Stanford has accepted a $12 million dollar anonymous donation to form an institute to study stem cells and cancer cells. Some of that money will be used to clone a human embryo to use as a source of embryonic stem cells.
Stanford University announced Tuesday its intention to clone human embryos, becoming the first U.S. university to publicly embrace the politically charged procedure. The intent of the project is to produce stem cells for medical research.
This private donation demonstrates that nothing short of an outright ban on cloning and on ESC work will stop this kind of work from going forward. Enough governments are either outright supporting this kind of work (eg the UK) or legalizing it while not providing much public funding (eg the USA) that the work is going to go forward.
Cloning is done by taking the nucleus of an adult human cell (typically a skin fibroblast cell) and transferring it into an unfertilized human egg. The success rate for doing this is low enough that it is likely that several attempts will be required before a viable embryonic stem cell line can be made.
The big mystery in cloning is just what happens when the adult nucleus is placed in an unfertilized egg. There must be chemicals and proteins in the cytoplasm of an unfertilized egg that cause a nucleus to revert to an earlier stage of development. If that process of reversion (called de-differentiation) could be better understood then eventually it should become possible to transfer adult differentiated cells into adult stem cells and into other cell types.
"Stanford University is not cloning human embryos," the university declared in a statement Tuesday night, after some confusion arose earlier in the day about its intentions for the new institute.
Stem cells are the precursors of the various cell types that make up all the organs of the body, and, like cancer cells, are marked by a seemingly limitless capacity to proliferate. Controversy arises because the embryos must be destroyed to produce a new line of stem cells.
They want to do it if they think they won't be stopped by political pressure.
Later the university put out a second news release - which one faculty member called ambiguous - and held a press conference to clarify its position. Two faculty members, speaking on condition of anonymity, said they believed the university was hoping to avoid controversy, but probably did not wish to completely foreclose the option of expanding into cloning research.
“We’re not cloning embryos, and we’re not going to clone embryos,” said Stanford spokeswoman Ruthann Richter.
However, at a news conference at Stanford later in the evening, scientists acknowledged that embryos maybe produced by cloning at some time.
“The state of California has said nuclear transfer [the scientific term for cloning] is an acceptable and legal technology and in fact will be supported and funded by the state,” said Paul Berg, a Stanford Nobel laureate. “Cloning is not a nasty word.”
By "Cloning embryos" Richter means that they are not going to do reproductive cloning to create babies that are genetically identical to the DNA donors. But, yes, they really do intend to do cloning to create human embryonic stem cell lines (hESC) for research to develop medical therapies. This is often called therapeutic cloning (at least its called that by the people who are in favor of it). Some religious people see therapeutic cloning as even more morally objectionable than reproductive cloning because the therapeutic clone could in theory become a full human but is prevented from doing so because its never implanted into a womb. Instead its cells are used to do experiments or to grow organs or to inject into a person to replenish cells in the same way that adult stem cells do. To some (though by no means all) religious folks this is seen as murder.
The political battle over this issue will continue to limit the amount of funding available in the USA for doing hESC research. I do not expect to see any increase in federal hESC research funding for years to come. Its also not inconceiveable that additional legislative restrictions could be enacted in the USA. Therefore we can only hope that the scientists who are working with adult stem cells and on general problems of how cells differentiate will find other ways to create therapies that will do the same things that hESC researchers are trying to accomplish.
I am still very optimistic about the future use of stem cells to grow replacement organs, to send in cells to reseed stem cell reservoirs (which will eventually be a widely used aging reversal therapy), and for other therapeutic purposes. A lot of hESC research is being done in other countries, some hESC research is being done in the USA with private money, and also non-human ESC research will still be done in the USA. Much of how ESC operate and differentiate can be worked out in mice and so various important questions in developmental biology will still be worked out. Plus, adult stem cell research does not face the political obstacles that hESC faces.
If ways can be found to de-differentiate adult stem cells and also even to de-differentiate fully differentiated cells (which is what cloning does - but we don't understand exactly how cloning does it) then there will no longer be a need to use human eggs for cloning or use embryo cells left over from IVF. Given that the political climate is not going to improve any time soon it seems to me that scientists should lobby for a very big increase in funding on research into de-differentiation. Lets figure out how to "program around" the problem by learning how to signal the genome in an adult differentiated nucleus to become a relatively less differentiated cell. This is what cloning does, albeit in a hit-or-miss way that is somewhat of a black box mystery at this point. There are compounds in an unfertilized egg's cytoplasm that have the effect on an implanted adult nucleus of making it become less differentiated. We need to discover what those compounds are and how to manipulate their delivery into cells.
Of course, if how to do de-differentiation becomes well enough understood that it becomes possible to make an adult differentiated cell to turn into an embryo cell then religious folks will raise objections to the creation of such cells just as they object to the creation of embryonic cell lines by other means. But lets get legalistic here: if we achieve enough control over the de-differentiation process to be able to stop one step short of creating true embryonic cells we will have cells that are sufficiently undifferentiated as a starting point for therapeutic purposes. Yet strictly speaking we will not have cells that are embryonic.
|Share |||Randall Parker, 2002 December 10 06:08 PM Bioethics Stem Cells|