There are vast amounts of
information about stem cells and weeding through it all can
be daunting for many of us. This fact sheet provides a clear
overview of some stem cell basics and will allow you to move
on towards further reading in areas that spark your
Unique Properties of Stem
Stem cells have several unique properties that separate them
from other cells:
They are unspecialized
They can proliferate or
self-renew, which means they are capable of replenishing
themselves for long periods of time by dividing.
They can differentiate
into specialized cells such as a nerve or heart cell.
Potency of Stem Cells
A stem cell's potency is a term used to denote its ability
to give rise to other cells in the body. Stem cells can be
separated into several potency categories:
Totipotent stem cells:
they can differentiate into any type of cell in the
human body, including the placenta.
Pluripotent stem cells:
they descend from totipotent stem cells and after
several days, can differentiate into any type of cell
except for totipotent stem cells.
Multipotent stem cells:
these descend from pluripotent stem cells and can
differentiate into many cell lines within a specific
type of tissue.
Unipotent stem cells:
this type of stem cells is a descendant of a multipotent
stem cell and can give rise to a single cell type.
Sources of Stem Cells
Stem cells may be derived from several sources and research
is currently ongoing for therapeutic use of stem cells from
all sources. The isolation and extraction of stem cells
allows them to be categorized as:
Embryonic stem cells:
they are extracted from embryos and are thought to hold
the most potential, because these cells can give rise to
virtually any specialized cell in the human body.
Adult stem cells: these
are present in adult tissues such as the bone marrow,
brain and blood but are limited in potential relative to
embryonic stem cells.
Cord blood stem cells:
this source of stem cells is derived from cord blood and
is thought to hold enormous potential in treating
Benefits of Stem Cells
Stem cells are currently used to treat cancers such as
leukemia. You may be familiar with the concept of bone
marrow transplants, which have been used for decades now to
provide a healthy source of cells in the body. Other
diseases that stem cells may help include:
Spinal cord injuries
Type I diabetes
Why the Ethical Debate?
In a nutshell, the derivation of stem cells from an embryo
is what has prompted such massive debate amongst the public,
politicians, scientists and religious groups. Because an
embryo is destroyed after stem cells are extracted,
opponents argue that this is the equivalent of killing a
potential life. Fortunately, newer techniques are currently
being investigated which will allow for embryonic stem cell
extraction without either destroying an embryo or creating
one with the potential for life. Supporters also argue that
the potential benefits of stem cells outweigh the ethical
It's important to have a basic understanding of stem cells
because they are currently used to treat diseases such as
cancer that may one day affect you or a loved one. The
public also holds some responsibility to challenge
researchers when we see research areas that potentially pose
ethical problems. It is the public who can help to ensure
that stem cell research is transparent and morally
performed. This will allow for everyone to reap the full and
extensive benefits of stem cell research.
(Author: Ian Murnaghan - Explore Stem Cells)