TAIM Flashcards
What are the characteristics of malignant tumours?
→growth
→invasiveness
→metastasis
What are the key steps in cancer progression?
→transformation
→angiogenesis
→motility and invasion
→metastasis
What happens in transformation in cancer progression?
→extensive mutagenic
→epigenetic changes
→clonal selection
What happens in angiogenesis of cancer progression?
→new blood vessel formation (overcomes limitations imposed by hypoxia
What happens in motility and invasion in cancer progression?
→epithelial to mesenchymal transition
What is metastasis?
→colonisation of target organs (ability to expand from micrometastases)
What is the difference between angiogenesis and vasculogenesis?
→Angiogenesis is the formation of new blood vessels from pre-existing vessels
→Vasculogenesis is the formation of new blood vessels from progenitors
What are the three types of angiogenesis and what does each lead to?
→Developmental/ vasculogenesis= organ growth
→Normal
angiogenesis= wound repair, placenta
→Pathological angiogenesis= tumour angiogenesis
What is the maximum size of tumours without their own blood supply?
→1-2 mm3
Describe the angiogenic process
→Tumour switches on expression of angiogenic genes/factors
→they initiate new blood vessel growth
→New network of blood vessels grows in and around the tumour
→increasing the delivery of oxygen and nutrients
that allows it to increase growth
→provides a route for cells to shed off and spread
What allows directional growth of new vessels toward a tumour?
→Chemotaxis signals
What is a strong stimulus for tumour angiogenesis?
→hypoxia→
What is hypoxia?
→low oxygen tension <1% O2
What genes are activated by hypoxia?→
→VEGF
→GLUT-1
→u-PAR
→PAI-1
What are the 4 factors that stimulate the directional growth of endothelial cells?
→Vascular Endothelial Growth Factor (VEGF)
→Fibroblast Growth Factor 2 (FGF 2)
→Placental growth factor (PlGF)
→Angiopoietin 2 (Ang 2
How are factors that stimulate directional growth of endothelial cells found in the cells?
→stored bound to components of the extracellular matrix