Embryology 7: Embryonic Stem Cells Flashcards
Two properties of stem cells
Self-renewal, able to differentiate
Where do stem cells come from
Inner cell mass
Pluripotent
Can contribute to any cell types in the body
Criteria for human embryonic stem cells (4 criteria)
Originated from a pluripotent cell population (i.e. ICM/blastocyst. 2. Proliferates for a long time 3. Maintains normal karyotype (number, structure of chromosomes) 4. Able to differentiate into tissues of all three germ layers
Three things ES cells can be used for
- Study mechanisms of human cell differentiation and embryo development 2. Produce large quantity of human cell types (to test drugs and screening) 3. generate specific human cell types (tissue replacement therapy)
Reason why FDA is cautious about ES clinical trials
May cause cancer (teratocarcinoma)
What are induced pluripotent stem cells (iPS)?
Turning your own adult cells into embryonic stem cells
Which molecules are involved in creating iPS?
Oct4
Sox2
cMyc
Klf4
What are the benefits of iPS?
- Patient-specific stem cells for replacement therapy (no immune rejection)
- Generate stem cells carrying specific genetic disease mutations (can help us understand how certain diseases work)
What are the potential drawbacks of iPS?
You can generate aberrant behavior (cancer) from:
- Incomplete programming (stem cell retaining some of the old adult features)
- Unexpected effects of introduced molecules and neurons in the experimental manipulation
What is a potential solution that can reduce the negative effects of iPS?
Generate more stem cell lines from blastocysts of a wide range of genetic/racial backgrounds
What is the ethical concern regarding stem cells?
Generation of stem cells = destruction of blastocyst (life)
