Chapter 43: Human Cancer Viruses
Viruses can cause cancer in animals and humans. A principle of viral carcinogenesis is that
(A) Retroviruses cause most types of human cancer.
(B) Not all infections with a human cancer virus lead to tumor formation.
(C) Short latent periods elapse between time of virus infection and tumor appearance.
(D) Animal models seldom predict cellular mechanisms in human cancer.
(E) Host factors are insignificant in influencing the development of virus-induced human cancer.
Cellular oncogenes represent activated genes involved in cancer. A second class of cancer genes is involved in cancer development only when both alleles of such a gene are inactivated. The second class of genes is called
(C) Tumor suppressor genes
A 38-year-old woman is diagnosed with cervical cancer. This cancer is common worldwide and has a sexually transmitted viral etiology. The causative agent of human cervical cancer is
(C) Human papillomaviruses, high-risk types
Retroviruses encode an enzyme called reverse transcriptase. The function of the reverse transcriptase enzyme is
(B) RNA-dependent DNA polymerase activity
(C) DNA-dependent RNA polymerase activity
(D) RNA-dependent RNA polymerase activity
(E) Topoisomerase activity
Two months after a kidney transplant, a 47-year-old man developed nephropathy. Up to 5% of renal allograft recipients develop nephropathy. A viral cause of some of the nephropathy cases has been identified as
(B) Human papillomavirus, all types
(C) Human papillomavirus, low-risk types
(E) Human cytomegalovirus
Human papillomavirus can cause cancer in humans and is most commonly associated with