WS3: Cancer Stem Cells

Question 1

Cancer stem cell definition:

Answer 1

• Cancer cells with the ability to self-renew and to act as a precursor for other cancer cells within a tumour

Question 2

Cancer stem cells: Relevance to cancer treatment

Answer 2

• May be more resistant to treatment (e.g. drug efflux)
• Can repopulate tumour after treatment (relapse)

Question 3

How are cancer stem cells obtained?

Answer 3

• Biopsy
• Circulating tumour cells (requires enrichment)

Question 4

Methods of characterisation of cancer stem cells:

Answer 4

• Fluorescent tagged antibodies
  -> FACS, flow cytometry imaging
• Antibody coated magnetic beads
• Dielectric properties/cell size
• Immunohistochemistry (IHC)

Question 5

FACS: How it works

Answer 5

• Fluorescence activated cell sorting
• Specialised flow cytometer enabling collection of cells into distinct groups
• Utilises specific fluorophores for biomarkers -> enables quantification of biomarkers on cells
• CSC-specific biomarkers can be enriched using FACS
• Can be used to determine the tumorigenicity of CSC with other approaches

Question 6

How does flow cytometry work?

Answer 6

• Particles are pulled through in a line due to laminar flow at the tip of the needle
• Laser passed through -> filtered incrementally to separate detectors -> information transmitted to electronics
• Filters have a threshold for wavelengths above which light will be reflected (and the rest passes on to the next)

Question 7

Model organisms in CSC studies

Answer 7

• Mouse/rat xenograft
• Zebrafish
• Chorioallantoic membrane assay / model (hen egg chick membrane)
  -> increasing concentrations of cells -> quantitative determination of efficiency of tumour formation