“Cellular & Sexual Reproduction”

Class R5

Warm-up

1. A cell that undergoes repeated mitosis without cytokinesis would have

a. many daughter cells.

b. fewer chromosomes.

c. many nuclei.

d. cancerous properties.

C. Mitosis is the division of the nucleus. Without cytokinesis, or cell division, mitosis alone will lead to a multinucleate cell.

Warm-up

2. If you were studying the causes of cancer, which topic might interest you?

a. cyclin-dependent kinases

b. centromere structure

c. spindle-fiber structure

d. cell membranes

A. One of the causes of cancer is mutations in the proteins that regulate the cell cycle, some of which are cyclin-dependent kinases. These enzymes would be a useful place to begin understanding the causes of cancer.

Warm-up

3. Some cancers have a genetic component to them, if a parent has a cancer the children are more likely than the average population to develop the cancer. Why might this be?

a. Cancers require more than one mutation to occur.

b. Cancers are inherited but remain dormant until a certain age.

c. Parents and children are often exposed to similar environmental factors.

d. Cancers are often recessive traits and require alleles from both parents.

A. Cancers are often caused by multiple mutations, inheriting one mutation from a parent means the individual has to develop fewer mutations to

develop the cancer.

Warm-up

4. A stem cell has potential medical uses because it

a. undergoes mitosis.

b. is not specialized in structure and function.

c. is similar to a cancer cell, providing a study system.

d. undergoes apoptosis.

B. A stem cell’s usefulness lies in the fact that it is unspecialized and therefore has the potential to develop into cells of different kinds that might be used

to repair damaged tissue.

Man who lost his face

Graphic

Squamous cell carcinoma

Common Cancers in US

Let’s get into groups and discuss

Basic Cancer Facts

http://www.cancer.gov/cancertopics/types/commoncancers

Cancer Facts and Figures2015

http://onlinelibrary.wiley.com/doi/10.3322/caac.21254/pdf

http://www.cancer.org/acs/groups/content/@editorial/documents/document/acspc-044552.pdf

Treatments and Survivorship

http://www.cancer.org/acs/groups/content/@research/documents/document/acspc-042801.pdf

Facts

http://www.youtube.com/watch?v=-JqvN8-S7_M&edufilter=na

Treatments

What do YOU believe?Determine whether the statements are true or false

based upon your knowledge of cancer

The risk of dying from breast cancer in the United States is increasing.

False

• Review and plot the “Breast Cancer Trends” data.

Cancer can be spread from person to person.

False

• Cancer cannot be passed from one person to another.

• Though cancer itself isn’t contagious, sometimes viruses, which are contagious, can lead to the development of cancer.

–HPV & Hepatitis C can lead to cervical and liver cancer.

What someone does as a young adult has little effect on their chance of getting cancer later in life.

False

• Most cases of cancer are the consequence of many years of exposure to several risk factors.

• What you eat, whether you exercise, whether you sunburn and especially, whether you smoke as a young person have a substantial influence on whether you develop cancer later in life.

There is currently a cure for cancer but the medical industry won’t tell the public about it because they make too much money treating cancer patients.

False

• Think about it – plenty of doctors and their loved ones die of cancer each year. Why would anyone hide such an important discovery?

• Think about the speed with which other medical breakthroughs and vaccines and antibiotics have been announced and applied.

• And remember, cancer is many diseases rather than a single disease, and cures are already available for many forms of cancer. Fewer than half of all people with cancer in the U.S. actually die of the disease.

Treating cancer with surgery can cause it to spread throughout the body.

False

• Specialists in cancer surgery know how to safely take biopsy samples and to remove tumors without causing spread of the cancer.

• In many cases, surgery is an essential part of the cancer treatment plan.

Cancer can be effectively treated.

True

• The four major types of treatment for cancer are surgery, radiation, chemotherapy and biologic therapies.

Cancer is a group of over 100 diseases.

