a growth factor protein called IGF-2. When Zhang purified IGF-2 and added it in a solution to hematopoietic stem cells that he had isolated, the stem cells increased eight-fold in number.

Zhang then discovered that two more growth factor proteins, Angiopoietin-like 2 and ?, abbreviated as angpt12 and angpt13, were also abundantly expressed in these stem-cell supporting cells. When Zhang combined these two proteins with IGF-2 and added them to hematopoietic stem cells, the result was a 30-fold increase.

"People have been culturing and working with these cells for years, and never before have we seen such an increase," says Zhang.

A 30-fold expansion, if replicated in human cells, could open up a number of doors for researchers working on adult stem cells. Currently, patients with certain blood diseases are treated with stem cells. These stem cells can be acquired either from a donor's bone marrow, or even from cord blood (donated cord blood, or the patient's own). Still, in both these cases, the actual number of stem cells from a donor often falls short of the number needed to adequately treat the patient. This technique could directly address this problem.

Gene therapy is another area where these findings can be of immediate value, Lodish says.

With gene therapy, a genetic defect is corrected by administering a healthy version of the gene into a patient. For example, a physician isolates hematopoietic stem cells from a patient, introduces a harmless virus into them that expresses a correct version of the m utated gene, and then re-administers the stem cells back into the patients. While many clinical trials have succeeded, some ended tragically when the virus ended up activating a cancer-causing gene. Because of this, the Food and Drug Administration is not currently approving any gene-therapy clinical trials.

"If, before the stem cells have been re-introduced into the patients, the physicians could first multiply them in the lab, they could then run assays determining if the virus has landed in any undesirable places," says Lodish. "They could then discard those bad cells, and only administer the good ones to the patients."

But most importantly, these findings aid basic research. "We want to know all sorts of things, like what genes are active in this stem cell, or how this stem cell decides to develop into one kind of cell as opposed to another," says Lodish.

Lodish and his colleagues are collaborating with researchers at Lund University in Sweden to repeat these results with human cord blood.


'"/>

Source:Whitehead Institute for Biomedical Research


Related biology news :

1. Powerful new tool for studying brain development
2. Powerful genome ID method extended to humans
3. New lab technique identifies high levels of pathogens in therapy pool
4. Brain-mapping technique aids understanding of sleep, wakefulness
5. Study reveals new technique for fingerprinting environmental samples
6. Researchers pioneer new gene therapy technique using natural repair process
7. Newer imaging techniques may lead to over-treatment
8. Gene silencing technique offers new strategy for treating, curing disease
9. Mosaic mouse technique offers a powerful new tool to study diseases and genetics
10. Researchers devise new technique for creating human stem cells
11. New technique rapidly detects illness-causing bacteria
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/14/2017)... June 15, 2017  IBM (NYSE: IBM ) is introducing ... event dedicated to developing collaboration between startups and global businesses, ... 15-17. During the event, nine startups will showcase the solutions ... various industries. France ... market, with a 30 percent increase in the number of ...
(Date:5/6/2017)... RAM Group , Singaporean based ... in biometric authentication based on a novel  ... to perform biometric authentication. These new sensors are based on ... Ram Group and its partners. This sensor will have ... and security. Ram Group is a next generation ...
(Date:4/17/2017)... , April 17, 2017 NXT-ID, Inc. (NASDAQ: ... announces the filing of its 2016 Annual Report on Form 10-K ... Commission. ... 10-K is available in the Investor Relations section of the Company,s ... the SEC,s website at http://www.sec.gov . 2016 Year ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... ... , ... Dr. Bob Harman, founder and CEO of VetStem Biopharma, Inc. ... The event entitled “Stem Cells and Their Regenerative Powers,” was held on August ... MPVM was joined by two human doctors: Peter B. Hanson, M.D., Chief of Orthopedic ...
(Date:10/10/2017)... ... October 10, 2017 , ... ... 13 prestigious awards honoring scientists who have made outstanding contributions ... scheduled symposium during Pittcon 2018, the world’s leading conference and exposition for laboratory ...
(Date:10/9/2017)... Phoenix, Arizona (PRWEB) , ... October 09, 2017 ... ... of Kindred, a four-tiered line of medical marijuana products targeting the needs of ... production and packaging of Kindred takes place in Phoenix, Arizona. , As operators ...
(Date:10/7/2017)... 6, 2017  The 2017 Nobel Prize in ... Jacques Dubochet, Joachim Frank and ... cryo-electron microscopy (cryo-EM) have helped to broaden ... biology community. The winners worked with systems manufactured ... produce highly resolved, three-dimensional images of protein structures ...
Breaking Biology Technology: