Chapter 16 Cell Bio
What happens to a cell that is carrying damaged DNA if both of its TP53 alleles become inactivated? 1) It lacks the genetic integrity required for controlled growth. 2) It lacks the genetic integrity required for uncontrolled growth. 3) It fails to be destroyed.
1) It lacks the genetic integrity required for controlled growth. 3) it fails to be destroyed
Which of the genes below would be a viral gene? 1) ABC 2) Gef 3) par 4) Raf
3) par
What happens quite often to the number of normal receptors in the plasma membranes of malignant cells as compared to normal cells?
Malignant cells usually have a much larger number of plasma membrane receptors than normal cells.
What do all of the environmental agents that can cause cancer have in common?
They can all alter the genome.
The development of chronic myelogenous leukemia tumor-resistance to Gleevec appears to usually be caused by mutations in the ABL portion of the fusion gene. Therefore, what is thought to be the best drug regimen for treating CML?
a cocktail of several different inhibitors that target different parts of the Abl protein
The genes involved in tumorigenesis constitute a specific subset of the genome whose products are involved in which of the following activities
progression of a cell through the cell cycle adhesion of a cell to its neighbors apoptosis repair of DNA damage
The cancer vaccine Provenge has been designed to teach a person's immune cells to attack what cancer?
prostate cancer
The cancer vaccine Provenge has been designed to teach a person's immune cells to attack what enzyme?
prostatic acid phosphatase
Studies of identical twins suggest that ________. 1) the genes we inherit have a significant influence on our risks of developing cancer 2) the greatest impact on cancer development comes from genes altered during our lifetime 3) genes play a very small role in cancer development 4) genes play no role in cancer development
1 and 2 1) the genes we inherit have a significant influence on our risks of developing cancer 2) the greatest impact on cancer development comes from genes altered during our lifetime
What types of genetic alterations might make humans more likely to develop a particular type of cancer? 1) those that a human obtains from his/her parents 2) viralline mutations 3) those that occur during a human's lifetime 4) automatic mutations
1 and 3 those that a human obtains from his/her parents and those that occur during a human's lifetime
The fact that tumor cells depend, in many cases, on glycolysis may reflect ________. 1) the high metabolic requirements of cancer cells 2) the low metabolic rate of cancer cells 3) the high oxygen levels the cancer cells usually encounter 4) an inadequate blood supply within the tumor
1 and 4 the high metabolic requirements of cancer cells and an inadequate blood supply within the tumor
Which of the genes below would be a human gene? 1) ABC 2) Gef 3) par 4) Raf
1) ABC
___________ of miRNAs ____________. 1) Expression; has been shown inhibit the expression of human oncogenes 2) Abnormal expression; has been implicated as a causal factor in tumor cell invasiveness and metastasis 3) Expression; has been shown inhibit the expression of RAS and MYC 4) Abnormal expression; has been implicated as a causal factor in tumor cell size
1) Expression; has been shown inhibit the expression of human oncogenes 2) Abnormal expression; has been implicated as a causal factor in tumor cell invasiveness and metastasis 3)Expression; has been shown inhibit the expression of RAS and MYC
A well-known cell-survival pathway involves a kinase called _______ that is activated by the _______, leading to a larger chance that the cell will survive a stimulus that would normally lead to its destruction. 1) PKB, phosphoinositide PIP3 2) PKB, phosphoinositide PIP2 3) AKT, phosphoinositide PIP3 4) PKA, phosphoinositide PIP2
1) PKB, phosphoinositide PIP3 3) AKT, phosphoinositide PIP3
Which of the following are actions of p53? 1) The p53 protein can bind to several members of the Bcl-2 family proteins in a manner that stimulates apoptosis. 2) The p53 protein can bind to Bax proteins at the outer mitochondrial membrane, directly triggering membrane permeabilization and release of apoptotic factors. 3) The p53 protein can bind to several members of the Bcl-2 family proteins in a manner that stimulates meiosis. 4) The p53 protein can bind to Bax proteins at the outer mitochondrial membrane, directly triggering membrane permeabilization and release of apoptotic factors.
1) The p53 protein can bind to several members of the Bcl-2 family proteins in a manner that stimulates apoptosis. 2) The p53 protein can bind to Bax proteins at the outer mitochondrial membrane, directly triggering membrane permeabilization and release of apoptotic factors.
How can one identify oncogenes? 1)by introducing the DNA suspected of containing the oncogene into cultured cells and looking for altered growth properties 2) by fusing two normal cells together 3) by fusing two malignant cells together 4) by introducing the DNA suspected of containing the oncogene into cultured cells and looking for altered nuclear membranes
1) by introducing the DNA suspected of containing the oncogene into cultured cells and looking for altered growth properties
Oncogenes are __________. 1) really eukaryotic cellular genes that were incorporated into the viral genome during a previous infection 2) genes that originated in bacterial genomes 3) genes that originated in viral genomes 4) genes that originated in bacterial genomes, moved to viral genomes and were eventually transferred to eukaryotes
1) really eukaryotic cellular genes that were incorporated into the viral genome during a previous infection
Which cells below possess unlimited proliferation potential, have the capacity to produce more of themselves and can give rise to all of the cells of the tissue? 1) stem cells 2) progenitor cells 3) differentiated end products of a tissue 4) anatomical cells
1) stem cells
Which of the following is being used as an antiangiogenic drug? 1) the small molecular weight kinase inhibitor Sutent 2) the small molecular weight kinase Nexavar 3) the small molecular weight kinase inhibitor Nexavar 4) the humanized antibody Avastin
1) the small molecular weight kinase inhibitor Sutent 3) the small molecular weight kinase inhibitor Nexavar 4) the humanized antibody Avastin
Why is the use of angiogenesis inhibitors less likely to have adverse side effects when used to treat cancers? 1) Angiogenesis inhibitors target normal, genetically stable, endothelial cells, which continue to respond to the presence of these agents. 2) Angiogenesis inhibitors have low affinity for blood vessels. 3) Angiogenesis inhibitors are unstable and do not survive long enough to induce resistance. 4) Angiogenesis inhibitors are stable and survive too long to induce resistance.
1)Angiogenesis inhibitors target normal, genetically stable, endothelial cells, which continue to respond to the presence of these agents.
Under the same conditions that lead cultured normal cells to exhibit decreased growth rates, what happens to malignant cells? 1) They continue to grow and divide. 2) They pile on top of one another forming clumps. 3) Their growth rates decrease. 4) They fail to respond to the types of signals that cause normal cells to cease growth and division.
1, 2 and 4 They continue to grow and divide. They pile on top of one another forming clumps. They fail to respond to the types of signals that cause normal cells to cease growth and division.
What types of genetic alterations might make humans more likely to develop a particular type of cancer? 1) those that a parent obtains from his/her child 2) germline mutations 3) those that occur in eggs after menopause 4) somatic mutations
2 and 4 germline mutations and somatic mutations
What evidence suggests that while viruses may play a role in cancer development and increase a person's risk of developing cancer, they are rarely the sole determinant responsible for the disease? 1) Human papilloma virus (HPV) is transmitted by sexual intercourse. 2) Although HPV is found in ~90% of human cervical cancers, most women infected with the virus never develop the cancer. 3) HPV is found in ~90% of human cervical cancers, and women infected with the virus develop the cancer. 4) All women infected with HPV develop cervical cancer.
2) Although HPV is found in ~90% of human cervical cancers, most women infected with the virus never develop the cancer.
Why do tumor viruses transform normal cells into cancer cells? 1) They take over the normal cells and cause them to make progeny viruses. 2) They carry genes whose products interfere with the cell's normal growth-regulating activities. 3) They carry genes whose products interfere with the cell's normal bioenergetics pathways. 4) They carry genes whose products interfere with the cell's normal secretory activities.
2) They carry genes whose products interfere with the cell's normal growth-regulating activities.
