Viruses and Human Cancer
Summary of Key Points
• More than 15% of human cancers are known today to be caused by viruses.
• A hallmark of virally induced cancers is that they are associated with persistent viral infections.
• Although some viruses encode oncogenes that directly contribute to the cancers they cause, other viruses are thought to result in cancer indirectly by causing chronic destruction of the target organ from which the cancer arises.
• The etiologic role of viruses in cancer is established through a combination of epidemiological and molecular evidence.
• In many cases, the cancers caused by the virus represent dead-end streets for the virus; that is, the virus is no longer able to replicate in the cancer.
• Virally induced cancers can be prevented through the use of effective prophylactic vaccines.
• Viral genes expressed in associated cancers represent targets for therapeutic vaccines and viral-specific anticancer drugs.
1. You identify the presence of a new virus in a human cancer. You further learn that certain viral genes are expressed in this cancer. What criteria would you use to establish a causal role for the virus in this cancer?
A Epidemiological evidence for an association of the virus with this cancer
B Determine if the viral genes expressed transform cells in tissue culture
