Stem Cells

Ridhi Singh, Akshita Sahi, Pavitura Kanagasabai, Siddhesh Anand, Nimalan Chandrasekara, Reuben Gurupatham

Human Research and History

History of Stem Cells

•Scientists have been looking into stem cells since the 1960s, this is because cell propagation and differentiation were seen to be the building blocks of humans

History of Stem Cells• In 1963, a scientist named

Dr. Ernest McCulloch, discovered stem cells but oddly that was not the main goal of his experiment. ▫ Medical Researcher at

the Ontario Cancer Institute in Toronto, Canada.

History of Stem Cells•Experiment: Exposed mice to powerful

radiation that all the blood and bone marrow cells were killed. After, he injected normal house bone marrow cells into some of the experimental mice and irradiated bone marrow cells into others.

•Bone Marrow: where new blood cells are grown, both in mice and people

History of Stem Cells•Because radiation was used to kill cancer,

Dr. Ernest conducted the experiment to calculate how sensitive bone marrow cells were to radiation

•When examining the results, it was concluded that there was no difference between mice with irradiated bone marrow and mice with normal bone marrow.

History of Stem Cells•Dr. Ernest though realized that the mice’s

spleens had small whitish bumps in them.•He also knew that mouse spleens and

bone marrow grew new blood cells•After plotting the data on a graph, Dr.

Ernest concluded that the number of cell injections and the number of spleen bumps had matched up.

History of Stem Cells•This was the discovery of stem cells•Though it was discovered in 1960, it wasn’t

until 1963 that it was published (scientific papers)

•Proved that colonies were formed from single cells that were able to duplicate themselves and create colonies of different kinds of blood cells.

•They were called stem cells as new blood cells ‘stemmed’ from those cells.

History of Stem Cells

•This discovery set many scientists off to further develop stem cells

•They were amazed at this particular property as if they had developed it properly, could cure cancer

Background Information

What are stem cells?•Cells in the body which have the capacity

to develop to many other types of cell in a body.

•Classified into 2 main types: Adult and embryonic Stem cells

•Further research upon the functioning of these cells can enable one in the future to make cells and tissues for therapeutic purposes

Pictures/Diagram showing the structure of a cell

• The Stem cells can be found in the bone marrow.

• The cells are also known as the future of medicine.

The Importance of Stem Cells

Importance•In the body, stem cells are used for tissue

development and repair.•As they are unspecialised

and undifferentiated, they hold the potential to treat countless medical conditions.

Cosmetic Uses• Breast Implants

▫Current breast implants are composed mainly of silicone, which is unnatural and can cause side effects.

▫Stem cells can be used to repair damaged breast tissue and to enlarge breasts for cosmetic purposes.

• Hair Treatment▫Medical treatments and genetics can

cause hair loss.▫Stem cells can be used to repair damaged

scalp and create new hair follicles.

Medical Uses• There are countless medical conditions than can

potentially be treated with stem cells.• Cancer

▫Stem cells replenish the blood cells of cancer patients, as chemotherapy destroys both cancerous cells and bone marrow cells.

• Organ ▫As stem cells are undifferentiated and unspecialised,

they can become specified to fulfil the purpose of vital organs, such as the liver.

▫They can be used to repair damaged organs and can even be used to create new organs for a patient.

Medical Uses – cont.•Gene Therapy

▫The stem cells of a patient with a genetic disease and mixed with a virus with the correct gene.

▫Once the virus has transferred the normal gene into the stem cells, the stem cells are fused with the bone marrow.

▫This is a promising procedure because it effectively replaces the abnormal gene with the normal gene.

Research•It is believed that birth defects and cancer are

due to an abnormal reproduction of stem cells.•Further research of stem cells can allow more

effective treatments and cures to be developed.

• In addition, more knowledge of the specific causes for cancer can allow researchers to develop tips to prevent such conditions.

