Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.
First clinical trial with reprogrammed stem cells. Today, a Japanese woman became the first patient to be treated with cells derived from reprogrammed iPS-type stem cells. The patient received cells matured into a type of cell damaged in the most common form of blindness, age-related macular degeneration.
Those cells, a normal part of the eye’s retina, were made from stem cells created from a skin sample donated by the patient several months ago. In the intervening time the resulting retinal cells have been tested in mice and monkeys to make sure they will not cause tumors. Because the cells have the same genes as the patient, researchers believe they may not be rejected by the patient’s immune system in the absence of immune suppressive drugs—the beauty of iPS technology.
Right now, that technology is much too cumbersome and time consuming to result in a broadly applicable therapy. But if this first clinical trial proves the immune system get-out-of-jail-free theory, it should intensify efforts to make iPS technology more efficient.
Cancer cells don’t handle their sugar well. Sugar has a bad rep these days. Now, it looks like manipulating sugar metabolism might lead to ways to better treat leukemia and perhaps, make therapies less toxic to normal cells. It turns out cancer cells are much more sensitive to changes in sugar level than normal blood stem cells or the intermediate cells that give rise the various branches of the blood system.A team led by old friend and colleague at the Harvard Stem Cell Institute, David Scadden, first looked at sugar metabolism in normal blood forming stem cells and their intermediate cells. They found that the parent stem cell and their direct offspring, those intermediate cells, behave differently when faced with various manipulations in sugar level, which makes sense since the intermediate cells are usually much more actively dividing.
But when they manipulated the genes of both types of cells to make them turn cancerous, the cancer cells from both were much more sensitive to changes in sugar metabolism. In a university press release picked up by ScienceCodex David said he hoped to interest drug companies in developing ways to exploit these differences to create better therapies.
Magnets and nanoparticles steer stem cells. Getting stem cells to where they are needed to make a repair, and keeping them there is a major challenge. A team at Los Angeles’ Cedars-Sinai hospital that we fund (but not for this study) has taken an approach to this problem that is the equivalent of holding your pants up with a double set of button, a belt and suspenders.
Treating damaged hearts in rats they first loaded iron-containing nanoparticles with two types of antibodies, one that recognizes and homes to injured heart tissue and one that attracts healing stem cells. After infusing them into the animal’s blood stream, they placed a magnet over its heart to hold the iron nanoparticles near by. The iron provided the added benefit of letting the team track the cells via magnetic resonance imaging (MRI) to verify they did get to and stay where they were needed.
In a press release from the hospital picked up by ScienceDaily the lead researcher Eduardo Marban said:
“The result is a kind of molecular matchmaking,”
The study was published in Nature Communications and you can read about other work we fund in Marban’s lab trying to figure out once you get the stem cells to the heart exactly how do they create the repair.
Reprogrammed stem cells turned into white blood cells. We have written often about the difficulties of getting stem cells to create fully mature blood cells. Last week we talked about a Wisconsin team breaking the barrier for red blood cells. Now, a team at the Salk Institute is reporting success for white blood cells.
Starting with iPS-type stem cells they got the mature white cells via a two-step process. First they manipulated one gene called Sox2 to get the stem cells to become the right intermediate cells. Then they used a gene-regulating molecule called a micro-RNA to get the middleman cells to mature into white blood cells.
In a press release from the Salk, lead researcher Juan Carlos Izpisua Belmonte noted the clinical importance of the work:
“In terms of potential clinical applications, the hematopoietic system represents one of the most suitable tissues for stem cell-based therapies. . .”
The team published the research in the journal Stem Cells and the web portal BioSpace picked up the release.
Book on early spinal cord injury clinical trial. The title of a book on the first ever clinical trial using cells from embryonic stem cells kind of says it all: Inevitable Collision: The Inspiring Story that Brought Stem Cell Research to Conservative America.
The book details the personal stories of the first and fifth patients in the spinal cord injury trial conducted by Geron. That company made the financial decision to end its stem cell product development in favor of its cancer products. But the spinal cord injury trial is now set to restart, modified to treat neck injuries instead of back injuries and at higher doses, through CIRM funding to the company that bought the Geron stem cell business, Asterias.
In a press release from the publisher, the book’s author explained her goal:
“Through this book I hope to bridge the gap between science and religion and raise awareness of the importance and power of stem cell research.”
The fifth patient in the Geron study, Katie Sharify, is featured in our “Stories of Hope” that have filled The Stem Cellar this week.