Stem Cells and Ethics

Your Assignment for Wednesday

‘This house proposes that the procurement and use of embryonic stem cells for scientific research is unethical’

What does ‘Emergent properties’ mean’?

‘The whole is greater than the sum of its parts’Occurs at all levels of life, from unicellular

organisms to the most complex of living systemsSurface tension, cohesion and adhesion are

emergent properties of polar water moleculesCell function is an emergent property of the

combination of organelles and the cell exomembrane/endomembrane system

Cardiac output is an emergent property of endothelial cells, cardiac muscle and vascular tissue

Colonies of primitive unicellular organisms don’t show emergent

properties Prokaryotic organisms or

primitive eukaryotic organisms (algae) may exist in colonies of identical cells

While the cells co-operate, they do not fuse to form a single mass and so don’t form a single organism

Multicellular organisms demonstrate

differentiationCells are specialised:

Blood cells Muscle cells Retinal cells Glandular cells Epithelial cells

Each cell has the same DNA, but only a section of it is expressed

Cell Differentiation Harvard Animation

Your Research ToolsBBSRCBlog

What are stem cells?Cells that are able to generate more specialised

types of cell types through the process of cell differentiation

Cells that can divide to make identical copies of themselves, through self-renewal

You can learn all about stem cells by watching the beautiful animation from Utah Genetics here:

Stem Cells

Different types of stem cells

1. Embryonic Stem Cells Here, you can learn how

embryonic stem cells are made:

Quck guide to Embryonic stem cells

Here is the BBC video on how embryonic stem cells are made:

How to make stem cells

Different types of stem cells

2. Somatic Stem Cells (also called adult stem

cells) Exist naturally in the

body Used for bone marrow

transplants Can only differentiate

into dedicated cell types

Adult Stem Cells are committed to become one

type of cell

Stem cells in the adult brain:Are they still working for us now?

Stem cells in mature skeletal muscle:Is there power still in our stem cells?

Different types of stem cells

3. Induced pluripotential Stem Cells Created artificially in the

lab by ‘reprogramming’ a patients own cells

Made from patient’s own cells – fat, skin, fibroblasts

Can become any cell in the body (even a whole mouse!)

Induced pluripotential Stem Cells – The future!

Learn the story of iPS stem cells from Utah Genetics…

IPS stem cells

Pros and Cons to iPS cell technology

Pros:Cells would be genetically identical to patient or donor of skin

cells (no immune rejection!)Do not need to use an embryo

Cons:Cells would still have genetic defectsOne of the pluripotency genes is a cancer geneViruses might insert genes in places we don’t want them

(causing mutations)

Different types of stem cells

4. Therapeutic Cloning: ‘patient-specific embryonic stem cells’

Can theoretically create pluripotent stem cells from patient’s own cells

Ethically highly controversial

Scientists have not yet grown a cloned human to the blastocyst stage

Different types of stem cells

Stem Cells used in medicine: Treatment of leukaemia

Stem cell transplants have been successfully used since 1968 to treat patients with leukaemia

Patients with leukaemia first have their own abnormal blood cells destroyed by radiotherapy

Then the patients own bone marrow stem cells are replaced with a transplant (into the bloodstream) from a healthy patient’s bone marrow

If the transplant is successful, then the stem cells will migrate into the bone marrow and begin to produce new, healthy leucocytes

You can learn all about leukaemia treatment by linking here onto Utah Inc:

Utah Genetics

Stem Cells used in medicine: Umbilical Cord Blood

Umbilical cord blood stem cell transplants have been used for treatment of leukaemia.

Unbilical cord blood stem cells are less prone to immune rejection

They are considered a potent resource for transplant therapies

Embryonic Stem cells are pluripotent

What can we use Stem Cells for?

To provide lab-grown human or animal tissue for identifying new treatments for disease (rather than using animals in research)

TO produce new human tissue and organs to replace damaged ones

To repair tissue by stimulating stem cells already in the body To use stem cells from patients with inherited genetic

diseases (e.g. cystic fibrosis, some forms of Parkinson’s disease) to study the disease

To better understand diseases like cancer To investigate human development

Stem Cell Research is a fast-moving subject

Stem cell grandparentsBrand new spermFirst trial of human embryonic stem cellsTracheal transplantStem cell nobel prize

The Stem Cell Ethical Debate

The Ethical QuestionsUntil recently, the only way to get pluripotent stem cells for research was to remove the inner cell mass of an embryo and put it in a dish. The thought of destroying a human embryo can be unsettling, even if it is only five days old.Stem cell research thus raised difficult questions:• Does life begin at fertilization, in the

womb, or at birth?• Is a human embryo equivalent to a human

child?• Does a human embryo have any rights?• Might the destruction of a single embryo

be justified if it provides a cure for a countless number of patients?

• Since ES cells can grow indefinitely in a dish and can, in theory, still grow into a human being, is the embryo really destroyed?

Ethics and iPS: Problem solved?

With iPS cells now available as an alternative to hES cells, the debate over stem cell research is becoming increasingly irrelevant. But ethical questions regarding hES cells may not entirely go away.Inevitably, some human embryos will still be needed for research. iPS cells are not exactly the same as hES cells, and hES cells still provide important controls: they are a gold standard against which the "stemness" of iPS cells is measured.Some experts believe it's wise to continue the study of all stem cell types, since we're not sure yet which one will be the most useful for cell replacement therapies.An additional ethical consideration is that iPS cells have the potential to develop into a human embryo, in effect producing a clone of the donor. Many nations are already prepared for this, having legislation in place that bans human cloning.

Key Ethical Questions (1)MORALITY AND HUMANITY OF EMBRYOS

1. At what point does an embryo/ blastocyst have full moral status?

2. Is there a ‘moral cut-off’ at 14 days after fertilisation?

3. Does an embryo’s moral status increase as it develops?

Key Ethical Questions (2)1. Is there anything wrong with using spare

embryos left over from fertility treatment?2. Is it morally justifiable to use embryonic stem

cells as a means to an end, if they will provide huge benefits from human health?

3. Should we be using embryonic stem cells at all, if we have the alternatives of stem cell lines derived from umbilical cord blood or induced pluripotential stem cells?

Arguments about embryonic cells

Arguments about Somatic Cell Nuclear Transfer

Arguments about the Moral Status of the

Embryo (1)

Arguments about the Moral Status of the

Embryo (2)

Arguments about the moral status of the

embryo (3)

Arguments about the moral status of the

embryo (4)

Links on ethics related to Stem Cell research

Stem Cell Ethics FactsheetEthics and Embryos FactsheetAre embryos human? – a conversation…