Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Powerful technique for multiplying adult stem cells may aid therapies

23.01.2006


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 –3, 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 mutated 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.

David Cameron | EurekAlert!
Further information:
http://www.wi.mit.edu

More articles from Life Sciences:

nachricht New technology offers fast peptide synthesis
28.02.2017 | Massachusetts Institute of Technology

nachricht Biofuel produced by microalgae
28.02.2017 | Tokyo Institute of Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

New technology offers fast peptide synthesis

28.02.2017 | Life Sciences

WSU research advances energy savings for oil, gas industries

28.02.2017 | Power and Electrical Engineering

Who can find the fish that makes the best sound?

28.02.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>