Overexpression Of bFGF Research Articles

Tropism-shifted AAV-PHP.eB-mediated bFGF gene therapy promotes varied neurorestoration after ischemic stroke in mice.

AAV-PHP.eB is an artificial adeno-associated virus (AAV) that crosses the blood-brain barrier and targets neurons more efficiently than other AAVs when administered systematically. While AAV-PHP.eB has been used in various disease models, its cellular tropism in cerebrovascular diseases remains unclear. In the present study, we aimed to elucidate the tropism of AAV-PHP.eB for different cell types in the brain in a mouse model of ischemic stroke and evaluate its effectiveness in mediating basic fibroblast growth factor (bFGF) gene therapy. Mice were injected intravenously with AAV-PHP.eB either 14 days prior to (pre-stroke) or 1 day following (post-stroke) transient middle cerebral artery occlusion. Notably, we observed a shift in tropism from neurons to endothelial cells with post-stroke administration of AAV-PHP.eB-mNeonGreen (mNG). This endothelial cell tropism correlated strongly with expression of the endothelial membrane receptor lymphocyte antigen 6 family member A (Ly6A). Furthermore, AAV-PHP.eB-mediated overexpression of bFGF markedly improved neurobehavioral outcomes and promoted long-term neurogenesis and angiogenesis post-ischemic stroke. Our findings underscore the significance of considering potential tropism shifts when utilizing AAV-PHP.eB-mediated gene therapy in neurological diseases and suggest a promising new strategy for bFGF gene therapy in stroke treatment.

Effects of dual-gene modification on biological characteristics of vascular endothelial cells and their significance as reserving cells for chronic wound repair

bFGF is a commonly used and reliable factor for improving chronic wound healing, and hSulf-1 expression is abundant in surrounding cells of chronic wound tissue and vascular endothelial cells, which can reverse the effect of bFGF and inhibit the signalling activity of cell proliferation. In this study, an adenovirus, Ad5F35ET1-bFGF-shSulf1, was designed for establishing the dual-gene modified vascular endothelial cells, which were used as the repair cells for skin chronic wound. Ad5F35ET1-bFGF-shSulf1 infected ECV304 cells in vitro and mediated the overexpression of bFGF and the knockdown of hSulf-1, which effectively activated the AKT and ERK signal transduction pathways, facilitate cell proliferation and migration, with the cell viability to 128.29% at 72 h after infection, compared to 66.65%, 73.74%, 87.63%, 103.14% in the blank control, Ad5F35ET1-EGFP-shNC, Ad5F35ET1-shSulf1, Ad5F35ET1-bFGF groups, respectively. In the rat ear skin injury model, the wound healing was significantly accelerated in the Ad5F35ET1-rbFGF-shrSulf1 group compared to the blank control group (p = 0.0046), Ad5F35ET1-EGFP-shNC group (p = 0.0245), Ad5F35ET1-shrSulf group (p = 0.0426), and Ad5F35ET1-rbFGF group (p = 0.2853). The results demonstrated that this strategy may be a candidate therapy for chronic injury repair.

Basic Fibroblast Growth Factor (bFGF)-Overexpressed Bone Marrow Mesenchymal Stem Cells (BMSCs) Orchestrate Lung Cancer Development and Fibroblast Growth

Lung cancer is one of most common cancer with a complicated pathogenesis and a poor prognosis. This study aimed to investigate the role of bFGF and BMSCs in lung cancer progression. BMSCs were transfected with bFGF mimic or NC and then co-cultured with lung cancer cells followed by measuring cell migration by Transwell assay and proliferation by CCK-8 assay, expression of bFGF, E-cadherin, and Vimentin by RT-qPCR and Western blot. The BMSCs were positive for CD90, CD71, CD29 and CD45. Overexpression of bFGF in BMSCs resulted in increased lung cancer cell proliferation at 24 h, 48 h and 72 h. Meanwhile, bFGF overexpression also significantly promoted cell migration and invasion as well as upregulated bFGF (4.03±0.36 ng/μl) and E-cadherin (3.64±0.27 ng/μl) and downregulated Vimentin (1.45±0.19 ng/μl). In conclusion, co-culture of BMSCs overexpressing bFGF and lung cancer cells enhances BMSCs differentiation and promotes cancer cell development possibly through regulation of E-cadherin and Vimentin expression, indicating that this might be a novel approach for the treatment of lung cancer.

BFGF overexpression adipose derived mesenchymal stem cells improved the survival of pulmonary arterial endothelial cells via PI3k/Akt signaling pathway.

