[Inhibition of angiogenesis and growth of malignant gliomas in the athymic nude rat model: immunotherapy against "basic fibroblast growth factor"].

An important feature of malignant progression in human gliomas is increased polymorphism of tumor cells associated with karyotypic heterogenity and a variety of secondary changes, one of which is increased angiogenesis. The capability of brain tumors for angiogenesis most probably is the earliest sign for malignancy in 95% of cases and occurs before typical changes of histology appear. Malignant brain tumors are known to produce several angiogenic growth factors. One of the most potent of these factors is the basic fibroblast growth factor (bFGF). In an experimental study human U87 MG glioma cells (2.10(5) cells/50 microliters) were implanted through a burrhole into the cerebral cortex in a group of 25 nude rats. After 3 weeks we found a reproducible extensive tumor growth with extensive neovascularization. Immunohistochemical evaluations proved a high expression of bFGF in the tumor. A parallel group of xenotransplanted rats were treated with 33 micrograms of rabbit anti-bFGF antibodies during tumor cell implantation. Thereafter, the same dosages of antibodies were administrated intracranially twice a week for 3 weeks. We found a significant inhibition of tumor vascularization and growth compared to other groups who had no treatment or who received irrelevant immunoglobulins or saline as a control. Our results indicate that inhibition of tumor angiogenesis might contribute to inhibition of tumor growth in malignant gliomas.