Basic Fibroblast Growth Factor Receptor Research Articles

Significance of basic fibroblast growth factor and fibroblast growth factor receptor protein expression in the formation of fibrotic focus in invasive ductal carcinoma of the breast.

A fibrotic focus (FF) is a scar‐like area within invasive dnctal carcinoma (IDC) of the breast, and has been shown to be a marker of high aggressiveness of IDC. In order to investigate the mechanism of FF formation in IDC, expression of basic fibroblast growth factor (bFGF) and flbroblast growth factor receptor (FGFR) was studied. One hundred and forty‐nine IDCs were divided into solid tumors and scirrhous tumors. Immunohistochemistry was used to determine the expression of bFGF and FGFR proteins in both tumor cells and fibroblasts forming FF. Scirrhous tumors with FF showed a significantly higher frequency of bFGF protein expression than those without (P=0.017), whereas, in solid tumors, the presence of FF was not significantly associated with the frequency of bFGF protein expression (P=0.143). In addition, scirrhous tumors showed a significantly higher frequency of FGFR protein expression than solid tumors (P=0.001). Among IDCs having FF and expressing bFGF protein, a significantly larger number of fibroblasts expressing FGFR protein within FF was observed in scirrhous tumors than in solid tumors (P=0.016). The results of this study suggest that in scirrhous tumors the interaction between tumor cells and stromal fibroblasts plays an important role in the formation of FF, and that there is a paracrine mechanism between bFGF protein from tumor cells and FGFR protein in fibroblasts.

Up-regulation and down-regulation of genes expressed in cocultures of rat Sertoli cells and germ cells.

To better understand the molecular interactions between somatic and germ cells in the mammalian testis, we have begun to analyze with mRNA differential display changes in gene expression induced by coculturing rat Sertoli cells and germ cells. We have identified 10 cDNAs that are either down-regulated or up-regulated in cocultures of germ cells and Sertoli cells. Three genes expressed in Sertoli cells and three genes expressed in germ cells were down-regulated in Sertoli cell-germ cell cocultures, whereas four genes were up-regulated in the cocultures. Northern blot analysis was used to establish the expression pattern of the mRNAs encoded by the cDNAs and to define the sizes of the differentially expressed mRNAs. Sequence analysis of the cDNAs and computer searches against the GenBank and EMBL DNA databases were used to relate the ten cDNAs to known genes. Of the three Sertoli cell cDNAs, one appeared identical to transferin, while the other two shared regions of similarity to an endoplasmic reticulum stress protein and to a pro-alpha 2 XI collagen, respectively. The three germ cell cDNAs shared sequences with fibronectin, with a basic fibroblast growth factor receptor and with an IgG gamma 2b, respectively. The four cDNAs that were up-regulated in the Sertoli-germ cell cocultures showed similarity to an isoform of casein kinase 1 delta, to an epidermal growth factor, to a statin-related protein, and to an integral membrane glycoprotein. These data demonstrate that a number of specific genes are up- and down-regulated when germ cells and Sertoli cells are cocultured, and suggest these genes are important in cell to cell communication during spermatogenesis.

Immunolocalization of basic fibroblast growth factor receptors in internal thoracic artery and saphenous vein grafts

Immunolocalization of basic fibroblast growth factor receptors in internal thoracic artery and saphenous vein grafts

Neurotrophic Factors, Cytokines and Stress Increase Expression of Basic Fibroblast Growth Factor in Retinal Pigmented Epithelial Cells

Basic fibroblast growth factor (bFGF) and FGF receptors have been localized to photoreceptors and retinal pigmented epithelium (RPE), but the function of bFGF in adult retina and RPE is unknown. Exogenous bFGF has a neuroprotective effect in retina and brain and its expression is increased in some neurons in response to cytokines or stress. In this study, we investigated the effect of light, other types of stress, neurotrophic factors, and cytokines on bFGF levels in cultured human RPE.Some agents that protect photoreceptors from the damaging effects of constant light, including brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor, and interleukin-1β, increase bFGF mRNA levels in RPE cells. Intense light and exposure to oxidizing agents also increase bFGF mRNA levels in RPE cells and cycloheximide blocks the increase. An increase in bFGF protein levels was demonstrated by ELISA in RPE cell supernatants after incubation with BDNF or exposure to intense light or oxidizing agents. These data indicate that bFGF is modulated in RPE cells by stress and by agents that provide protection from stress and support the hypothesis that bFGF functions as a survival factor in the outer retina.

