1. Ch 21 & 19 Gene Mutations
Cancer

2. Objectives
Describe how mutations may affect traits. Cite examples of mutagens.
Present a position on mutations, genetic technology, and bioethics

3. Mutagens- cause mutation in the base sequence of DNA
Radiation
UV rays
X rays
Gamma rays
Chemicals
Tobacco n-nitrosonornicotine mixed with alcohol
Vinyl chloride
Benzoapyrene
Benzene
Asbestos
Radon

4. Mutagens
Viruses
Hepapitis B and C (liver cancer)
Epstein-Barr
Human papillomavirus
Retroviruses which are RNA that use the human body to change the DNA
Kaposi’s sarcoma- suppresses the immune system
HTLV-1 hairy cell leukemia

5. Ames test
Determines if a substance is a mutagen

6. Loss of function Mutations
Are changes in the nitrogen base of a DNA molecule that stop a function.
Cyclin is a protein that sends the cell into mitosis.
If it is mutated the cell will go repeatedly into mitosis.
Proto-oncogenes make proteins that prevent apoptosis. They accelerate the cell cycle and turn on the production of Cyclin.
Tumor suppressor genes make proteins that stop the cell cycle and cause apoptosis.
P53 activates repair enzymes or stops cell cycle. One proto-oncogene shuts down p53.
Many tumors lack p53.

7. Bax
Protein that promotes apoptosis.
Has 8 consecutive G bases.

8. Cancer types Carcinoma- epithelial tissues
Adenocarcinoma- skin, breast, ovary, cervix, liver, pancreas, intestines, lung, prostate, thyroid.
Sarcoma- muscle and connective tissue
Leukemia- blood
Lymphoma- lymph

9. Cancer is not yet cured 1st cancer gene discovered in 1990.
Breast cancer 1 (BRCA1)
BRCA2 are tumor suppressor genes.
Mutation in both genes (one from each parent) produce cancer.
RB gene is a tumor suppressor gene. Found from eye cancer retinoblastoma.

10. Skin cancer test

11. Telomerase gene Enzyme that keeps genes a constant length.
When turned off, this gene produces cancer cells.

12. HeLa cells
Henrietta Lacks, woman had 5 children, had vaginal bleeding in Doctors found a quarter size tumor on her cervix. Samples of the tumor were sent to Johns Hopkins University.
She died after 8 months.
Her cells were still living and multiplying in the lab of Johns Hopkins.
Jonas Salk used these cells to make a vaccine for polio.
1974 her cells were still multiplying.

13. Mutations
Deletions
Additions
Substitutions
Inversions

14. Sickle cell anemia
Deletion of one base in the hemoglobin gene

15. Videos https://www.youtube.com/watch?v=LOX_59RSF68