This is a review of a relatively rare, but highly aggressive skin cancer called Merkel Cell Polyomavirus. It is one of the few cancers directly attributed to a virus, and as such, is atypical in terms of treatment. promising therapy for the condition (Griffiths, et al., 2013). Due to the nature of the MCPyV, there appears to be a complex relationship between the regions of the cell structures that encode both large and small T-antigen proteins that arguably both enhance and restrict the cells ability to replicate.
Merkel Cell Carcinoma is a relatively rare, but highly aggressive type of skin cancer. Discovered in 2008, it is typically caused by a virus known as Merkel Cell Polyomavirus (MCPyV). At times, the disease may be known as APUDoma, a primary neuroendocrine carcinoma of the skin, or primary small cell carcinoma. However, from a pathological perspective, 80% of Merkel Cell Carcinoma (MCC) are called by the polyomavirus. Interestingly, the virus has a clonal integration into the cancerous cells, and a particular mutation only when in the cancerous cell, not a healthy skin cell. No other cancers have been confirmed to be caused by this virus, and because of the viral origin of the cancer, immunotherapies are one of the most promising avenues for treating virus-positive MCC. However, at present, little is known regarding the virus-host interactions from a biochemical perspective. Research does show, though, that a new function of the MCPyV small T-Antigen (ST) may serve as an inhibitor of transcription and provide a promising therapy for the condition (Griffiths, et al., 2013).
Due to the nature of the MCPyV, there appears to be a complex relationship between the regions of the cell structures that encode both large and small T-antigen proteins that arguably both enhance and restrict the cells ability to replicate. Research does indicate that these antigens are important parts of the molecular mechanisms within cell death and cancer development, but are yet to be fully explained.
As a cancer, MCC typically presents as a relatively painless, yet firm, nodule with flesh-colored, red or blue tumors that vary in size from .5 cm to more than 5 cm, and tend to enlarge rapidly. They arise almost anywhere on the body, but most originate on areas that have more sun-exposure than others -- the head and neck, arms, or even legs in areas in certain climates. MCC cancers are virulent local cancers that tend to spread rapidly into the muscle tissue, subcutaneous fat and fascia, metastasize early and move into the lymph system, spreading through blood vessels into the liver, respiratory tract, brain and osteological system.
Recent research has shown that most patients who have tumors containing MCV have higher antibody levels than other healthy adults. From an epidemiological perspective, the cancer occurs most often in Caucasian males between 60-80, males being twice as likely to contract the disease. It is commonly mistaken as another type of histological cancer, but the incidence is increasing rapidly. As well, immune suppression may robustly increase the odds of developing the disease -- MCC occurs more than 30 times more often in individuals with chronic leukemia and 14 times more often in individuals with HIV. Because it is still relatively uncommon, though, treatments have typically been focused upon surgery, radiation/chemotherapy and sentinel lymph node biopsies.
Another interesting aspect of the disease is that MCPyV negatively regulates transcriptional activation and limits the cellular mechanisms ability to repair itself chemically. Polyomavirus STs do have important functions in viral replication and transformation, which is why it is often difficult to discern the actual expression of MCPyV on cellular protein-based molecules.
You’re 71% through this paper. Sign up to read the full paper.
Sign Up Now — Instant Access Already a member? Log inAlways verify citation format against your institution’s current style guide requirements.