cell migration, metastasis Flashcards
altered growth/homeostasis
division increases with normal apoptosis
normal division with decreased apoptosis
excess proliferation
division without suspension: do not need to be adhered
cross basement membrane
bypass apoptosis signals
necrosis in center (hypoxic)
growth continues around perimeter
microenvironment: components that impact development
fibroblasts: remodel connective tissue, make room for cancer growth
immune cells: survival signals
metastasis: invasion
tumor growth begins in epithelium
EMT: loss of polarity and adhesion
MMPs
break connective tissue
cells can then go to capillary
intravasation
cells squeeze past endothelium and enter capillary
enter circulation
extravasation
circulatory system delivers cells to site of metastasis
cells squeeze out of endothelium
Hif1-a
transcription factor
stimulates VEGF
vessels proliferate, capillaries develop and deliver directly to site of metastasis
lamellipodium
blob at the front end of the cell, mediates fusion with substrate and movement
Arp 2/3 in cell migration
mediates actin nucleation
generates lamellipodium
protrusion
PM pushed out at the front of the cell (in the lamellipodium)
leads to substrate attachment via focal adhesions
focal adhesions
connect lamellipodium to substrate
integrins
bind integrins
one set releases actin
can bend back to lesses ECM affinity (inactive vs active forms)
Rho-GTPases
activate actin-myosin II
MLCK is phosphorylated
