MI 3.2 Quiz
Marker Analysis
A genetic technique whereby the sequence of the gene is not directly analyzed, but the mutant copy (allele) of the gene is inferred through analysis of a genetic marker
Allele
Any of the alternative forms of a gene that may occur at a given locus
How did a timeline of cancer screenings for someone of the opposite sex compare to your timeline? What was the same? What was different?
As a female, my timeline includes screenings for cervical and endometrial cancer. Since males do not have a uterus, they do not have to worry about getting screenings for this type of cancer. Instead, males will have screens for prostate cancer included on their timeline.
Ways to prevent Cancer
Avoid tobacco and other smoke products, Use sunscreen, Limit alcohol, Limit fat and calories, eat fruit and vegetable
BRCA
Either of two tumor suppressor genes (BRCA1 and BRCA2) that in mutated form tend to be associated with an increased risk of certain cancers and especially breast and ovarian cancers
True of False? Using oral contraceptives - decreases ovarian cancer risk.
False, it increases cancer risk
Race is a ________ risk for developing cancer; Caucasians have a higher risk of developing skin cancer.
Biological
Cryosurgery
Surgery in which diseased or abnormal tissue (as a tumor or wart) is destroyed or removed by freezing (as by the use of liquid nitrogen)
Which allele is associated with the BRCA2 mutation? Explain your answer.
The allele which is associated with BRCA2 mutation is allele 3. Both Jennifer and Laura are known to have the BRCA2 mutation and have had breast cancer. Allele 3 is the only allele that the two patients share which means that it must be the one associated with the BRCA2 mutation.
BRCA2 is what type of gene?
Tumor Suppressor Genes
Virologist
A specialist in virology, the branch of science that deals with viruses
Two More Main Sections of a Scientific Lab Report
Acknowledgments and Ciations
Why do you think routine cancer screenings are so important?
Routine cancer screenings are important because the ability to catch cancer early can help make treatment easier and faster along with a lower risk of death. If cancer is caught before it even gets a chance to fully develop, removal of the tumor is a much easier process than it would be at a later stage when chemotherapy would need to come into play.
Discussion
clearly and completely explain and interpret the results of the experiment. The analysis should refer to the Introduction section of the report and discuss how the results reported in the Results section support, refute, or add to the existing knowledge.
Results
fully and clearly indicate the actual observations, measurements, or other results from the experiments. It should be written in paragraph form and use charts, diagrams, pictures, or other graphics as needed for clarity.
Skin Cancer Lab Procedures Summarized
1.Get and label sterile water (WT and MUT yeast). 2. 0.25ml yeast suspension to 0.5ml water and vortex for each yeast type. 3. Label petri dishes for each yeast type. 4. Dump the correct yeast in the correct dish and spread with spreader. 5. Let sit to soak. 6. Uncover then cover in plastic wrap. 7. Cover half of the dish with foil to block out light on half the dish. 8. Expose to UV light. 9. Grow overnight at 30C. 10. Observe (MUT only grows in shade, WT can grow in both but more in shade).
Given what you know about these two strains of yeast, what role does a cell's ability to repair DNA play in how well it tolerates exposure to sunlight?
A cell's ability to repair DNA allows cells to better tolerate sunlight exposure. The yeast with the ability to repair DNA was able to grow a bit in the area that was exposed to UV light whereas the mutated yeast couldn't grow in the area with UV exposure since their DNA had been damaged and the cell couldn't repair it.
The lifetime chance of developing breast cancer is greatly increased in someone who has inherited an altered BRCA1 or BRCA2 gene. What role does environmental risk play into whether or not this person actually develops breast cancer?
A person who has a mutation in the BRCA1 or BRCA2 and also has bad habits could make it a lot easier for them to develop breast cancer. In general, there are certain habits which make it more likely for a person to develop cancer such as an unhealthy diet and a lack of physical activity. In a person with a BRCA mutation, the risk factor from environmental risk is even higher than a regular person. A person with the mutation must be extra careful.
