Thanksgiving is this week and there is plenty to be thankful for. A great house, a great family, new Radiohead music, etc. But I wanted to take a minute and recognize a potential scientific breakthrough that we could all be very thankful for if it pans out.
This week, CNN and many other news sites reported a breakthrough in the area of stem cell research: the ability to reprogram normal adult cells to become “stem cell-like” again. This finding is hugely significant because this technique could replace the current one which requires fertilized human egg cells. This older technique is viewed by many (myself included) as unethical since it destroys a human embryo by harvesting its stem cells. This practice was even viewed as unethical by the Bush administration and a ban on federal funds for its practice was instituted. Of course, this doesn’t mean labs all over the country weren’t doing it, they just weren’t doing it on the tax-payers dime.
Just to break it down for you, the “older” method for stem cell research was to obtain a fertilized human egg and remove the nucleus from it. The nucleus was then replaced with the nucleus from an adult cell. This could be thought of as a cloned human embryo. The embryo would them begin to proliferate and stem cells would develop. These cells are the ones that could become any cell in the body depending on how their DNA is expressed. It is thought that through these cells, scientists could grow out whatever types of cells they want and use them to treat diseases by replacing malfunctioning cells with brand new ones grown from the patient’s own tissues. All of that is still very speculative, but within the realm of reason. Obviously, however, those of us who believe that human life begins at conception are opposed to the systematic destruction of human embryos for scientific experimentation.
Today I had the opportunity to read one of the two scientific papers published this week claiming to have found a way around the ethical dilemma of the old method. The researchers have found a way to cause adult human cells to behave as though they were embryonic stem cells. What’s more, they claim the technique is actually much simpler and cheaper than the old nuclear transfer method. They take four specific transcription factors and place them into adult cells via a retrovirus. The transcription factors are then expressed in the cell and this expression leads to the cells becoming pluripotent (meaning the cells have the potential to become a variety of tissues). In fact, the researchers state that the cells are very difficult to distinguish from the standard embryonic stem cells. If true, this is amazing.
As expected, however, there is a catch. Because these new induced pluripotent stem cells (iPS cells) are produced using retroviruses, it is difficult to control the level to which the transcription factors are integrated into the adult cells DNA. The paper states that each clone had more than 20 integration sites, which means 20 copies of the factors were spliced into the DNA. This could cause the cell to become cancerous, indeed ~20% of the mouse cells experimented on developed into tumors. Not good.
Furthermore, the efficiency of this technique is still not good. The paper states that for every 5 x 104 adult cells they induced, only about 10 actually grew into colonies of iPS cells. A very low efficiency.
So my point is that while this research is definitely promising, I always worry when the media picks this stuff up and runs with it. Judging from CNN’s headline, you’d think that the research is flawless and that human uses are ready to go. That all the problems are solved. Far from it. However, this shows that the field is advancing faster than anyone thought possible. Perhaps we really are only a few years away from ethical stem cell treatments of diseases like Parkinson’s. In any case, we can be thankful this holiday weekend that God has given us a propensity to want to discover new things and probe further into the intricacies of His creation.