Basic fibroblast growth factor, its high- and low-affinity receptors, and their relationship to form-deprivation myopia in the chick

Form deprivation myopia in chickens is a widely accepted model to study visually-regulated postnatal ocular growth. Recently we showed that basic fibroblast growth factor-2 provides a “stop” signal for the growing eye. To understand further its action, we have localized basic fibroblast growth factor-2 and its low- and high-affinity receptors in the chicken eye, and determined the localization of basic fibroblast growth factor receptors in the inner plexiform layer with respect to that of neurotransmitter systems known to play a role in form-deprivation myopia. By immunocytochemistry and in situ hybridization, two complementary methods, we found that nearly all cells in the retina, and scleral chondrocytes, contain basic fibroblast growth factor-2 protein and messenger RNA as well as high-affinity basic fibroblast growth factor receptor protein and messenger RNA. Immunocytochemical localization of basic fibroblast growth factor-2 binding sites (a high resolution alternative to autoradiography), combined with N-glycanase and heparitinase treatment or heparin competition, revealed additional binding sites in specific synaptic layers of the inner plexiform layer and low-affinity binding sites in the choroid and optic fibre layer. Some binding sites in the synaptic layers were found to co-stratify with neurites of dopamine-, vasoactive intestinal polypeptide- or enkephalin-containing amacrine cells, suggesting that basic fibroblast growth factor-2 could modulate synaptic transmission to or from these cells. Form deprivation did not affect the levels of basic fibroblast growth factor receptor-1 messenger RNA in retina/retinal pigment epithelium/choroid (Northern blotting), but it abolished the decrease in amount of extractable basic fibroblast growth factor normally observed in the dark (Western blotting). The results are discussed with respect to previous findings on basic fibroblast growth factor-2 and basic fibroblast growth factor receptor-1 localization in the avian and other vertebrate eyes, and their relevance to form-deprivation myopia. The widespread distribution of basic fibroblast growth factor-2 and its receptor makes it impossible to predict which cells might mediate the action of basic fibroblast growth factor-2 in form-deprivation myopia. However, the alteration in amounts of extractable retinal basic fibroblast growth factor-2 in form-deprived, dark-adapted retinas, in which basic fibroblast growth factor-2 probably serves as a “stop” signal for ocular growth, is consistent with a role for basic fibroblast growth factor-2 in the regulation of ocular growth.

EGF in combination with depolarization or cAMP produces morphological but not physiological differentiation in PC12 cells

In response to nerve growth factor (NGF) or basic fibroblast growth factor (bFGF) receptor activated Ras/extracellular signal-regulated kinase (ERK) signaling, PC12 cells undergo a prototypical neuronal differentiation program, characterized by neurite extension and upregulation of voltage-gated ion channels. The epidermal growth factor (EGF) receptor also activates Ras/ERK signaling, but produces proliferation instead of differentiation. In the presence of depolarizing concentrations of KCl, however, EGF elicits neurite outgrowth through the synergistic actions of the Ras/ERK and cAMP signaling pathways. To assess if EGF and KCl/cAMP elicit the same suite of differentiation events as does NGF and bFGF, we used patch clamp recording to determine if EGF in the presence of KCl or a cAMP agonist also induced physiological differentiation as defined by upregulation of ion channels. Chronic NGF treatment of PC12 cell cultures elicited robust morphological differentiation, a threefold increase in mean calcium channel current density, and an eightfold increase in mean sodium channel current density. Sibling cultures chronically treated with EGF in the presence of high KCl or a cAMP agonist also displayed morphological differentiation, but had calcium channel current densities which were no larger than untreated, undifferentiated cells. Additionally, the increase in mean sodium channel current density induced by EGF in the presence of KCl or cAMP was no greater than the increase observed with EGF alone. Thus, although EGF in the presence of KCl or cAMP is sufficient to induce morphological differentiation as defined by neurite outgrowth, synergism of the Ras/ERK and cAMP/PKA signaling pathways is not sufficient to promote the fully physiologically differentiated PC12 phenotype.