Melanoma
A tumor of high malignancy that starts in melanocytes of normal skin or moles and metastasizes rapidly and widely
Genetic Marker
Alteration in DNA that may indicate an increased risk of developing a specific disease or disorder
Hereditary Cancer
An inherited disorder in which affected individuals have a higher-than-normal chance of developing certain types of cancer, often before the age of 50
Model System
An organism chosen to study broad biological principles. Yeast cells are a good model system because they are single-celled organisms that are easy to grow. Since they are eukaryotes, their DNA is organized and replicated in much the same way as mammalian DNA.
Microsatellite (also known as Short Tandem Repeats-STRs)
Any of numerous short segments of DNA that are distributed throughout the genome, that consist of repeated sequences of usually two to five nucleotides, and that are often useful markers in studies of genetic linkage because they tend to vary from one individual to another. The more repeats present in an STR, the longer the DNA fragment will be. The shorter DNA fragments will migrate the farthest down the gel.
The most common form of skin cancer is
Basal cell carcinoma
What conclusions can you draw from the experiment you designed and ran?
Based on our experiment, sunscreen in general does seem to protect from UV light. This is proven by the larger amount of growth on the SPF plates in comparison to the growth on the control plate. It is unclear the effect that different SPF levels have on protecting the yeast since all of the SPF plates looked the same. It is likely that this is due to errors in the experiment.
Hepatitis B Virus (HBV) and Hepatitis C virus (HCV)
Both viruses are known to cause liver infection. The long-term infection caused by these viruses increases a person's chance of developing liver cancer. There is a vaccine available to prevent HBV infection. There are a few medications available that are effective in treating HBV and HCV infections
Sporadic Cancer
Cancer occurring occasionally, singly, or in scattered instances
Familial Cancer
Cancer that occurs in families more often than would be expected by chance. These cancers often occur at an early age, and may indicate the presence of a gene mutation that increases the risk of cancer. They may also be a sign of shared environmental or lifestyle factors.
Michael is a nonsmoker with a family history of colon cancer who used to live in Florida. He spent many days fishing and swimming without sunscreen. He is in his forties. What cancer screening is not appropriate for him?
Colonoscopy starting age 50 years
How do you think Dan's death could have been prevented?
Dan's death could have been prevented had he been aware of the warning signs and took precautionary measures. Since Dan spent a lot of time outside, he could have been protecting himself by wearing sunscreen, hats, sunglasses, and other protective clothing. If Dan knew what to watch for when it came to his moles, it is possible he would have caught cancer earlier. For example, when one of his moles started bleeding and growing, had he identified that as a sign of melanoma he may have been able to get treatment faster which would have prevented cancer from spreading.
What is 5-FU's mechanism of action?
Fluorouracil mainly works by blocking an enzyme called thymidylate synthase, which performs one of the steps in the process of making thymine in cells from a uracil-like precursor. With this enzyme shut down, cells quickly run out of thymine, meaning they can no longer make new DNA. And if they can't make new DNA they can't multiply, so they die.
F.U. - Fluorouracil
Fluorouracil, or 5-FU, is a powerful drug in the chemotherapy arsenal, used to treat breast, stomach, bowel, and other types of cancer.
Would this be a career area you would be interested in pursuing? Why or why not?
I don't think that virology is a career that I would want to pursue because I think that I would enjoy working with cells more than viruses. While viruses are interesting and mysterious I kind of hate them and they are technically nonliving. I think working with cells has more to offer for me, and that does still involve a bit of virus knowledge that I enjoy (such as transmission and replication).
How do you feel about prophylactic surgeries for those who test positive for the breast cancer gene? Explain.
I think that prophylactic surgeries are a good thing. Prophylactic mastectomy is surgery to remove one or both breasts to reduce the risk of developing breast cancer. According to the National Cancer Institute, prophylactic mastectomy in women who carry a BRCA1 or BRCA2 gene mutation may be able to reduce the risk of developing breast cancer by 95%. That is a massive improvement and for a patient who is at risk it could be extremely helpful. It is better to be preventative than wait for the disease to take over.
