Tuesday, November 20, 2007

Induced Pluripotent stem cell lines

It is amazing to see how the Catholic Church and George Bush can hold us all in thrall regarding human embryonic stem cell research. Because of the opposition to deriving stem cells from human embryos which destroys the embryo, eminent scientists are now reduced to attempting to find stem cell alternatives and have done so - by creating induced pluripotent stem cell lines derived from human somatic cells, an advance (?) which is being heralded today in the NY Times. In other words, we can regress human skin cells to an embryonic state by introducing retroviruses including c-Myc (cancer cells) to do so. The only problem with this is that it also creates tertomas which are nasty little creatures - effectively a germ cell tumor which may contain hair, teeth, bones, eyeballs, torsos and hands. Yuk, as Leon Kass would say. Here's an idea: instead of trying to create human embryonic stem cells from someone's nose or foreskin, let us do the research on embryos as nature intended.


SabrinaW said...

PZ Myers at Pharyngula has some good points about what the actual ramifications of this research are, and also highlights the reality that without ESC research, this would not have been even possible. Also, the stem cells produced have had so many internal regulation mechanisms disabled that there is a high chance of any recipient of these developing cancer.

In short, all is not decided, and the biggest potential from this may just be that we can conduct more research without as many roadblocks and with more direction, not that we could derive cures or treatments from this procedure.

Terry Tomsick said...

Thank you Sabrina for your excellent comments. I urge our readers to check out PZ Myers' site at http://scienceblogs.com/pharyngula/2007/11/stem_cell_breakthrough.php.

LifeEthics.org said...

Most of the basic research was done in mice - look at the history of Yamanaka & Takahashi's research.

You're way off on the teratomas: the *ability* to form teratomas in immune-deficient mice is one of the tests necessary if a researcher wants to prove that the cells are embryonic-like or pluripotent stem cells. (As opposed to multipotent - the fact that his cells did not was a criticism of Atala's amniotic stem cell work.)

Embryonic stem cells have always had all the problems that you mention - including the retrovirus manipulation in many cases - look up "first transplantable lung cells" from the Houston, Texas Stem cell researchers - in addition to the ethical problem of requiring the destruction of human embryos and the necessity to consider buying or bartering for oocytes.

Embryonic stem cells have the same concerns about reliably directing the cells toward the desired cell line, about the lack of regulation inherent in the primitive cells in culture, and ensuring that a more primitive cell - a future tumor - was not transplanted with the derived, less plastic cells.

One advantage that the new process offers that has never been achieved before, is the ability to make patient specific cells - not just for a few elite who could afford to buy the oocytes, but for everyone.

The viruses used are strongly suppressed in the culture conditions used to direct development and are well known - the research to remove them from the DNA is not predicted to be all that hard.

In the meantime, Yamanaka and Thomson are getting ready to patent and sell their cell lines for drug research and basic science, as well as the anticipated transplants.

bmmg39 said...

I'm not sure why you think one needs to be Catholic or Republican in order to have an ethical qualm with destroying human beings (as, scientifically, we know human embryos are) for medical research. Adult stem cells are already doing for human patients what the more unstable, less controllable embryonic stem cells have thus far proven incapable of doing -- but, hey, if what you want is embryonic cells, these embryonic-like cells will do just fine.