New Cancer-Causing Virus Confirmed By Scientists
Cytomegalovirus (CMV) was confirmed as one of the causes of most common salivary gland cancers. The study was conducted at USC Laboratory for Developmental Genetics and it isolated less than ten oncoviruses (viruses that can cause cancer) including Human Papilloma Virus (HPV).
The study was published in the Experimental and Molecular Pathology online journal, and it is part of a larger series of studies conducted at USC. The combined results highlight the CMV’s role in causing cancer, virus that can either induce cell mutation directly or promotes tumor formation by exploiting cellular weaknesses.
Study leader Michael Melnick, concluded that CMV is a oncovirus after laborious studies conducted on human salivary glands as well as rodents.
CMV has a very high incidence in human and can lead to devastating consequences in patients with compromised immune systems and can also lead to severe birth defects if a woman was exposed to cytomegalovirus for the first time before birth. Besides salivary gland cancer, cytomegalovirus can be linked to other cancer types according to Melnick.
At least 60% of the US population has been exposed to cytomegalovirus, and most healthy patients with uncompromised immune system will become carriers. The virus is inactivated and remains dormant in the salivary glands. The exact cause of reactivation is yet unknown.
This particular study demonstrates not only the presence and intense activity of cytomegalovirus in tumors but also establishes a link between virus-created proteins amount and cancer severity.
Previous studies have shown that salivary glands from newborn mice exposed to cytomegalovirus, lead to salivary gland cancer. Afterwards virus interaction with cells was studied, trying therefore stopping cancer progression.
Melnick and his research team besides linking cytomegalovirus and salivary gland cancer, also discovered a molecular pathway that was being exploited by cytomegalovirus to cause cancer. That particular pathway is the same for both mice and humans and it is only active during the embryonic development stage. Cytomegalovirus deactivates this pathway leading to tumors that help the virus multiply.
The problem with salivary cancer is that they are usually late-diagnosed and the fact that the affected area is very near the face makes the surgical treatment problematic and quite a challenge. With these study results, there is hope for better prevention and treatment options , maybe similar to HPV- cervical cancer measures implemented.
Not so distant into the future, Melnick expects to possess more information about the link between viral infections and tumor formation. “This should be a most fruitful area of investigation for a long time to come,” he said