Stem Cells and Differentiation Flashcards
multipotent vs oligopotent
multipotent: stem cells can differentiate into different types of cells in a closely related family (ex: hematopoietic sc)
oligopotent: stem cells can differentiate into a few cells (ex: lymphoid or myeloid sc)
what type of modification is required for cell to change from totipotent —> pluripotent —> multipotent —> unipotent?
epigenetic modifications
(DNA methylation, histone acetylation or methylation, etc)
what are the key properties of stem cells
unspecialized/undifferentiated
can self-renew
can be induced to differentiate into different cell types
how is stem cell self-renewal regulated?
cell-intrinsic regulation: [Sox2-Oct4-Nanog] transcription factors and DNA brining protein [Ronin] negatively regulate differentiation-promoting genes [such as GATA4, GATA6]
cell-extrinsic regulation: ligands which work through STAT3 and SMAD to block MAPK pathway (important pathway for differentiation gene expression)
what are the known adult stem cell types?
- hematopoietic (all blood cells)
- mesenchymal (connective tissue, muscle, bone)
- neural
- epithelial (lining of GI)
- skin
neutrophils, basophils, eosinophils, macrophages, platelets, and RBC are derived from ____ progenitor cell
myeloid
(lymphoid progenitor gives rise to B/T lymphocytes and NK cells)
from what stage of embryo development are embryonic stem cells derived?
blastocyst - use the inner cell mass (ICM)
what type of cell is totipotent
zygote only
transdifferentation
directed re-programming of cells - partially or terminally differentiated cell reverts to an earlier developmental stage and is re-directed to be a different cell type
what is the new theory of cancer cells
cancer is stem cell disorder and not a simple mechanism whereby cell proliferation is disrupted
cancer stem cells can persist in tumors as distinct population making relapses and metastasis likely (are not affected by conventional chemotherapies)
