Biological Behaviour of Tumours (week 10) Flashcards
What is the difference between gatekeeper and caretaker TSGs?
Gatekeeper: negative cell cycle regulators, positive apoptosis regulators
Caretaker: maintain genetic stability
What is the difference in the power of a mutation to affect a proto-oncogene / TSG?
An oncogene acts dominant to a proto-oncogene, so only one copy is required to be mutated to affect function. A TSG mutation is recessive so both copies must be mutated for any effect to be had.
Do tumour cells require growth factors to grow?
No. They also do not respond to anti-growth signals.
Why do tumour cells produce tolemerase emzyme?
To stop the shortening of the telomere, to remain normal length so that cell division can continue indefinitely
What is p53 and what is its role in tumour development?
Transcription factor that controls expression of TSGs. Tumours can inactivate p53 to lose the apoptotic response.
How do tumours sustain angiogenesis?
Induce vascular endothelial growth factor to actively recruit endothelial cells which proceed to construct new blood vessels.
Briefly explain how tumours are able to metastasise
Mutation of E-cadherin gene (adhesion molecule) results in epithelial-mesenchymal transition. Mesenchymal cells can break through BM and invade underlying stroma, which allows tumour cells to travel by blood / lymphatic system.
Define the terms stage and grade.
Stage: how far advanced the tumour is e.g. extent of growth / spread.
Grade: how aggressive the tumour is e.g. how differentiated, how quickly it transitions from benign to malignant
What is TMN staging?
Tumour: size and extent
Metastases: presence and extent
Nodes: presence and number of lymph node mets
What type of staging is used in colorectal cancer?
Dukes
Genetic change seen in leukaemia and lymphomas
Translocation
CA-125 serum marker detects
Ovarian cancer
Enzyme association with acquisition of cellular immortality in tumours
Telomerase
Tumours that arise in bladder
Transitional cell
Benign tumour of ovary
Cystadenoma
