Cancer

• What is cancer the result of?

  Uncontrolled cell division
• What are mitosis and the cell cycle controlled by?

  genes
• What do cells normally do when they have divided enough times to make enough new cells?

  • They stop

  BUT if there is a MUTATION in a gene that controls cell division, the cells can grow out of control
• what happens if there is a mutation in a gene that controls cell division?

  The cells can grow out of control. The cells keep on dividing to make more and more cells, which form a tumour
• What is cancer?

  A tumour that invades surrounding tissue
• what can uncontrolled cell division lead to?

  the formation of cancers and tumours
• what are many cancer treatments directed at?

  Controlling the rate of cell division
• What are some treatments for cancer designed to do?

  • Control the rate of cell division in tumour cells by disrupting the cell cycle
  • This KILLS the tumour cells
  • HOWEVER these treatments do not DISTINGUISH tumour cells from normal cells- they also KILL NORMAL BODY CELLS that are dividing
• Why are the treatments more likely to kill tumour cells?

  Tumour cells divide more frequently than normal cells
• what do some cell cycle stargets of cancer treatments include?

  1. G1 - chemotherapy prevents the synthesis of enzymes needed for DNA replication. If these are not produced, the cell is unabble to enter the synthesis phase= cell cycle disrupted and cell forced to kill itself
  2. S phase- radiation and some drugs damage DNA. At several points in the cell cycle the DNA in the cell is checked for damage. if severe damaged detected, the cell will kill itself- preventing further tumour growth
• briefly describe g1?

  cell growth and protein production
• briefly describe S phase?

  DNA replication
• when is the dna in the cell checked for damage?

  several points in the cell cycle including just before and during S phase