Week 3 - Stem Cells and Differentiation Flashcards
What are stem cells
Undifferentiated cells that can divide to produce more stem cells or produce specialised cells
Describe asymmetrical division
Stem cell divides to produce identical undifferentiated stem cell and also a cell that can differentiate as a unipotent ‘precursor cell’ with different genetic instructions
What is stem cell potency
A stem cell’s ability to differentiate into other cell types e.g Totipotent = high potency, unipotent = low potency
Pluripotency
Can give rise to any cell type found in the human body
What is totipotency
Cells that can give rise to all cell types of the human body and to the embryonic membrane
Where are pluripotent cells found
In the ICM of the human embryo
Example of totipotent cell
Zygote and morula
Multipotentcy and examples
Can give rise to tissue-specific cell types of the body e.g haematopoietic/mesenchymal stem cells (blood/connective tissue stem cells)
What is an oocyte
Cell in ovary which can undergo meiotic division to form an ovum
Briefly describe the process of induced pluripotent stem cell
When adult somatic cells are reprogrammed back to pluripotency
Define somatic stem cells
Undifferentiated cells that produce cells other than those involved in reproduction and are used to replenish and regenerate dying/damaged cells
Where are stem cells found
Skin
Intestine
Liver
Brain
Bone marrow
Why are adult stem cells hard to isolate
Few in number
Difficult to culture
What are cancer stem cells
Stem cells that are thought to cause cancerous tumours
What is the problem with traditional chemotherapy
It kills cancerous cells but doesn’t target the route cause of the problem: cancer stem cells
What is the most effective chemotherapy combination to kill cancer for good and why is this
Cancer stem cell targeted cancer therapy (kills the cancer stem cells) AND traditional chemotherapy (targets the cancerous cells) - important as well because cancer cells can convert back into cancer stem cells and start the process all over again
What is the name of the recent therapy that was promising against cancer stem cells
CD47
Which regulatory molecules are responsible for how regenerative medicines work and explain
Growth factors which stimulate cell and tissue function through influencing cell differentiation
Influencing cell differentiation can lead to a change in what
Biochemical activity
Cellular growth
Regulation of rate of proliferation
Outline how stem cell therapy works in leukemia for example (a
Blood stem cells collected from healthy donor with same blood type (if allogenic) or affected patient from bone marrow/blood (if autologous)
Patient with faulty blood cells has their own blood (haematopoetic stem cells) killed through chemotherapy/radiation
Healthy stem cells implanted into patient which go on to produce healthy blood cells
Define regenerative medicine
the repair or replacement of damaged or diseased human cells or tissues to restore normal function
Autologous transplant
Cells/tissue obtained from same patient
Allogenic transplant
Cells/tissue obtained from a different patient
List 6 potential therapeutic uses for stem cells
Stem cell transplant for conditions such as leukaemia
Eye corneal repair
Cartilage transplants
Making of new blood in vitro
Tissue repair
Drug screening
Vehicle for gene therapy
Which type of stem cell is useful for stem cell transplant
Adult stem cells
Are adult stem cells easy/hard to culture
HARD
Which stem cell is associated with rejection problems during allogeneic transplantation
Embryonic stem cells
Describe the 2 hypothesises for the production of cancer stem cells
Normal stem cell mutates to become a cancerous stem cell
Somatic cell mutates to gain cancer characteristics and stem. cell like characteristics
