19. Cancer Genetics

Overview of Cancer

Open Question
Go to the website http://www.cancer.gov and select 'Cancer Types' on the top menu bar. Scroll down to 'Breast Cancer' and click. Select 'Cases & Prevention' from the options. Click 'More information' and select 'BRCA Mutations: Cancer Risk and Genetic Testing'. Use the information on this page to answer the following questions.As a special project, instead of selecting 'Breast Cancer' from the list of types of cancer, select another cancer you would like to know more about and produce a short summary of what you find.
Open Question
What kind of information will be made available by The Cancer Genome Atlas (TCGA)? What sort of role do you think TCGA information will play in cancer diagnosis and cancer treatment in the future?
Open Question
Go to the website http://www.ncbi.nlm.nih.gov/omim and enter 'Lynch syndrome' in the Search box at the top of the page. From the list of options given, select '#120435—Lynch Syndrome.' Use the information you retrieve to answer the following questions.What are the approximate rates of cancer that develop in people carrying a mutation of one of these genes?
Open Question
Go to the website http://www.ncbi.nlm.nih.gov/omim and enter 'Lynch syndrome' in the Search box at the top of the page. From the list of options given, select '#120435—Lynch Syndrome.' Use the information you retrieve to answer the following questions.Provide a brief summary of the normal functions of the protein products of these genes.
Open Question
Go to the website http://www.ncbi.nlm.nih.gov/omim and enter 'Lynch syndrome' in the Search box at the top of the page. From the list of options given, select '#120435—Lynch Syndrome.' Use the information you retrieve to answer the following questions.What genes are most commonly mutated in Lynch syndrome?
Open Question
Go to the website http://www.ncbi.nlm.nih.gov/omim and enter 'Lynch syndrome' in the Search box at the top of the page. From the list of options given, select '#120435—Lynch Syndrome.' Use the information you retrieve to answer the following questions.There are two types of Lynch syndrome. What are they?
Open Question
Genetic counseling has not been discussed in this chapter, but it is a service provided by trained professional counselors who also have detailed knowledge of medical genetics, as described in Application Chapter A. Genetic counselors provide details about gene mutations and have knowledge of most of the details of diseases associated with genetic abnormalities. With regard to genetic testing to identify one's personal risk of cancer, what are the three or four topics you think are most important to be able to discuss with a genetic counselor?
Open Question
If a cell suffers damage to its DNA while in S phase, how can this damage be repaired before the cell enters mitosis?
Open Question
How do translocations such as the Philadelphia chromosome contribute to cancer?
Open Question
Mammography is an accurate screening technique for the early detection of breast cancer in humans. Because this technique uses X rays diagnostically, it has been highly controversial. Can you explain why? What reasons justify the use of X rays for such a medical screening technique?
Open Question
DNA sequencing has provided data to indicate that cancer cells may contain tens of thousands of somatic mutations, only some of which confer a growth advantage to a cancer cell. How do scientists describe and categorize these recently discovered populations of mutations in cancer cells?
Open Question
How do normal cells protect themselves from accumulating mutations in genes that could lead to cancer? How do cancer cells differ from normal cells in these processes?
Open Question
Describe the difference between an acute transforming virus and a virus that does not cause tumors.
Open Question
Epigenetics is a relatively new area of genetics with a focus on phenomena that affect gene expression but do not affect DNA sequence. Epigenetic effects are quasi-stable and may be passed to progeny somatic or germ-line cells. What are known causes of epigenetic effects, and how do they relate to cancer?
Open Question
Radiotherapy (treatment with ionizing radiation) is one of the most effective current cancer treatments. It works by damaging DNA and other cellular components. In which ways could radiotherapy control or cure cancer, and why does radiotherapy often have significant side effects?