Cancer. But what is cancer? 9/30/16. Ch. 5 Cancer BIOL 100. What causes Cancer?

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1 Ch. 5 Cancer BIOL 100 Cancer What causes Cancer? Smoking radiation (soar, nucear) carcinogenic chemicas Hormones viruses But what is cancer? Cancer occurs when ce division goes out of contro Cancer is a faiure of the natura ce cyce 1

2 What makes the ce cyce fai? Cancers start with a MUTATION of DNA This causes a MUTATION in a GENE A GENE is the genetic directions for making a PROTEIN Mutated Gene Mutant Protein The resuting mutated protein causes a faiure in the natura ce cyce, causing the ces to divide uncontroaby. Cancer Is a Genetic Disorder Mutation: change in genetic makeup that, in this case, causes ces to become cancerous Carcinogens: substances that increase rate of mutations and cancer risk Maignant: Tumor has invaded surrounding tissues Metastasis: Process in which ces are invasive and move to other sites in the body Not a tumors are cancerous, benign tumors, increase in size, but do not metastasize 2

3 2 kinds of genes contro ce cyce: Oncogenes and tumor suppressor genes Oncogenes: contro ce division make proteins that trigger ces to divide Tumor suppressor genes: turn off ce division A faiure of either oncogenes or tumor suppressor genes can cause ces to divide uncontroaby. Cancer and Heredity Most cancers are from environmenta mutations But some can be inherited Inherited mutations do not give you cancer, but can make you more predisposed to deveop cancer. Chronic Myeoid Leukemia Uncontroed proiferation of white bood ces Triggered by genetic mutation of chromosomes Piece of chromosome 9 gets swapped with a piece of chromosome 22 Resuts in a MUTATED GENE caed BCR-ABL - This mutated gene makes a MUTATED PROTEIN BCR-ABL - The mutated protein makes the white bood ces divide uncontroaby 3

4 Cancer Treatments Historica treatments: remove / ki the cancer Surgery Radiation Chemotherapy New treatments: disrupt the process by which cancer ces mutipy = Targeted Therapies 1990's: Oregon Heath and Sciences University professor Brian Druker CML mutated gene creates mutated protein BCR-ABL 4

5 HER2+ human epiderma growth factor receptor 2 VEGF-A Vascuar endotheia growth factor-a VENOM PEPTIDE paraytic Anti-cancer (soricidin) - breast - ovarian - prostate Anti-cancer Effect: Soricidin Disrupts a protein found in high numbers in cancer ces that is NOT found in high amounts in norma ces This protein forms a cacium ION CHANNEL on the pasma membrane Inactivating this ion channe protein causes cancer ces to sefdestruct EFFECTS OF SORICIDIN 5

6 Shrew Protein: Not ony can be used to ki the cancer ces, but aso identify them at cancer stage 1 Attach a marker to the protein see if the marker binds to the ce. If yes the protein must be bound to the cacium ion channe protein ce must be cancerous. Now in human trias Stage 1 cinica trias: test drug's SAFETY Stage 2 cinica trias: test drug's EFFICACY Stage 3 cinia trias: repeat of above with many more peope Cancer Research in the News #1 AVASTIN Targeted therapy for bowe cancer In advanced bowe cancer, Avastin ony heps 10% - 15% of patients. Some medica insurance companies have dropped Avastin accordingy. Why does it not hep more peope? 6

7 Avastin targets a growth factor protein This protein exists in TWO major forms One form of the protein ENHANCES tumor growth The other form SUPPRESSES tumor growth Avastin interrupts BOTH forms of the protein What to do? Test cancer ces to see if patients have more of the growth enhancer protein, or more of the growth suppressor protein. Ony prescribe Avastin if the patient has more of the growth enhancer protein. Cancer in the News #2 Fasting might improve chemotherapy Chemotherapy uses toxic chemicas to ki cancer ces Aso can ki heathy ces 7

8 What did fasting do? Study with mice: Fasted for 2 days prior to chemotherapy Tumors in fasting mice shrank more Fewer heathy ces destroyed Why?? Fasting made heathy ces reroute energy from growing and dividing to interna maintenance ony Cancer ces continued to divide and mutipy Chemotherapy preferentiay attacks ces that are in the process of dividing SUMMARY: Cancer is a faiure of the ce cyce Cancer is caused by genetic mutations creating a mutated protein New therapies are targeted therapies Advances are being made daiy in cancer research. Breakthroughs can come from unikey sources. 8