A lack of a functional TP53 gene __________. 1) causes a cell carrying damaged DNA to be destroyed 2) causes a cell carrying damaged DNA to fail to be destroyed 3) will allow genetically unstable cells to continue to divide 4) will stop genetically unstable cells from dividing a) 1 b) 2 c) 3 d) 4 e) 2 and 3
2) causes a cell carrying damaged DNA to fail to be destroyed 3) will allow genetically unstable cells to continue to divide
What effect does the altered receptor that is the product of the avian erythroblastosis virus have on the cells infected with the virus? 1) The infected cells stop growing. 2) The infected cells proliferate in an uncontrolled manner. 3) The infected cells undergo apoptosis. 4) The infected cells hyperdifferentiate.
2)The infected cells proliferate in an uncontrolled manner.
What happens if one cultures cells from a tumor lacking a functional RB gene after reintroducing a wild-type copy of the gene into those cells? 1) The cancer phenotype remains. 2) The cancer phenotype is more extreme. 3) The cancer phenotype disappears. 4) The cells immediately die.
3) The cancer phenotype disappears.
What generally happens if cells that have been transformed into cancer cells in culture by carcinogenic chemicals or viruses are introduced into a host animal? 1) Nothing happens; they do not survive in the host. 2) They are reconverted to normal cells in the host. 3) They generally cause tumors in the host animal. 4) The host animal's immune system destroys the transformed cancer cells.
3) They generally cause tumors in the host animal.
How might blocking angiogenesis have a negative impact as a cancer treatment? 1) by creating a higher oxygen tension in the tissue 2) by concentrating tumor cells at a particular location in the body 3) by creating a more O2-deficient environment for the tumor cells 4) by driving tumor cells to seek out other sites in the body
3) by creating a more O2-deficient environment for the tumor cells 4) by driving tumor cells to seek out other sites in the body
Which cells generally lack the ability to divide? 1) stem cells 2) progenitor cells 3) differentiated end products of a tissue 4) anatomical cells
3) differentiated end products of a tissue
Which of the following is true of healthy G1 cells? 1) The p53 protein is found at very high levels. 2) The probability of apoptosis in these cells is very high. 3) The p53 protein is found at very low levels.
3) the p53 protein is found at very low levels
Which of the following is a difference that has been noted between tumor cells and normal cells from the same patient? 1) The tumor cells in a particular patient tend to be larger than normal cells from the same patient. 2) The normal cells in a particular patient tend to be larger than tumor cells from the same patient. 3) Tumor cell microsatellite DNAs often have lengths different from the corresponding sequences in normal cells from the same patient. 4) Normal cells have more mitochondria than tumor cells.
3)Tumor cell microsatellite DNAs often have lengths different from the corresponding sequences in normal cells from the same patient.
Put the following events in the correct order. 1) p53 is unable to bind to MDM2. 2) The expression of the p21 and BAX genes is activated. 3) ATM is activated. 4) DNA experiences damage from UV-light or chemotherapy drugs. 5) ATM phosphorylates p53. 6) p53 remains in the nucleus, instead of being transported into the cytosol.
4 - 3 - 5 - 1 - 6 - 2
__________ is new blood vessel formation.
Angiogenesis
Mutant forms of which of the following genes have been associated with melanomas and colorectal cancers, respectively?
BRAF and APC
Which molecule do Bexxar and Zevalin antibodies attack?
CD20
What was the initial explanation for the sensitivity of cancer cells to radiation therapy and chemotherapy as compared to normal cells?
Cancer cells are sensitive to radiation and chemotherapy because they divide more rapidly.
You culture cells and selectively block MYC gene expression. What is the effect on the cells?
Cell progression through G1 is blocked.
What virus seems to be related to the development of Burkitt's lymphoma in African patients, while it is associated only with minor infections, like mononucleosis, in the Western world?
Epstein-Barr virus
_____________ is an inherited disease in which individuals develop many (hundreds or thousands) of premalignant polyps from epithelial cells lining the colon wall.
Familial adenomatous polyposis coli
Chronic infection with what stomach-dwelling bacterium has been associated with certain gastric lymphomas?
Helicobacter pylori
________ is a humanized antibody directed against a cell surface receptor called _____ that binds a growth factor responsible for stimulating the proliferation of breast cancer cells.
Herceptin, Her2
You study two cell lines. In one, the MDM2 protein is overexpressed; in the other the p53 protein is absent. What difference would you expect in the behavior of these two cell lines?