EGF in combination with depolarization or cAMP produces morphological but not physiological differentiation in PC12 cells

In response to nerve growth factor (NGF) or basic fibroblast growth factor (bFGF) receptor activated Ras/extracellular signal-regulated kinase (ERK) signaling, PC12 cells undergo a prototypical neuronal differentiation program, characterized by neurite extension and upregulation of voltage-gated ion channels. The epidermal growth factor (EGF) receptor also activates Ras/ERK signaling, but produces proliferation instead of differentiation. In the presence of depolarizing concentrations of KCl, however, EGF elicits neurite outgrowth through the synergistic actions of the Ras/ERK and cAMP signaling pathways. To assess if EGF and KCl/cAMP elicit the same suite of differentiation events as does NGF and bFGF, we used patch clamp recording to determine if EGF in the presence of KCl or a cAMP agonist also induced physiological differentiation as defined by upregulation of ion channels. Chronic NGF treatment of PC12 cell cultures elicited robust morphological differentiation, a threefold increase in mean calcium channel current density, and an eightfold increase in mean sodium channel current density. Sibling cultures chronically treated with EGF in the presence of high KCl or a cAMP agonist also displayed morphological differentiation, but had calcium channel current densities which were no larger than untreated, undifferentiated cells. Additionally, the increase in mean sodium channel current density induced by EGF in the presence of KCl or cAMP was no greater than the increase observed with EGF alone. Thus, although EGF in the presence of KCl or cAMP is sufficient to induce morphological differentiation as defined by neurite outgrowth, synergism of the Ras/ERK and cAMP/PKA signaling pathways is not sufficient to promote the fully physiologically differentiated PC12 phenotype.

O-016 Endometrial polyps from menopausal women have relative overexpression of basic fibroblast growth factor-receptor (FGF-R) compared with autologous endometrium

O-016 Endometrial polyps from menopausal women have relative overexpression of basic fibroblast growth factor-receptor (FGF-R) compared with autologous endometrium

Expression of the Aryl Hydrocarbon Receptor Is Regulated by Serum and Mitogenic Growth Factors in Murine 3T3 Fibroblasts

The aryl-hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates biological responses to planar aromatic hydrocarbons such as benzo[alpha]pyrene. However, no endogenous physiological ligand for the AhR has been identified. Since the AhR regulates bioactivity to common environmental pollutants, and since it is predicted to play an important physiological function, we have investigated the expression of the AhR during the cell cycle of murine 3T3 fibroblasts. We show here that stimulation of growth-arrested 3T3 cells with serum results in increased expression of AhR protein. Serum-induced expression of AhR in synchronized, serum-stimulated cells occurs at the onset of DNA synthesis (S phase) and is maximal at time points corresponding to late S phase. Transient transfections with an AhR-promoter-luciferase construct demonstrate that reporter gene transcription from the AhR promoter is regulated in a serum-dependent manner. Serum-dependent induction of AhR expression is prevented by an inhibitor of tyrosine kinase activity. Ligand-activated growth factor receptors (platelet-derived growth factor receptor basic fibroblast growth factor receptor) as well as an ectopically expressed tyrosine kinase (the v-Src oncoprotein) induce AhR expression in the absence of serum. Therefore, tyrosine kinase signaling is both necessary and sufficient for induction of AhR expression. Studies with the G1 blocker sodium butyrate show that the signal transduction pathways mediating serum-stimulated progression through the cell cycle are distinct from those that induce AhR expression. These data suggest that transcriptional regulation of the AhR is important in determining cellular sensitivity to the actions of AhR ligand(s) and that the AhR may play a role during the cellular proliferative response.

