Flashcards in advantages and disadvantages of iPSC vs embryonic stem cells Deck (19):
what are the 6 pros of IPSc?
- cells readily available
- unlimited proliferative ability
- can potentially form any cell type
- modelling human genetic diseases
- few ethical issues
- have some genetic background to patient therefore rejection of transplant is low
what are the negatives given in the lecture for iPSCs?
- low reprogramming rate
- potential to form tours
- genetic mutations can occur during long term culture
what are the 4 pros of ESCs?
- they are available from IVF clinics
- unlimited proliferative abilities
- pluripotent can potentially form all adult cell types
- can be sed fir toxicity testing and development of new drugs
what are the 4 disadvantages if ESCs
- have a different genetic background to donor so there is a risk
- potenital for forming tumours such as teratomas
- genetic mutations may arise during long term culture
- major ethical issues
what was found when they looked for chromosomal changes in ESC lines? which chromosomes were most affected?
120 human ES cell lines were analysed for karyotype abnormalities and group according to whether abnormalities were seen at early or late passage. Most (66%) were normal but the study identified a tendency to acquire chromosomal abnormalities with prolonged culture. Chromosomes 1, 12, 17 and 20 were most commonly affected.
what region in the genome was found to be particularly changed when human ES lines were observed, why is this?
a minimal amplicon in chromosome 20q11.21, including three genes expressed in human ES cells, ID1, BCL2L1 and HM13, occurred in >20% of the lines. Of these genes, BCL2L1 is a strong candidate for driving culture adaptation of ES cells
what is the problem with culture adaption in ES cells, what can this result in?
Culture adaptation of human pluripotent stem cells. During prolonged culture many cells either die or differentiate, leading to selection for cells carrying mutations that permit them to grow (self renewal). Culture adaptation leads to cells with enhanced growth characteristics and sometimes to embryonal carcinoma cells (malignant ES cells) that have lost the ability to differentiate.
what are the 3 disadvantages of using adult stem cells?
- veyr rare and often difficult to obtain
- may have limited proliferative ability
- may have limited potency, producing just a few cell types
what are the advantages of adult stem cells?
- can be isolated from patient thereby reducing the chance of rejection
- can be used to test patient specific responses to drugs
- modelling human genetic diseases disorders
- few ethical issues
give an example of adult stem cells being used for regenerative medicine for a woman
Claudia Castillo suffered severe damage to her left Bronchus as a result of Tuberculosis. A trachea was isolated from a recently deceased donor and stripped of its living cells, leaving a collagenous frame. This was seeded with tracheal cells made from Claudia’s bone marrow stem cells, incubated in a “bioreactor” for 4 days, then used to replace the damaged bronchus. The transplant was successful and not rejected by Claudia’s immune system.
why do ESCs have unlimited proliferative capacity?
- they have telomerase
what would cause teratoma formation ?
- residual pluripotent and undifferentiated ESCs in transplants
what is an important use of ESCs?
- they can be used to look at development and the factors involved differentiation
what must be remembered when using ESCs to look at development?
- they have been selected for proliferation and in vitro survival
are ESCs from pre or post implantation?
why is the ESC good for very early development studies?
t provides access to the popula- tion of early precursor cells that are difficult if not impossible to identify in vivo.
what is good about ESCs in terms of mutation analysis?
it could allow the study of targeted mutations of genes that may be lethal in vivo but can be studied in vitro.
what is the problem of ESC in terms of cell numbers ?
difficult to get large numbers or repeating tissues