Age-related molecular disease Flashcards
(120 cards)
What is incidence?
Number of new cases in a given time period.
What is the incidence rate?
Number of new cases/Number of persons at risk.
What is prevalence?
Total number of cases.
Prevalence rate?
Total number of cases/ Total population size.
What leads to a cancerous tumour?
An imbalance between apoptosis and and cell divsion.
How long does cancer take to develop?
Years to decades.
Where do cancers origanate from?
Single aberrant cell.
What is the affect of tumour supressing proteins on ageing?
Increases it.
What are 2 two types of cancer-critical genes?
Proto-oncogenes
Tumour suppressors
How do Proto-oncogenes cause cancer?
Mutated or overexpressed result in too much cell proliferation.
What was the first oncogene known?
Ras.
What are tumour suppressors?
Protects the cell from cancer.
What is gene X?
Tumour suppressor.
What happens when deletion or point mutation in coding sequences occurs?
Hyperactive protein is made in normal amounts.
What happens when a regulatory mutation?
Normal protein greatly overproduced.
What happens when gene amplification occurs?
Normal protein greatly overproduced.
What happens when chromosome rearrangement occurs?
Nearby regulatory DNA sequences cause normal proteins to be overproduced.
Fusion to actively transcribed genes produces hyperactive fusion protein.
How many mutations does it take for a somatic cell to become cancerous?
3.
What kinds of mutations lead to the overactivation of the cell cycle?
Ras or Myc.
What is the role of Rb?
Inhibits the cell cycle until cells are ready to divide.
How does the Rb control the cell cycle?
It is mutated which leads to the start of the cell cycle.
What happens when mitogenic signalling is excessive?
Inhibits the cell cycle.
Why is ageing a risk factor for cancer development?
- Time.
- Decline in quality control.
How can age-related decline in protein homeostasis contribute to cancer?
The gradual likelihood of mutations being accumulated as damaged protein isn’t being removed fast enough.