Mechanisms of cell deviance Flashcards
What are some environmental factors for cancer?
diet, infectious agents, radiation, tobacco
What are the mechanisms to prevent mutation?
Cell cycle control
* Proof reading mechanisms
* Genetic code
What causes cancer
need multiple mutation, e.g. loss of function and gain of function- uncontrolled proliferation
How do cancer cells evolve to move to different locations?
they are genetically unstable with high mutation rates and other chromosomal abnormalities, they lack adhesion molecules, when one cell proliferates (through paracrine signalling) the cells around it will also proliferate
Oncogene
gene with a dominant behaviour that leads to a gain-of-function mutation, this causes excessive cell survival and proliferation
Tumour-Suppressor gene
need to have a mutation on both genes as it’s a recessive mutation, if this occurs it no longer works (aka tumours no longer supressed)
p53
can repair or trigger apoptosis for mutated cells
What happens when cells lose their ability to proliferate?
they senesce
What is ROS?
Reactive oxidative species
What are the two ways ROS can be formed?
Mitochondrial stress and external insults
What is Oxidative stress?
an imbalance between pro-oxidative and anti-oxidative events
What do anti-oxidants do?
reduce the amount of ROS produced
What are some Enzymatic anti-oxidants?
Catalase, Glutahione group, Thioredoxin, Superoxide dismutase
What are some Non-enzymatic anti-oxidants?
Reduced Glutathione, Vitamins C and E
What is a RAS protein?
oncogene that signals for cell proliferation
What are adhesion molecules?
cell surface proteins involved in the binding of cells with other cells
Neoplasia
new growth
Neoplasm
any tumour with uncontrolled growth
Tumour
swelling
Oncology
Greek- describes swelling
Benign
slow growing and do not metastasise
Malignant
invasive, features of metastasis
Anaplasia
loss of differentiation to become a more primitive cell type
Cancer
malignant neoplasm
What can cause cell senescence
End of replication problem-telomeres
shortening
DNA damage
Stress and external stimuli
How does cell senescence relate to age?
Increase in age increases the amount of cells that senesce
What can ROS Lead to?
mitochondrial damage which can lead to abnormal cell growth
What are the two major sources of ROS in your body?
Mitochondria and NADPH oxidases
What can AGE lead to?
Chronic conditions
How are AGE formed?
Schiff base interacts with a ROS to form an Amadori Product
Where does Protein folding occur?
In the ER
What mediates protein folding?
Chaperone proteins
What does UPR do?
Signalling cascades activated to repair protein homeostasis
- Signalling extends beyond a ‘simple’ repair of misfolding events
- Affects protein translation levels
- Affects immune response
- Affects cell survival, autophagy, redox balance,
