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A cell should remain in interphase and not
divide if...
- signals from surrounding cells tell the cell
not to divide
- there are not enough nutrients in the cell
- the DNA has not yet been replicated
- the DNA is damaged
These checkpoints are regulated by special
proteins
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A group of diseases that results in
uncontrolled cell division
A result from the change of DNA that controls
the cell cycle
One or more of the checkpoints fails so the
cell and all its subsequent daughter cells
continue to divide uncontrollably
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Tumour: a mass of cells resulting from
rapid cell growth
Benign: tumours that stay
confined in a small area,
causing little damage
• Malignant: dangerous
tumours that break away and
move to other areas of the
body
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A
normal cell will live for between 50 and 60
cellular divisions. Cancer cells are
“immortal” because they never stop dividing.
A normal cell will undergo apoptosis if it is
damaged genetically, whereas a cancer cell
will continue to divide.
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When DNA is replicated sometimes the
process is not perfect and random changes
occur– this is called a mutation
These changes can result in the death of a
cell or allows the cell to divide rapidly until
all the nutrients are used up
Carcinogen: any environmental factor that
can cause a mutation (cancer)
Tobacco smoke, radiation (X-rays, UV rays),
certain chemicals in plastics
cancer video 1 cancer video 2
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If cancer runs in your family you can get
tested for it early
Especially if you are surrounded by certain
carcinogens your whole life
Screening does not prevent cancer but it
increases the chance of detecting it and
treating it successfully
Self checks for unusual lumps
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Using an endoscope (fibre
optic cable that delivers
light and a tiny camera) to
look into a patient and
search for and remove any
abnormal growths
Eg. Colon cancer
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Are used to view bones and
different tissues (lungs,
breasts)
X-rays can cause damage to
DNA and are harmful to the
cells of a growing fetus –
pregnant woman do not get
X-ray exams
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CT Scan: X-rays from multiple
viewpoints are taken
These are assembled digitally
on a computer
MRI: radio waves and a strong
magnetic field create more
detailed images in 3D
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Surgery: removing the damaged cells (tumour)
Chemotherapy: using drugs that stop/slow down
the cells from dividing. Shrinks the tumour and
spreads through the whole body to attack any
unknown cancerous tissues. There are many side
effects (hair loss, weakness).
Radiation: since cancer cells divide rapidly they
are damaged easily by certain radiations.