Ganglioside effects on basic fibroblast and epidermal growth factor receptors in retinal glial cells

Gangliosides have long been implicated in cell growth regulation and play an important role as modulators in protein phosphorylation. In order to better understand the glycosphingolipids and growth factors interact, we examined the modulation of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) effects on retinal Müller glial cells (RMG), following modification of their GG composition. Treatment of MG cells with GG (GM1, GT1b) and asialoGM1 resulted in modifications of several aspects of cellular responses to EGF- and FGF-receptor (R) activation: mitogenesis, cell migration, tyrosine phosphorylation of the EGF-R and FGF-R and even their cellular substrates were particularly influenced by GG. Indeed GG caused modifications of EGF-R and FGF-R autophosphorylation kinetics. GG long term effects (mitogenesis and migration) correlate with short term effects (tyrosine phosphorylation) and differences in receptor tyrosine kinase signalling could explain the specificity in growth factor responses.

Heparin-Induced Overexpression of Basic Fibroblast Growth Factor, Basic Fibroblast Growth Factor Receptor, and Cell-Associated Proteoheparan Sulfate in Cultured Coronary Smooth Muscle Cells

Basic fibroblast growth factor (bFGF), a potent mitogen for arterial smooth muscle cells (SMCs), plays a pivotal role in the pathogenesis of arteriosclerosis and restenosis. Heparin in nanogram quantities may promote or even be required for binding of bFGF to its cognate receptor. Conversely, heparin in microgram doses is a strong inhibitor of arterial SMC replication in vitro and in vivo. Bovine coronary SMCs (cSMCs) express bFGF, bFGF receptor (FGF-R1), and cell membrane-integrated proteoheparan sulfate (HSPG). These three molecules are known to form a trimolecular complex that promotes signal transduction and mitogenesis. The bFGF synthesized by cSMCs is distributed to an intracellular and a pericellular compartment. Resting cultured cells retain about 80% of their bFGF intracellularly; 20% is found in the pericellular region. During proliferation, 70% to 80% of total bFGF is expressed in the pericellular compartment. Trypsinization generates soluble forms of the complex of bFGF with the ectodomains of the bFGF receptor and cell membrane-integrated HSPG in the pericellular compartment, thus allowing quantification of pericellular bFGF by a highly specific enzyme immunoassay. Standard heparin inhibits the proliferation of cSMCs by up to 80% in a concentration range between 10 and 100 micrograms/mL medium in a dose-dependent manner but increases the protein content of cSMCs compared with proliferating control cells. The heparin-induced increase in cellular protein content includes a 60% to 100% increase in the expression of pericellular bFGF, FGF-R1, and cell membrane-integrated HSPG. Thus, under heparin treatment, the heparan sulfate side chains of cell membrane-integrated HSPG incorporate more [35S]sulfate, and the proportion of [35S]heparan sulfate among total glycosaminoglycans increases from 36% to 52%. Fluorescence-activated cell sorting analysis and [3H]thymidine incorporation experiments provide evidence for multiple effects of heparin, including blocks at early and late checkpoints of the cell cycle in heparin-treated cells. These results indicate that heparin, despite its anti-proliferative potency, stimulates the expression of all components of the bFGF system even in coronary SMCs in which growth is inhibited.

The basic fibroblast growth factor and its receptor in pulmonary adenocarcinomas: an investigation of their expression as prognostic markers.

The expression of basic fibroblast growth factor (bFGF) and its receptor, the high-affinity type I basic fibroblast growth factor receptor (FGFR-1): were immunohistologically studied in tissues specimens from 167 patients with a pulmonary adenocarcinoma. Of the 167 specimens, 82 (49%) expressed bFGF and 104 (62%) expressed FGFR-1, bFGF and FGFR-1 were simultaneously expressed in 72 (43%). It was also found that many patients who showed intensely positive staining for bFGF were also positive for FGFR-1, and that the expression of bFGF or FGFR-1 or both was associated with p-stage, T and N factors. The overall prognosis was significantly poorer in the bFGF-positive or FGFR-1-positive patients than in negative patients (P < 0.01). The prognosis was also significantly poorer in all patients positive for both bFGF and FGFR-1 than in those negative for both (P < 0.01); this was also true for stage I patients (P < 0.05). Multivariate analysis showed that bFGF had a significant affect on prognosis, whereas FGFR-1 did not. As FGFR-1 is significantly linked with the bFGF expression, it may be that FGFR-1 interferes with the bFGF effect on survival. These findings suggest that bFGF and FGFR-1 play important roles in tumour progression, and that bFGF expression may be a useful prognostic marker for pulmonary adenocarcinomas.

Differential modulation of basic fibroblast and epidermal growth factor receptor activation by ganglioside GM3 in cultured retinal Müller glia.

Polypeptide growth factors and membrane-bound gangliosides are involved in cell signaling, including that observed in cells of neural origin. To analyze possible interactions between these two systems, we investigated the modulation of short- and long-term responses to basic fibroblast and epidermal growth factor (bFGF and EGF, respectively) in cultured retinal Müller glial cells following experimental modification of their ganglioside composition. These glial cells readily incorporated exogenously administered GM3 ganglioside, which was not substantially metabolized within 24 h. Such treatments significantly inhibited bFGF-induced DNA replication and cell migration, while having much less effect on analogous EGF-mediated behaviors. To explore GM3/growth factor interactions further, different aspects of glial metabolism in response to bFGF or EGF stimulation were examined: membrane fluidity, growth factor binding, global and individual changes in growth factor-induced phosphotyrosine levels, and growth factor-induced activation of mitogen-activated protein kinase. GM3 reduced the intensity of immunocytochemical labeling of phosphotyrosine-containing proteins within bFGF-stimulated cells and down-regulated FGF receptor activation and tyrosine phosphorylation of its cellular substrates, whereas similar parameters in EGF-stimulated cells were much less affected. Hence the data reveal a complex relationship in normal neural cells between polypeptide growth factors and membrane-bound gangliosides, which may participate in retinal cellular physiology in vivo.

Basic fibroblast growth factor regulates the conversion of pro- luteinizing hormone-releasing hormone (Pro-LHRH) to LHRH in immortalized hypothalamic neurons

Growth factors are commonly associated with the regulation of cellular proliferation and differentiation. In established cells, growth factors can also serve as trophic agents. Immortalized LHRH neurons contain basic fibroblast growth factor (bFGF) receptors. Although these receptors are coupled to activation of protein kinase C, and phorbol esters are strong activators of protein kinase C-stimulated LHRH release, bFGF did not influence LHRH secretion from these cells. To clarify this discrepancy, the effects of bFGF and phorbol ester on pro-LHRH biosynthesis, protein processing, and secretion were examined in GT1-7 cells. Phorbol ester stimulated LHRH secretion, whereas bFGF either had no effect or stimulated LHRH release depending upon the antiserum used. Pro-LHRH levels in lysate and medium were depressed by phorbol esters; concentrations in bFGF-treated cells were somewhat lower than those in unstimulated controls. HPLC analyses revealed that both agents enhanced the release of LHRH intermediate products into the medium. C-Terminally extended forms of LHRH, especially LHRH-[Gly11], were prominent in medium from bFGF-stimulated neurons. Levels of LHRH were depressed relative to those in the control or phorbol ester groups. These data indicate that phorbol esters control the biosynthesis, secretion, and, to some extent, processing of pro-LHRH. The effects of bFGF are novel because this factor regulates processing of the prohormone so that LHRH-intermediate products are predominantly secreted instead of LHRH. By enhancing the secretion of these intermediates over that of LHRH, bFGF can control the biological activity of the decapeptide and regulate LHRH neuronal function.

Basic fibroblast growth factor regulates the conversion of pro-luteinizing hormone-releasing hormone (Pro-LHRH) to LHRH in immortalized hypothalamic neurons.

Growth factors are commonly associated with the regulation of cellular proliferation and differentiation. In established cells, growth factors can also serve as trophic agents. Immortalized LHRH neurons contain basic fibroblast growth factor (bFGF) receptors. Although these receptors are coupled to activation of protein kinase C, and phorbol esters are strong activators of protein kinase C-stimulated LHRH release, bFGF did not influence LHRH secretion from these cells. To clarify this discrepancy, the effects of bFGF and phorbol ester on pro-LHRH biosynthesis, protein processing, and secretion were examined in GT1-7 cells. Phorbol ester stimulated LHRH secretion, whereas bFGF either had no effect or stimulated LHRH release depending upon the antiserum used. Pro-LHRH levels in lysate and medium were depressed by phorbol esters; concentrations in bFGF-treated cells were somewhat lower than those in unstimulated controls. HPLC analyses revealed that both agents enhanced the release of LHRH intermediate products into the medium. C-Terminally extended forms of LHRH, especially LHRH-[Gly11], were prominent in medium from bFGF-stimulated neurons. Levels of LHRH were depressed relative to those in the control or phorbol ester groups. These data indicate that phorbol esters control the biosynthesis, secretion, and, to some extent, processing of pro-LHRH. The effects of bFGF are novel because this factor regulates processing of the prohormone so that LHRH-intermediate products are predominantly secreted instead of LHRH. By enhancing the secretion of these intermediates over that of LHRH, bFGF can control the biological activity of the decapeptide and regulate LHRH neuronal function.

