Chapter 13 Self-check questions

. The IARC has classified Helicobacter pylori (H. pylori) as a human carcinogen. Which of the following is false?

H. pylori is a virus that causes stomach cancer.

H. pylori infection can induce stomach cancer in animals.

H. pylori is a bacterium that causes stomach cancer.

H. pylori eradication has been demonstrated to reduce the incidence of gastric cancer in intervention trials.

. Which of the following statements about Kaposi's sarcoma-associated herpesvirus (KSHV; HHV8) is false?

Viral product LANAinhibits the tumor suppressor products p53 and RB.

HIV infection and resulting immunodeficiency acts as a co-factor.

Viral gene products such as the TAX protein activate host proto-oncogenes.

The mechanism of KSHV tumorigenesis has been suggested to occur via paracrine neoplasia, whereby infected cells release factors that promote tumor formation in neighboring cells.

. How does H. pylori CagA protein contribute to tumorigenesis?

It induces surrounding cells to produce paracrine growth factors.

It inhibits the function of p53 and RB.

It induces anti-inflammatory genes through the NF-κB pathway.

By binding to SHP-2 it mimics a gain-of-function oncogenic mutation of this proto-oncogene.

. Approximately, what percentage of all cancers is caused by infectious agents and inflammation?

10%

20%

50%

75%

. Which one of the following statements about NF-κB is false?

It is a dimeric transcription factor and is a proto-oncogene.

It acts as a ligand-dependent transcription factor that can be activated by anti-oxidants.

NF-κB may be activated by infectious agents, carcinogens, or stress.

It is sequestered in the cytoplasm by an inhibitor prior to activation.

. Which one of the following is not a strategy aimed at preventing cancer caused by infectious agents and inflammation?

Eradication of H. pylori infection by the use of antibiotics.

Vaccines.

Administration of aspirin and other non-steroidal anti-inflammatory drugs.

Activating the NF-κB pathway.

. All of the following downstream effects of NF-κB activation are important for carcinogenesis except for:

inhibition of apoptosis.

induction of the Bcl-X_L gene.

activation of anti-inflammatory genes.

activation of the VEGF gene.

. Which one of the following molecules is not involved in a chronic inflammatory response and subsequent tumorigenesis?

Reactive oxygen and nitrogen species.

Chemokines that promote angiogenesis.

Cytokines that promote proliferation.

Cag A produced by macrophages.

. Which of the following statements about human papillomavirus (HPV) is true?

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.

HPV16 and HPV58 are high risk forms for cervical cancer and are targeted only by the approved nonavalent vaccine, Gardasil 9.

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.

HPV16 and HPV18 types have not been associated with oral/throat cancers and so the currently approved cervical cancer vaccines will not help prevent these cancers.

. The condition called dysbiosis is:

the imbalance of the cytokines and chemokines during inflammation

associated with dystonia

the imbalance of the types of bacteria in our microbiome

a causative agent for obesity

. Using your knowledge of the STAT activation pathway, which are NOT possible therapeutic targets?

Inhibiting IL-6 and IL-6R

Inhibiting MAPK

Inhibiting JAK

Inhibiting STAT dimerization

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