Transcript Cell cycle and cancer

The Cell Cycle and Cancer
Cell Cycle Review
Put these stages into the correct order.
Remember - it’s a cycle!
What happens at each stage?
Gap 1 (G1 phase)
Telophase
Cytokinesis
Anaphase
Prophase
Synthesis(S-phase)
Metaphase
Gap 2 (G2 phase)
The Cell Cycle
Mitosis is only a small part of the ‘life’ of a cell. The
process from one cell division to the next is known
as the cell cycle.
There are 4 parts to the cell cycle:
Gap 1
These stages are all parts of
Synthesis
interphase.
Gap 2
Mitosis
Cancer
What is it?
Uncontrolled cell division, caused by a genetic
mutation.
Tumours are masses of cells dividing by
uncontrolled mitosis.
They can be benign or malignant.
Control of cell division
Cells divide to ensure that dead or
damaged cells are replaced. The rate of
cell division is controlled by two genes:

Proto-oncogene –
stimulates cell division.

Tumour suppressor gene –
slows or inhibits cell division.
In normal cells the activities of these
two genes is balanced, however if a
mutation occurs in one of these
genes problems can arise.
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Oncogenes
If a point mutation occurs in
a proto-oncogene it can
form an oncogene. This can
stimulate excessive cell
division, leading to the
formation of a tumour.
If a point mutation occurs in
a tumour suppressor gene
it can become inactivated.
This allows the rate of cell
division to increase
unregulated.
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Cancer
What is it?
Uncontrolled cell division, caused by a genetic
mutation.
How does this relate to the cell cycle?
If a drug interferes with the cell cycle, we can
interrupt cell division.
How could drugs interrupt the cell
cycle?
Examples:
- inhibition of DNA polymerase
- binding to DNA to prevent binding of
DNA polymerase
- prevention of spindle formation
- inhibition of helicase
Q9 Jan 2010 BIOL2
Q9 Jan 2010 BIOL2
Q9 Jan 2010 BIOL2
Q9 Jan 2010 BIOL2