Stem Cell Research - The Whys and Wherefores
the Democratic National Convention, Ron Regan, Jr., made a speech
pleading the cause of human stem cell research. He said, "There
are those who would stand in the way of this remarkable future,
who would deny the federal funding so crucial to basic research.
They argue that interfering with the development of even the earliest-stage
embryo, even one that will never be implanted in a womb and will
never develop into an actual fetus, is tantamount to murder."
He went on to say "Éit does not follow that the theology
of a few should be allowed to forestall the health and well-being
of the many. And how can we affirm life if we abandon those whose
own lives are so desperately at risk." What he was referring
to was the politicizing of the science by the present Administration,
which has purloined the issue to use as fuel to fire its obsessive
opposition to abortion.
Stem cell research has become polemic, and as a result, much needed
funding has been slow in coming to shore up its very promising
future. This is not to say that the science would have progressed
sufficiently in time to save Ron Regan, Jr's father (the former
president, Ronald Regan), from the ravages of Alzheimer's, but
it may have. That it came too late is in no doubt, but there are
some extremely encouraging signs to indicate that stem cells may
eventually be able to repair brain cells damaged by diseases such
as Alzheimer's and Parkinson's. And much, much more.
in order to provide you with the necessary information to participate
in the ongoing debate, let us start from the beginning, by examining
both what stem cells are and what they can do.
Cells are unlike any other kind of cell in the body, in that they
have the potential to become any one of many different cell types
and act as a means of repairing damaged organs and tissues. They
have three main characteristics:
They can divide and renew themselves over long periods of time,
perhaps even indefinitely (as long as the person is alive).
They are "unspecialized" (called undifferentiated) cells
i.e. they do not start out as muscle, nerve, heart, etc., they
are just 'blank'.
They can become specialized (differentiated) cells, e.g. heart,
lung, nerve, etc.
are distinct types of stem cells; these are embryonic stem cells
and adult stem cells. The stem cells can be further differentiated
into embryonic germ cells and fetal stem cells. There are also umbilical
cord blood stem cells, and placental stem cells. Of these several
kinds of stem cells, the most versatile are those that only exist
for the first few divisions following fertilization, and contain
all the genetic information necessary to create every cell in the
human body, including the placenta; these are called totipotent
cells. In as few as three to four more cell divisions, the cells
then become known as pluripotent, and although still very versatile
they can no longer become placental cells. The next phase is known
as multipotent, which means that while the cells can still become
several other cell types, they are now somewhat limited in number.
A good example of a multipotent cell would be a hematopoietic cell,
in other words a blood stem cell that can become a different type
of blood cells (red corpuscles, platelets, etc), but would be unable
to develop into muscle cells. The final stage would be when the
cells have become differentiated, and have thus become committed
to being something specific.
Although the science has come a long way, since University of Wisconsin-Madison
biologist, James Thompson, writing in the journal 'Science', reported
the first ever isolation of human embryonic stem cells, back in
November of 1998, scientists are still struggling to force cell
differentiation. Because stem cells do not spontaneously differentiate
into any one of the 220 different cells types, researchers rely
on three basic techniques, influenced by two specific factors: external
Chemicals secreted by other differentiated cells affect
the molecules in the microenvironment (culture), providing the
essential nutrients to promote differentiation
Physical proximity with already differentiated cells, i.e. pluripotent
allowed to clump together form "embryoid bodies" and
can become, for example, nerve or tissue cells.
By inserting specific genes to direct differentiation
have probably heard mention of stem cell lines, but not known what
they are: Essentially, cells are taken (or harvested) from four
to seven day old embryos, when it comprises no more than about 100
cells altogether. The scientist will take cells from the inner most
part of the embryo and place them in a culture dish, with nutrients
specifically designed to promote cell growth. A cell line is established
when healthy cells continue to grow and multiply, without differentiating.
As they continue this process, and each culture dish becomes full,
cells are transferred into yet more culture dishes. The original
thirty or so cells can yield millions - these are the lines.
stem cells have caused considerable controversy, because they are
harvested from embryos, developed mostly from human eggs fertilized
in vitro (in other words in a test tube), but which are destroyed
as a consequence. They are NEVER implanted in any woman's womb,
which goes a long way toward negating the abortion/pro-life debate.
When George W. Bush took office, in January of 2001, his opposition
to stem cell research was already well documented. He was so opposed
to it that in the February of the same year he put all Federal funding
of stem cell research on hold. However, on August 9, 2001, in a
political move designed to appease growing opposition to the moratorium,
and even some of his own colleagues, Bush announced that he would
permit funding but only for 60 embryonic stem cell lines, all of
which had existed before he came into office; some lines had been
around for upwards of twenty-five years. And while some of the older
lines had come from aborted or spontaneously aborted fetuses, even
Washington D.C.'s Catholic Georgetown University is using them in
research, with the tacit blessing of the Church, which understands
that the original fetuses were not aborted for research purposes,
and also because the ultimate goal of the new science is to benefit
mankind. Evidence of this Administration's "moral" aversion
to embryonic stem cell research can be found in the disparate levels
of the funding since it voiced its displeasure: $10 million versus
the $170 million given to adult stem cell research.
distinct advantages of embryonic stem cells are that there is an
almost limitless supply, and they are extremely easy to grow in
culture. The biggest downside being that of the potential for a
body rejecting the newly transplanted cells.
stem cells are far fewer in number and considerably harder to isolate;
largely because they are only found among already differentiated
cells throughout the body. An enormous number of adult stem cells
are needed for replacement therapies. However, they also show considerable
promise for cell-based therapies, because once harvested from the
host body, grown then reintroduced, they do not pose the same threat
of rejection that embryonic stem cells do.
STEM CELL THERAPIES - NOW & THE FUTURE:
of their ability to become so many different cell types, stem cells
provide limitless potential to treat a myriad of diseases: from
organ regeneration to immune system reconstruction. Currently, leukemia
patients account for some 75% of the stem cell transplants facilitated
by the National Marrow Donor Program (NMDP), but there are also
many other diseases that are and will be treatable using the science.
Of potential successes, Type 1 Diabetes may soon be curable by pancreatic
islet cells recreated to provide insulin, and paraplegics may have
their injured spinal cord cells replaced, enabling them to walk
again. Heart attack victims may regenerate damaged tissue, and once
again hear their hearts beat strongly. It is possibly a Brave New
World, but stem cell research could well prove to be as truly Earth
changing as was the discovery of penicillin, if not more so. All
we need now is enough funding to keep the dream alive, and perhaps
sooner, rather than later, we will begin to see near miraculous
cures to otherwise incurable diseases.
more information, I would suggest you visit the following sites:
NIH Stem Cell Information Website
Stem Cell Research Foundation
Debate - CNN.com
Treatable by Stem Cell transplant
Clinic's Overview of Stem Cell Research & Treatments:
Cord Blood Stem Cells Information:
a really good graphic presentation of stem cell line formation: