Transcript 3-5 mutations

Cancer
Above is a picture of two human cancer
cells sitting next to each other right before
they're about to divide into four cells.
They're derived from the now famous
"HeLa" line of cancer cells, which were
taken from Henrietta Lacks in 1951 and
used for medical research without her
permission. "Understanding how cells
divide is critical to understanding how
cancerous cells multiply and take over,"
according to Dr. Paul D. Andrews,
University of Dundee, Scotland)
What is Cancer?
• A disease where cells grow and
divide uncontrollably.
• It’s mitosis gone wrong!
Cancer: Unregulated Cell Division
Watch Normal Cells vs. Cancer Cells
divide. Pay attention to the differences!
http://www.youtube.com/watch?v=IeUA
NxFVXKc&app=desktop
How Does Cancer Grow?
•
Cancer is a gradual process:
– Normal cells have a clock letting them know when to start and stop
dividing.
– However, sometimes a cell’s DNA can become mutated.
– A cell needs at least 3-5 mutations to be considered cancerous.
– Each mutation makes the cell divide FASTER and changes its appearance
– The mutated cells keep dividing creating a mass called a tumor.
– The tumor grows bigger by recruiting blood vessels to help nourish it with
food and oxygen.
How Does Cancer Spread?
• Some tumor cells can break free from the mass.
• They use the blood stream to travel to a new location.
• Metastasis describes a cancer that has spread.
• The cancer is now considered malignant.
Activity: How Cancer Grows
Go to:
http://www.pbs.org/wgbh/nova/cancer/grows.html#
Review the animation to watch how cancer grows.
Who is at Risk?
• Anyone can develop cancer.
• However, some people are at a higher risk.
– This is because some people are born with cancerous
mutations.
– This puts them closer to reaching the 3-5 mutations
needed for a cell to be considered cancerous.
Cancer Treatments
– Surgery: Usually used before cancer has spread
– Chemotherapy: Intravenous drugs used to kill
or slow the growth of cancer cells by stopping
cell division.
– Radiation: Beams of high energy waves used to
kill cancerous cells (shown above)
Cancer Video Review
• Cancer: from a healthy
cell to a cancer cell
(4 min 39 seconds)
– http://www.youtube.co
m/watch?v=8LhQllh46y
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