Research and Therapeutic Value of Stem Cells Higher Human Biology Unit 1 – Sub-Topic 1 (d)

Learning Intention To discuss therapeutic uses of stem cells and the ethical issues about their use.

Stem cell research Stem cell research provides us with a wealth of information and can be studied in a variety of ways, including: how cell processes such as growth, differentiation and gene regulation work the study of diseases and their development drug testing therapeutic uses in the treatment of diseases e.g leukaemia (bone marrow transplant), Hunter’s disease and heart disease therapeutic uses in medicine - skin grafts for burns and stem cell grafts for cornea repair. Video Clip

Or they could become nerve cells that could heal spinal cord injuries. For example, stem cells could be turned into new bone cells and then injected into weak or broken bones. Or they could become nerve cells that could heal spinal cord injuries. Skin cells could replace burnt skin, and brain cells could help people who have suffered brain damage. A cool video showing heart cells beating in a dish…. http://www.youtube.com/watch?v=RO4pAc21M24 Stem cells could be taken from someone with heart disease and be turned into heart cells, which can gather in a dish and throb! They could then be injected back into the patient to rebuild their heart tissue and combat heart disease.

Parkinson's disease Parkinson's is a very common disease starting with mild symptoms, a mask-like face, stiffness and tremors until sufferers eventually become immobile. It is caused by a slow deterioration of certain brain cells (neurons) and there's no cure. Replacing the affected brain cells seems more hopeful than finding better drugs. Many people think that stem cells could be grown into new brain cells that could help to treat or even cure Parkinson's.

Windpipe transplant clip 1

Corneal stem cell therapy Stem cells extracted from healthy eye, cultured (grown) and transplanted back into the damaged eye Repairs cornea Shorter waiting time than traditional donation Reduced chance of rejection as patient’s own cells transplanted Sky news clip

Describe how stem cells have contributed to corneal transplants and skin grafts.  stem cells isolated from the patient's healthy eye new tissue can be cultured/grown transplanted back into the damaged eye, repair the damaged cornea. Shorter waiting time than corneal donation Skin grafts  Stem cells isolated from healthy skin New tissue grown / cultured dehydration and infection are risks until graft done. Produces skin cells much more quickly. reduces the time patient at risk.

Therapeutic stem cell cloning

Presentation task Using what you have learned already and adding further research, create a presentation that covers the following aspects of stem cells: the biology of stem cells – what is a stem cell, types of stem cells the potential of stem cells – details of one or two research projects involving stem cells that you have found particularly interesting, details of potential therapies stem cell dilemmas – explore the moral and ethical issues surrounding stem cell research (personal points of view can be expressed if desired). You will be assessed using all three of the above criteria as well as on the overall quality of your presentation.

To help you find out more about the research on different medical conditions being investigated HERE IN SCOTLAND go to the following site. Your task is to find out more about one condition and explain how stem cell are being investigated as a possible treatment

Not in my backyard!

Ethical issues surrounding stem cells Practices using adult (tissue) stem cells remain fairly uncontroversial. Many pro-life and religious groups argue that embryos have human rights, should not be destroyed and should not be created simply for scientific research. Opposing arguments include the potential to discover cures for diseases for which there are currently none and improved treatment of a range of medical conditions.

Regulation of stem cell use The laws surrounding embryonic stem cells and adult stem cells differ because while both have similar capacities in differentiation, their modes of derivation are not. Only adult cells are used in the UK for therapeutic use. While embryonic stem cells are taken from embryos, adult cells can be taken from consenting adults.

Regulations surrounding the use of embryonic stem cells The research must be licensed by the Human Fertilisation and Embryology Authority (HFEA). Researchers must justify that the creation of an embryo is necessary and that the work could not be carried out in another way. Embryos over the development stage of 14 days cannot be used as this is the stage at which there is some primitive development of the nervous system.

Cloning Human reproductive cloning is illegal in the UK. As a result of the Human Reproductive Cloning Act (2001) nobody in the UK is allowed to use cell nuclear transfer, or any other technique, to create a child.

Compare the location and functions of embryonic and tissue (adult) stem cells.  (7 marks) Stem cells are undifferentiated cells capable of repeated division to both more stem cells and cells that will later differentiate to form specialised cells. Embryonic stem cells (ESCs) are found in the inner cell mass of the blastocyst. ESCs are capable of repeated division… …to form more ESCs and other cell types. ESCs are: capable of forming all the other cell types of the body / pluripotent Tissue stem cells (TSCs) are found throughout the juvenile and adult body. TSCs are capable of repeated division to form more TSCs and other cell types. TSCs: can only form cells of the organ to which they belong / are multipotent. e.g. bone marrow tissue cells can only give rise to bone marrow cells, red blood cells, platelets, phagocytes and lymphocytes.

Some useful Video Clips – Stem Cells and Ethics http://www.educationscotland.gov.uk/video/h/video_tcm4664297.asp?strReferringChannel=highersciences&strReferringPageID=tcm:4-658424-64&class=l3+d142456+d143862 http://www.bbc.co.uk/learningzone/clips/stem-cell-research-and-medicine/6013.html http://www.bbc.co.uk/learningzone/clips/ethics-of-using-foetal-stem-cells-for-stroke-treatment/5888.html http://www.bbc.co.uk/learningzone/clips/alternative-to-embryo-stem-cells-developed-by-researchers/6581.html http://www.bbc.co.uk/programmes/p00k7j7w http://www.bbc.co.uk/learningzone/clips/stem-cell-research/14287.html

Questions Name one medical condition that is routinely treated using tissue stem cells. From where in the human body are these cells obtained? Give an example of a medical condition that might be treated in the future using stem cells. Why does stem cell research using human embryos raise ethical issues? Why is it important that stem cell research is carefully regulated?

Answers Bone marrow transplants or skin grafts. From donor bone marrow or by taking a small sample of skin cells. Diabetes, Alzheimer's, Parkinson’s, spinal cord injury, Stroke. It raises ethical issues because human embryos have the potential to become human beings. To ensure the quality of stem cells used and the safety of the procedures are of the highest order and that there is no abuse of the system.

Learning Outcomes Stem cell research provides information on how cell processes such as cell growth, differentiation and gene regulation work. Stem cells can also be used as model cells to study how diseases develop or for drug testing. The therapeutic uses of stem cells include bone marrow transplants, skin grafts for burns and stem cell grafts for cornea repair. The ethical issues of stem cell use and the regulation of their use