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
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.