CE L5 Angiogenesis - Epigen, metas and angio intro Flashcards
what is epigenetics?
changes to the structure, not sequence of DNA
which affects DNA trancscription
what sort of changes take place in epigenetics? (2)
Addition of chemical groups to DNA or histone proteins
most commonly DNA methylation and and histone acetlyation
does the acylation of histones increase or decrease transcripion?
what enzyme does this?
increase
acetyl transferases
what epigenetic balance is altered in cancer
balance of acetylation and deacetylation enzymes occurs in cancer so you get too much/too little transciption
~Define metastisis
Cancer breaking away from site of origin and recolonizing at a distant site.
~Define metastisis
Cancer breaking away from site of origin and recolonizing at a distant site.
What is the fundamental different between benign and malignant growths?
Ability to metastasise
Effect of metastasis on prognosis
poor
Why do we want to predict sites of metastasis? 2
target them
catch them early
What size tumour is big enough to a blood supply and therefore metastasis
2mm
How does the cell come off the tumour to metastasis
break down of in cell-cell adhesion and degradation of the basal lamina
6 processes that lead to break away of cell
- Mutation in E-caherins
- Change in integrin expression
- Induce surrounding stromal cells to produce MMPs
- Intravasation (by degredation of basal lamina)
- Transport through blood vessels
- Extravasation (e-selectin)
What is E-cadherins?
Adhesion molecules
mutate in cancer to relax cell cell adhesion
2 theories about the site of metastasis?
First pass organ
Premetastatic niche
What is the premetastatic niche theory of metastasis site?
tumour cells recolinise in tissues that have similar growth factors or have been prepared to receive tumour cells
(extra: antigrowth signals in the niche don’t work, niche independent or the niche is prepared by the primary tumour)
