Oncology 5 Flashcards
What are the steps of apoptosis?
- cellular membranes disrupted, cytoplasmic and nuclear skeletons broken down
- cytosol is extruded
- chromosomes degraded, nucleus fragmented
- shriveled cell corpse engulfed by macrophages
How long does it take for the cell to disappear after apoptosis?
24 hours
What are the two components of apoptosis?
- sensors
- effectors
apoptosis: sensors
Internal sensors of DNA damage or abnormality stimulate the release of effector agents
apoptosis: effectors
- Stimulated by abnormality sensors
- Mitochondria release chemicals to trigger apoptosis
What does “sustained angiogenesis” mean?
- has a self-building vascular supply
- commands blood to come to them
What happens to cells when they are a certain distance from a source of oxygen and nutrients?
stop growing
What do cancer cells use to signal growth of new blood vessels and sustain growth?
VEGF
VEGF =
vascular endothelial growth factor
Vessel anatomy: What is different about the normal vasculature and tumor vasculature?
- normal is highly organized
- tumor is highly disorganized with abnormal architecture
What are some of the characteristics of tumor vasculature?
- tortuous
- dilated
- uneven diameter
- excessive branching and shunts
- highly permeable
Which characteristic of tumor vasculature promotes metastasis?
high permeability
How do chemotherapy agents target angiogenesis?
- blocking VEGF receptors
- interfering with tyrosine kinase
- interfering with intracellular activator pathways
What do the drugs that end in -MAB do?
starve the tumor of nutrients
What do drugs that end in NIB do?
prevent cell from dividing and growing
