Final exam Bio of Cancer

The chemical Tetradecanoyl phorbol acetate is classified into which of the following group?

A tumor promoter

Which of the following is a characteristic of cancer cells?

Ability to grow in suspension cultures

Which of the following is an epigenetic modification that may lead to cancer?

Acetylation of histones associated with DNA

What causes Barrett's esophagus and how can it be prevented?

Acid reflux ;prevented by reducing weight

What is a major difference between basal cell carcinoma and melanoma?

Basal cell carcinoma does not metastasize whereas melanoma usually does.

What protein is referred to as the immortality or anti-apoptosis protein that prevents release of cytochrome C from mitochondria?

Bcl-2

Which of the following blocks the internal apoptotic pathway or release of cytochrome C from mitochondria?

Bcl-2

Cancer cells can pump out toxic chemotherapies, why don't they pump out endostatin and become resistant to its effects?

Because endostatin does not directly target the cancer cell and it binds at the surface of its target

Why is the presence of the bacterium Fusobacterium nucleatum of concern to oncologists?

Because it causes the production of an oncomir within cells of the colon

Why are syngeneic mice used in cancer cell studies?

Because scientists can look at rejection of cancer cells by an immune response to the mutated peptides and not due to a foreign graft transplant

Why is a cancer patient called Emily considered a pioneer in cancer therapy?

Because she was the first person to be cured with engineered T cells

Why have experiments in mice raised concerns regarding core needle biopsy of human breast cancer?

Because the biopsy can increase the rate of lung metastases

Why do diabetics who use metformin to control their disease have a lowered risk for cancer?

Because the drug causes cells that have a mutated p-53 to die, even though they can not undergo apoptosis

Why is obesity considered a risk factor for developing cancer?

Because the inflammation that accompanies obesity is a tumor promoter

Why don't cancer cells undergo senescence or aging after about 70 cell divisions like normal cells do?

Because they can enzymatically extend their telomeres.

Why don't cancer cells undergo apoptosis following DNA damage?

Because they have mutations in the genes coding for ATM or p-53

Why are cancer cells genetically unstable?

Because they possess mutations in DNA repair enzymes

How does a bacterium within your colon, called Fusobacterium nucleatum, become a major risk factor for the development of colon cancer?

By stimulating colon cells to produce an onco-Mir or microRNA that prevents the synthesis of phosphatases

How did Folkman propose that a person with cancer could live a long life without disease or the debilitating and lethal effects of cancer?

By taking an inhibitor of angiogenesis that prevents metastatic foci from growing and interfering with bodily functions.

What is the basic mechanisms behind the PET scan used in detecting tumors.

Cancer cells undergoing aerobic glycolysis take up radioactively labelled glucose at a much greater rate than surrounding tissue

Which of the following events is seen during apoptosis and occurs following activation of the death receptor on the surface of cancer cells?

Caspases are activated and this leads to degradation of DNA within the nucleus

Why does a high cholesterol diet pose a risk factor for breast and prostate cancer?

Cholesterol conversion to estrogen and testosterone, both are tumor promoters

What cancer appears to be an exception to the 5 mutation rule because one major chromosomal event is typically seen?

Chronic Myleogenous Leukemia

How is the internal apoptosis pathway activated?

DNA damage triggers the accumulation of p-53 which in turn causes leakage of mitochondrial cytochrome C and activation of caspases.

What is the basis for the AMES test?

Detection of a reverse mutation in a strain of Salmonella that requires histidine to grow

What is considered the biggest factor in the decrease of lung cancer deaths within the United States of America.

Education regarding the link between smoking and lung cancer

Down Syndrome individuals have a marked decrease in the incidence of cancer due to which of the following?

Extra copies of the gene coding for a class of collagen

How are the levels of the transcription factor HIF 1 regulated?

HIF l alpha is hydroxylated by prolyl 4 hydroxylase, ubiquinated, and along with VHL tumor suppressor protein it is targeted for the proteosome

In order to prove that tumor cells need to produce a blood supply, Folkman performed the following experiment:

He injected tumors into the anterior chamber of the eye and into the limbus region of the eye and examined their growth in these two areas

Why did a doctoral student in Dr. Folkman's laboratory decide to collect and study mouse urine?