Systematic Mapping of Potential Binding Sites for Shc and Grb2 SH2 Domains on Insulin Receptor Substrate-1 and the Receptors for Insulin, Epidermal Growth Factor, Platelet-derived Growth Factor, and Fibroblast Growth Factor

Multipin peptide synthesis has been employed to produce biotinylated 11-mer phosphopeptides that account for every tyrosine residue in insulin receptor substrate-1 (IRS-1) and the cytoplasmic domains of the insulin-, epidermal growth factor-, platelet-derived growth factor- and basic fibroblast growth factor receptors. These phosphopeptides have been screened for their capacity to bind to the SH2 domains of Shc and Grb in a solution phase enzyme-linked immunosorbent assay. The data revealed new potential Grb2 binding sites at Tyr-1114 (epidermal growth factor receptor (EGFR) C-tail); Tyr-743 (platelet-derived growth factor receptor (PDGFR) insert region), Tyr-1110 from the E-helix of the catalytic domain of insulin receptor (IR), and Tyr-47, Tyr-939, and Tyr-727 in IRS-1. None of the phosphopeptides from the juxtamembrane or C-tail regions of IR bound Grb2 significantly, and only one phosphopeptide from the basic fibroblast growth factor receptor (Tyr-556) bound Grb2 but with medium strength. Tyr-1068 and -1086 from the C-tail of EGFR, Tyr-684 from the kinase insert region of PDGFR, and Tyr-895 from IRS-1 were confirmed as major binding sites for the Grb2 SH2 domain. With regard to Shc binding, the data revealed new potential binding sites at Tyr-703 and Tyr-789 from the catalytic domain of EGFR and at Tyr-557 in the juxtamembrane region of PDGFR. It also identified new potential Shc binding sites at Tyr-764, in the C-tail of basic fibroblast growth factor receptor, and Tyr-960, in the juxtamembrane of IR, a residue previously known to be required for Shc phosphorylation in response to insulin. The study confirmed the previous identification of Tyr-992 and Tyr-1173 in the C-tail of EGFR and several phosphopeptides from the PDGFR as medium strength binding sites for the SH2 domain of Shc. None of the 34 phosphopeptides from IRS-1 bound Shc strongly, although Tyr-690 showed medium strength binding. The specificity characteristics of the SH2 domains of Grb2 and Shc are discussed. This systematic peptide mapping strategy provides a way of rapidly scanning candidate proteins for potential SH2 binding sites as a first step to establishing their involvement in kinase-mediated signaling pathways.

Stimulation of endothelial cells by doses of basic FGF-saporin that are lethal to smooth muscle cells.

Basic fibroblast growth factor (FGF) receptors are up-regulated in proliferating (vs. quiescent) aortic smooth muscle cells, according to the results of recent studies. This up-regulation allows the ribosome inactivator saporin (if linked to basic FGF) to enter and kill proliferating, but not quiescent smooth muscle cells in vitro and in vivo. The authors now report that endothelial cells exhibit a different response. In 10% serum, FGF-SAP (0.1-1 nM) stimulates protein synthesis and cell division in subconfluent endothelial cells, but inhibits protein synthesis and cell division in subconfluent smooth muscle cells. Endothelial cells were inhibited at 10 nM FGF-SAP. A stimulatory response was seen in smooth muscle cells only at 0.1 nM FGF-SAP, and only after serum deprivation. Both cell types were resistant to FGF-SAP at high cell density. These responses correlated with FGF receptor density, which was sixfold higher in smooth muscle than endothelial cells and twice as high in serum-free smooth muscle cells as in serum-deprived smooth muscle cells. Moreover, a dose of FGFSAP that inhibited neointimal smooth muscle accumulation after balloon injury did not inhibit reendothelialization. Thus, there is a dose range at which FGF-SAP has unique properties that may make it useful in the treatment of vascular injury.

