Chapter 4 - Somatic Mutation Theory Flashcards
Explain how tumor progression is a multistep progress.
Tumor progression is the result from an accumulation of DNA mutations. There has to be at least 4 to 8 mutations to convert into a malignant cell.
Why does cancer increase with age?
Mutations have to happen over decades
What is the Somatic Mutation Theory?
Cancers are caused by a series of genetic mutations
Name the simplest type of Mutation and what it is
Single base mutation, one base is changed to a different one
Why does a mutation promote cancer
If a normal protein is coded to control cell division then a mutant gene might produce an abnormal protein resulting in the loss of control in cell division
Where do mutations come from?
Mutations arise because of random mistakes in DNA replication
Do all mutations cause cancer? Why?
No, out of the entire genome only 2% consist of genes that code for proteins while the other 98% is non coding. Basically most mutations are in non coding areas of the genome
Mutations that don’t relate to cancer?
Passenger Mutations
How can cancer risk be increased?
By increasing the mutation rate
Explain why there is still a chance for a non-smoker to develop lung cancer
Mutations will occur spontaneously. There is still a chance that a non smoker can develop lung cancer, they will just be at less risk
What is the correlation of cumulative cell division and cancer risk?
As the number of cell divisions increase so does the chances of developing a spontaneous mutation
Why are cancers more common in epithelial cells?
Epithelial cells have more cellular division
Why does it take such a long time for the 4 to 8 mutations to develop?
- Cancer needs a mutation in both the cell and the DNA repair pathway
The risk of cancer can be increase in 2 ways. What are they?
- Increase in the mutation rate
2. Increase in the number of cell divisions
Why arent all tumor cells identical? List 2 reasons
- Different levels of resistance
2. Different sensitivity