He wanted to isolate the substance that inhibited secondary metastases from growing

Why did a scientist in Folkman's lab design a special cage to collect mouse urine?

He wanted to purify a substance that prevented the growth of metastatic foci.

Which of the following is not an example of benign tumors?

Hepatoma

What enzyme is responsible for the Warburg effect?

Hexokinase 2

The high rate of aerobic glycolysis exhibited by cancer cells is due to:

High levels of type II hexokinase

Which of the following molecules increases the level of telomerase within cancer cells?

Hypoxia inducible factor

What is the function of prolyl-4-hydroxylase within your own body?

In the presence of normoxia it adds a hydroxyl group to a protein that is a transcription factor for vascular endothelial growth factor

What cytokine can activate the signal transducer and activator of transcription 3?

Interleukin 6 a cytokine released from fat cells

By what mechanism may vitamin C play a role in decreasing angiogenesis?

It accelerates HIF-1 alpha inactivation following its hydroxylation.

What is the function of cyclin D?

It activates a cyclin dependent kinase at the beginning of the cell cycle

Why is nicotine alone considered a risk factor for increased cancer and infectious diseases?

It causes defects in the dendritic cell system

HIF-1 alpha is important in the field of cancer biology because

It causes the production of VEGF

What is the function of the rabbit liver homogenate in the AMES test?

It contains enzymes that convert pre-carcinogens to carcinogens

How does the pleiotropic protein p-53 block the epithelial to mesenchymal transition seen during metastasis?

It induces a micro-RNA that prevents translation of the genes coding for snail and slug

How does H. pylori cause stomach cancer?

It induces double strand breaks in DNA following chronic inflammation

What is the function of the liver homogenate that is used in the AMES test for carcinogens?

It is a source of enzymes that can convert polyaromatic hydrocarbons to active carcinogens

How is endostatin produced within the human body?

It is produced by the primary tumor enzymatically degrading collagen

Which of the following describes the role of the ATM protein?

It is protein that participates in the detection of DNA damage

What is the Warburg effect?

It is the increased rate of glycolysis exhibited by cancer cells in the presence of oxygen

How does the enzyme prolyl hydroxylase 4 bring about the inactivation of hypoxia inducible factor?

It places a hydroxyl group on HIF-1 alpha resulting in attachment of ubiquitin

Which of the following characteristics describes the gene p53?

Its gene product accumulates following DNA damage

What causes many cancer cells to shift to the glycolytic pathway to obtain energy?

Low oxygen levels causes the expression hypoxia inducible factor

Positron emission tomography to identify rapidly dividing cancer cells within the patient is based upon the cancer cell's ability to:

Metabolize radioactive glucose at an elevated rate

Although human breast cancer is promoted by estrogen, suspected viral initiators in non-hereditary forms are:

Mouse mammary tumor virus and a human papilloma virus

What are two transcription factors induced by inflammatory cytokines that activate signaling pathways for survival within cancer cells?

NFkappaB and Stat3

Gastric esophageal reflux disease can lead to the development of Barrett's Disease, an inflammatory condition of the esophagus that may lead to cancer. What is a major risk factor for development of GERD?

Obesity

What mechanism accounts for the Hayflick limit?

Shortening of telomeres

What is Moh's surgery and why is it beneficial?

Surgical excision of a skin cancer with histological examination of the margins of the resection

The AMES test for mutagenic/carcinogenic substances is based on which of the following premises?

That a specific bacterial mutant can undergo a reverse mutation when exposed to a carcinogen.

Examine the following figure from your text and choose the following correct statement:

The data indicates that repeated exposure of tumors to endostatin causes it to cease growing

When angiogenesis occurs within a growing cancer, which of the following cells is stimulated to divide?

The endothelial cells surrounding the tumor

If DNA is methylated at cytosine residues, especially within promoter regions, what is the result?

The gene that is methylated cannot be transcribed into messenger RNA

I a comparative study of a high fat diet versus a high carbohydrate diet, which diet was associated with higher incidence of liver cancer?

The high fat diet

What is the basis for the positron emission tomography technique used in detection of cancer?

The incorporation of radiolabelled glucose into the cancer cell at an increased rate

What is an alternative to core needle biopsy for both early detection, cancer cell analysis and monitoring the prognosis/recurrence of breast cancers?

The isolation and detection of circulating tumor cells from a blood sample of the patient.

What is one known mechanism that explains the loss of adhesiveness between cancer cells?

The loss of E-cadherin from the surface of the cell

What is a consequence of the Warburg effect that is deleterious to the functioning of immune cells?

The production of lactic acid and thus a decrease in pH around the tumor

The retinoblastoma gene when mutated is involved in the causation of a cancer on the retina, leading to blindness, often at an early age. What role does this gene play in a normal cell cycle.

The retinoblastoma protein is a tumor suppressor protein, that when phosphorylated, allows cells to pass through the cell cycle

The concept of the "Hayflick Limit" is explained by which of the following observations:

The telomeres of normal cells shorten with each cell division and limit the number of cell divisions

What explains the dramatic decrease in deaths from uterine cancer in the U.S.?

The widespread use of the Pap test

Actinic keratoses are of concern to dermatologists and are typically removed with a combination of liquid nitrogen and the topical drug aldara. Why the concern?

They are a precursor for squamous cell carcinomas

How do micro RNAs function to regulate cancer cell development or prevention?

They bind to messenger RNA and prevent its translation

How do non-motile, cancerous epithelial cells become motile and migrate to other body sites?

They convert from an epithelial phenotype to a mesenchymal phenotype.

Why were two Nobel immunologists awarded the Nobel prize in 2018?

They discovered that cancer cells express proteins that check or inhibit immune cells

Why do normal cells die if not attached to a substrate?

They do not receive survival signals from the integrins and die via anoikis

How can cancer cells grow rapidly if they use a primitive bacterial pathway that yields only 2 net ATP per glucose molecule?

They dramatically increase the number of molecules that uptake and metabolize glucose.

What is the function of cyclin-dependent kinases with the cell?

They phosphorylate proteins that control the cell cycle.

Why did Folkman's lab place cancer cells within a chamber that was then placed within the cheek pouch of a a hamster?

They wanted to determine if cancer cells had to be in direct contact with endothelial cells to stimulate their division

What key criterion does a pathologist look for in determining if a tumor is metastatic?

Whether the cells of the growth have crossed the basal lamina

Why does a mutated p-53 gene contribute to the Warburg effect?

Without p-53 protein as a transcription factor there is no

Which of the following carcinogens is activated by epoxide formation?

aflatoxin

Which of the following are natural inhibitors of angiogenesis?

angiostatin, endostatin, thrombospondin

During experiments in the rabbit's eye, which part of the rabbit's eye produced the least amount of angiogenesis after tumor implantation?

anterior chamber

The sources of endostatin and angiostatin are the precursor proteins ______________ and _________________ respectively.

collagen and plasminogen

What enzyme released from cancer cells and macrophages results in the production of endostatin from its substrate?

collagenase

A tumor that has metastasized itself to the liver most likely originated in which of the following organs?

colon

What are two proteins that form the apoptosome?

cytochrome C and Apaf-1

What two proteins does hypoxia inducible factor induce within a cancer cell?

hexokinase 2 and vascular endothelial growth factor

In tissues displaying hyperplasia which of the following would be observed?

increased cell number

Phosphorylation is catalyzed by enzymes that regulate the activity of protein molecules. What are these enzymes called?

kinases

What viruses are suspected to be involved in the causation of some human breast cancers?

mouse mammary tumor virus and human papilloma viruses

What protein can bind and inactivate cyclin dependent kinases?

p-21

What induces the transcription of the protein Puma and what does Puma do within the cell?

p-53; binds and inhibits activity of Bcl-2

How are CAR T cells produced for cancer therapy?

patient's T cells are engineered with a receptor specific for a marker on the cancer cells

Which of the following enzymes is released from cancer cells and produces plasmin

plasminogen activator

Which of the following dietary constituents is a known major risk factor for development of colon cancer?

red meat

Which of the following suffixes designates a cancer as arising from connective tissues?

sarcoma

What are micro RNAs?

small non-coding RNAs that regulate messenger RNA activity in cells

If you were to analyze the genes activated within mesenchymal cancer cells, which ones would be associated with their motility?

snail and slug

A type of cancer that contains a mixture of all three germ cell layers is called:

teratocarcinoma

Cachexia or wasting syndrome seen in cancer patients is caused by:

tumor necrosis factor