metastasis Flashcards
metastasis
the disease shifted from one part of the body to another
seed and soil theory
tumours metastase elsewhere due to congenial soil here that is compliment with what the tumour needs
mechanistic theory
mechanical forces and circulatory patterns between the primary tumor and the secondary site account for organ specificity
explain what theory isaiah fiddler had on metastasis
the circulation of blood and lymphatics is important but eventually what decides if a tumor stays is that the microbial environment fits that of the tumor
how is it that you can have different metastasises
a tumor makes clones with different genotypes, thus you can have different metastasis
EMT
process in which epithelial cells will get more mesenchymal cells in order to transform into a migratory phenotype
what characteristics do mesenchymal cells have that makes them able to migrate and invade more
no cell polarity, less adhesion, low level of E cadherin and high level of N caderin
what causes destruction of the ECM
matrix metalloproteinases (MMP)
explain the TGF beta pathway responsible for regulation of invasion and migration processes in cancer
TGF beta gets activated because of binding with a ligand. it will then express SMAD4 which causes TWIST and SNAIL to be activated which causes EMT to happen
by which cells is oxygen sensing done in tumour cells
HIF-1A
how does angiogenesis work in tumours
HIF-1A senses hypoxia and releases VEGF (pro angiogenic facotr), also there is protease expression leading to basement membrane degradation. tip cells migrate along angiogenic factor gradiënt. endothelial cells will become stalk cells which make up the main body of the new vessel. VEGF makes that DLL4 binds to Notch-1 receptors, PDGF-B stimulates pericyte attachment and recudes proliferation and VEGF sensitiviy. blood starts to flow
what is the funciton of E cadherin
it is essential to keep cells together
can you explain the relationship of E cadherin and B catenin
B catenin is bound to E cadherin. when E cadherin gets lost the B catenin will be able to become loose and thus cause cell proliferation
what is the role of integrin in metastasis
integrin helpt the ECM to stay put. when integrin is lost it will be easyer to invade the ECM and a cell will proliferate more
in which site of metastasis can you often see a cannonball
cannonball from the kidney is often seen in the lung