Mr. Smith is a professional landscaper and spends the majority of his day working outside in the sun. What advice would you give him so that he can lower his risk for developing skin cancer?
I would tell Mr. Smith to always wear sunscreen and reapply every two hours in case he sweat it off. I would also tell him to wear a hat and sunglasses to shade his face and protect his eyes. If it is not too hot, Mr. Smith should try to wear long sleeves and pants to protect his arms and legs from too much sun exposure.
You have been contracted to design a new medical intervention to help prevent skin cancer. What type of medical intervention would you design? Describe your medical intervention and explain how it works to prevent skin cancer.
I would try to create some time of gene therapy to alter the skin cell DNA to be more resistant to UV light to help prevent the UV light from damaging the DNA. This would help prevent the mutations caused by UV light that usually lead to skin cancer.
If you were to perform this experiment again, what would you do differently? Why?
If I were to do this experiment again, I would use less yeast. We used 1 mL of yeast and I think that that was too much yeast so I would reduce it to 0.25 mL of yeast. I would also put it under the UV light for longer. I think that it was only under the light for 2.5 minutes when should have been in there longer but we ran out of time. I think that these are the factors that had the most impact on the results so I want to correct them to see if the results change.
How was 5-FU discovered?
In 1954, researchers Abraham Cantarow and Karl Paschkis found that liver cancer cells took up radioactive uracil much more easily than normal liver cells. Cancer cells tend to put uracil into their DNA, even though it shouldn't normally belong there, only in RNA. At the same time another scientist, Charles Heidelberger, was investigating how chemicals containing fluorine could bind to important proteins in cells and stop them from working. So he asked chemists at the company Hoffman-La Roche to make a version of uracil containing fluorine - fluorouracil, or 5-FU. When he tested it in mice, Heidelberger was pleased to find that his new drug had a potent anti-cancer effect, publishing his findings in the journal Nature in 1957. Clinical trials followed throughout the 1960s and 70s, working out how best to give fluorouracil and what doses to use. One problem is that the drug needs to be given continuously, because it is quickly broken down in the body. This only really became possible in the 1970s with the development of intravenous drug delivery pumps that patients could carry around with them
Explain whether you think Judy's family occurrences of breast and ovarian cancers are sporadic, hereditary, or familial.
It is hereditary as her maternal grandfather, mother and sister were all diagnosed with breast cancer. Since it was close family members and one specific gene it makes it a hereditary cancer. These cancers aren't affected as much by environmental factors as much as others such as lung cancer, so these cancers wouldn't be familial. There is also only one main gene that is causing the cancer which further enforces that it is hereditary.
Why is it important for a cell to be able to efficiently repair its DNA?
It is important for a cell to be able to repair its DNA so it can survive any potential damage to its DNA by repairing the issues quickly. Otherwise, it can result in permanent damage to the cell and the organism (if it is multicellular) such as mutations that lead to protein errors or the potential for cancer.
Which family members have the BRCA2 mutation? Explain your answer.
Jennifer, Laura and Judy because they all have allele 3. Allele 3 is the allele that is linked to the BRCA2 mutation so since these three are the ones with allele 3 they have the mutation.
Is Judy a good candidate for BRCA1 or BRCA2 genetic testing? Explain your answer.
Judy is a good candidate because her sister, Jennifer, developed breast cancer at a very early age. Judy's mother, Laura, also had breast cancer. Since breast cancer runs in Judy's family, she has a high chance of developing it and should be tested to further evaluate the risk of her developing cancer.
How can lifestyle choices increase your risk of developing cancer?
Lifestyle choices such as diet, exercise, and smoking can affect a patient's risk of developing cancer. For example, someone who smokes frequently has a much higher chance of developing lung cancer than someone who doesn't smoke at all. Maintaining a healthy diet and a regular exercise routine also help prevent the development of cancer as well by keeping the body healthy.
Colon and rectal cancers are found most often in which group of people?
