Presentation on theme: "C ANCER Read information about cancer, watch the animations and videos, and complete the activities. Answer all numbered questions in red on a separate."— Presentation transcript:
C ANCER Read information about cancer, watch the animations and videos, and complete the activities. Answer all numbered questions in red on a separate piece of paper.
A N O VERVIEW OF C ANCER Cancer is a disease caused by normal cells changing so that they grow and divide in an uncontrolled way. Click CANCER ANIMATIONS and watch animation 1.CANCER ANIMATIONS
N ORMAL C ELLS In multi-cellular organisms, like humans, cell division is highly regulated. Normal growth and healing is very orderly and is controlled by three key factors: Anchorage dependence - Cells will only progress through the cell cycle if they are anchored to a tissue in the body. Density-dependent inhibition - Cells will only progress through the cell cycle if there is room. This means that cells stop dividing when the area becomes too dense (crowded). Genes - Cells will only progress through the cell cycle when they are told to by your genes. Genes that control the cell cycle are called cyclins.
N ORMAL C ELLS It seems that human cells are pre-programmed to reproduce up to 50 or 60 times maximum. Then they die. If a cell is damaged it can die early – cell suicide is called apoptosis.
N ORMAL C ELLS In summary – Normal Cells Reproduce themselves exactly Stop reproducing at the right time Stick together in the right place Self destruct if they are damaged Become specialized or 'mature‘
N ORMAL C ELLS Click CANCER ANIMATIONS and watch animations 2 & 3.CANCER ANIMATIONS
1. How many times can a normal cell divide? 2. What are the three ways normal growth is controlled? 3. What is apoptosis? 4. Why do you think apoptosis is so important to cells?
H OW C ANCER C ELLS A RE D IFFERENT Cancer cells do not follow the cell’s control system… They don't stop reproducing don't obey signals from other cells don't stick together don't specialize, but stay immature
5. How are cancer cells different from normal cells?
H OW C ANCER F ORMS Cancer forms due to multiple mutations. The mutations that cause cancer interfere with the normal timing of the cell cycle. Click CANCER ANIMATIONS and watch animation 5.CANCER ANIMATIONS
Click CANCER QUEST and watch the video.CANCER QUEST
What is a mutation? How many mutations does it take to develop cancer?
H OW C ANCER F ORMS Cancer forms due to multiple mutations. You have heard about several of the mutations that can occur through the animations and video. Each of the following slides describes one such mutation.
8. Make a table with the headings below and fill it in as you read the next 5 slides! GeneWhat it normally does What it does when it mutates Proto-onco genes Tumor suppressor genes P53 gene DNA repair genes Angiogenesis genes Metastasis genes
H OW C ANCER F ORMS MUTATION TO: proto-oncogenes Some genes (proto-oncogenes) encourage cells to multiply or 'double'. Remember, normally, in adults, this would not happen very often. But if these genes become mutated (oncogenes), they tell the cell to multiply all the time. This creates too many cells for the body.
MUTATION TO: tumor suppressor genes Some genes (tumor suppressor genes) are in the cell specifically to stop the cell multiplying or doubling. If one of these 'tumor suppressor genes' becomes mutated and stops working, then the cell may carry on and on multiplying. In other words it becomes immortal, which is one of the properties of a cancer cell.
MUTATION TO: p53 gene. The best known tumor suppressor gene is called p53. This gene normally stops cells with other damaged genes from reproducing and encourages them to destroy themselves (apoptosis). Remember that all cells have the ability to self-destruct and that this ability is essential to the life of a multi-cellular organism. Mutated p53 genes do not work properly and therefore apoptosis does not occur even when necessary. Cells with defective p53 genes will continue to accumulate mutations. p53 is damaged or missing in most human cancers.
MUTATION TO: DNA repair genes These genes normally repair any damage to the DNA that makes up the cell's genes. If these DNA repair genes are damaged, then other mutations are not repaired and the cell can copy the mutations into its daughter cells. These genes have been found to be damaged in some human cancers, including bowel cancer.
MUTATION TO: angiogenesis genes Normal cells have genes that can produce proteins which switch blood vessel growth on and genes that produce proteins which switch blood vessel growth off. These genes are essential to life – allowing pregnant women to nurture their babies in the womb, patients to heal from injuries and children to grow. The normal balance between the two genes (on and off) is important. Mutations in the angiogenesis genes can result in abnormal blood vessel formation around cancerous tumors. These vessels provide limitless food and Oxygen to the tumors.
