A study demonstrating the existence of a new transmissible herpesvirus may lead to additional therapeutic approaches for Kaposi's sarcoma (KS), a cancer that remains one of the major AIDS-associated malignancies. The study findings were reported at The American Society of Hematology's 37th Annual Meeting in Seattle.
Kaposi's sarcoma can be fatal, and is characterized by the growth of lesions on the skin, in the gastrointestinal tract, or in the lungs, brains, or other organs. The cause of KS remains unclear, although present evidence suggests the involvement of a sexually transmitted agent.
The study, conducted by researchers at Cornell University Medical College, isolated a fragment of herpes viral DNA (KSHV-DNA) from AIDS-associated KS lesions and from AIDS-related body cavity-based lymphomas. This DNA fragment also was found in non-AIDS related KS, further reinforcing the idea of an association between the new herpesvirus and the pathology of KS.
When a tumor cell line that carries KSHV-DNA was utilized to isolate viral particles produced by these cells, it was noted that the KSHV-DNA was contained inside the viral particles since it was protected from the action of a DNA-degrading enzyme. The virus contained in the isolate was infectious and could transmit the KSHV-DNA to human B-lymphyocytes.
This infection was blocked by foscarnet (Foscavir), an inhibitor of viral DNA replication that is currently approved by the FDA for the treatment of cytomegalovirus retinitis, an opportunistic viral infection. Further studies may establish the potential of foscarnet as a treatment for KS.