Pulmonary arterial hypertension (PAH) is characterized as pulmonary arterial endothelial dysfunction and endothelial cells over proliferation, therefore, the repair of pulmonary arterial endothelial cells has been a common goal in treating PAH. In the present study, human adipose derived mesenchymal stem cells (ASCs) were transfected with bFGF lentiviral vector and co-cultured with monocrotaline pyrrole treated human pulmonary arterial endothelial cells (HPAECs). The results showed that bFGF-ASCs improved the proliferation, viability and decreased the apoptosis of HPAECs, besides, improved PAH was observed in PAH rat models. Western blot analysis showed that the PI3k and p-Akt protein expression level increased in HPAECs, suggesting the activation of the PI3k/Akt signaling pathway. With the administration of LY294002, the bFGF induced HPAECs survival and PI3k/Akt signaling activation were successfully blocked. The present study demonstrated that bFGF transfected ASCs improved the survival of HPAECs by activating the PI3k/Akt pathway.

Prognostic Value of Basic Fibroblast Growth Factor (bFGF) in Lung Cancer: A Systematic Review with Meta-Analysis.

BackgroundBasic fibroblast growth factor (bFGF) is known to stimulate angiogenesis and thus to influence the proliferation, migration and survival of tumor cells. Many studies examined the relationship between human bFGF overexpression and survival in lung cancer patients, but the results have been mixed. To systematically summarize the clinical prognostic function of bFGF in lung cancer, we performed this systematic review with meta-analysis.MethodStudies were identified by an electronic search of PubMed, EMBASE, China National Knowledge Infrastructure and Wanfang databases, including publications prior toAugust 2014. Pooled hazard ratios (HR) for overall survival (OS) were aggregated and quantitatively analyzed by meta-analysis.ResultsTwenty-two studies (n = 2154) were evaluated in the meta-analysis. Combined HR suggested that bFGF overexpression had an adverse impact on survival of patients with lung cancer(HR = 1.202,95%CI, 1.022–1.382). Our subgroup analysis revealed that the combined HR evaluating bFGF expression on OS in operable non-small cell lung cancer (NSCLC) was 1.553 (95%CI, 1.120–1.986); the combined HR in small cell lung cancer (SCLC) was 1.667 (95%CI, 1.035–2.299). There was no significant impact of bFGF expression on survival in advanced NSCLC.ConclusionThis meta-analysis showed that bFGF overexpression is a potential indicator of worse prognosis for patients with operable NSCLC and SCLC, but is not associated with outcome in advanced NSCLC. The data suggests that high bFGF expression is highly related to poor prognosis. Nevertheless,more high-quality studies should be performed in order to provide additional evidence for the prognostic value of bFGF in lung cancer.

Blocking Infralimbic Basic Fibroblast Growth Factor (bFGF or FGF2) Facilitates Extinction of Drug Seeking After Cocaine Self-Administration.

Drug exposure results in structural and functional changes in brain regions that regulate reward and these changes may underlie the persistence of compulsive drug seeking and relapse. Neurotrophic factors, such as basic fibroblast growth factor (bFGF or FGF2), are necessary for neuronal survival, growth, and differentiation, and may contribute to these drug-induced changes. Following cocaine exposure, bFGF is increased in addiction-related brain regions, including the infralimbic medial prefrontal cortex (IL-mPFC). The IL-mPFC is necessary for extinction, but whether drug-induced overexpression of bFGF in this region affects extinction of drug seeking is unknown. Thus, we determined whether blocking bFGF in IL-mPFC would facilitate extinction following cocaine self-administration. Rats were trained to lever press for intravenous infusions of cocaine before extinction. Blocking bFGF in IL-mPFC before four extinction sessions resulted in facilitated extinction. In contrast, blocking bFGF alone was not sufficient to facilitate extinction, as blocking bFGF and returning rats to their home cage had no effect on subsequent extinction. Furthermore, bFGF protein expression increased in IL-mPFC following cocaine self-administration, an effect reversed by extinction. These results suggest that cocaine-induced overexpression of bFGF inhibits extinction, as blocking bFGF during extinction permits rapid extinction. Therefore, targeted reductions in bFGF during therapeutic interventions could enhance treatment outcomes for addiction.

Reciprocal Regulation of Axonal Filopodia and Outgrowth during Neuromuscular Junction Development