In cells containing overexpressed MDM2, p53 levels will be low; in cells lacking the TP53 gene, p53 levels are also low; thus there is no difference in behavior.
What does telomerase do?
It maintains telomeres at the ends of chromosomes, thus allowing cells to continue to divide.
Which statement below is a correct statement about the abilities of normal cells and cancer cells to grow and divide when cultured under conditions favorable for cell proliferation?
Malignant and normal cells grow and divide at similar rates
What is unusual about the inheritance of retinoblastoma, given that it appears to be inherited as a dominant trait?
Not all children who inherited the RB deletion developed retinoblastoma.
A well-known cell-survival pathway involves a kinase called _______ that is activated by the _______, leading to a larger chance that the cell will survive a stimulus that would normally lead to its destruction. 1) PKB, phosphoinositide PIP3 2) PKB, phosphoinositide PIP2 3) PRB, phosphoinositide PIP3 4) PKA, phosphoinositide PIP2
PKB, phosphoinositide PIP3
How does PTEN affect the balance between proapoptotic and antiapoptotic signals?
PTEN removes the phosphate group from the 3-position of PIP3 converting it to PI(4,5)P2, which cannot activate PKB (AKT) and thus throws the balance in a proapoptotic direction.
Who made the first known correlation between environmental agents and cancer development?
Percivall Pott
____________ is a rare childhood cancer of the eye's retina.
Retinoblastoma
The first oncogene discovered was _____, which codes for a _______.
SRC, tyrosine protein kinase
What evidence suggested that the elevated sensitivity of cancer cells to radiation therapy and chemotherapy was not due to their more rapid division?
Some cancer cells divide more slowly than their normal counterparts, yet they are still more sensitive to drugs and radiation than are normal cells.
You are studying two rodent cell lines, one malignant and one normal. You carry out an experiment in which you fuse malignant and normal cells. What happens?
Some of the hybrid cells lose malignant traits.
How does the behavior of the altered receptor that is the product of the avian erythroblastosis virus differ from the wild type form of the receptor?
The altered receptor constitutively stimulates cell growth in the presence and absence of the growth factor.
After the DNAs attached to the glass slide of a microarray are exposed to a probe, how are they usually visualized?
The cDNA probes are fluorescently labeled.
Why can cancer cells proliferate in the absence of serum?
The cell cycle of cancer cells does not depend on signals transmitted from serum growth-factor receptors located at their surface.
If Raf is mutated so that it is "on" constitutively, what is the effect on the cell?
The cells lose growth control.
About 25% of breast cancers are composed of cells that overexpress the HER2 gene. What property does the overexpression of this gene confer upon the tumor cells
These cells are especially sensitive to growth factor stimulation.
How are drug companies trying to combat the ability of the BCL-2 gene to lower the effectiveness of chemotherapy?
They are trying to develop drugs that make cancer cells more likely to undergo apoptosis.
Patients suffering from familial adenomatous polyposis coli have typically been found to have _________, which is the site of the _________.
a small chromosome 5 deletion, APC tumor-suppressor gene
Against what form of cancer is Mylotarg most effective?
acute myeloid leukemia
William Coley, a New York physician in the late 1800s, studied spontaneous remissions of terminal cancer cases. He read that one man, who had an inoperable neck tumor, had gone into remission after what event?
after a streptococcal infection beneath his skin
What happens if a G1 cell sustains genetic damage? 1) The p53 protein concentration rises very rapidly. 2) There is no increased expression of the p53 gene. 3) The p53 protein exhibits an increase in stability.
all of the above
The avian erythroblastosis virus contains an oncogene called erbB that encodes ___________.
an altered EGF receptor that is missing part of the extracellular domain that binds to the growth factor
The BCL-2 oncogene is the oncogene most closely linked to _________; it encodes a membrane-bound ____________.
apoptosis, protein that normally acts to inhibit apoptosis
Mutant forms of tumor-suppressor genes act _____; both copies of the gene must be _______ before their protective function is lost.
as dominant Mendelian traits, mutated or deleted
After his initial discoveries and for the rest of his life, Coley tried to develop a ______ extract that when injected under the skin would stimulate a patient's immune system to destroy their malignancy. His approach called ________ worked against some uncommon__________.
