Genomic Instability

Cancer cells exhibit genomic instability. Chromosomal rearrangements and duplications are often seen in the karyotype of cancer cells. Cells normally will stop in the cell cycle if DNA is damaged. Several proteins have been identified that act to halt the cell cycle until DNA damage is repaired.

p53 protein

• increases in activity in response to DNA damage.
  
  
• leads to G1 arrest (pause in cycle) or apoptosis (cell death).
  
  
• is defective in many different types of cancer and therefore the cells do not stop divding when DNA is damaged.

	Cell Differentiation
	Mutations Affecting Cellular Processes
	Accumulation of Mutations in Cancer
	Cell Proliferation
	Genomic Instability
	Familial Cancers