Cloning is cloned again: New Nature Paper is 3rd on Human SCNT
by Knoepfler Lab Stem Cell Blog
A new human therapeutic cloning paper is out today (2011), the third in a matter of months. This one is from the lab group of Dr. Dieter Egli published in Nature demonstrating production of nuclear transfer embryonic stem cells (NT-ESCs) from an adult human somatic donor via somatic cell nuclear transfer (SCNT).
This human SCNT paper follows on the heels of a similar paper (Chung, et al.) from Bob Lanza’s group published in Cell Stem Cell and the pioneering Mitalipov human SCNT paper (Tachibani, et al.) in Cell in 2013.
Together these three papers have proven that human therapeutic cloning to make patient-specific ES cells is absolutely the real deal and that it presents a new therapeutic option based on stem cells in the years and decades to come.
This Egli group paper, Yamada, et al., is entitled “Human oocytes reprogram adult somatic nuclei of a type 1 diabetic to diploid pluripotent stem cells”.
So what’s the scoop on this new Yamada human SCNT paper?
The main conclusions fit with those of the previous Tachibani and Chung papers. Oddly enough, one of the most important sets of data is tucked away as Extended Data Figure 8 (see above) that nicely summarizes the paper’s data.
There are some additional technical data that may prove useful for additional labs to make NT-ESCs by therapeutic cloning of human somatic cells such as surprisingly the inclusion of fetal bovine serum (FBS; see the figure above, the far right two columns showing that addition of FBS seems to really boost the process of making NT-ESC lines. This team also made NT-ESC from a Type I Diabetic patient highlighting the future clinical potential of this technology.
What about the bigger picture?
As I mentioned in a previous post providing broader perspectives on translating human NT-ESCs to the clinic there are some key challenges and I list the top 5 hurdles. I called human therapeutic cloning to make NT-ESCs the stem cell story of the year for 2013.
It’s still a very big deal in 2014. The two new 2014 human SCNT papers just raise the intensity of this story to another level. It will be a fascinating story to continue to follow.
[Note: In case you didn’t manage to “get it” in the amazing tangle of deceptive descriptive terms used in this article about HUMAN cloning, this “new” SCNT cloning technique for the purpose of making “embryonic stem cells” (1) FIRST makes a human embryo, which constitutes human embryo research. (2) It THEN allows the cloned embryo to develop to the blastocyst stage, THEN removes the stem cells thus killing the embryo. There is nothing “therapeutic” there FOR THE EMBRYO who is cloned!
What about the PATIENTS they want to use these “stem cells” for “therapy” for?? Wonder if these guys remember that such stem cells could not possibly produce “patient specific” stem cells for “therapy”. (1) The human genome is defined as all the DNA in a cell -- both nuclear and mitochondrial. In SCNT, only the nuclear DNA of the patient’s cell is transferred, therefore the cloned embryo and its stem cells will not include the mitochondrial DNA of the patient. (2) The cloned embryo will also still contain the mitochondrial DNA from the enucleated egg, DNA that was NOT in the original patient’s cell = foreign genes. (3) Various transcription factors and vectors (viruses or bacteria) are required during the process = more foreign genes. (4) Thus the resulting cloned embryo (and his/her stem cells) are genetically unique, never having existed before. (5) All these foreign genes will be seen as “not-self” by the original patient’s immune system which will cause a serious debilitating if not deadly immune rejection reaction in the patient. What’s so great about that?
The same thing goes for the “sister” nuclear transfer technique: germ line cell nuclear transfer (GLCNT), since the early germ cells are also diploid and thus can be cloned. Someone needs to clue these researchers in before they get sued for negligence, malpractice, manslaughter, wrongful death and other torts, etc. Say, who’s funding this research anyway??
See this chart, from Tachibana et al using the same technique, both kinds of cloning result in a living embryo. The foreign DNA from the mitochondria in the egg are NOT MARKED. Once the “egg with somatic nucleus” is activated by shock, you get an EMBRYO (NOT MARKDED!): http://www.ipscell.com/2013/05/cloning/. The article first appeared here. - DNI