Download Cancer is known as a real threat to human health

Potential role of Cytomegalovirus in cancer
Marjan Mehrab Mohseni
Cancer is known as a real threat to human health. Worldwide, it is among the most
common causes of death. Cancer occurs when cells become abnormal and keep dividing
and multiplying without control or order, forming a tumor or neoplasm. Cancer cells
develop because of damage to DNA. Most often when DNA becomes damaged the body
is able to repair it. In cancer cells, the damaged DNA is not repaired. In normal cells,
there are some ways to protect DNA from being damaged, one of which is called
methylation. Therefore, it is reasonable to assume that abnormal patterns of methylation
could be seen in patients with cancer. Various factors like smoking, radiation, chemicals,
and viruses are known to be associated with cancer.
Viruses have affected humans since ancient time. Rabies, polio, and smallpox are typical
examples of viral diseases that have been observed since many centuries ago, although
their causative agents remained unknown for quite a long time. One of the viruses that is
speculated to be associated with different kinds of cancers is called cytomegalovirus.
This virus belongs to a family of viruses that cause fever blisters and chickenpox. Often
infection by cytomegalovirus gives no symptoms, but in patients with weak immune
system, like patient suffering from AIDS, clinical disease is more prevalent.
The interaction between virus and host plays a key role for determining the outcome of
infection. Viruses, including cytomegalovirus, likely try to exploit cell machineries of
host for their own sake. In my study, I tried to figure out whether there was an association
between infection with cytomegalovirus and methylation, which is a protecting factor
against cancer. I observed by microscopy that cytomegalovirus infection causes one of
the methylteransferase enzymes of the host to move out of nucleus, which suggests
reduced DNA methylation. This might be one of the mechanisms that leads to cancer.
Degree project in biology fall 2007
Examensarbete i biologi, 20p
Biology Education Center, Uppsala University, Department of Clinical Neuroscience,
Center for Molecular Medicine, Karolinska Institute, Stockholm
Supervisors: Prof. Tomas Ekström and Mohsen Karimi