Human Impact

Adult Stem Cells vs. Embryonic Stem CellsAdult Stem Cells Embryonic Stem Cells• Mulitpotent

▫ Cells are limited to the types they can produce

• Abundance is rare• Harder to identify• No chance of immume

rejection

• Pluripotent▫ Cells are able to

produce any type of cell• Found abundantly • Easier to identify• High chance of immune

rejection

The Ethical Issue: Using Embryonic Stem Cells• Embryonic stem cells are those which are taken

from the embryo or fetus• Most cells are taken from eggs that have been

through IVF with informed consent• Debate about whether it is right to take away a life

that could have existed as the egg would have to be destroyed in order to conduct research▫Can be seen as a human life being taken for the sake

of science ▫People believe that it is not right to ‘play god’

• Most agree that the research, however, should continue with limits

Applications

Applications of Stem Cells• Stem cells are differentiated to turn

into specialized cells that are used to recover damaged tissues and organs.

• Turning genes on and off is central to cell differentiation.

• Human stem cells are used to test new drugs.

• Medications are tested for safety on differentiated cells generated from human pluripotent cell lines.

• Stem cells create the generation of cells and tissues that could be used for cell therapies.

• Differentiated stem cells provide a renewable source of replacement cells and tissues to treat diseases.

Applications of Stem Cells• Stem cells can:

▫ renew blood and bones after chemotherapy▫ be used in skin replacement▫ be used in brain cell transplantation▫ provide dopamine for patients of Parkinson’s disease▫ be used to possibly reverse blindness▫ be used in bone marrow transplants▫ be used in general to replace cells and tissues to treat

diseases including Alzheimer's diseases, spinal cord injury, stroke, burns, skin and heart disease, diabetes, osteoarthritis, rheumatoid arthritis, Parkinson's disease, rheumatoid arthritis, muscular dystrophies and liver diseases

After chemotherapy…• Stem cells offer the opportunity

of transplanting a live source for self-regeneration.

• Bone marrow transplants (BMT) are a well known clinical application of stem cell transplantation.

• BMT can repopulate the marrow and restore all the different cell types of the blood after high doses of chemotherapy, our main defense used to eliminate endogenous cancer cells

Bone marrow stem cells

Skin replacement• Stem cells made it possible for scientists to grow skin from a

patient’s plucked hair. • Skin stem cells or keratinocytes reside in the hair follicle and

can be removed when a hair is plucked. • These cells are cultured to form an epidermal same as the

patients own skin and provides tissue for an autologous graft, avoiding problems of rejection.

• Autologous skin grafting is limited since only a fraction of the skin can be repaired by this method and it creates additional injuries at the donor sites.

Brain cell transplantation• Neural stem cells were only

until recently thought to be embryonic, but many researchers prove otherwise.

• Applying stem cells for brain cell transplantation is difficult.

• Potential targets of neural stem cell transplants include stroke, spinal cord injury, and diseases like Parkinson’s Disease.

• So, neural stem cells can’t easily be used in brain cell transplantations.

A group of cultured adult human neural

stem cells.

Treating Parkinson’s Disease•Stem cells provide dopamine, a chemical

lacking in victims of Parkinson’s Disease.•Parkinson’s Disease involves the loss of cells

which produce the neurotransmitter dopamine.•Fetal cell transplants for Parkinson’s Disease

reported survival and release of dopamine from the transplanted cells.

•Use of stem cells for this disease has some side effects which include autosensitization (automatic immunization) to dopamine.

Reversing blindness•Stem cells isolated

from the eyes can help retinal regeneration.

•This can lead to a possible cure for damaged or diseased eyes and may help reverse blindness.

A human eye repaired using stem cells.

Bone marrow transplants•Bone marrow transplantation is a well-

established treatment for blood cancers and other blood disorders.

•Hematopoietic stem cells (HSCs) or blood stem cells, present in the bone marrow are currently the only type of stem cells commonly used for therapy.

•HSCs are used to treat leukemia, lymphoma and several inherited blood disorders.

Treating genetic skin diseases• Epidermolysis bullosa, which is

characterized by an extreme fragility of the skin, is treated using skin stem cells.

• Correction of a severe epidermolysis bullosa can be achieved by transplantation of genetically modified keratinocyte stem cells.

• Genetically corrected skin tissue heals perfectly well and biopsies from the graft demonstrate that the recombinant skin has a normal histology and expression of the transgene remains stable even a year after treatment.

