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

Serum evaluation of basic fibroblast growth factor in cervical cancer patients

We present the data of 105 serum samples from 20 patients suffering from cervical cancer. Mean serum levels of basic fibroblast growth factor (bFGF) in patients with or without tumor present were 31.3 +/- 32.1 (minimum 0, maximum 156.7) pg/ml and 4.8 +/- 6.8 (minimum 0, maximum 29.6) pg/ml, respectively (P = 0.0001). bFGF reached a sensitivity of 65.7% at a specificity of 91.5% when applying a cut-off level of 15 pg/ml. Four patients relapsed after complete remission. A continuous increase of bFGF serum levels before the clinical detection of relapse (lead time) was seen in two cases with a mean lead time of 4 months. Preoperative serum levels were not of prognostic value and showed no correlation with pelvic lymph node metastasis. These preliminary results indicate that in cervical cancer patients soluble bFGF may be useful in early detection of primary tumors, recurrences and monitoring of therapy.

Heat-induced bFGF gene expression in the absence of heat shock element correlates with enhanced AP-1 binding activity

Basic fibroblast growth factor (bFGF) has been shown to be a potent mitogen and a promoter of angiogenesis. It has been hypothesized that the expression of the bFGF gene may be induced by stress of various types. To test that hypothesis, we investigated the expression of the bFGF gene during heat treatment in adriamycin-resistant (MCF-7/ADR) and -sensitive (MCF-7) human breast carcinoma cells. Under normal growth conditions, the bFGF mRNA was detected in MCF-7/ADR cells, while it was not detectable in MCF-7 cells by Northern blot analysis. During heating at 41 degrees C, the level of bFGF mRNA increased in MCF-7/ADR cells and the message became detectable in the MCF-7 cell line. However, after continuous heating at 41 degrees C for 24 h, the bFGF mRNA level decreased to control level in MCF-7/ADR cells. Interestingly, simultaneous treatment with heat and 60 micrograms/ml H-7 (1-(isoquinolinylsulfonyl)-2-methylpiperazine, a potent PKC inhibitor) decreased the level of bFGF mRNA in MCF-7/ADR cells. These results suggest that a protein kinase, likely PKC, is involved in the transcriptional regulation of the heat-enhanced bFGF gene expression in human breast carcinoma cells. Although no heat shock element can be identified in the promoter of the bFGF gene, we observed that the AP-1 binding activity to a TPA responsive element (TRE)-like sequence in the promoter of bFGF gene was enhanced by heat, as tested by mobility shift assay. Antibody developed against the c-Jun and c-Fos proteins inhibited the AP-1 binding activity to TRE. Therefore, the AP-1 complex appears to be responsible for the heat-enhanced binding to the TRE-like motif of the bFGF gene. Furthermore, the increased AP-1 binding activity does not require new protein synthesis but activation of the preexisting c-Jun proteins.

The role of hyaluronan in tumour neovascularization (review)

Tumour growth and metastasis are totally dependant upon neovascularization. The target cell for tumour neovascularization is the blood-vessel endothelial cell, and specific angiogenic molecules produced or induced by the tumour are believed to initiate the process. In this report, we review one of these angiogenic molecules, the glycosaminoglycan hyaluronan (HA), which appears to have differing roles in neovascularization depending on its molecular mass. High-molecular-mass HA is anti-angiogenic whereas oligosaccharides of HA, of specific size, actively stimulate endothelial-cell proliferation and migration, 2 of the key events associated with neovascularization, and induce angiogenesis in vivo. We provide details of the action of HA oligosaccharides on endothelial cells, from binding to cell-surface receptors, through activation of signal transduction pathways and gene expression to protein synthesis, cell proliferation and cell migration. We also suggest a model to account for HA of differing molecular mass being present, at different locations, within a single tumour and how this HA aids both general tumour growth and tumour metastasis.

