Brca1 And Brca2 Mutations, Breaks In DNA, Leukemia, Somatic Cells & Cancer
The key terms of this chapter include Somatic Cells, Cancer, Gene, Proto-oncogene, cycle, mutation, Stem, Translocation, Chromosomes, Micrornas, Oncogene, Cancerous, Protein, Somatic, Telomerase, Suppressor, Transcription, Tumor, Cancer-causing, Case-control, Fusion, Germline, Leukemia, Lung, Myeloid, Pancreatic, rRcessive, Syndrome, Virus, Anti-cancer, Anti-oncogene, Antibodies, Apoptosis, Carcinogens, Sporadic Cancers, Chemotherapy. Chronic Myeloid Leukemia
In normal differentiated somatic cells, telomerase
A. adds material to the ends of chromosomes with each cell division.
B. is not expressed and telomere tips erode with each division.
C. removes telomere tips with each division.
D. is overexpressed and cells undergo apoptosis.
E. repairs double strand breaks in DNA.
Sporadic cancers result from
A. recessive or dominant mutation in a somatic cell.
B. recessive or dominant germline mutation.
C. mutation in a sperm or oocyte.
D. exposure to a cancer-causing virus.
E. lack of a cell cycle in affected cells.
Dana Reeve, the wife of actor Christopher Reeve, died at a young age from lung cancer, although she had never smoked. Her cancer was likely caused by
A. a germline mutation.
B. two somatic mutations in the same lung cell.
C. exposure to carcinogens.
D. second hand smoke.
E. stress from caring for her husband, who had a spinal cord injury.
A. divide uncontrollably and then die.
B. are particularly sensitive to extracellular signals.
C. divide uncontrollably and are immortal.
D. are impossible to grow in culture.
E. have an extra set of chromosomes, which keeps them dividing.
Cancer cells are not
A. contact inhibited.
The connection between stem cells and cancer is that
A. all stem cells are also cancer cells.
B. cells may become cancerous by expressing “stemness” genes.
C. stem cells rescue cells that have become cancerous.
D. stem cells become cancerous if a person smokes.
E. both stem cells and cancer cells have inactivated telomerase.
A proto-oncogene can become an oncogene when
A. it is shut off.
B. it is translocated next to a highly expressed gene.
C. it is translocated next to a gene that is not being expressed.
D. checkpoints are added to the cell cycle.
E. the cell cycle temporarily runs backwards.
A(n) _______ is a type of cancer-causing gene that promotes cancer by activating cell division at an inappropriate time or place.
A. DNA repair gene
B. tumor suppressor gene
E. somatic cells
The oncogene that causes Burkitt’s lymphoma results from
A. A translocation that moves a proto-oncogene next to an antibody gene.
B. an inversion that places a proto-oncogene next to a transcription factor gene.
C. a point mutation in a proto-oncogene.
D. a virus that inserts next to a proto-oncogene.
E. a deletion of an anti-oncogene.
Chronic myeloid leukemia is caused by a translocation that creates
A. a proto-oncogene.
B. a fusion protein that acts like a transcription factor, activating cell cycle control genes.
C. a protein that increases growth factor production.
D. a fusion protein that deregulates the cell cycle of myeloid white blood cells.
E. a deletion of a whole chromosome.
The cause of p53-related cancers is
A. fetal cells that remain in a child or adult, dividing too frequently.
B. continual expression of the telomerase gene, which keeps cells dividing.
C. deletion of cell cycle checkpoint genes.
D. failure to repair damaged DNA, allowing the cell to continue dividing.
E. a translocation between chromosomes 12 and 15.
A. broken single DNA strands
B. increased likelihood of a translocation
C. interference with repair of a double-strand DNA breaks
D. attracting radiation from the environment to the DNA, where it causes breaks
E. undergoing mutations that form ring chromosomes
BRCA1 and BRCA2 mutations
A. are X-linked.
B. are incompletely penetrant.
C. are translocations.
D. cause several types of leukemia.
E. are in oncogenes.
A way that a microRNA can cause cancer is to
A. insert into an oncogene.
B. insert into a tumor suppressor gene.
C. cause a translocation.
D. block translation of tumor suppressor gene transcripts.
E. duplicate the genome.
Mutations in microRNAs can explain families who have different cancers but do not have mutation for known family cancer syndrome genes because
A. microRNAs are specific to families.
B. a single type of microRNA can have many targets.
C. microRNAs also serve as oncogenes.
D. exposure to different environmental toxins triggers transcription of particular microRNAs.
E. they caused reversion of the family cancer syndrome mutations.
Which type of study would compare the incidence of colon cancer among Japanese and Americans of Japanese descent?
E. gene expression profile
Which of these are thought to have anti-cancer benefits?
A. heterocyclic aromatic amines (HAs)
B. cruciferous vegetables such as broccoli
C. red meats
D. baked potatoes
E. fried foods
The diets of 250 patients with pancreatic cancer are compared to the diets of 250 healthy individuals, over a four month period. The patients and controls are matched one for one for age, sex, and body mass index. The cancer patients tended to eat more barbecued meat, and none of them were vegetarians. The healthy group included 30 vegetarians and only four of the 250 regularly ate barbecued meat. The researchers conclude that it would be worthwhile to further test the hypothesis that compounds in charred meat cause pancreatic cancer. What type of study is this?
B. nutritionally controlled
Traditional cancer treatments include
A. prayer and rationalization.
B. surgery, chemotherapy, and radiation.
C. nutritional therapy and physical therapy.
D. monoclonal antibodies and cytokines.
E. gene therapy.
Invasive malignant tumors typically contain mutations that affect the cytoskeleton and allow the cell to move from where it is anchored.
Research has shown that a “cocktail” of several drugs, each acting on a different cellular pathway, is the best approach to treat many cancers.