Oncogenes and Tumour Suppressor Genes Flashcards
In which tissues are carcinoma found?
Epithelial
In which tissues are sarcomas found?
Muscle, blood vessels, bone, fibroblasts
In which tissues are leukaemia/lymphomas found?
Circulating cells of blood and lymph systems.
What is a benign tumour?
A tumour that does not invade surrounding tissue or spread to other organs.
What is a malignant tumour?
A tumour that invades and destroys adjacent normal tissue. It can spread to distant organs via the circulatory system.
Do most mutations cause cancer?
No, many are passenger mutations and not cancer causing.
What are the clonal origins of cancer?
Monoclonal - usually arises from one cell.
If cancer comes from mutation on X chromosome, for women cells can be identified as cancerous or not due to X-inactivation.
What kind of in vivo assays can be done?
Tumour formation in animals:
Transgenic and knockout strains
Application of cancer causing agents.
Give four of the main risk factors for cancer.
Smoking
Diet
Viruses
Family history
What is a protooncogene?
A gene that has a normal role and function, but the potential to do bad (cause cancer) if mutated.
What does CDK stand for?
Cyclin dependent kinases.
What is the restriction point?
Cells receive signals from outside telling it to proliferate. It will stop if signals stop, up until restriction point.
When would anaphase be blocked?
During mitosis - if chromatids are not properly assembled on mitotic spindle.
When would entrance to M be blocked?
End of G2 - if DNA replication is not completed.
When would entrance to S be blocked?
End of G1 - if genome is damaged.
What would be halted in the middle of S phase if the genome is damaged?
DNA replication.
Name 3 oncogenes.
ras
myc
bcl-2
Name two tumour suppressor genes.
p53
Rb