Monoclonal antibodies against heparin-binding growth factor II/basic fibroblast growth factor that block its biological activity: invalidity of the antibodies for tumor angiogenesis.

Abstract

Two monoclonal antibodies (mAbs) against bovine heparin-binding growth factor II (HBGF-II)/basic fibroblast growth factor (bFGF) were obtained from mouse hybridoma cell lines. They were highly specific for bFGF from bovine, human, and mouse sources and did not cross-react with bovine heparin-binding growth factor I (HBGF-I)/acidic fibroblast growth factor (aFGF). The immunoglobulin class and subclass of these mAbs were IgGI, Kc. The apparent dissociation constant (Kd) for bFGF of these mAbs ranged from 10-9 to 10-10 M. One mAb (bFM-2) also cross-reacted with heat-inactivated bFGF, while the other mAb (bFM-1) did not, suggesting that bFM-1 recognized the conformation of the bFGF molecule necessary for its biological activity. These mAbs inhibited growth of cultured bovine capillary endothelial cells in both the presence and absence of exogenous bFGF, indicating the autocrine action of this growth factor in in vitro growth of these cells. On the other hand, injection of these hybridoma cell lines s.c. into the backs of athymic mice resulted in development of highly vascularized solid tumors and a sustained high level of anti-bFGF activity in the blood of the tumor-bearing mice. These findings suggest that bFGF is not essential as an autocrine or paracrine growth factor for angiogenesis in vivo. These mAbs should be useful in further studies on the physiological role and the conformation-function relationship of bFGF because they block its biological activity.

Human chondrosarcoma secretes vascular endothelial growth factor to induce tumor angiogenesis and stores basic fibroblast growth factor for regulation of its own growth

“…Two opposite results have been reported: an anti-bFGF antibody inhibited tumor growth, 24,54,55 but on the other hand, it did not prevent tumorigenesis. 56,57 In the therapy of chondrosarcomas, the system of delivery of anti-bFGF antibody to tumor cells is considered to be the most important point, because bFGF is trapped around tumor cells. We propose that anti-bFGF therapy requires a peritumoral or intratumoral approach to chondrosarcoma, because anti-bFGF antibody hardly infiltrates into cartilage-specific ECM as described.…”

Bombesin antagonists inhibit proangiogenic factors in human experimental breast cancers

“…The monoclonal antibody generated against bFGF, clone bFM-1, was purchased from Upstate Biotechnology (Lake Placid, NY, USA). The antibody was used at a final dilution of 1 : 20 000; it recognises the active conformation of bFGF molecule and is specific for bFGF from bovine, human and murine sources (Matsuzaki et al, 1989).…”

Kinetics of integrin expression in the mouse model of proliferative retinopathy and success of secondary intervention with cyclic RGD peptides

“…To determine the temporal expression pattern of the a v -type integrins in relation to two of its inducers, VEGF and bFGF, Western-blot analysis of retinal protein extracts of four retinae from four different animals for each time point was carried out using the following antibodies: a polyclonal rabbit antibody directed against mouse a v b x -integrin (0.1 mg/ml), a polyclonal rabbit antibody directed against the N-terminal domain of VEGF (0.1 mg/ml; Santa Cruz, Ismaning, Germany), a polyclonal rabbit antibody directed against purified bovine brain bFGF with high specificity against mouse bFGF [16] (5 mg/ml).…”