Chapter 13 Questions

Which of the following statements about Kaposi's sarcoma-associated herpesvirus is false? a. Viral products inhibit the tumor suppressor products p53 and RB. b. HIV infection acts as a co-factor. c. Viral gene products such as the TAX protein activate host proto-oncogenes. d. Viral gene products, such as viral cyclin, drive cell proliferation and contribute to tumorigenesis.

c. Viral gene products such as the TAX protein activate host proto-oncogenes. (TAX is a product of Human T-cell lymphotropic virus type -1 and not Kaposi's sarcoma-associated herpesvirus; the viral product LANA interferes with the function of p53 and RB)

All of the following downstream effects of NF-kappaB activation are important for carcinogenesis except for: a. inhibition of apoptosis b. induction of the Bcl-XL gene c. activation of anti-inflammatory genes d. activation of the cyclin D1 gene

c. activation of anti-inflammatory genes (activation of pro-inflammatory genes is important for carcinogenesis)

The IARC has classified Helicobacter pylori (H. pylori) as a human carcinogen. Which of the following is false? a. H. pylori is a virus that causes stomach cancer. b. H. pylori infection can induce stomach cancer in animals. c. H. pylori is a bacterium that causes stomach cancer. d. H. pylori eradication has been demonstrated to reduce the incidence of gastric cancer in intervention trials.

a. H. pylori is a virus that causes stomach cancer. (it is a bacterium, not a virus)

Which of the following statements about human papilloma virus (HPV) is true? a. HPV16 and HPV18 are high risk forms that account for over 65% of HPV distribution in cervical cancer and are targeted by all the approved cervical cancer vaccines. b. HPV16 and HPV58 are high risk forms for cervical cancer and are targeted only by the approved nonavalent vaccine, Gardasil 9. c. HPV6 and HPV11 do not contribute to cervical cancer but cause genital warts. These types have not been targeted by any approved cervical cancer vaccine. d. HPV16 and HPV18 types have not been associated with oral/throat cancer and so the currently approved cervical cancer vaccines will not help prevent these cancers.

a. HPV16 and HPV18 are high risk forms that account for over 65% of HPV distribution in cervical cancer and are targeted by all the approved cervical cancer vaccines.

Approximately, what percentage of all cancers is caused by infectious agents and inflammation? a. 10% b. 20% c. 50% d. 75%

b. 20% (about 1/6th)

Which one of the following statements about NF-kappaB is false? a. It is a dimeric transcription factor and is a proto-oncogene. b. It acts as a ligand-dependent transcription factor that can be activated by antioxidants. c. NF-kappaB may be activated by infectious agents, carcinogens, or stress. d. It is sequestered in the cytoplasm by an inhibitor prior to activation.

b. It acts as a ligand-dependent transcription factor that can be activated by antioxidants.

In a mouse model of gastric cancer induced by H. pylori, bone marrow-derived stem cells were shown to be recruited and to have which of the following roles? a. To cause the differentiation of cancer cells. b. To contribute to angiogenesis c. To contribute to the gastric cancer d. To cause apoptosis of gastric cancer cells

c. to contribute to the gastric cancer

How does H. pylori CagA protein contribute to tumorigenesis? a. It induces surrounding cells to produce paracrine growth factors. b. It inhibits the function of p53 and RB. c. It induces anti-inflammatory genes through the NF-kappaB pathway. d. By binding to SHP-2 It mimics a gain-of-function oncogenic mutation of this proto-oncogene.

d. By binding to SHP-2 it mimics a gain-of-function oncogenic mutation of this proto-oncogene. (a is the mechanism for Kaposi's sarcoma-associated herpesvirus; b is the mechanism for human papilloma virus; c: other H. pylori proteins induce pro-inflammatory genes through NF-kappa B)

Which one of the following molecules is not involved in a chronic inflammatory response and subsequent tumorigenesis? a. reactive oxygen and nitrogen species which help fight infection. b. chemokines that promote angiogenesis c. cytokines that promote proliferation d. CagA produced by macrophages

d. CagA produced by macrophages (it is produced by H. pylori and causes cell transformation upon injection into cells by the bacterial secretion system)

Which one of the following is not a strategy aimed at preventing cancer caused by infectious agents and inflammation? a. eradication of H. pylori infection by the use of antibiotics. b. vaccines c. administration of aspirin and other non-steroidal anti-inflammatory drugs d. activating the NF-kappaB pathway

d. activating the NF-kappaB pathway (a strategy aimed at preventing cancer must involved inactivating the NF-kappaB pathway)