Therapeutic cloning, growing nerves and reprogramming cells: Stem cell stories that caught our eye

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.

A modest advance in therapeutic cloning. This week a Korean team announced that they had used the same techniques used by an Oregon team just about a year ago to create the first embryonic stem cell lines by a process known as Somatic Cell Nuclear Transfer (SCNT) that is commonly called therapeutic cloning. The process requires putting the nucleus of an adult cell into a donor egg and tricking the egg into thinking it was fertilized so that it begins to divide. The main advance in the current announcement deals with the age of the donor cells. The Oregon team took the nucleus from cells from a small skin sample of newborns, but the Korean team used much older donors, one as old as 75. Since our the genetic material in the nucleus of our cells is known to become less robust and amenable to change as we age, getting the procedure to work with older donors is important for true therapeutic cloning where the goal is creating stem cell lines that can give rise to repair tissues that genetically match the patient.

Much of the coverage was a bit overwrought about the degree of this advance and some of it predictably raised the specter of full human cloning, which no one envisions. Forbes did a nice piece putting the cloning issue in perspective and Reuters’ wire story used a good quote from Harvard’s George Daley placing the work in perspective with prior research. We wrote about some of the controversy created by the original Oregon cloning research last year.

Lab-grown esophagus long way from clinic. A paper in the journal Nature Communication about growing an esophagus in the lab for a rat patient got a good deal of pick up in the media this week—probably more than it deserved. This may have been in part because the main researcher was Paolo Machiarini who has received considerable press for his prior work creating replacement trachea for human patients. But being a simple airway, the trachea is considerably easier to mimic than the esophagus that has to deal with a regular barrage of food of many textures. Also the rat esophagus in this study is much smaller than a human replacement would need to be, and the report only involved three rats, so the entire study should be viewed as very preliminary. The Huffington Post did a better job than most outlets in putting the work in perspective.

Could Silly Putty be good for your brain? It is amazing how a reference to a toy from our childhood increases the press attention to some pretty serious science. We have often written about the importance of paying attention to the neighborhood a stem cell grows in if you want it to mature into the type of tissue you want. A team at the University of Michigan found that embryonic stem cells much more readily become the type of nerves that control our muscles if they are grown on threads from one of the key components of Silly Putty. Since maturing stem cells into specific tissues remains the end goal of much of our field, this is important work and was published in the prestigious journal Nature Materials. But it might not have seen the light of day in the popular press without that Silly Putty. Kudos to the writer at U of M. Red Orbit did one nice piece on the work and the site The Doctor Will See You Now did another.

Great update on reprogramming cells. For serious science wonks who want to catch up on some of the absolute latest science on cell reprogramming Nature posted a blog from a conference CIRM sponsored with the Keystone group just last week. It covers disease modeling, getting stem cells in a dish to mimic the older cells seen in diseases of aging, and many more topics.

Don Gibbons