Which of the following would NOT be an indicator that a particular virus is carc
ID: 274135 • Letter: W
Question
Which of the following would NOT be an indicator that a particular virus is carcinogenic in human and why?
a) observing a greater frequency of the associated cancers in individuals having unprotected sex and sharing needles for intravenous drug abuse
b) prolonged epidemiological study demonstrating fewer cancers in a population having been vaccinated for the virus in question relative to unvaccinated populations
c) identifying cancerous cells containing alternating x-chromosome inactivation when assessin Barr bodies
d) identifying cancers frequently containing the virus in patients with AIDS, inelderly populations, or in transplant recipients
Explanation / Answer
C. Identifying cancerous cells containing alternating X chromosome inactivation would not be an indicator that a particular virus is the one causing cancer. By default, females shut down one X chromosome at the time of development. However, it has been reported that there is a disappearance of Barr body during breast cancer. The process is genetically/epigenetically controlled at the time of development and does not need the presence of virus.
Whereas other process are dependent on viral infection followed by onset of cancer.