“Latest Stem Cells News”

UW-Milwaukee researcher Andrew Cohen has successfully developed a software program that facilitates predicting the evolution of stem cells. The program essentially speeds up what has been a tedious process for researchers in the past.

The program was published last week in the journal Nature Methods. It applies algorithmic information theory to the growth and movement of stem cells tracked over time to show what type of cells (i.e. brain, skin, etc.) they will eventually develop into.

“People look at images and take measurements by hand,” Cohen explained. “It takes a long time, and using computers makes the process a lot less tedious.”

Stem cells all start out the same before they develop into the different cells of our bodies. Scientists do not know what triggers the stem cell’s future growth pattern into a particular type of cell, but researchers like Cohen are figuring out how to predict the cell’s future based on measurements and math.

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Artificial intestines could be created thanks to stem cells. Intestinal stem cells grown in the laboratory have been manipulated to differentiate in order to produce all of the different types of cells that form intestinal epithelium, said a Dutch study, published in ‘Nature’ magazine by Hans Clevers of the Hubrecht Institute in Utrecht.
The study also outlines a more precise link between stem cells and their microenvironment.

It also offers a practical technique to generate new intestinal epithelium in the laboratory. Stem cells, which express the Lgr5 protein, were discovered on several specific regions of the intestinal epithelium, called crypts.
Clevers and his colleagues describe a long-term method transform single stem cells in culture that express Lgr5 in structures simulating the environment of the organ, which contain all of the different types of differentiated cells present in the intestinal crypts.

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An ‘antenna’ molecule, which is capable of guiding blood stem cells to their natural ‘home’, the bone marrow, has been discovered. The discovery could improve the efficiency of umbilical cord stem cell transplants. This type of transplant is not efficient when there are not many umbilical cord stem cells present, since few of them are able to reach the bone marrow from the blood.
Reported by Nature magazine, the discovery was made by David Scadden of the Harvard Stem Cell Institute in Boston. The stem cells, which normally renew the population of blood cells in the body (red and white blood cells and platelets), are found in the bone marrow, but continuously move throughout blood in circulation, and eventually end up back in the bone marrow.

This is the reason why blood stem cells transplants are never highly efficient. In fact, the injected stem cells are not always able to make it back to the bone marrow, where they need to be present in order to function. These researchers have discovered a guide molecule, a protein called ‘GSA’, which is like an antenna placed on the surface of the cells, which guides them back to the marrow. Researchers have demonstrated in mice that have received stem cell transplants, that with drugs that activate GSA, the injected stem cells easily find their way to the bone marrow and the transplant functions more efficiently.

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Perhaps in the not-too-distant future people who need “to rebuild” their prostate will be able to do so using stem cells removed from prostate tissue. This week Nature magazine reported that a group of Genetech researchers in San Francisco has isolated stem cells extracted from prostate tissue of an adult mouse and used them to generate new prostate cells in the same rat. Wei-Qiang Gao, the coordinator of the study, described the factors that made these cells, which are able to regenerate on a long term basis.

In the same study, researchers reported that they were able to identify a certain number of cell surface markers able to identify the cells that are candidates to become prostate stem cells. These markers seem to function also for other types of stem cells. These markers include CD117, a specific marker used to identify a rare population of adult mouse stem cells that scientists have isolated, and with in vivo transplants, have used them to generate a new prostate. The discovery opens up new prospects for those who have had operations for prostate cancer, since they now may be able to generate a new prostate using their own stem cells.

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Scientists at the FIRC (Italian Foundation for Cancer Research) Institute of Molecular Oncology of the European Institute of Oncology in Milan have revealed how to eliminate cancer stem cells, the true reason for cancer’s incurability. Researchers led by Pier Giuseppe Pelicci, Director of the Department of Experimental Oncology of the European Institute of Oncology, and Professor of general pathology at the University of Milan, have discovered how cancer stem cells become immortal.

The same oncogenes that are responsible for triggering the process of tumor formation, also impede stem cells from growing old, and allow them to maintain their ability to form new tumor tissue. Basically, early cancer ‘mother’ cells replicate slower than other cells giving them time to repair damage making them virtually immortal. This discovery was published in Nature magazine.

“Current drugs”, a note from the oncologists that worked on the project explained, “are directed at later cancer cells, the ‘daughter cell’. This discovery paves the way for a phase of cures aimed at hitting original cancer stem cells or the mother cells”. New drugs with this function are already in the clinical testing phase on human beings: “In the next 5-10 years these drugs could become available for some types of tumors”. The study was performed in collaboration with the University of Milan.

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Andreas Trumpp

Andreas Trumpp and his colleagues from the German Cancer Research Center have recently spoken about a “silent reserve” of stem cells, wondering what type of medical impact the discovery made in Heidelberg of “dormant stem cells” could have.

Usually, dormant bone marrow cells activate and multiply only in a crisis or emergency to react to serious cellular loss due to a virus or hemorrhage. When their work is done, they return to a dormant stage. This withdrawal phase keeps them protected from mutations, cellular toxins, and other dangerous substances, since the cells do not divide and are not subject to modifications or various types of aggressions.

According to the Trumpp group’s discovery, the dormant reserve can even be recruited artificially using alpha interferon proteins, as reported in Nature magazine (10.1038/nature07815).
This is an important result for various reasons. Alpha interferon is the body’s response to viral attacks on cells. Its release can be an intense, sort of SOS for the cell.

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