The role of vascular permeability factor and basic fibroblast growth factor in tumor angiogenesis

In the last decade a considerable amount of research has been dedicated to studying the process of angiogenesis. In the field of tumor biology angiogenesis is a relevant subject of investigation as well, since newly formed blood vessels are required for the growth of tumors and provide an exit route for metastasizing tumor cells. In this review we discuss some aspects of tumor angiogenesis with emphasis on the role that growth factors bFGF and VPF play in this process. A number of biochemical characteristics and biological properties of the two factors and their receptors are reviewed, and the expression of bFGF and VPF in both normal tissues and in tumors is discussed. Finally, we speculate on the use of bFGF and VPF expression as a diagnostic parameter and on possible clinical applications.

Vasculature in Nontumorous Hypophyses, Pituitary Adenomas, and Carcinomas: A Quantitative Morphologic Study

Vascular supply is essential for tumor proliferation and metastasis formation. Correlation was noted between vascular density and tumor size as well as metastases in several tumor types. The aim of the present study was to assess vascular density in nontumorous hypophyses, pituitary adenomas, primary pituitary carcinomas, and carcinomas metastatic to the pituitary. Twenty nontumorous hypophyses, 87 endocrinologically active or inactive pituitary adenomas, 8 primary pituitary carcinomas, 8 metastatic carcinomas, and 10 randomly selected noninvasive and 6 invasive adenomas were included in the study. Tissues were fixed in formalin, embedded in paraffin, cut, stained with hematoxylin and eosin, PAS, and immunostained for adenohypophysial hormones as well as Factor VIII-related antigen using the streptavidin-biotin-peroxidase complex method. Four counts were performed: percentage of capillary area, number of vessels per field, percentage of endothelial cells, and number of endothelial cells per field. The results show that pituitary adenomas have significantly lower vascular densities as compared to nontumorous adenohypophyses. Prolactin-producing adenomas removed from untreated patients have the highest counts and growth hormone-producing adenomas the lowest counts. However, the observed differences among adenoma types are not of statistical significance. No differences are noted between noninvasive and invasive tumors. Primary pituitary carcinomas show no significant increase in vascular densities. Some metastatic tumors exhibit high vascularity. It can be concluded that pituitary adenomas have a limited capacity to induce angiogenesis. Lack of significant angiogenesis may play a role in the slow pace of pituitary tumor growth and rarity of metastases.

Current pathologic methods for measuring intratumoral microvessel density within breast carcinoma and other solid tumors

Abundant evidence has shown that tumor growth and metastasis are dependent upon tumor angiogenesis (TA). TA refers to the growth of new vessels toward and within the tumor. Until TA occurs, tumors grow no larger than 2-4 mm in diameter. Also, TA is necessary at the beginning and at the end of the metastatic cascade of events. Thus, it seems reasonable that increasing intratumoral microvascular density (iMVD) might correlate with greater tumor aggressiveness, such as a higher frequency of metastases and/or decreased survival. Indeed, in 1991 my colleagues and I reported a statistically significant association between greater incidence of metastases in patients with breast carcinoma and increasing iMVD. Microvessel density was measured with a light microscope in a single area of invasive tumor (200x field or 0.74 mm2) representative of the highest microvessel density (neovascular "hot spot"). This was done after endothelial cells, lining the microvessels, had been highlighted with anti-factor VIII-related antigen/von Willebrand's factor (F8RA/vWF). Subsequent studies by other investigators, using either anti-F8RA/vWF or other relatively vessel-specific reagents such as anti-CD31, have shown that the association of greater tumor aggressiveness with increasing iMVD exists not only in breast carcinoma, but also in other solid tumors. This article reviews the methods of highlighting intratumoral vessels and describes the techniques for counting these vessels for assessing iMVD.

Angiogenesis in cancer, vascular, rheumatoid and other disease

Recent discoveries of endogenous negative regulators of angiogenesis, thrombospondin, angiostatin and glioma-derived angiogenesis inhibitory factor, all associated with neovascularized tumours, suggest a new paradigm of tumorigenesis. It is now helpful to think of the switch to the angiogenic phenotype as a net balance of positive and negative regulators of blood vessel growth. The extent to which the negative regulators are decreased during this switch may dictate whether a primary tumour grows rapidly or slowly and whether metastases grow at all.