Molecular Biology of the Cell by Bruce Alberts, Alexander Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter Walter by by Bruce Alberts, Alexander Johnson, Julian Lewis, David Morg

1130 Chapter 20: Cancer
Table 20–2 Viruses Associated with Human Cancers
Virus Associated cancer Areas of high
incidence
DNA viruses
Papovavirus family
Papillomavirus (many
distinct strains)
Hepadnavirus family
Hepatitis-B virus
Herpesvirus family
Epstein–Barr virus
Warts (benign)
Carcinoma of the uterine
cervix
Liver cancer (hepatocellular
carcinoma)
Burkitt’s lymphoma (cancer
of B lymphocytes)
Nasopharyngeal carcinoma
Worldwide
Worldwide
Southeast Asia, tropical
Africa
West Africa, Papua
New Guinea
Southern China,
Greenland
Human herpesvirus 8 Kaposi’s sarcoma Central and Southern
Africa
RNA viruses
Retrovirus family
Human T-cell leukemia virus
type I (HTLV-1)
Human immunodeficiency
virus (HIV, the AIDS virus)
Flavivirus family
Hepatitis-C virus
Adult T-cell leukemia/
lymphoma
Kaposi’s sarcoma (via
human herpesvirus 8)
Liver cancer (hepatocellular
carcinoma)
Japan, West Indies
Central and Southern
Africa
Worldwide
For all these viruses, the number of people infected is much larger than the number who
develop cancer: the viruses must act in conjunction with other factors. As described in the text,
different viruses contribute to cancer in different ways.
with hepatitis-C virus, which has infected 170 million people worldwide, is also
clearly associated with the development of liver cancer.
The main culprits, as shown in Table 20–2, are the DNA viruses. The DNA
tumor viruses cause cancer by the most direct route—by interfering with controls
of the cell cycle and apoptosis. To understand this type of viral carcinogenesis, it
is important to review the life history of viruses. Many DNA viruses use the host
cell’s DNA replication machinery to replicate their own genomes. However, to
produce a large number of infectious virus particles within a single host cell, the
DNA virus has to commandeer this machinery and drive it hard, breaking through
the normal constraints on DNA replication and usually killing the host cell in the
process. Many DNA viruses reproduce only in this way. But some have a second
option: they can propagate their genome as a quiet, well-behaved passenger in
the host cell, replicating in parallel with the host cell’s DNA (either integrated into
the host genome, or as an extrachromosomal plasmid) in the course of ordinary
cell-division cycles. These viruses will switch between two modes of existence
according to circumstances, remaining latent and harmless for a long time, but