Kaposi’s Sarcoma

Abstract

Kaposi's sarcoma (KS) (Kaposi, 1872) is classified into at least three forms: 1) the classic form; in elderly men of southern European, Jewish, and Italian origin, 2) the endemic form; among native populations in equatorial Africa and 3) the epidemic form; as a complication of AIDS. As one additional form could be posttransplantation KS in organ transplant recipients. Histologically, KS is composed of two characteristic features; a proliferation of angiomatous lesion and of spindle-shaped cells. The pathological entity of the disease is still controversial. As a cause of the disease, human cytomegalovirus (HCMV) has been the subject based on epidemiologic, serologic, geopathologic and histopathologic observations. About half of KS cases with AIDS has shown evidence of HCMV infection as cytomegalic viral inclusions of the cells. In contrast, about 30% of AIDS cases without KS showed histological HCMV infection. A connection between HCMV and KS was suggested by the detection of herpes-type virus particles in several KS tissue culture lines and in a tumor specimen. DNA and RNA homologous with HCMV sequences have been detected in tumor tissue of both endemic and epidemic KS by electrophoretic methods. HCMV sequences was detected in extracted DNA of 30% of classic KS, using Southern blot technique. In situ hybridization technique using specific DNA probes for HCMV has been developed to reveal endogenous nucleic acid sequences in fixed tissue sections. However, some reports showed that by the in situ technique only a small number of KS cells in the AIDS cases and no case of the classic KS were positive for HCMV within KS lesions. HCMV infections are ubiquitous. There is a very high seropositivity of HCMV in African inhabitants as well as in Africans with endemic KS. A strong association between HCMV and KS was not known. As for HIV itself in AIDS with KS, previous studies have showed the presence of chromosomal abnormalities of KS cells, but not revealed the presence of HIV DNA sequences in KS. Vascular tumors were produced by NIH/3T3 cells transfected with KS DNA of AIDS. An oncogene isolated by transfection of KS DNA encodes a growth factor; FGF. Isolation of rearranged human transforming gene following transfection of KS DNA was performed. DNA having transforming genetic elements which have been repetitively transmitted into phenotypically normal NIH/3T3 cells through cycles of transfection was isolated from tissues of KS with AIDS.(ABSTRACT TRUNCATED AT 400 WORDS)