Cancer
- Acquired Mutations: A mutation that occurs in individual cells after fertilisation
- A mutation in genes linked to the rate of cell division can lead to uncontrolled cell division.
- Tumour: A mass of abnormal cells brought about by uncontrolled cell division
- Malignant (Cancer): Tumour that invades and destroy surrounding tissues
Tumour Suppressor Gene
- Normal: Slows cell division through production of proteins that stop cells dividing or apoptosis
- Mutation: Gene will become inactivated so protein is not produced. Cell divides uncontrolled
Proto-oncogene
- Normal: stimulates cell division through production of proteins which results in cell division
- Mutation: the gene can become overactive and stimulates cells to divide uncontrollably
- A mutated proto-oncogene is called an oncogene
Types of Tumour:
- Malignant:
- Cancer
- Rapid growth
- Invasive of surrounding tissue
- Metastasis: tumour cells can spread via blood/lymphatic systems
- Benign
- Non-cancerous
- Slower growth
- Covered in fibrous tissue that prevents invading other tissue
- Greatly harmless, however can cause blockage and pressures and may develop into malignant
Tumour Cells
Tumour Cells differ from normal cells as:
- Nucleus is larger and darker
- Some cells have more than 1 nucleus
- Irregular shapes
- Not all proteins needed to function are produced
- Different antigens
- No response to growth regulating processes
- More frequent mitosis
Causes of Tumour Growth
- Abnormal Methylation
- Addition of -CH3 onto DNA is used to regulate gene expression as it can determine whether a gene is transcribed and translated
- Hypermethylation (too much methylation)
- Hypomethylation (too little methylation)
- Oestrogen in Breath Cancer