Angiogenic activity in the CSF in human malignancies

Microvessel count and cerebrospinal fluid basic fibroblast growth factor in children with brain tumours

Tumour growth is angiogenesis-dependent; brain tumours have more intense neovascularisation than other tumours and produce basic fibroblast growth factor, a potent angiogenic mediator. Because little is known about the release of basic fibroblast growth factor from brain tumours into extracellular fluids, we tested cerebrospinal fluid (CSF) from 26 children and young adults with brain tumours and 18 controls for basic fibroblast growth factor and for proliferative activity on cultured capillary endothelial cells. We also measured the density of microvessels in tumours by immunohistochemical staining. Basic fibroblast growth factor was detected in the CSF of 62% (16 of 26) patients with brain tumours but in none of the controls. Specimens with basic fibroblast growth factor stimulated DNA synthesis of capillary endothelial cells in vitro. Endothelial proliferative activity was blocked by neutralising antibodies to basic fibroblast growth factor. Basic fibroblast growth factor correlated with mitogenic activity in CSF in vitro (p < or = 0.0001), and with density of microvessels in histological sections (p < or = 0.005). A microvessel count of > or = 68 per 200 x field was associated with tumour recurrence (p = 0.005) and with mortality (p = 0.02). Basic fibroblast growth factor in brain tumours may mediate angiogenesis as measured by microvessel density in histological sections, so has potential as both a marker for neoplasia and a target for tumour treatments. Furthermore, evaluation of cerebrospinal fluid basic fibroblast growth factor, along with microvessel quantitation in biopsied tumours, may provide improved prognostic information for the management of patients with brain tumours.

Localization of basic fibroblast growth factor, a mitogen and angiogenic factor, in human brain tumors

Fibroblast growth factor (FGF) is a potent angiogenic factor and a mitogen for a variety of mesoderm- and neuroectoderm-derived cell types (e.g., fibroblasts, endothelial cells, astrocytes, oligodendrocytes). After application of a monospecific polyclonal antiserum, we localized basic FGF on frozen sections of 73 human brain tumors using immunohistochemistry. FGF was present in a variable number of tumor cells (16/16 astrocytomas, 5/5 ependymomas, 0/3 benign and 4/7 anaplastic oligodendrogliomas, 11/12 glioblastomas, 11/11 meningiomas, 6/6 neurilemmomas, 0/3 pituitary adenomas, 2/2 choroid plexus papillomas, 0/1 neurocytoma, 2/2 benign fibrous histiocytomas, 2/5 metastatic carcinomas). FGF was detected in vascular cells of 59 tumors and in fibroblasts of connective tissue stroma from all papillomas and metastases. These results tend to indicate FGF involvement in the malignant progression of gliomas due to an autocrine or paracrine action. Histopathological aspects of malignant gliomas (e.g., pseudopalisading or pathological vessels) could be related to FGF activity.

Detection of angiogenesis activity in malignant bladder tissue and cells

Neoplastic and non-neoplastic mammalian urothelium was tested for angiogenesis activity in the rabbit iris assay. Tiny fragments of tissue were placed on a rabbit's iris and observed through a slit lamp stereoscope for as long as 4 days after implantation. Angiogenesis activity was demonstrated either by the appearance of new capillary growth or, following an injection of fluorescein, by a green fluorescence around an implant. Capillary proliferation was stimulated by 99 per cent of the specimens containing malignant urothelium, while only 9 per cent of normal urothelial specimens had this effect (p less than .001). Cells grown in vitro were similarly tested for angiogenesis by implanting 1 mm. fragments of collagen coated either with malignant or normal cells. A total of 92 per cent of the specimens covered with neoplastic cells induced angiogenesis, while only 15 per cent of the implants covered by normal cells caused this response (p less than .001). Benign reversible hyperplasia was induced in a rabbit bladder by systemic administration of cyclophosphamide, and an angiogenic response could not be detected in a small number of specimens. The results suggest that angiogenesis activity may be a reliable method for distinguishing between benign and malignant bladder tissue.

Angiogenic activity in fluid samples from tumoral patients

Tests were performed to study the angiogenic activity in samples of pleural fluid, ascites and cerebrospinal fluid, in patients with solid tumors and non-neoplastic diseases such as cerebrovascular accidents, cirrhosis, and congestive heart failure. The measurement of the angiogenic activity was carried out on chorioallantoid chick embryo membrane. The cerebrospinal fluid showed angiogenic activity in patients with primitive tumors of the central nervous system and also in cases where the tumor had extended into other organs. The cerebrospinal fluid of controls without tumor revealed angiogenic activity in 28% of the cases. There was a direct correlation between positive assays and age. Sixty-two percent of the samples of ascites from cancer patients were positive. Only 25% of the controls were positive. Only 10% of the pleural fluid from cancer patients was negative, and 75% of the control samples were negative.