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=IeUANxFVXKc&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)