MUTATION TO: metastasis genes In addition to the other genes you have looked at so far, there are a variety of other genes that can become mutated in cancerous cells. These mutations vary, but in some capacity change the cell – making it mobile so that it can detach, enter the blood stream and reattach elsewhere in the body. These mutations are dangerous because they allow the cancer to spread throughout the body. This makes it much more difficult to treat.
A CTIVITY Examining Colon Cancer
Based on the graph, or your knowledge of cancer, discuss the following questions as a group ◦ How likely is a 10 year old to develop colon cancer? ◦ How likely is a 30 year old to develop colon cancer? ◦ How likely is a 50 year old to develop colon cancer? ◦ How likely is a 70 year old to develop colon cancer? 9. The biggest ‘risk factor’ in developing cancer is not smoking or tanning, but getting old, how do you think we can explain that?
You are now ready to use the hit simulator. See Ms. Franko for a copy of the directions and questions! HIT SIMULATOR
H OW M UTATIONS F ORMS Cancer forms due to multiple mutations. So what causes mutations? ◦ Mutations can come from environmental agents such as ultraviolet light, nuclear radiation or certain chemicals. ◦ Mutations can occur due to mistakes that occur when a cell copies its DNA in preparation for cell division. ◦ Click CANCER ANIMATIONS and watch animation 4.CANCER ANIMATIONS
10. What is a carcinogen?
T YPES OF C ANCER There are over 100 types of cancer. Each one is named based on where it forms in the body. Each one is caused by a unique set of mutations.
11. What are the 3 most common cancers in men? Women? Discuss: Did any of the 2012 statistics surprise you? 12. Looking at that list and thinking about what causes mutations. Try to make a list of at least 5 ‘risky behaviors’ that may lead to people developing cancer.
C ANCER S YMPTOMS & T REATMENTS Cancers can cause different symptoms according to where they are in the body. A cancer may press on a nerve, or another nearby body organ. It may also cause symptoms by releasing chemicals or hormones into the bloodstream. These effects will eventually disrupt normal cell, tissue and organ function. There are three major treatment methods for cancer. ◦ Chemotherapy ◦ Surgery ◦ Radiation
Chemotherapy – traditional Chemotherapy literally means 'drug treatment'. In cancer treatment, the term chemotherapy means treatment with cell killing (cytotoxic) drugs. A person may have just one chemotherapy drug or a combination of different chemotherapy drugs. There are more than 90 different drugs currently available and new ones are being developed all the time.
Chemotherapy – magic bullet drugs A newer branch of chemotherapy has recently become available for some cancers. These drug focus on protein replacement or blockage instead of killing cells. These drugs have far fewer side effects. Examples include: ◦ Anti-Veg-F – a drug that uses proteins to block angiogenesis (results in tumor shrinkage) ◦ Glevic – a drug that uses a protein to block an oncogene (results in slower cell division)
Surgery Surgery is cutting away tissue from the body. For some cancers, surgery is the only treatment a patient may need. It is likely to cure small, early stage cancers that have not spread to other parts of the body.
Radiotherapy / Radiation Radiotherapy means the use of 'radiation', usually X-rays, to treat illness. Doctors have a lot of experience using radiotherapy in medicine. About 4 out of 10 people with cancer (40%) have radiotherapy as part of their treatment. It can be given ◦ From outside the body as external radiotherapy, using X-rays, 'cobalt irradiation', electrons and more rarely other particles such as protons. ◦ From within the body as internal radiotherapy, by drinking a liquid that is taken up by cancer cells or by putting radioactive material in, or close to, the tumor. Radiotherapy destroys the cancer cells in the treated area. Although normal cells are also affected by radiation, they are better at repairing themselves than the cancer cells.
13. List the 3 ways we treat cancer? (if you are not familiar with any of them you may want to write a brief description) 14. What is the difference between traditional chemotherapy and ‘magic bullet’ drugs?
You are done! If you still have time try the review slides that follow…
____1CarcinogenAA tumor that is characterized by uncontrolled growth / cancerous ____2MutationBThe spread of cancerous cells to other parts of the body ____3MetastasisCA gene that slows down or stops the cell cycle. ____4P53DA chemical that tends to produce a cancer. ____5AngiogenesisEThe formation and development of blood vessels. ____6OncogeneFA gene that stimulates the cell cycle. ____7Tumor suppressor gene GA change in the DNA molecule. ____8MalignantHCell death ____9ApoptosisIA protein in cells that recognizes damage and initiates cell death
Cancer Vocabulary Review The Cell Cycle "Battleship"