Cancer

• Cancer can result from mutation in mitosis regulator genes
• Mutation causes non-functional proteins which can lead to uncontrolled division (tumours) due to mitosis not being regulated

  • Unethical to not treat cancers
• Benign Tumour


  Slow rate of division, non-cancerous, localised with a capsule
• Malignant Cancer


  Fast rate division, cancerous, unspecialised, can metastasise and grow projections, creating blood supplies

  • Treated with chemo/radiotherapy, but can reoccur
• Cancer can be caused due to mutation in the tumour supressor gene or oncogene

  • Linked to abnormal methylation or increased oestrogen
• Oncogenes


  Mutated version of proto-oncogene, which create a protein involved in intiation of DNA replication and mitosis

  • Mutation results in process being permanently active, continuous division
• Tumour Supressor Genes


  Produce proteins to slow down cell division and cause cell death

  • Mutation results in no proteins due to a change in primary structure, meaning continuous cell division and mutated cells would not be identified and destroyed
• Abnormal Methylation


  Methylation can turn activate or inhibit a gene

  • Hypermethylation of the tumour surpressor gene causes it to be inactive, inhibiting it
  • Hypomethylation of oncogenes causes permanent activation
• Increased Oestrogen


  Menopause stops production of oestrogen, so fat cells in breast tissue produce oestrogen instead

  • Increased likelihood of breast cancer as oestrogen binds to a gene that initiates transcription, if it is a proto-oncogene, then permanent activation of cell division