15 - Cancer Stem Cells Flashcards
Why are most cancers from stem cells?
because they last decades in the body
What are the 3 mechanisms for maintaining a stem cell population?
asymmetric division | symmetric divisions | locally directed divisions
What are asymmetric divisions of stem cells?
1 stem cell 1 parent cell
What are symmetric divisions of stem cells?
2 stem cells 1 differentiates
What are locally directed divisions of stem cells?
niche directs differentiation after a symmetrical division
What is stem cell cancer?
stem cell can’t make differentiated daughter cells in each division = proliferates and self-replicates = forms a tumor
What is cancer due to stem cells?
daughter cells from stem cell = can’t differentiate = forms a tumor
What are cancer stem cells?
cells within tumors that can repopulate a tumor | self-renew and accumulate mutations during renewal cycles
Are stem-cell derived cancers more aggressive and more mutable?
too dependent on growth factor | not aggressive enough | may not know how to walk
What are the 2 general models for cancer heterogeneity?
stochastic model | cancer stem cell model
What is the stochastic model?
all cells have equal but low probability of extensive proliferation
What is the cancer stem cell model?
only a small subset the cancer stem cells can initiate tumor growth
What are techniques we can use to identify and target the cancer stem cells that can form a tumor?
look at surface expression using FACS and fluorophore | antibody staining
What is the fluorescence activation process?
antibodies are conjugated with fluorochromes (FITC) = recognize specific molecules on cell surfaces
What is fluorescent intensity?
emitted fluorescence intensity is proportional to the number of binding sites on a cell
