Basic fibroblast growth factor as a growth factor for SRV-2-infected simian retroperitoneal fibromatosis cells, an animal model for AMS related Kaposi's sarcoma

Basic fibroblast growth factor (bFGF) and vascular endothelial cell growth factor (VEGF) were demonstrated to be important factors sustaining the grow th of Kaposi's sarcoma. RF cells were used to provide a model to study the pathogenesis of Kaposi's sarcoma. In this paper, we demonstrated that bFGF is present in the RF cells, cultured media, and tissues from monkey. The bi ological activities of bFGF on RF cells were also studied in vitro with ser um-free media. The bFGF from serum-free conditioned media is biologically a ctive to stimulate RF cells in certain media condition. The mitogenic effec t was abrogated by sheep neutralizing anti-bFGF antibody. Furthermore, the effect of antibody was reversed by the addition of exogenous bFGF. ELISA me asurements indicating the growth potency of conditioned media correlated wi th the amount of bFGF in the conditioned media. The data from flow cytometr y demonstrated the co-existence of SRV-2 and bFGF among RF cells and RF tis sues. Immunohistochemical staining of RF tissue blocks for bFGF revealed th at bFGF was present in the tumor and the presence of bFGF was not caused by the artifact of tissue culture. These results indicate that bFGF is an imp ortant growth factor to promote RF cell growth in vitro and RF tumor in viv o. Further studies are required to determine the relationship between the i nteraction of bFGF, SRV-2, and VEGF. This model also provides an adequate a lternative to the model induced by simian immunodeficiency virus (SIV) to s tudy the Kaposi's sarcoma.