The first human trials for the treatment of blindness using induced
pluripotent stem cells has brought the hope of creating stem cell
therapies that do not rely upon destroyed embryos back in the public
eye.
However, moral and medical questions surrounding the research on “iPSCs”
have raised questions about whether the process is living up to its
hopes of providing an innovative advance in biotechnology without
relying on the destruction of embryos.
“Morally, there is no doubt that iPSC technology is a huge improvement
over destroying IVF embryos or cloning embryos to gain pluripotent stem
cells,” Rebecca H. Taylor, a clinical lab specialist in molecular
biology and author of the Catholic bioethics website “Mary Meets Dolly,”
told CNA, “but they are not totally free from ethical issues.”
Taylor pointed to the widespread use of some “morally tainted” cell
lines – that is, cells taken from aborted human beings – in various
branches of scientific research, including in the creation of induced
pluripotent stem cells.
The upcoming medical trial, approved by the Japanese government in late
July, will be the first human trials using induced pluripotent stem
cells.
To treat the patients’ macular degeneration, scientists will take cells
from tissue elsewhere in the patients' bodies and introduce genetic
factors that allow the adult cells to become pluripotent stem cells: a
type of cell capable of turning into a wide variety of tissues.
Having converted the cells into stem cells, the scientists will program
the cells to grow new retinal material which can then be transferred
back into the patients' eyes. Since the tissue comes from the patient's
own body, scientists expect that there will be little or no chance of
rejection of the new retina pieces.
The scientists anticipate that this therapy will be able to stop damage
and vision loss caused by macular degeneration, while current drug
therapies can only slow the disease's progress.
The technique used in these human trials differs greatly from other stem
cell techniques used in the past. Unlike adult stem cells, which are
already coded to make only certain kinds of cells, the induced
pluripotent cells can be harvested from a number of tissue sources, and
turned into almost any other kind of tissue in the body.
The only other kind of tissue with such diverse potential is embryonic
stem cells, which have been the subject of research hopes for decades.
Since embryonic stem cells come from “a human organism that is
genetically different” than the subject who will be treated with them,
Taylor explained, they are more likely to be rejected by the subject
than are tissues grown from induced pluripotent stem cells.
“If proven safe to use in patients, iPSC technology may mean
genetically-matched stem cell therapy for a variety of diseases,” she
added.
The creation of induced pluripotent stem cells also offers the hope of a
morally superior means of advancing stem cell research. Embryonic stem
cells have been the subject of controversy for nearly two decades
because the harvesting of embryonic stem cells requires the controlled
creation and subsequent destruction of human life in its earliest
stages.
Since induced pluripotent stem cells offer “patient-specific pluripotent
stem cells without creating and destroying a cloned embryo,” Taylor
said, they offer a “huge improvement over destroying” human embryos for
stem cell research.
However, norms surrounding the way scientists induce a pluripotent state
introduce moral concerns to induced pluripotent stem cell research.
In order to induce a pluripotent state in adult cells, two things must
typically happen: genetic factors must be introduced into the cell, and
the factors must be activated.
However, the current standard processes
to achieve both of these steps involve the use and destruction of human
embryos.
Dr. Mahendra Rao, director of the Center for Regenerative Medicine at
the National Institutes of Health, explained to CNA that “the Yamanaka
protocol is routine” in the medical community.
This process, created by Nobel laureate Shinya Yamanaka, was used as a
means of limiting the creation and destruction of embryos for research.
His technique calls for the growth of factors in a human cell line,
Hek293, and the activation of those factors by a virus in order to
induce a pluripotent state. This process will be used in the Japanese
human trials.
However, the Hek293 cell line was begun with tissue taken from the
kidney of a human person who was aborted in the Netherlands during the
early 1970s.
“The fact that a cell line of illicit origin was used as a tool in this
technique does morally taint the research,” Taylor explained.
She added that this cell line is “ubiquitous in labs all over the
world,” and that it and other “cell lines derived from abortions that
occurred decades ago are common tools in biotechnology.”
Taylor added
that it is so common, that she was “sure many researchers have no idea
where these cell lines originated or that they are morally tainted.”
The use of this cell line and other research derived from aborted
subjects has been addressed by Vatican theologians.
In its 2005 “Moral
Reflections on Vaccines Prepared from Cells Derived from Aborted Human
Foetuses,” the Pontifical Academy for Life noted that even though the
abortions occurred over 40 years ago, “they do not cease to pose ethical
problems.”
They concluded that “vaccines with moral problems pertaining to them may
also be used on a temporary basis” if it is a life-threatening disease
and there are no alternative vaccines.
Otherwise, Catholics and others who wish to respect life at all stages
ought to abstain from their use, as well as further research using that
technique.
The Pontifical Academy for Life emphasized, “there remains a moral duty
to continue to fight and to employ every lawful means in order to make
life difficult for the pharmaceutical industries which act
unscrupulously and unethically,” and encouraged the creation and
investigation of morally sound research alternatives.
In the years since the creation of induced pluripotent stem cells, there
has been the creation of morally sound research alternatives, and new
techniques that do not depend upon the destruction of embryos are in
development.
The genetic factors used in the Yamanaka process can be cultured in
“other cell lines, that were obtained morally,” Taylor clarified.
Brendan Foht, assistant editor of the bioethics journal The New
Atlantis, explained to CNA that “there are other ways of getting those
genes expressed and reprogrammed” that avoid the use of genetic factors
and proteins altogether.
He noted that research has been done on moving past the Yamanaka process
because of the virus’ tendency to mutate cells during the activation of
the genetic factors, thus potentially creating cancers.
In 2008 Yamanaka discovered that pluripotent stem cells could be created
through the introduction of plasmids – a ring of genetic material –
into an adult cell. These rings of genetic code are easily grown in
bacterial cells, and would not rely upon embryo destruction at all.
Scientists are also looking now to replace the use of the genetic
factors with drug-like chemicals, which are created in a lab and do not
depend upon growth in the objectionable embryonic cell line or any other
living cell.
Given the forward steps toward creating ethically-produced induced
pluripotent stem cells, the moral standing of the induced pluripotent
stem cell trial in Japan is thrown into serious doubt.
Pointing to the Vatican’s statements on the use of vaccines relying on
embryo-destructive research and their permissibility only in in
life-threatening cases with no other moral alternatives, Foht suggested
that the Japanese trial is immoral.
Even with the alternatives and breakthroughs present, however, Foht said
pro-life advocates “need to persuade the scientific community to do
ethical research,” and continue to speak against unethical and
objectionable research.
Taylor echoed the need to speak out against induced pluripotent stem cell research that uses embryonic cells.
“We need to make sure that we object to cell lines of illicit origin
whenever we hear of their use in science or medicine,” so that
investigation of moral research will be continued and that “iPSC
technology may soon be free of that particular moral stain.”