Expression of basic fibroblast growth factor and fibroblast growth factor receptor in advanced gastric carcinoma.

The expression of basic fibroblast growth factor (bFGF) and fibroblast growth factor receptor (FGFR) mRNA was examined in gastric carcinomas by immunohistochemistry and in situ hybridization, respectively. In the 20 advanced carcinomas examined, bFGF was found in 14 (70.0 per cent) and was confined to the tumour cells, whereas FGFR mRNA was demonstrated in 12 (60.0 per cent) and seen in both tumour cells and endothelial cells. The bFGF and FGFR mRNA-positive carcinomas were larger, were more frequently classified as undifferentiated adenocarcinoma, more frequently invaded the serosal layer, and had a higher rate of lymph node metastases than the bFGF and FGFR mRNA-negative carcinomas. Patients with bFGF and FGFR mRNA-positive carcinomas appear to die earlier than those with bFGF and FGFR mRNA-negative tumours. The values for the carcinomas that were positive for either bFGF or FGFR mRNA fell between these two groups. The findings suggest that the autocrine/paracrine bFGF/FGFR channel is associated with undifferentiated gastric carcinomas and may lead to a poorer prognosis.

Expression of basic fibroblast growth factor and its receptor in human pancreatic carcinomas.

We examined the expression of basic fibroblast growth factor (FGF) and FGF receptor by immunohistochemistry in 32 human pancreatic ductal adenocarcinomas. Mild to marked basic FGF immunoreactivity was noted in 19 (59.4%) of the 32 tumours examined, and 30 (93.3%) of the tumours exhibited a cytoplasmic staining pattern against FGF receptor. The tumours were divided into two groups according to the proportion of positively stained tumour cells: a low expression group (positive cells < 25%) and a high expression group (positive cells > or = 25%). No statistically significant difference in tumour size, differentiation, metastases or stage was found between the low and high basic FGF expression groups. However, a significant correlation was found between FGF receptor expression level and the presence of retroperitoneal invasion, lymph node metastasis, and tumour stage. In addition, low FGF receptor expression was significantly associated with a longer post-operative survival as compared with high FGF receptor expression, whereas there was no significant difference in post-operative survival between the low and high basic FGF expression groups. Increased expression of FGF receptor is correlated with the extent of malignancy and post-operative survival in human pancreatic ductal adenocarcinomas. Thus, overexpression of FGF receptor may prove to be a more useful prognostic marker than basic FGF expression level in pancreatic cancer patients.

Distribution of the basic fibroblast growth factor and its receptor gene expression in normal and degenerated rat intervertebral discs.

Using a rat spondylosis model, the distributions of cells expressing the basic fibroblast growth factor and its receptor were investigated in normal and degenerated intervertebral discs. Cell-proliferating activity in degenerated discs was also assessed. This study was conducted to determine whether basic fibroblast growth factor is related to intervertebral disc degeneration. Basic fibroblast growth factor stimulates proliferation and matrix synthesis of cultured intervertebral disc cells. Immunohistochemistry and in situ hybridization histochemistry were conducted to detect cells with basic fibroblast growth factor-like immunoreactivity and fibroblast growth factor receptor messenger RNA, respectively. Cell-proliferating activity was evaluated by AgNOR staining. In degenerated discs, round chondrocytes with basic fibroblast growth factor-like immunoreactivity and fibroblast growth factor receptor messenger RNA are scattered instead of spindle-shaped cells in the normal anulus (normal anular cells), which are devoid of basic fibroblast growth factor-like immunoreactivity and fibroblast growth factor receptor messenger RNA. The proliferating activity of these chondrocytes is suggested to exceed that of normal anular cells. Basic fibroblast growth factor is suggested to promote proliferation of chondrocytes in degenerated discs in an autocrine or paracrine manner. Basic fibroblast growth factor may be related to intervertebral disc degeneration as a proliferation-stimulating factor of chondrocytes that replace normal anular cells during disc degeneration.