Neoplasm 3 Flashcards
What are oncogenes?
Stimulate cell growth.
What are tumour suppressor genes?
Slow down cell growth
What is initiation regarding to cancer?
1st mutation acquired- can be oncogene, tumour suppressor, apoptosis evasion or DNA repair mutation
Affects single group of cells
Further accumulation of mutations is known as _.
Promotion - often results in dysplasia
Progression marks the capacity of a tumour to have _ _ growth.
Unregulated, Abnormal.
Metastatic. Malignant
What are the 3 categories of growth receptors?
- Receptors with intrinsic tyrosine kinase activity
- Receptors without tyrosine kinase activity
- 7 transmembrane G protein coupled receptors
Example of a tyrosine kinase receptor. (dont memorise)
C-KIT. mutated in GI stromal tumours.
Imatinib common treatment
RAS mutation affects which cancer? (3)
Colon, lung, pancreatic
BRAF mutation affect which cancer?
Melanoma
What is the function of Myc?
Nuclear transcription factor that promotes growth- DNA replication
Mutation commonly seen in lymphoma
Most commonly mutated kinase in cancer is the _
PI3K.
The p53 protein is an example of a _ _ gene.
Tumour suppressor
What are the steps involved in the action mechanism of p53?
- Senses DNA abnormalities in G1 of cell cycle. If found, the cell cycle is paused.
- Increases levels of p21- a CDK inhibitor
- Cyclins produce CDK.
- If abnormality is corrected- cell cycle resumed
If not- p53 induces apoptosis
What is the role of PTEN’s?
Produce p27, which inhibit CDK production and cell cycle progression
Without p27- Uncontrolled proliferation
Very common genetic mutations of DNA repair genes that cause breast cancer? (2)
BRCA 1 & 2
