Stem Cell Research

How’s it coming along these days? Any progress? Do the scientists still have to use embryos
for the cells? I think it’s an important issue and should be vigorously pursued…
Anyone? Doc Mercotian? (sp)

The first thing to realize about stem cells is that there are multiple kinds. What you get from embryos are called totipotent stem cells, which means that they can develop into any kind of cell whatsoever. You can get stem cells from other sources, but they’re all already partially specialized, so cells from any given source can only be used for some purposes. There are some groups that are pushing for techniques to revert specialized stem cells into totipotent cells, but those same groups have also prohibited all research into human cloning, which is the exact same thing.

Actually no. ESC are pleuripotent which means they can develop into any cell in the 3 germ layers and therefore can develop into any cell that the adult or fetus. However they can not develop into extraembryonic tissue such as the placenta which totipotent stem cells can do.

I’m not following how that is exactly like cloning.

The hard part of cloning is getting an adult cell to turn back into something that can develop into all tissues. Once you do that, you’ve basically got the equivalent of a fertilized egg.

Note that there is also research being done on adult stem cells and non-human stem cells. Each angle of approach adds something to our knowledge and capabilities.

As far as I know there has been no “big breakthrough” result from stem cell research, but those in the field feel quite confident significant results will be coming along.

It depends on what you mean. I agree there have been no big breakthroughs yet in the practice of medicine, but there have been huge breathroughs in the basic science. The biggest recently is the ability to create iPSCs (induced pluripotent stem cells). By addition of a few proteins to an adult cell, the cells have been reprogrammed to turn into pluripotent cells. Even more recently, people have been able to retarget adult cells to another tissue type, without going through the intermediate of turning them into stem cells. What is especially exciting is that it wasn’t done by some random luck. There is scientific understanding behind it. We are moving to the time when reprogramming of cells will be just another engineering discipline. This is both exciting and frightening at the same time, but it is certainly a breakthrough, in my opinion.

Some big news that’s failry recnet is that two companies have actually started clinical trials with embryonic stem cells.

Geron -for spinal cord injuries

ACT - for macular degeneration (vision loss due to cell death within a part of the eye)

These are the first 2 actual trials with humans. Now, it’s likely that nothing will come of them (clinical trials have a high failure rate), but there is now a path to follow for other companies using hESC therapies in clinical applications. I was at a talk given by the CEO of Geron where he detailed their development process. It was over $40 million and they submitted 22,000+ pages of supporting documentation, both of which are the largest values ever for a Phase 1 trial. Others will likely be less, since they won’t have to make the same errors and false starts Geron did (the trailblazer with the FDA is always in for a rough ride).

The other approaches are promising, but key issues keep being discovered. With IPS cells (the transformed skin cells), they almost always form tumors. Research is under way to correct this, but it’s a major obstacle. Also, the IPS cells tend to have more genetic anomalies as compared to embryo derived stem cells, including knockouts of tumor suppressing genes.

If Geron and ACT can get through their trials without significant tumorgencity, it’s a major step forward.

Sorry that wasn’t clear, I was referring to the former, something that the general public would know about, understand, and relate to.

Thanks all, for your informative answers…

I also just read an article where a pharm company developed what was essentially skin in a can. Skin stem cells were sprayed on burn victims creating new, healthy layers of skin.


At the beginning of the month, this news story certainly made waves in the general public. Adult stems cells collected from a person’s skin are used to treat second degree burns in a new way, by being “sprayed” on the areas of burn with something much like an airbrush.

Amusingly enough, it created waves in *both *medical circles and technologycircles.

'Though it’s not the embryonic stem cells that have so many panties in a bunch, it’s an example of how even adult (and therefore limited) stem cells do indeed have practical use. Embryonic stem cells, being so much more plastic, can only have even greater practical use.

Pretty dang cool, if you ask me.

I thought the term for full ability is plenipotent. Is this no longer used, being replaced by totipotent and pluripotent? Are all three words synonymous?