Stem Cells

Question 1

describe the process of stem cell differentiation

Answer 1

unspecialised stem cells acquire specialised structural or function features characterising the cell.
stem cells undergo asymmetric division = procuring 2 dissimilar daughter cells

Question 2

describe the outcome of the 2 daughter cells

Answer 2

one daughter cell is identical (maintains stem cell line)
the other has different genetic instructions and reduced proliferative activity, and will become a precursor (differenciate into one of few cell types)

Question 3

what are totipotent stem cells?

Answer 3

gives rise to embryonic membrane and any cell type in the adult body (zygote, morula)

Question 4

what are pluripotent stem cells?

Answer 4

can give rise to any cell type in adult body (inner mast cells of blastocyst, cell nucleus of adult tissue can be reprogrammed into induced pluripotent stem cells)

Question 5

what are multipotent stem cells?

Answer 5

gives rise to tissue specific cell types in the adult body (hematopoetic/neural/mesenchymal cells)

Question 6

what are unipotent stem cells?

Answer 6

gives rise to one specific cell type of the adult body (epithelial stem cells)

Question 7

state the order of hierarchy in stem cell potency

Answer 7

totipotent, pluripotent, multipotent, unipotent

Question 8

what are adult/somatic stem cell and where could they be found?

Answer 8

undifferentiated cells found throughout the body that replenish dying/damaged cells
identified in skin, intestine, liver, brain and bone marrow

Question 9

what are the problems of obtaining adult/somatic stem cells?

Answer 9

difficult to isolate, few in number, difficult to keep them proliferating in culture

Question 10

what are induced pluripotent stem cells? (iPSCs) and what are they treated with?

Answer 10

a way to make pluripotent stem cells without using embryos
treated with transcription factors (KLF4) to induce and maintain pluripotency

Question 11

what can cancer stem cells do?

Answer 11

exhibit characteristics of both stem cells and cancer cells, ability to generate more stem cells (self-renewal) and to produce cells that differentiate), CSCs have ability to seed tumours when transplanted into an animal host

Question 12

what method of cancer treatment kills cancer stem cells?

Answer 12

CSC targeted cancer therapy, drug kills tumour stem cells and prevents tumour and stem cells from growing

Question 13

what are stem cell growth factors? and what do they cause?

Answer 13

regulatory molecules that stimulate cell and tissue function through influencing cell differentiation
cause changes in biochemical activity, cellular growth and regulatory rate of proliferation

Question 14

what can stem cells be used for?

Answer 14

regenerative medicine (repair or replace damaged or diseased cells to restore normal function), tissue repair, drug screening, vehicles for drug therapy

Question 15

give an example of regenerative medicine and the process gone through

Answer 15

stem cell therapy in bone marrow transplant, from individual with same tissue type (HLA type), can now be done from blood sample using peripheral blood stem cells (PBSC), a course of injections stimulates release of stem cells into blood

Question 16

how can stem cells be used in making new blood? what is the main benefit of this?

Answer 16

using pluripotent stem cells, donors/recipients only have to be blood group matched rather than tissue matched (lower rejecting risk)
benefit - blood donation systems not needed, valuable for those living with blood disorders (beta-thalassemia) who require regular blood transfusions