Unit 3: Cancer Flashcards
What is cancer ?
A group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body
What is cancer characterised by ?
Cell cycle deregulation and uncontrolled proliferation
What are the 5 main types of cancer ?
1) Carcinoma
2) Sarcoma
3) Lymphoma/Leukemia
4) Blastoma
5) Germ cell tumour
How does cancer develop ?
1) Mitogen binds to cell surface receptor
2) This activates an intracellular signalling cascade
3) Increases proteins needed for cell cycle
- Mutations can happen at any of this stages and this is how this develops
What causes mutations (6) ?
- Free radicals
- Radiation
- UV light
- Viruses
- Bacteria
- Errors in DNA replication
What is Carcinogenesis ?
Formation of a cancer
How many independant mutations are needed for cancer ?
2-12 mutations
What 2 types of cell never enter G0 ?
- Epithelial cells
- Bone marrow stem cells
What is a tutor suppressor gene ?
They encode proteins that stop a cell from proliferating out of control or inducing apoptosis
What is a proto-oncogene ?
A gene that has the potential to cause cancer, usually encode proteins that promote growth, inhibit apoptosis or both
What is an Onco gene ?
A mutant form of proto-oncogene = a cancer cell
What is needed for cancer to occur ?
Mutations in both oncogenes and tumour suppressor genes
What is the relationship between cyclin and cancer ?
Cyclin is over expressed and this is seen in many cancers. This leads to a faster cell cycle so tumours are able to grow faster
What is the function of tumour suppressor genes ?
- Prevent cell cycle progression
- Increase apoptosis
Give an example of a tumour suppressor gene in the cell cycle
Rb
