ESTABLISHMENT AND CHARACTERIZATION OF 2 NEW KAPOSIS-SARCOMA CELL-CULTURES FROM AN AIDS AND A NON-AIDS PATIENT

We have established and characterized two new Kaposi's sarcoma (KS) ce ll lines derived from skin biopsies: AIDS-KSISTIV (from an AIDS-associ ated KS) and KSISTVIII (from a sporadic KS). AIDS-KSISTIV and KSISTVII I are composed mostly of spindle-shaped cells. They show similar patte rns of immunohistochemical staining and are positive for smooth muscle (smooth muscle alpha-actin) and fibroblastoid (TE7) markers. Neither of these lines express the endothelial marker von Willebrand factor VI II. These immunohistochemical patterns are similar to numerous other K S lines that we and others have established. When seeded on a reconsti tuted basement membrane (''Matrigel''), AIDS-KSISTIV and KSISTVIII cel ls form branching colonies and invade into the Matrigel, as do other K S cultures that we have previously examined. This behaviour on Matrige l is similar to that of malignant sarcoma cells of different origin. T he expression of vimentin and the morphology of the invasive colonies on Matrigel suggest that KS-derived cells are poorly differentiated me senchymal cells. KS lesions are characterized by a conspicuous neovasc ularization, which appears to be derived from host cell recruitment. W e tested the capability of the KS-cell supernatants to induce an angio genic response in vitro. The new lines are able to stimulate human end othelial cell chemotaxis and invasion through Matrigel-coated filters. No differences in angiogenic potential in vitro were observed between the AIDS and the non-AIDS case, as we previously noted for other esta blished cultures. Our new lines have the properties of true KS cells a nd confirm that KS spindle cells from HIV-positive or -negative patien ts have identical phenotypic and behavioural characteristics in vitro.