DNA repair and genetics of cancer Flashcards
What does spontaneous deamination cause?
conversion of cytosine to uracil
How many hallmarks of cancer are there?
8
What is the major impact of the RB mutation in cancer?
Proliferative signalling
BRCA1 is involved in which DNA repair pathway?
Homologous recombination
How many key proteins are in the RAS family?
3
what is the major function of K-RAS?
intracellular cell signalling molecule
Which cancer has Chernobyl been linked with?
Thyroid cancer
How many genes have been linked to cancer
700 or 1%
What is a somatic mutation
An alteration in DNA that occurs after conception
How can DNA and genes be damaged
Depurination
Spontaneous deaminationn
Exposure to mutagenic agents
Errors in DNA replication and repair
What can DNA damage affect
Normal growth genes - mutated into oncogenes
Tumour suppressor & DNA repair genes inactivated
What is an oncogene
A proto-oncogene that has been altered or mutated
What does a proto-oncogene do and what happens when it is altered
Promotes differentiation and proliferation of normal cells.
A mutation causes change in amount of protein produced
What is a tumour suppressor and what happens when they are inactive
Genes that regulate the growth of cells
Lose the ability to produce protein that controls controls cell growth
What are the 3 basic steps of DNA repair
Excision
Resynthesis
Ligation
What pathways repair double stranded breaks
Homologous recombination
Non-homologous end joining
What pathway are BRCA1 and 2 involved in double strand breaks
Homologous recombination
What is DNA methylation
Methyl groups added to certain DNA bases can silence gene activity
What is a histone modification
Combination of molecules can attach to histones, altering the activity of the DNA wrapped around them