BackgroundThe assembly of the vertebrate neuromuscular junction (NMJ) is initiated when nerve and muscle first contact each other by filopodial processes which are thought to enable close interactions between the synaptic partners and facilitate synaptogenesis. We recently reported that embryonic Xenopus spinal neurons preferentially extended filopodia towards cocultured muscle cells and that basic fibroblast growth factor (bFGF) produced by muscle activated neuronal FGF receptor 1 (FGFR1) to induce filopodia and favor synaptogenesis. Intriguingly, in an earlier study we found that neurotrophins (NTs), a different set of target-derived factors that act through Trk receptor tyrosine kinases, promoted neuronal growth but hindered presynaptic differentiation and NMJ formation. Thus, here we investigated how bFGF- and NT-signals in neurons jointly elicit presynaptic changes during the earliest stages of NMJ development.Methodology/Principal FindingsWhereas forced expression of wild-type TrkB in neurons reduced filopodial extension and triggered axonal outgrowth, expression of a mutant TrkB lacking the intracellular kinase domain enhanced filopodial growth and slowed axonal advance. Neurons overexpressing wild-type FGFR1 also displayed more filopodia than control neurons, in accord with our previous findings, and, notably, this elevation in filopodial density was suppressed when neurons were chronically treated from the beginning of the culture period with BDNF, the NT that specifically activates TrkB. Conversely, inhibition by BDNF of NMJ formation in nerve-muscle cocultures was partly reversed by the overexpression of bFGF in muscle.ConclusionsOur results suggest that the balance between neuronal FGFR1- and TrkB-dependent filopodial assembly and axonal outgrowth regulates the establishment of incipient NMJs.

Expressions of bFGF and PTEN in cervical carcinoma and their clinical significance

To investigate the expressions of bFGF and PTEN in cervical carcinoma and their clinical significance. Tissue microarray technique and immunohistochemistry SP method were used to detect the expressions of bFGF and PTEN in 143 cases of invasive carcinoma of cervix (ICC) and 20 cases of normal cervical epithelium remote from tumor (NCE). The relationship between the expressions of bFGF and PTEN in ICC and some factors relating to clinical pathology of cervical carcinoma such as histopathological grading, lymph node metastasis, stroma involvement and FIGO staging were analyzed. The rate of the positive expression of bFGF in ICC was significantly higher than that in NCE 88.8% (127/143) vs. 25.0% (5/20, P = 0.000). The rate of positive expression of PTEN in ICC was significantly lower than that in NCE 67.1% (96/143) vs. 100.0% (20/20, P = 0.000). The expression of bFGF was positively correlated with lymph node metastasis and histopathological grading (r = 0.239, P = 0.004 and r = 0.369, P = 0.000, respectively). The expression of PTEN was negatively correlated with FIGO staging, histopathological grading and lymph node metastasis (r = -0.189, P = 0.024; r = -0.211, P = 0.011; r = -0.321, P = 0.000, respectively). The expression of bFGF was negatively correlated with the expression of PTEN in ICC (r = -0.261, P = 0.002). The overexpression of bFGF and underexpression of PTEN are closely related to the invasion and growth of cervical carcinoma. Detection of the expression of both bFGF and PTEN may be of value in further understanding the biological behavior and predicting the prognosis of cervical carcinoma.

Basic Fibroblast Growth Factor-Mediated Overexpression of Vascular Endothelial Growth Factor in 1F6 Human Melanoma Cells is Regulated by Activation of PI-3K and p38 MAPK

Background: 1F6 human melanoma xenografts overexpressing either the 18 kD (18kD) form or all (ALL) forms of human basic fibroblast growth factor (bFGF) demonstrate an abundant number of microvessels and accelerated growth. We now examined whether bFGF mediates vascular endothelial growth factor (VEGF) expression.Methods: Quantitative RT-PCR was used to determine bFGF and VEGF mRNA, VEGF protein secretion was measured by ELISA and VEGF promoter activation was assessed by a dual luciferase activity assay. Western blot was carried out to detect phosphorylation of bFGF-regulated target proteins.Results: In 1F6-18kD and 1F6-ALL clones VEGF mRNA was increased 4- to 5-fold and VEGF protein secretion was highly stimulated due to activation of the VEGF promotor. PI-3K, p38 MAPK and ERK1/2 MAPK pathways were activated, while inhibition of PI-3K or p38 resulted in, respectively, 55% and up to 70% reduction of VEGF mRNA overexpression. A concurrent 60% decrease in VEGF protein secretion was mostly apparent upon inhibition of PI-3K. Inhibition of ERK1/2 hardly affected VEGF mRNA or protein secretion. Two unselected human melanoma cell lines with high metastatic potential contained high bFGF and VEGF, while three non- or sporadically metastatic cell lines displayed low bFGF and VEGF.Conclusion: These data indicate that stimulation of VEGF protein secretion in response to bFGF overexpression may contribute to increased vascularization and enhanced aggressiveness in melanoma.

Basic fibroblast growth factor-mediated overexpression of vascular endothelial growth factor in 1F6 human melanoma cells is regulated by activation of PI-3K and p38 MAPK.

