George Murphy, M.D., professor of pathology at Jefferson Medical College of Thomas Jefferson University in Philadelphia, and Masatoshi Deguchi, M.D., visiting scientist from Tohuku University in Sendai, Japan, have created a mouse model that resembles an early form of KS. To accomplish this, they have grown and characterized a line of mouse skin cells in the laboratory that they believe are analogous to the cells that go awry early on in human KS.
The type of cell, termed a "dermal dendrocyte," increases dramatically in number in tumors in early human KS, he says. When Dr. Murphy and his co-workers injected the dermal dendrocytes directly into normal mouse skin, the injected areas developed features similar to human KS.
The findings may lead to insights into the origins of other diseases, such as scleroderma, abnormal wound healing and a chronic form of graft-versus-host-disease involved in bone marrow transplantation.
Dr. Murphy and his group report their findings November 1 in the American Journal of Pathology.
According to Dr. Murphy, KS usually begins as one of many bruise-like areas on the skin that develops over time into tumors. KS may also affect internal organs, particularly in AIDS, and may be fatal.
Dermal dendrocytes which have been known to exist only since 1985 may play roles in wound healing or in the immune system. There is evidence for both.
"It's interesting that in AIDS, it is occurring in the setting of immune disease, and involves an immune cell proliferating abnormally," he says. What's more, "KS can occur in areas of trauma," he says, "and a wound healing cell might be proliferating abnormally" in such conditions.