Men and Women over 50 years
Describe a situation where the timeline you created might have to be adjusted for someone else based on the person's family history or lifestyle.
One situation where the timeline we created would have to be adjusted would be if the person had a mutated BRCA gene. Having a mutated BRCA gene would increase the patient's risk for breast cancer. In order to combat this, the timeline would be adjusted to include more frequent breast cancer screenings that also start earlier in life. For example, the screenings would start in the patient's late twenties or early thirties rather than mid-forties.
What can you do in your everyday life to reduce your risk of developing cancer?
One thing that you can do in your everyday life to reduce your risk of developing cancer is to maintain a healthy diet. By eating the recommended balanced diet consisting of fresh fruits and vegetables and minimum processed snacks, you can lower your risk for developing cancer. You can also avoid smoking or avoid areas that people like to smoke. Second hand smoke can be harmful as well. By avoiding smoke, you reduce your risk of developing cancer.
Human Papillomavirus (HPV)
Sexually transmitted infection. Causes abnormal cells to start growing and eventually can turn into cancer cells. Main cause of cervical cancer. Linked to mouth and throat cancer. There is a vaccine available that protects against 4 types of the HPV virus
What should patients using 5-FU expect with treatment?
Side effects are Diarrhea, Nausea, and possible occasional vomiting, Mouth sores, Poor appetite, Watery eyes, sensitivity to light (photophobia), Taste changes, metallic taste in mouth during infusion, Discoloration along the vein through which the medication is given, Low blood counts Your white and red blood cells and platelets may temporarily decrease. This can put you at increased risk for infection, anemia, and/or bleeding, Skin reactions (Dry, cracking, peeling skin. Darkening of the skin (hyperpigmentation), darkening of the skin where previous radiation treatment has been given (radiation recall)), Hair thinning, Nail changes - discoloration, loss of nails (rare)(see skin reactions), Hand -foot syndrome (Palmar-plantar erythrodysesthesia or PPE) -skin rash, swelling, redness, pain and/or peeling of the skin on the palms of hands and soles of feet. Serious adverse reactions to Fluorouracil are; chest pain, EKG changes, and increases in cardiac enzymes - which may indicate problems with the heart (see Cardiovascular events). These symptoms are very rare but increased for patients with a prior history of heart disease.
If yeast cells repair damage to their DNA in a similar manner to humans, what do these results tell you about the degree of DNA repair that occurs in our cells each time we expose ourselves to sunlight?
Since the yeast repairs DNA the same way as humans that means that sunscreen cannot protect every single cell so it is important to protect the skin because the amount of damage can build up and lead to more complications. It makes it harder for the DNA to repair itself every time.
What causes cancer?
Some viruses or bacteria (One example of a human cancer causing virus is hepatitis B which causes liver cancer), Some chemicals, Cigarette smoke contains more than two dozen different chemicals capable of causing cancer, Carcinogens are in many work environments such as asbestos and leather and wood dust, Industrial pollution Radiation, High exposure to x-ray radiation and sunlight increase incidence of cancer, Hereditary, Diet, and hormones, Certain genes are known to cause specific types of cancer, Age also tends to increase cancer risk
What warning signs were there that Dan had skin cancer?
The first major warning sign that Dan had skin cancer was when a mole he had since he was a child began to bleed and grow. The change in the size of the mole is unusual and should have been a sign that something was wrong.
Why use a negative control when running gel electrophoresis? If a band shows up in this lane, what does it tell you about your PCR products?
The negative control is used when running the gel electrophoresis is because it is easier to detect any contamination that could possibly occur. If a band shows up in that lane then it will tell you that some sort of contamination happened, at some point, in the PCR products.
How do pyrimidine antagonists work?
The pyrimidine antagonists act to block the synthesis of pyrimidine-containing nucleotides (C and T in DNA; C and U in RNA). The drugs used to block the construction of these nucleotides have structures that are similar to the natural compound. By acting as 'decoys', these drugs can prevent the production of the finished nucleotides. They may exert their effects at different steps in that pathway and may directly inhibit crucial enzymes. The pyrimidine antagonist may also be incorporated into a growing DNA chain and lead to termination of the process.