bacterial, Coley's toxin, soft-tissue sarcomas
Which of the following enzymes is known to be expressed at a high level in the cancer cells of patients suffering from acute myeloid leukemia and at low levels in the cancer cells of patients suffering from acute lymphoblastic leukemia?
catalase
Hypoxic conditions ___________.
cause cancer cells to activate a transcription factor called Hif can cause cancer cells to induce the formation of new blood vessels can promote the migratory properties of cancer cells can cause the spread of a tumor
For what disease is the human monoclonal antibody Arzerra likely to be approved for treatment?
chronic lymphocytic leukemia
Retinoblastoma is inherited as a ____________.
dominant genetic trait
When telomerase appears in a cell, it is not because the coding sequences of the gene have been changed. Instead, the protein produced is essentially normal, but it is being produced at an abnormal time. A gene that is normally repressed has been activated for some reason. Such an alteration in cell behavior is referred to as a(n) _________ change.
epigenetic
With respect to cancer genetics and the cancer genome, what are passenger genes?
genes that are subject to mutation but have no effect on the phenotype of a cancer cell
Which screening test just being developed will be able to warn us of the types of cancer to which we may be most susceptible by looking for the presence of specific genes associated with various types of cancer?
genomics
Under what circumstances are tumor cells likely to undergo apoptosis when they have sustained damage to DNA?
if they have a functioning TP53 gene
__________ is an approach that tries to get the immune system more involved in the fight against cancer.
immunotherapy
Because they act to _______ tumorigenesis, the miR-15a and miR-16 miRNAs can be thought of as _________.
inhibit, tumor suppressors
What is the most important property of a cancer cell, whether it is in the body or the culture dish?
its loss of growth control
Which of the following is presently being used as a screening procedure for cancer?
mammography for detecting breast cancer Pap smears for detecting cervical cancer PSA determinations for detecting prostate cancer colonoscopy for detecting colorectal cancer
What is the name for tiny regulatory RNAs that negatively regulate the expression of target mRNAs?
microRNAs
Judah Folkmann suggested that solid tumors __________.
might be destroyed by inhibiting their ability to form new blood vessels
Cancer results from the uncontrolled proliferation of a single wayward cell and is therefore considered to be _________.
monoclonal
A single layer of cells that covers a culture dish is called a(n) _________
monolayer
Which of the following is a biomarker that may at some point could reveal the presence of cancer through a blood test or screening?
mutant DNA abnormal carbohydrates distinctive metabolites presence of cancer cells
If patients with advanced CML are initially treated with Gleevec, they generally develop resistance to the drug within a few months. What seems to cause the resistance?
mutations in the ABL portion of the fusion gene
If any of the proteins involved in mismatch repair are damaged, the mutation rate and cancer risk will rise; this is called the ___________.
mutator phenotype
Which screening test just being developed will be able to screen based on the relative levels of various proteins in the blood?
proteomics
Which one of the following viruses does not appear to be linked to human cancers?
rhinovirus
Raf is a ________ protein kinase that resides at the head of the _______
serine/threonine, MAP kinase cascade
The cancer vaccine GRNVAC1 has been designed to teach a person's immune cells to attack what enzyme?
telomerase
What enzyme is responsible for maintaining the length of the DNA sequences on the ends of chromosomes (telomeres)?
telomerase
Against what protein is the treatment for metastatic colon cancer Vectibix directed?
the EGF receptor
What part of the cell cycle does the pRB protein help to regulate?
the G1 - S transition
What is the oncogene that is most often mutated in human tumors and what does it encode?
the RAS gene, a GTP-binding protein that serves as an on-off switch for a key cell signaling pathway that controls cell proliferation
Whether a cell lives or dies after a particular event depends to a large degree on ________ between ________ and _________ signals.
the balance, proapoptotic, antiapoptotic
What is the material called serum that is added to culture media?
the fluid fraction of the blood
The sis oncogene of the simian sarcoma virus was derived from what normal cellular gene?
the gene for platelet-derived growth factor (PDGF)
What is a xenograft?
transplant of cells from one organism to an organism of a different species
Another word for malignant transformation is ________.
tumorigenesis
