Cancer Cells

1. Which one of the following leads to the others?
a. Cells aren't susceptible to density-dependent inhibition
b. Cells do not enter the G-arrest state
c. Cells do not recognize contact inhibition
d. Cells grow in low nutrient concentrations
e. None of the above

2. Which of the following is not a characteristic of cancer cells?
a. Lack fibronectin
b. Produce plasminogen activator
c. Increased lectin receptors
d. Produce chorionic gonadotropic hormone
e. None of the above

3. Addition of fibronectin to malignant cells would have all of the following effects except which one? The malignant cells would:
a. Flatten out
b. Move when in contact with other cells
c. Not recognize density-dependent inhibition of growth
d. Adhere to one another
e. None of the above

4. In cell culture, cancer cell lines:
a. Require the constant addition of nutrient
b. Require the constant addition of growth factors
c. Must be transferred to new growth medium after a few cell divisions
d. Stop growing at the monolayer stage
e. None of the above

5. Turpentine does not cause cancer, however it can cause tumors to appear. This indicates that turpentine is:
a. An initiator
b. A carcinogen
c. A promotor
d. A mutagen
e. None of the above

6. All of the following are methods of activating oncogenes except:
a. Chromosomal translation
b. DNA rearrangement
c. Gene amplification
d. Point mutation
e. Stimulating cell division

7. All of the following are true about human RNA viruses. Which one of the following is necessary for an RNA virus to be oncogenic?
a. Ability to replicate in a human cell
b. Possess a protein coat
c. Possess reverse transcriptase
d. Possess genes
e. All of the above

8. Oncogenic DNA viruses differ from oncogenic RNA viruses in that the RNA viruses must:
a. Can remain latent in a host cell
b. Possess oncogenes
c. Possess reverse transcriptase
d. Can replicate in human cells
e. None of the above

9. The protein-tyrosine kinase activity is 30 to 50 times greater in cancer cells than in normal cells suggesting that:
a. Cancer is due to excessive phosphorylation of proteins
b. Cancer is due to gene amplification
c. Cancer is due to growth factor production
d. Sarcoma cells produce src protein and normal cells do not
e. None of the above

10. In cancer cells, the Ras proteins are bound to GTP more often than G protein in normal cells. This suggests that cancer is due to:
a. Excessive amounts of G protein
b. Excessive amount of GTP
c. G protein activation
d. G protein inhibition
e. None of the above

11. Which one of the following acts in the nucleus to produce a malignant transformation?
a. Growth factor
b. Receptor protein-tyrosine kinase
c. G proteins
d. Protein-serine/threonine kinase
e. Transcription factor

12. The cause of cancer is best described by which one of the following statements?
a. Cancer is the result of a single mutation
b. Cancer is a multistep accumulation of mutations
c. Cancer is the result of a poor diet
d. Cancer is the result of a viral infection
e. None of the above

13. Cells from a crown gall produce abnormal tumor cells in cell culture. When the cells are grafted onto a healthy plant, they produce normal cells. You can conclude that:
a. Cancer is caused by changes in the nucleus
b. The absence of promotor factors causes normal growth
c. The presence of normal growth factors causes normal growth
d. Cancer is inherited
e. b and c

14. The following are mechanisms of action of anticancer drugs. Which one is specific for tumor cells?
a. Blocking the mitotic spindle
b. Hydrolyzing asparagine
c. Inhibition microtubule formation
d. Inhibiting RNA synthesis
e. None of the above

15. Samples from three females (#1, 2, and 3) from a family with familial breast cancer were examined by Southern blotting for gene nm23 and a mutant form of the oncogene p53. Patient 1 has 2 nm23 alleles and 2 p53 alleles. Patient 2 has 1 nm23 and 2 p53 alleles and breast cancer. Patient three has 2 nm23 alleles. The results indicate that:
a. nm23 is a tumor suppressing gene
b. The mutation p53 is inherited
c. The mutated p53 always causes cancer
d. A spontaneous mutation occurred
e. None of the above