Cancer : A Genetic Disease

1. Cancer :A Genetic Disease Drill: Write down 1 thing you know about the disease. What would you most like to learn about cancer / What question would you most like answered?

2. It affects millions of lives every year – so always use respect when discussing cancer

3. What is Cancer? • Cancer is a growth of cells that do not stop dividing. It is a progressive disease.

5. Benign vs. Malignant Tumors • A Benign (buh-nine) tumor is one made of cells that don’t spread around the body. • A malignant (aka cancerous) tumor is made of cells that can spread throught the body and make new tumors.

6. What causes cancer? • Mutations in certain genes cause the cancer cells to divide without stopping. (Normal cells stop growing when they’re in contact with other cells)

7. What causes these mutations? • Anything that can cause mutations in cells is a carcinogen.

8. Ok… but what causes mutations? 1: Certain chemicals can alter a DNA sequence by changing the sequence of bases.

9. 2: Radiation:Careful with that Sunlight!

10. 3: Viruses • Many viruses, like this one (HPV) can insert their genetic information into the DNA of their hosts. This mutation can sometimes lead to cancer. • HPV causes genital warts & is strongly linked with cervical cancer. • Why do you think the HPV vaccine (approved in the last year) is controversial?

11. Mutation Happens • Mutations happen all of the time in your body – but your cells have a lot of tricks for keeping your DNA in good shape!

12. The DNA Repair Kit • The DNA repair kit is a group of enzymes that fix mutations when they happen. • Cells may commit suicide (called apoptosis) when important genes malfunction, preventing cancer.

13. Broken Repair Kit = bad news. • Some mutations cause the repair kit to malfunction. • For example, a mutation in a gene that makes a DNA repair enzyme might make a non-functional protein or no protein at all! • Cells with bad repair kits will then accumulate more mutations

14. It’s Probability! That’s why cancer rates increase with age.

15. What we’ve seen so far: • Cancer is an uncontrolled growth of cells. • What process isn’t controlled anymore? • Cancer is a progressive disease. • Malignancy is one of the most dangerous characteristics of cancer – what is it? • Cancer is caused by mutations in DNA that affect cell growth and function • Cancer cells accumulate more mutations.

16. Can it be prevented? • Yes, but not 100% • Anything that reduces the number of mutations your cells suffer reduces your chances of developing cancer, so…

17. Are some people “predisposed” to cancer? YES • Being born with certain mutant forms of different genes can affect your chances of developing cancer. • For example – if some of your DNA repair mechanisms don’t work, you’re more likely to accumulate mutations. • If science could tell you approximately when you might develop cancer, would you want to know?

18. What genes are involved? Hundreds, perhaps thousands. • DNA microarrays like this one can show which genes a cell is transcribing, and how fast. • By comparing cancer cells to normal cells, scientists can identify what’s going wrong in cancer cells

19. Is cancer always fatal? NO!

20. Treatments • Surgery • Chemotherapy • Uses modified nucleotides to cause rapidly dividing cells (like cancer cells) to mutate and die off. • Radiation • Targets the cancer cells and destroies them.

21. The Future • Individualized genetic fixes • Drugs targeted to cancer cells • Gene therapy (inserting new genes to a person) • Better screening • Better tissue transplants – stem cells? • Nanobots?

22. Exit Ticket & Homework • Read “Cancer” pp . 211-214 • Exit Ticket: Answer the following questions before you leave! • What is cancer? • What causes cancer? • What cell process is uncontrolled in cancer cells?