Cancer Cell Death Flashcards
Where are the cell cycle checkpoints?
> After G1 (before S phase)
During S phase
During G2
During mitosis (spindle assembly checkpoint)
What is cornification?
Caspase-4 activation
What is intrinsic apoptosis?
Mitochondria and cascade associated apoptosis
What is extrinsic apoptosis?
Apoptosis that occurs via: death receptors (involving caspase 3 and 8 activation) or dependence receptor activation
What is anoikis?
This is a form of caspase-dependent cell death that is induced by anchorage-dependent cells; detaching from the surrounding extracellular matrix.
What is pyroptosis?
This is involved with antimicrobial responses during inflammation and requires the function of caspase 1
What is entosis?
Where a cell dies as a result of becoming engulfed by a neighbouring cell
What are the main differences between caspase-dependent and caspase-independent apoptosis?
Caspase-dependent apoptosis can be stopped by a caspase inhibitor, involves nuclear fragmentation, small scale DNA fragmentation and DNA ladders.
Caspase-independent apoptosis can’t be inhibited in this way, there is no nuclear fragmentation, there is large scale DNA fragmentation and no DNA ladders.
What are the forms of caspase-dependent cell death?
Anoikis, intrinsic apoptosis, extrinsic apoptosis (by death receptor and dependent receptors) and pyroptosis
What are the forms of caspase-independent apoptosis?
Autophagy, caspase-independent intrinsic apoptosis, enosis, necroptosis, neurosis and parthanatos
What is necroptosis?
Death receptor mediated cell death without caspase activation
What is immunogenic cell death?
A cell death modality that stimulates an immune response against dead-cell antigens, in particular when they derive from cancer cells.
What are the causes of apoptosis?
> Physiological activators - TNF, TGF etc.
Damage-related inducers such as heat shock, viral infection and free radicals
Therapy associated agents such as chemotherapy drugs
Toxins such as ethanol or beta-amyloid plaque
What are the morphological features of apoptotic cells?
> Cellular and nuclear condensation
Nuclear fragmentation
Nuclear and mitochondrial condensation
Cellular fragmentation
What are the biochemical features of apoptotic cells?
> DNA fragmentation
DNA fragments accumulate in the sub-G0/G1 phase
Phosphatidyl serine exposure (eat me signal)
What is the major control centre for regulating apoptosis?
Mitochondrion
What is the final step of apoptosis?
DNA fragmentation
What factors make cells resistant to apoptosis?
Bcl-2, NF-kB, STAT3, PI3K/AKT