Screening
To test or examine for the presence of something (as a disease). Early detection is the key to increase our chances of surviving cancer. Finding cancer before symptoms start to show increases the likelihood that the cancer is found at an early stage and treatment is more effective. Certain screenings can even prevent cancer.
Explain how two individuals can have different sized bands and how they may be associated with different alleles (for BRCA). You may support your explanation with a drawing.
Two individuals can have different sized bands that may be associated with different alleles for BRCA because each person has two different alleles; one from each parent. So if one set of parents passed down a different allele from the other parents then the individuals will end up with different alleles from one another which results in different sized bands.
Epstein-Barr Virus (EBV)
Type of herpes virus known for causing infectious mononucleosis. Infects and stays in the lymphocytes. Increasing risk of nasopharyngeal cancer and burkitt lymphoma. Linked to hodgkins diseases and stomach cancer. No vaccines or medications are available
When doing a self-examination for suspicious moles or spots on your skin, what should you look for?
When doing a self-examination remember to look for the ABCDEs. A is for Asymmetry when one half of the spot is unlike the other half. B is for Border, watch out for irregular, scalloped, or poorly defined borders. C is for Color, varying colors from one area to the next, such as shades of tan, brown or black, or areas of white, red, or blue. D is for Diameter, melanomas are usually greater than 6 millimeters, or about the size of a pencil eraser, when diagnosed, they can be smaller. E is for Evolving, the spot looks different from the rest or is changing in size, shape, or color.
Do you think this type of genetic testing should be available? What are the advantages and disadvantages of knowing what is in your genes?
Yes I think that this type of genetic testing should be available. Some of the advantages of knowing what is in your genes is being able to be prepared for possible diseases that could be prevented. Knowing you are susceptible to a disease allows the patient to begin prevention methods early. Some disadvantages are that it can make people more paranoid. By knowing you have a possibility of getting a disease, it can make some people more anxious and make them feel that it is inevitable and scare them rather than reassure them.
Gardasil® is a vaccine that is highly effective in preventing four types of HPV in young women who have not previously been exposed to the HPV virus. The vaccine targets HPV strains that cause 70 percent of cervical cancers and 90 percent of genital warts. The Centers for Disease Control and Prevention recommend that all girls between the ages of 11 and 12 years old should receive the vaccine. Do you think that this vaccine should be mandatory? Explain your opinion.
Yes I think that this vaccine should be mandatory, If the vaccine is highly effective and prevents 70% of cancer and even more genital warts, I see no reason to not make this a mandatory vaccine. It helps more people than it hurts and would project a large portion of the population from HPV diseases. Preventing the spread of dangerous diseases is important and HPV is a harsh disease so it makes sense to make vaccination for it mandatory.
Materials and Methods
list all materials used and indicate the step-by-step process used to complete the experiment
Abstract
one-paragraph, concise summary of the entire report and include information on the purpose, procedure, results, and conclusions.
Introduction
provide a clear purpose for doing the experiment. discuss and explain the previous activities the researcher did that form the knowledge base that led to the work being reported.
Title Page
quickly inform the reader who wrote the report, what the report is about, and why it was written.
Genetic risk factors
those determined by your genes and are inherited from your parents, such as sex, race, and whether or not you've inherited genes related to the disease.
Environmental risk factors
toxins found in your surrounding environment that increase your cancer risk, such as radon and asbestos.
Design a research study to look at one of the activity/disease associations found on your Student Response Sheet. Include the following information in your study
who will participate and how you will determine if the risk factor actually increases or decreases the chance of developing the disease.: I could do a study on lung cancer and its connection to secondhand smoking. It is known that smoking causes cancer but there is a bit less information when it comes to the hazards of secondhand smoking. We can observe groups of normal individuals, individuals who avoid smokers, and individuals that tend to hang around areas with smokers. We can then compare their risk factors and see if it increases their chances of developing lung cancer.