Bio- Ch.20
a drug that blocks __________ would also block angiogenesis
VEGF
activation of a proto-oncogene into an oncogene could occur due to a mutation or a change in the ______________________ of the wild type gene
expression
the oldest approach to treating cancer is __________________
surgery
T/F: chromosomes in cancer cells may be translocations
true
T/F: chromothripsis shatters several chromosomes and may kill the cell- or trigger cancer
true
T/F: somatic cells may develop mutations in cancer-causing genes
true
T/F: the process of a tumor spreading is called metastasis
true
T/F: translocations that join parts of nonhomologous chromosomes can turn proto-oncogenes into oncogenes
true
T/F: a mutation present in all stages of a tumor acts early in the disease process
true; a mutation present in al stages of a tumor acts early in the disease process- a mutation that occurs only in advanced stages of cancer acts late in the disease process
T/F: the older the tumor is, the more genetic changes it will have
true; older tumors have more genetic changes because they have had more time to accumulate mutations
oncogenes or tumor suppressor genes? - inactivation causes cancer - cancer entails a loss-of-function - often inactivated by a point mutation or deletion
tumor suppressor genes
RB1 and p53 are...
tumor suppressors
_______________ _______________ ______________ is targeted based on genetic information
tyrosine kinase inhibitor
cancer can result from a failure of ...
a cell cycle checkpoint
__________ _____________ pathways control what genes are expressed in a given cell type
cell fate; think: what is the fate of the cell? what it becomes depends on gene expression
_______________ ____________________ are associated with decreased risk of colon cancer
cruciferous vegetables
during the _______________ stage, the tumor grows and spreads locally, then attracts blood vessels and enters the bloodstream
invasion
a fusion protein can be produced due to the ____________________ of a proto-oncogene to a site next to another gene
translocation
CD133 is a cell surface molecule that is commonly used to identify cancer stem cells in certain types of tumors. CD133 is typically lost from cells...
at the late progenitor stage
tumor suppressor genes can cause cancer when they are...
inactivated
Which of the following events at the cellular level can result in development of cancer? - activation of cancer stem cells - increase in the proportion of stem cells within a tissue - defective tissue repair - induction of stem cell specialization - dedifferentiation
- activation of cancer stem cells - increase in the proportion of stem cells within a tissue - defective tissue repair - dedifferentiation
exposure to which chemicals or foods increases cancer risk? - cruciferous vegetables - insecticides - herbicides - fungicides - fumigants - cooked red meat
- insecticides - herbicides - fungicides - fumigants - cooked red meat
which of the following characteristics are typical of cancer cells? - more adherent than normal cells - loss of cell cycle control - dedifferentiated - lack contact inhibition - decreased mutation rate - can induce blood vessel formation
- loss of cell cycle control - dedifferentiated - lack contact inhibition - can induce blood vessel formation
VEGF stimulates ____________________ to bring blood supply to a tumor
angiogenesis
a tumor suppressor gene mutation that causes cancer is usually a ____________________
deletion
Does the following describe a driver mutation or a passenger mutation? - provides selective growth advantage to cells that defines the cancerous state - known to occur in about 200 genes
driver
T/F: duplication of a chromosome in a cancer cell reduces the copies of an oncogene
false; a duplication can increase the number of copies of a particular oncogene from two- one on each pair of homologs- to up to 100
T/F: All tumors are cancerous
false; a tumor is cancerous only if it infiltrates nearby tissue
T/F: changes in chromosome number, deletions, and duplications can cause cancer, but point mutations cannot cause cancer
false; all can cause cancer
T/F: cancer begins when a cell divides less frequently than it should
false; cancer begins when a cell divides more often than it should
T/F: most cases of cancer are caused by normal chromosomes
false; chromosome abnormalities cause these mutations that lead to cancer
T/F: most cancers are the result of a single genetic change
false; most cancers are the result of a series of genetic changes in several genes
T/F: oncogenes cause cancer when they are inactivated
false; oncogenes cause cancer when they are activated inappropriately
T/F: most cases of cancer arise from inheriting a cancer susceptibility allele from a parent
false; only about 10% of cancers are inherited
T/F: chromosomes in cancer cells exist in normal numbers
false; the chromosomes in cancer cells may be abnormal in number and/or structure
cancer susceptibility is passed onto future generations when a ________________ mutation has occurred
germline
oncogenes or tumor suppressor genes? - activation causes cancer - cancer entails a gain-of-function - activation is usually associated with a point mutation, translocation, or inversion
oncogenes
does the following describe a driver mutation or a passenger mutation? - does not cause cancer - occurs in cancerous and noncancerous cells - number of mutations increases with the patient's age
passenger
genes that normally stimulate cell division when it is appropriate are called _______________________
proto-oncogenes
__________________ is a method of treatment that causes adverse effects by harming healthy cells
radiation
a mutation that occurs in cells that do not develop into gametes is called a ________________ mutation
somatic
sporadic cancer is due to _________________ mutations
somatic; if it is sporadic, then it just occurs out of nowhere and is not inherited
cancer cells often have longer telomeres due to reactivation of the enzyme ________________
telomerase
traditional treatments for cancer, such as radiation and chemotherapy are effective because...
they kill rapidly dividing cells