True

There are more than 100 different types of cancer. The main categories of cancer include:

• carcinoma (cancer that begins in the skin or in tissues that line or cover internal organs);

• sarcoma (cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue);

• leukemia (cancer that starts in blood-forming tissue such as bone marrow and causes large numbers of abnormal blood cells to be produced and enter the blood);

• lymphoma and myeloma (cancers that begin in the cells of the immune system); and

• central nervous system cancers (cancers that begin in the tissue of the brain and spinal cord).

Cancer cells can be distinguished from normal cells because of their loss of normal growth.

True

• Normally, cells grow and divide to produce more cells as they are needed to keep the body healthy. Sometimes, this orderly process goes wrong. New cells form when the body does not need them, and old cells do not die when they should.

Cancer can only occur in specific cells in the body.

False

• The body is made up of many types of cells and all cancer begins in cells.

• Cancer can develop in any cell in the body which is why there are so many different types.

Cancer develops because of abnormal gene function.

True

• Scientists have learned that cancer is caused by changes in genes that normally control the growth and death of cells.

• Certain lifestyle and environment factors can change some normal genes into genes that allow the growth of cancer.

– Many gene changes that lead to cancer are the result of tobacco use, poor diet, exposure to ultraviolet (UV) radiation from the sun, or exposure to carcinogens (cancer-causing substances) in the workplace or in the environment.

• Some gene alterations are inherited (from one or both parents).

• However, having an inherited gene alteration does not always mean that the person will develop cancer; it only means that the chance of getting cancer is increased.

Cancer Game

http://bio-alive.com/games/cancer.htm

http://www.re-mission2.org/

http://www.cancergame.org/

http://scienceblog.cancerresearchuk.org/2014/02/04/download-our-revolutionary-mobile-game-to-help-speed-up-cancer-research/

32

But I’m Too Young!A Case Study of Ovarian Cancer

by

Nancy A. Rice, Department of Biology, Western

Kentucky University, and

Bruno Borsari, Biology Department, Winona State

University

Answers to the Case Questions

CQ1: Do you know someone personally that has had cancer?

A: Yes

B: No

The correct answer is: either A or B

CQ2: Abby wondered: what is the difference between cancer and tumor? What do you think?

A: The two terms can be used interchangeably as they are synonymous.

B: Cancer is a disease that eventually disrupts body functions whereas a tumor is a mass of cells with no apparent function in the body.

C: Cancer is a disease which affects men whereas a tumor may affect both men and women.

D: Cancer is a disease of the digestive tract whereas a tumor may develop anywhere in the body.

The correct answer is: B

Answers to the Case Questions

CQ3: Normal CA-125 levels are indicated by values of 35 U/ml or less. Abby’s CA-125 levels taken at two different times are indicated below. Is Abby likely to have a cyst or cancer?

A: Cyst

B: Cancer

The correct answer is: B

CQ4: Why does cancer primarily affect older people rather than young people?

A: Because the immune system of older people is not as effective in distinguishing normal cells from cancer cells.

B: Because older people have been exposed to more carcinogens.

C: Because cancer develops after multiple mutations have occurred which takes years to happen.

D: None of the above.

The correct answer is: C

Answers to the Case Questions

CQ5: What would you expect cells to be like if they did not have properly functioning p53?

A: The absence of p53 inside cells would cause them to divide more rapidly.

B: The absence of p53 could cause cells to replicate with damaged DNA that could ultimately lead to cancer.

C: The absence of p53 could cause cells to skip mitosis (M phase) and stay in S phase of the cell cycle.

D: The absence of p53 would have no effect on the cells.

The correct answer is: B

CQ6: The BRCA1 and BRAC2 genes that may be mutated in Abby’s cells would be considered?

A: An oncogene

B: A tumor suppressor gene

The correct answer is: B

Answers to the Case Questions

CQ7: How do cancer cells travel through the human body?

