1. Notes - Cancer and Cell Division
FACT: Each minute your body needs to make about 300 MILLION NEW CELLS!

2. I. Why Do Cells Divide?
A cell spends a good part of its life in a "G-phase" (growth phase) working and growing. However, cells inevitably wear out, break down and suffer injuries.
In addition, as organisms grow and change, they need new cells to make more skin tissue, bone tissue, muscle tissue. These new cells can only come from one place: OTHER CELLS - through the process of cell division, or mitosis.

3. II. What is Cancer?
Cancer is essentially a disease of mitosis - the normal 'checkpoints' regulating mitosis are ignored or overriden by the cancer cell. When these checkpoints are ignored, cells can begin to divide out of control.

4. Checkpoint:
Cell is normal  Cell moves to next stage of cycle
Cell is damaged  Cell does NOT move to next stage of the cycle.
Cell “kills itself” - apoptosis

6. III. What Causes Cancer?
Often cancer is caused by a DNA mutation that occurs in one of several genes that normally function to control cell division.
Example: The TP53 gene, the “tumor suppressor gene", usually functions to control the cell cycle. However, TP53 is mutated in over 50% of all human cancers.

8. IV. What are the two types of tumors?
Tumors can be either malignant or benign. Malignant tumors can be fatal because these tumors rob the body of vital nutrients and oxygen.
Malignant tumors can also disrupt the functioning of organs that they are in, or spread to other organs by metastasis.

9. As the tumor grows larger, it begins to release proteins from the cell to attract new blood vessel growth. (this is called angiogenesis)

10. Metastasis

11. Metastasis

12. V. What can you do to prevent cancer?
DNA damage can be caused by carcinogens such as cigarette smoke, UV rays, and pesticides.
Avoiding exposure to carcinogens can lower your risk of cancer.
However, some people are genetically predisposed to cancer (it runs in their family).

13. VI. How do you treat cancer once you have it?
There are many ways to treat cancer including chemotherapy, radiation, and prescription drugs.
Many cancer drugs target cells that are dividing by mitosis. As a result, some healthy cells usually die as a result of these treatments.