Dr Rachel Davies

• 1. Outline the evidence that cancer is a multi-step genetic disease

malignant metastasis is caused by many different genes at many different stages

• 2. Define the difference between oncogenes and tumour suppressor genes

oncogenes are created from pro-oncogene cells these are cells that if mutated once will form an oncogene which will cause increased stimulus for cell proliferation to occur

tumour suppressor genes include genes such as p53 or Rb

these genes must be mutated twice in order to be inhibited, if they are mutated twice they will not recognise when there is DNA damage and will not induce cell death/apoptosis in cells that need it.

there are two main types of tumour suppressor genes, these include gatekeepers & caretakers

p53 is an example of both of these genes

gatekeepers

Inhibit proliferation or promote the death of cells

(especially those with DNA damage)

Send negative signals to the cell signalling to not begin proliferation

caretakers