Stem Cells and Differentiation

Question 1

Explain potency of cells

Answer 1

The ability of a cell to differentiate into other cell types

Question 2

Process of differentiation to form diverse tissue types

Answer 2

1. Stem cell divides asymmetrically into 2 daughter cells
2. Identical daughter cell is self renewing
3. Other daughter cell has different gentic instruction with reduced proliferative capacity. Becomes progenitor cell

Question 3

List hierarchy of stem cell potency, using examples

Answer 3

Totipotent (zygote)
Pluripotent (inner cell mass of blastocyts, induced PSC)
Multipotent (neural stem cells, haemotopatic stem cells)
Unipotent (epithelial stem cells)

Question 4

Examples of adult tissue stem cells and their function

Answer 4

Haematopoietic stem cells - form blood and immune cells, regenerate blood
Intestinal stem cells - rapid renewal of epithelial lining
Neural stem cells - form neurons and glial cells

Question 5

Advantages of using different stem cells in medicine

Answer 5

Medical treatments and research, restore ability

Question 6

Disadvantages of using stem cells in medicine

Answer 6

Embyonic stem cells have ethical concerns as have ability to form another human

Question 7

Role of stem cells in cancer

Answer 7

Cancer stem cells (CSCs) - subpopulation of stem-like cells in tumour. Imortal cells exhibiting charachteristics of stem cells and cancer cells - can generate more stem cells and produce cells that differentiate.

Question 8

Potential medical applications of stem cells

Answer 8

Regenerative medicine: repair/ replace damged or diseased human cells or tissues
Tissue repair
Drug screening
Vehicles for gene therapy
Bone marrow transplant - treat blood disorders such as leukaemia
Holoclar - stem cell treatment to replace damaged SC in epithelium of cornea
Making new blood from induced pluripotent stem cells