A: Cancer travels through the body by way of sexual intercourse between a healthy person and one affected by the disease.

B: The circulatory system only is responsible for relocating cancer cells.

C: The lymphatic system collects fluids from capillaries and with it cancer cells, which are then delivered by the circulatory system.

D: They are moved around on neurons throughout the body.

The correct answer is: C

CQ8: Can surgery successfully cure a cancer that has metastasized?

A: No, all body cells are dividing uncontrollably.

B: Yes, it could remove all cells with defective cell-cycle regulation.

C: No, cancer cells are no longer localized in one spot.

D: Yes, if the tumor is benign.

The correct answer is: C

Post Question Answers

PQ1: Which is true of all cancers?

A: They are caused by viruses.

B: They are caused by chemical carcinogens.

C: They are caused by changes in DNA.

D: They are inherited.

E: They all respond in the same way to treatment.

The correct answer is: C

Rationale: This is an application question. Cancer results from the accumulation of mutations in genes that regulate the cell cycle. As a result of the mutation, the corresponding protein product either gains a function or is no longer active, and thus the cell is able to evade the normal controls in place for cell division. While a person’s susceptibility to a particular cancer can be associated with exposure to certain viruses or carcinogens, these ultimately result in DNA damage.

Post Question Answers

PQ2: A malignant tumor is more dangerous than a benign tumor because …

A: its cells are dividing faster.

B: it travels through the digestive tract.

C: it causes neighboring cells to mutate.

D: its cells engulf neighboring normal tissue cells.

E: its cells can acquire the capacity to invade other tissues.

The correct answer is: E

Rationale: This is a factual question. Malignant cancers have the potential to become metastatic—meaning they can move. This is the dangerous part of cancer. A localized tumor can be removed surgically and treated, but cancer that has metastasized is difficult to treat because it is no longer in one location. The stages of cancer are based upon this phenomenon. Stage 0 or 1 is very localized cancer, while metastatic cancers that are at distant sites from the primary tumor are Stage 5. A good prognosis is inversely correlated to stage.

Post Question Answers

PQ3: For a cell, a mutation in a tumor suppressor gene is most like?

A: A stuck accelerator.

B: Broken brakes.

C: A bad mechanic.

D: I don’t know.

The correct answer is: B

Rationale: This is an application question. In this analogy, an oncogene would be the stuck accelerator that gains a function to keep the cell cycle progressing. Tumor suppressors are normally the “brakes” in the cell cycle. Thus a mutation would be similar to losing your brakes on a car. A bad mechanic would be analogous to mutations in genes that repair DNA. If over the course of a cell’s life, DNA is not properly repaired it can eventually lead to cancer, just like a bad mechanic can result in an automobile breaking down.

Post Question Answers

PQ4: In 1971, Dr. Judah Folkman suggested that a tumor cannot grow beyond 1–2 mm without new blood vessels that provide nutrients to the tumor. In the 1990s, it was discovered that vascular endothelial growth factor (VEGF) stimulates the formation of new blood vessels. And now we know that many cancer cells secrete high levels of VEGF. From this information, one might predict:

A: Small tumors secrete more VEGF than large tumors.

B: Preventing VEGF production or action can stop tumors from growing.

C: Normal cells do not secrete VEGF.

D: Dr. Folkman won the Nobel Prize in Physiology and Medicine.

The correct answer is: B

Rationale: This is an application question.

Post Question Answers

PQ5: Can surgery successfully cure a cancer that has metastasized?

A: No, all body cells are dividing uncontrollably.

B: Yes, it could remove all cells with defective cell-cycle regulation.

C: No, cancer cells are no longer localized in one spot.

D: Yes, if the tumor is benign.

The correct answer is: C

Post Question Answers

TQ1: Which of the following would be most likely to cause a cell to become malignant (cancer)?

A: Activation of a proto-oncogene and inactivation of a tumor suppressor gene.