Human epidermal keratinocytes (HEK)

Global Impact

Organizations involved•Stem cell research has been expanded to

international grounds as it has evolved. •Some international organizations involved

in stem cell research and their applications include:▫International Stem Cell Forum▫ISSCR : The International Society for Stem

Cell▫MRC: The UK Medical Research Council

sponsors the UK Stem Cell Bank

Nations involved in research•Australia

▫Australian Stem Cell Centre•Canada

▫Canadian Institutes of Health Research (CIHR)

•China ▫Human Embryonic Stem Cell Research in

China•Europe

▫EuroStemCell

Nations involved in research•Japan

▫RIKEN Center for Developmental Biology•United Kingdom

▫Centre for Stem Cell Biology (Part of the University of Sheffield)

▫Institute for Stem Cell Research▫Institute of Human Genetics at the

University of Newcastle upon Tyne▫UK National Stem Cell Network

Evolution of Stem Cell Research

Evolution of Stem Cells• In the past, scientists have worked with two types of

stem cells (from animals and humans): embryonic and non-embryonic stem cells

▫Embryonic stem cell: undifferentiated cells derived from an early-stage embryo

▫Non-embryonic stem cell: rare undifferentiated cells found in many organs and tissues

Embryonic Stem Cell

Evolution of Stem Cells•Promising results from animal studies

have served as the basis for a small number of exploratory studies in humans

•1956: after experimenting with irradiated mice, the first bone marrow transplant was performed in New York▫Patient had leukemia and was treated with

a bone marrow from an identical twin

Evolution of Stem Cells•1960: it is discovered that bone marrow

contains at least two kinds of stem cells: blood or haematopoietic stem cells▫both kinds form all the types of blood cells

in the body and stromal stem cells that form bone and connective tissue

Evolution of Stem Cells•1968: British scientists became the first to

fertilise a human egg in a test tube▫Beginning of in-vitro fertilisation (IVF) technology

•1968: first ever bone marrow treatment used for non-cancer treatment to treat an eight-year old boy with a genetic disorder

Human embryo used for IVF

Evolution of Stem Cells•1973: New York, first bone marrow

transplant between two unrelated patients (received from donor in Denmark)

•1978: first IVF baby born in England

•1978: first blood stem cells are discovered in human umbilical cord blood

Evolution of Stem Cells• 1984-1998: retinoic acid is found to direct

pluripotent stem cells (most primitive cell) in differentiation

• 1989: pre-implantation genetic diagnosis (PGD) is developed▫Single stem cell can be removed from an IVF

embryo and tested for inherited diseases

Pluripotent stem cells

Evolution of Stem Cells• 1990: bone marrow programme initiated• 1995: scientists at the University of Wisconsin

derive the first embryonic stem cells from non-human primates

• 1998: scientists at the University of Wisconsin isolate and grow the first stem cells from human embryos (from IVF)▫Embryos were created and used for reproductive

purposes• 2001: US President George W. Bush permits

government funding of embryonic stem cell research

Evolution of Stem Cells

• 2004: California becomes first US state to provide its own funding to embryonic stem cell research

• 2006: researchers discovered specialized adult cells could be "reprogrammed" genetically to assume a stem-cell like state---this new type of stem cell was known as "induced pluripotent stem cells (IPSCs)“

In the Future...•Research on how “cell-based therapies"

could treat disease▫also known as "regenerative or reparative

medicine"•Have the potential to cure:

▫ Alzheimer's diseases, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis, rheumatoid arthritis...

In the Future...•Stem cell research continues to advance

knowledge on the development of an organism from a single cell and the replacement of damaged cells in adult organisms

•Used in laboratories to test new drugs and to develop model systems to study normal growth and identify birth defect causes

In The Future...•Scientific questions about the research

are growing as rapidly as its’ discoveries•Human umbilical cord blood is rich in

hematopoietic (blood) stem cells and is currently being used as an experimental alternative to bone marrow transplantation, and is being further researched

In The Future...•Possibilities of the research being misused

in the future

•Could lead humanity to better treat/cure diseases in future▫Gives social benefits for individuals and

economic gains for society

Conclusion

Concluding Statement •Stem cell research sets the basis for

medical progress.•These cells can be used to further study

the development of organisms. •Through stem cell research, cures for

several cell diseases, such as cancer, may be discovered.

•Stem cells can be the key component in the research and development of cytology.

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