Regulating the Cell Cycle

1. Regulating the Cell Cycle • What do you already know about cancer?

2. Regulating the Cell Cycle • the cell cycle has a built-in genetic signals to tell cells when to start and stop dividing • proto-onco genes – genes that encourage cell division • tumor suppressor genes – genes that inhibit cell division

3. Cancer • a disorder in which some cells lose the ability to control their own growth • these cells divide uncontrollably resulting in a tumor • tumor – an abnormal growth of tissue, not necessarily cancerous

4. Cancer • involves a loss of control over the cycle, malfunction of the “brakes” • the malfunction is caused by a mutation • Mutation – a change in a cell’s genes (DNA) • Oncogenes – mutated proto-onco genes that stimulate excessive division

5. Cancer • when cancer cells break loose from a tumor they can spread to other parts of the body, thus spreading the cancer • Metastasis – spreading of cancer from one area of the body to another • uncontrolled division can compromise the function of an organism and ultimately may cause death

6. Cancer Cancer and metastasis

7. Statistics(from the National Institutes of Health) • On average, in the US: • men have a 1 in 2 lifetime risk • women have a 1 in 3 lifetime risk • Cancer is the second leading cause of death in the US, after heart disease. • The National Cancer Institute estimates that approximately 8 million American alive today have a history of cancer

8. Risk Factors • Many Americans have a higher than average chance of developing cancer • Risk Factors can be broken into two categories: • Factors that you have control over • smoking, diet, environmental • Factors that you have no control over • genetics (family history), environmental

9. Treatment Options • Four major types of treatment options • Surgery – removal of the affected tissue • Radiation – exposing the affected area to ionizing radiation

10. Treatment Options • Four major types of treatment options • Chemotherapy – treatment using chemicals that harm rapidly dividing cells • Immunotherapy – enhancing the body’s immune system to help fight cancer

11. Follow up Question • In recent years, the gap between the number of people who develop cancer and the number who die from it has increased. What factors do you think are contributing to this gap?

12. Other Resources • Pg 126-127 in your textbook • National Institutes of Health • (see “Related Links” sections also…) • National Cancer Institute