B: Activation of a proto-oncogene and activation of a tumor suppressor gene.

C: Inactivation of a proto-oncogene and inactivation of a tumor suppressor gene.

D: Inactivation of a proto-oncogene and activation of a tumor suppressor gene.

The correct answer is: A

Gen Ed

Animation

http://www.insidecancer.org/

http://geneed.nlm.nih.gov/topic_subtopic.php?tid=142&sid=151

Animal Research

Part 1

Part 2

Why do we use animals?

Is it Justified

The Multibillion dollar lie

What Do You Know About Cancer?

"Tumors destroy man in a unique and appalling way, as flesh of his own flesh which has somehow been rendered proliferative, rampant, predatory, and

ungovernable . . . Yet, despite more than 70 years of experimental study, they remain the least

understood . . . What can be the why for these happenings?" —Peyton Rous, in his acceptance

lecture for the Nobel Prize in Physiology or Medicine (1966)

What Do You Know About Cancer?

• Cancer is the second leading cause of death in the US.

• Cancer occurs when cells grow and divide and don’t die as they should. It can spread to different parts of the body.

• Some cancers are inherited; other cancers may be caused by factors in the environment such as overexposure to sunlight or any exposure to tobacco smoke. We don’t know what causes all cancers.

What Do You Know About Cancer?

• Many cancers can be detected by medical exams.

• Many cancers can be treated with surgery, radiation therapy, chemotherapy, hormones, and biological therapy.

• People with cancer can live full, productive lives.

What Do You Know About Cancer

• Cancer is a group of more than 100 diseases that develop across time. Cancer can develop in virtually any of the body's tissues, and both hereditary and environmental factors contribute to its development.

• The growth and differentiation of cells in the body normally are precisely regulated; this regulation is fundamental to the orderly process of development that we observe across the life spans of multicellularorganisms. Cancer develops due to the loss of growth control in cells. Loss of control occurs as a result of mutations in genes that are involved in cell cycle control.

• No single event is enough to turn a cell into a cancerous cell. Instead, it seems that the accumulation of damage to a number of genes ("multiple hits") across time leads to cancer.

What Do You Know About Cancer

• Scientists use systematic and rigorous criteria to evaluate claims about factors associated with cancer. Consumers can evaluate such claims by applying criteria related to the source, certainty, and reasonableness of the supporting information.

• We can use our understanding of the science of cancer to improve personal and public health. Translating our understanding of science into public policy can raise a variety of issues, such as the degree to which society should govern the health practices of individuals. Such issues often involve a tension between the values of preserving personal and public health and preserving individual freedom and autonomy.

What Do You Know About Cancer

• Each of us has a chance of developing cancer sometime in our life.

• On average, in the United States, men have a 1 in 2 lifetime risk of developing cancer and women a 1 in 3 risk.

• Many Americans, however, have a higher than average chance of developing particular forms of cancer. For example, smokers have a 10-fold higher risk of developing lung cancer compared with nonsmokers. Likewise, women who have a mother, sister, or daughter who has had breast cancer have about a 2-fold higher chance of developing breast cancer compared with women who do not have such a family history.

• The National Cancer Institute estimates that approximately 8 million Americans alive today have a history of cancer. In 1998, more than 1 million new cases were diagnosed.

• In fact, cancer is the second leading cause of death in the United States, exceeded only by heart disease.

Cancer and the Cell Cycle

http://science.education.nih.gov/supplements/nih1/cancer/activities/activity2_animations.htm

http://www.aacr.org/home/scientists/science-education-for-the-next-generation-of-cancer-researchers/resources-for-students/learning-about-

cancer.aspx

Cyber Scavenger Hunt

Let’s go to the Computer Lab

Let’s put your web surfing skills to this test.

Cancer Supplements

http://science.education.nih.gov/supplements/nih1/cancer/default.htm

HW

None for tonight.