1. Uncontrolled cell growth and survival
Cancer
Uncontrolled cell growth and survival

2. Two Types of Tumors Benign (noncancerous) Look like cells around them
Have controls that prevent infinite division
Stay local
Malignant
Cells shaped improperly
Have lost controls that prevent cell division
Can metastasize
Normal fibroblast cell vs. Malignant fibroblast cell

3. Metastasis
Primary cancer cells can release signals to start growth of blood vessels (angiogenesis)
Cancer cells get nutrients, oxygen, and a passageway to elsewhere in the body
Secondary tumors result when cancer cells find a new home and thrive

4. Metastasis

5. Why Tumors are Harmful
Mutated cells can’t carry out normal functions (are not specialized)
Mutated cells crowd out normal cells
Mutated cells use up nutrients normal cells need

6. Carcinogens-chemical, physical, or biological agents that cause cancer
UV radiation
Tobacco
Some viruses (i.e. human papillomavirus- HPV)
Some toxins & chemicals
How do these all cause cancer?
They damage DNA!!!
Cancers result if they damage tumor suppressor genes or proto-oncogenes

7. What types of genes do carcinogens mutate?
Unit 5 - Reproduction (Topics 3-4)
OBJ 12
What types of genes do carcinogens mutate?
Proto-Oncogenes
Normal proteins stimulate cell division (Like the gas pedal)
Cause the cell to move into S phase
Mutation activates them permanently, turning them into “oncogenes”
Tumor Suppressor Genes
Normal proteins block cell growth and division (Like the brakes)
Mutations turns these genes off (inability to stop cell division)
p53 is an example (on chromosome 17)
Oncogenes are the mutated version of growth promoting genes: they have improved function, and encourage excess growth

8. Unit 5 - Reproduction (Topics 3-4)
OBJ 12
What does p53 do normally?
p53 is mutated in about 50% of human tumor cells

9. Unit 5 - Reproduction (Topics 3-4)