“Latest Stem Cells News”

The metabolic state of glioma stem cells, which give rise to deadly glioblastomas, is significantly different from that of the brain cancer cells to which they give birth, a factor which helps those stem cells avoid treatment and cause recurrence later.

Researchers with the UCLA Department of Radiation Oncology at UCLA’s Jonsson Comprehensive Cancer Center also found for the first time that these glioma stem cells can change their metabolic state at will, from glycolysis, which uses glucose, to oxidative phosphorylation, which uses oxygen.

The glioma stem cells’ ability to change their metabolic state at will also allow these stem cells that seed new cancer growth to evade treatment and remain alive, said Dr. Frank Pajonk, an associate professor of radiation oncology and senior author of the study.

“We found these cancer stem cells are substantially different in their metabolic states than the differentiated cancer cells they create, and since they act differently, they can’t be killed in the same way,” Pajonk said. “And as yet, we don’t have anything to target these glioma stem cells specifically.”

The study is published this week in the early online edition of the peer-reviewed journal Proceedings of the National Academy of Sciences.

Cancer cells take up large amounts of glucose, which fuels their grow and spread, and allows them to be differentiated from normal cells under Positron Emission Tomography (PET) scanning, which captures metabolic activity. Pajonk and his team found that the glioma stem cells took up much less glucose, which makes them difficult to detect with PET.

Targeting cancer metabolic pathways as a treatment has gained new interest in recent years. However, these cancer stem cells that take up less glucose could evade those treatments by utilizing glucose more efficiently through oxidative phosphorylation, which would not be targeted by such drugs.

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A research breakthrough has proven that it is possible to reprogram mature cells from human skin directly into brain cells, without passing through the stem cell stage. The unexpectedly simple technique involves activating three genes in the skin cells; genes which are already known to be active in the formation of brain cells at the foetal stage.

The new technique avoids many of the ethical dilemmas that stem cell research has faced.

For the first time, a research group at Lund University in Sweden has succeeded in creating specific types of nerve cells from human skin. By reprogramming connective tissue cells, called fibroblasts, directly into nerve cells, a new field has been opened up with the potential to take research on cell transplants to the next level. The discovery represents a fundamental change in the view of the function and capacity of mature cells. By taking mature cells as their starting point instead of stem cells, the Lund researchers also avoid the ethical issues linked to research on embryonic stem cells.

Head of the research group Malin Parmar was surprised at how receptive the fibroblasts were to new instructions.

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Scientists at the University of California have found a potential new use for human embryonic stem cells: helping cancer patients recover the cognitive function lost when their brains are treated with radiation.

People with tumors in their head or neck often undergo radiation therapy after the cancer is surgically removed. Radiation helps kill malignant cells left behind. But it also can debilitate the hippocampus, the brain region responsible for learning, memory and processing of spatial information.

The researchers wondered whether embryonic stem cells could pick up the slack.

So they radiated the heads of 18 rats. Two days later, six of those rats got two injections of human embryonic stem cells directly into the hippocampus. After four months, the researchers measured the rats’ cognitive abilities. They placed the rats in an arena with two Lego blocks and let them explore. When they were done, the researchers took the rats out of the arena and moved one block. Five minutes later, the rats went back in.

All of the animals studied both of the blocks, but the rats that were treated with stem cells spent far more time nosing around the one that had been moved. And the radiated rats that didn’t get stem cells lost half of their cognitive function, according to the study, published in the Proceedings of the National Academy of Sciences.

The results suggest that embryonic stem cells could spare cancer patients much of the short-term memory loss from cranial radiation.

from http://www.chicagotribune.com/news/chi-tc-nw-stem-cells-1113-1114nov16,0,4526555.story

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Everyone knows about the potential of stem cells in the medical field, but until today, no one had found a way to recognize them in an organ or tissue. Thanks to a new study published in the ‘Proceedings of the National Academy of Sciences’ by 2007 Nobel Prize winner for Medicine, Mario Capecchi and researcher at Cattolica University in Rome, Eugenio Sangiorgi, this obstacle has been overcome. Experts have found a new technique to find stem cells hidden in the pancreas.

“Although the journals talk a lot about this topic,” said Sangiorgi, who has collaborated with Capecchi for years, “in reality, we experts don’t understand them very well. For example, we don’t have a method to distinguish between a stem cell and another cell a priori in the same tissue. By observing the cell’s behavior we can then figure it out.”
In other words, when a researcher observes a particular tissue, it is not immediately possible to identify the cell with certainty and isolate it.
In some cases, like in the pancreas, until a few years ago, it was doubted if these cells were even present in the organ.

“Together with Professor Capecchi,” continued Sangiorgi, “some time ago we created a method to mark stem cells in tissues. A sort of little flag that could help us label the cells that we were looking for.” To arrive at this conclusion, they used a portion of DNA, which in an animal model, is activated with the use of a drug. Once the marker is ‘turned on’, a special fluorescent protein is produced (which won its discoverers, Osamui Shimomura, Martin Chalfie, and Roger Tsien, the Nobel Prize for Chemistry in 2008) and is able to illuminate the stem cells. “To understand if they were actually stem cells,” continued Sangiorgi, “we just had to wait: a normal cell will die sooner or later, while a stem cell maintains its capacity to divide and replicate.”
In the new article, Sangiorgi and Capecchi demonstrated with their new technique that certain cells located in the pancreas, called acinar cells, are stem cells in reality. These cells are responsible for the production of an important digestive enzyme.

This is an interesting discovery from another point of view: “In general,” said Sangiorgi, “it was thought that stem cells were cells without a precise function, and that they were undifferentiated and had no set objectives other than tissue regeneration. Instead we have learned that acinar cells, although they are stem cells, have a precise role in the pancreas. They are like soldiers who perform their job normally for the army, but if they are needed they are also available to work for the government too.”

This work has paved the way for new studies on stem cells including their potential risks: “Thanks to their extraordinary reproductive power, they can even become carcinogenic. But if we manage to discover a way to isolate and study them in other organs, we will be able to analyze their properties in-depth and provide many responses on how they function.”

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Piero Anversa

Piero Anversa, Italian scientist and director of regenerative medicine at the Brigham and Women’s Hospital of Harvard University in Boston is ready to perform the first biological by-pass in history. This evening in Milan during a meeting called ‘Futuro della Sanita’ (The Future of Health), Anversa explained that he has identified human coronary stem cells able to develop into coronary artery tissue.

He said, “My dream is for someone to have a heart attack, come to the hospital, and return home healthy.” For that to occur, it will be necessary to reproduce muscle and the large coronary vessels. He continued, “If we are able to accomplish this, it would change everything. Medicine that used to repair something that was damaged would become preventative. This will allow us to prevent cardiac deficiency.”

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Stem cells from the brain could be transplanted into the ear to cure hearing loss.
Often, age and overstimulation can damage ciliated cells that act like small microphones, allowing us to hear sounds, noise, and voices and are located in the deep ear (cochlea). About 10% of people experience damage to the cells in this area which leads to hearing loss. The loss of these cells is irreversible, but according to the Proceedings of the National Academy of Sciences (PNAS), a group of scientists from the University of California substituted them with stem cells taken from another area in the brain.

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