2. Gene mutationGene mutation  Change in DNA base sequence  Permanent  Only inherited if occur in gametes  2 types  Spontaneous  Errors in normal processes, rare  Ex. DNA segment moving from one location to another  Induced  Exposure dependent (ex. Chemicals, radiation)

3. Basic TerminologyBasic Terminology  Mutagens  Environmental agents known to create mutations within DNA (ex. UV radiation)  Carcinogens  Mutagens that cause cancer  “cancer-causing”  Ex. Smoking, chemicals used in industries, DDT **Cancer—accumulation of mutations over time**

4. What is so bad about radiation?  FREE RADICALS ! ! !  React with DNA— MUTATION!  Ex. X-Rays

6. DNA Technology

7. Gel ElectrophoresisGel Electrophoresis  Laboratory process for DNA fragment separation.  DNA separates based on the size of each DNA fragment  Restriction enzyme sites (where enzymes will cut DNA) unique to each person SO expose DNA to restriction enzymes

12. Latest TechnologyLatest Technology  Getting rid of our reliance on gel electrophoresis….any problems with old method?  Fluorescent labeling of DNA fragments  Creates a graph or “DNA fingerprint” showing repeat numbers based on how much fluorescence is present.

14. Cancer: the basicsCancer: the basics  Uncontrolled cell growth  Accumulation of mutations within genes  Gradual development

16. Cancer: the basics (cont.)Cancer: the basics (cont.)  Proto-oncogenes  Proteins formed from these genes maintain cell cycle and stop apoptosis  Mutations within these genes form oncogenes (maintain cell cycle, always simulated, do not listen to signals or conditions to stop)  Examples: ras gene, BRCA 1 oncogene (breast/ovarian cancer)

17. Cancer: the basics (cont.)Cancer: the basics (cont.)  Tumor suppressor genes -proteins formed from these genes prevent cell cycle and signal apoptosis -Prevent uncontrolled cell cycles and cell division with damaged DNA -Mutations within these genes cause the cell cycle to continue without control -Ex. Common ones seen in human cancer—RB, p53 genes for corresponding proteins

18. What can cause mutations leading to cancer?  Genetics/Heredity - certain individuals are more susceptible than others  Viruses  Environmental factors  Chemicals  Smoke  UV/radiation exposure—skin cancer

19. Cancer TerminologyCancer Terminology  Cancer in situ– tumor at primary site  Tumor:  When cancerous cells divide, they form a mass of cancer cells within an otherwise normal tissue  Benign tumor:  Cancerous cells remain in one spot  Growth does not continue  Noncancerous  Malignant tumor:  Cancer cells become invasive enough to impair the functions of one or more organs  Cancer cells have the ability to spread

20. Cancer Cell Terminology (cont.)  Metastasis:  The spread of cancer cells beyond their original site -Cancer cells can break away from tumor to invade other locations throughout the body  Angiogenesis:  The process where cancer cells develop their own blood supply to obtain continued nutrients so they can keep growing.  New blood vessels and the cancer cells use these to “fuel” their growth  Treatments can fight this process

22. How do we know a cell is cancerous?—Cancer Cell Traits 1) No differentiation -no function, abnormal appearance, unspecialized 2) Abnormal Nuclei -larger nucleus -abnormal chromosome numbers, more 3) No apoptosis -do not respond to signals from cell about abnormality or DNA damages -evade detection from the body’s immune system -do not die

23. How do we know a cell is cancerous?—Cancer Cell Traits 4) No contact inhibition/ anchor -cancer cells do not “listen” to neighbors -continue to grow despite being crowded by neighbors—tumor results 5) Go through metastasis -break away from tumor and invade other cells throughout the body 6) Go through angiogenesis -create blood supply to provide nutrients for continued growth

25. Normal v. Cancer CellsNormal v. Cancer Cells  Have density-dependent inhibition  Will only divide when attached to a substrate (anchored)  Must have sufficient growth factors or nutrients for division  Lack density-dependent inhibition  Will divide in solution or when not anchored  Unaffected by presence of external growth factors or nutrients