Background: 1F6 human melanoma xenografts overexpressing either the 18 kD (18kD) form or all (ALL) forms of human basic fibroblast growth factor (bFGF) demonstrate an abundant number of microvessels and accelerated growth. We now examined whether bFGF mediates vascular endothelial growth factor (VEGF) expression. Methods: Quantitative RT-PCR was used to determine bFGF and VEGF mRNA, VEGF protein secretion was measured by ELISA and VEGF promoter activation was assessed by a dual luciferase activity assay. Western blot was carried out to detect phosphorylation of bFGF-regulated target proteins. Results: In 1F6-18kD and 1F6-ALL clones VEGF mRNA was increased 4- to 5-fold and VEGF protein secretion was highly stimulated due to activation of the VEGF promotor. PI-3K, p38 MAPK and ERK1/2 MAPK pathways were activated, while inhibition of PI-3K or p38 resulted in, respectively, 55% and up to 70% reduction of VEGF mRNA overexpression. A concurrent 60% decrease in VEGF protein secretion was mostly apparent upon inhibition of PI-3K. Inhibition of ERK1/2 hardly affected VEGF mRNA or protein secretion. Two unselected human melanoma cell lines with high metastatic potential contained high bFGF and VEGF, while three non- or sporadically metastatic cell lines displayed low bFGF and VEGF. Conclusion: These data indicate that stimulation of VEGF protein secretion in response to bFGF overexpression may contribute to increased vascularization and enhanced aggressiveness in melanoma.

Research on promoting periodontal regeneration with human basic fibroblast growth factor-modified bone marrow mesenchymal stromal cell gene therapy

Recently, it has been found that effective periodontal regeneration can be induced by bone marrow mesenchymal stromal cell (BMSC) transplantation or local application of basic fibroblast growth factor (bFGF). The aim of the present study was to assess, in dogs, the efficacy of periodontal regeneration via the delivery of BMSC transfected with bFGF to repair destruction of periodontal tissue. BMSC from dogs were isolated, cultured and purified via density-gradient centrifugation. Polymerase chain reaction (PCR) was employed to clone bFGF cDNA from human periodontal cells, and the product was then ligated into the eukaryotic expression vector pDC316-IREs-EGFP. BMSC transfected with pDC316bFGF-IREs-EGFP were transplanted into root furcation defects of beagle dogs. After 6 weeks, regeneration in defects was assessed via clinical examination, X-ray, histologic observation and micro-CT analysis. DNA sequence analysis showed that the bFGF sequence of recombinant plasmid pDC316bFGF-IREs-EGFP was consistent with that reported by GeneBank. bFGF expression was detected with Western blotting, and active bFGF in supernatant was also observed. Our animal experiment proved that the regenerating speed of periodontal bone tissue in groups transplanted with BMSC containing the modified bFGF gene was higher than in those transplanted with BMSC alone. A successfully constructed eukaryotic expression vector containing human bFGF in pDC316bFGF-IREs-EGFP could produce bioactive bFGF in vitro. bFGF overexpression mediated by the recombinant plasmid pDC316bFGF- IREs-EGFP accelerated periodontal regeneration.

O 6-Methylguanine-DNA-methyltransferase promoter demethylation is involved in basic fibroblast growth factor–induced resistance against temozolomide in human melanoma cells

Basic fibroblast growth factor (bFGF) is a multifunctional protein and one of the most important growth factors in cutaneous melanoma development and progression. We hypothesized that high bFGF expression might be responsible for chemoresistance in advanced melanoma. M14 human melanoma cells expressing low levels of bFGF were successfully transfected with vectors encoding either the 18 kDa or all isoform proteins of bFGF. M14 cells and bFGF-overexpressing clones had a similar growth rate in vitro. Overexpression of 18 kDa or all isoform proteins of bFGF resulted in, respectively, 2.9- and 6.9-fold resistance against temozolomide. O6-alkylguanine-DNA-alkyltransferase (AGT) protein levels were highly elevated. Specific inhibition of AGT with O6-benzylguanine completely reversed the resistance in the 18 kDa clone, and partially in the clone overexpressing all isoforms. A methylation-specific PCR showed that at least in the 18 kDa overexpressing clone, increased AGT expression was the result of demethylation of the O6-methylguanine-DNA-methyltransferase promoter. In parental M14 cells, the demethylating agent 5-azacytidine generated AGT expression resulting in temozolomide resistance. Overexpression of all isoform proteins of bFGF, but not the 18 kDa isoform alone, resulted in 2.9-fold resistance against cisplatin, which could not be reversed by O6-benzylguanine. The expression levels of the mismatch repair proteins MSH2, MSH6, and MLH1 were not decreased, which likely excludes a defective mismatch repair system as a cause for cisplatin resistance. There were no changes in sensitivity to docetaxel and doxorubicin. In conclusion, bFGF overexpression can result in resistance against temozolomide mediated by demethylation of the O6-methylguanine-DNA-methyltransferase promoter.

Novel cystogenic role of basic fibroblast growth factor in developing rodent kidneys

Basic fibroblast growth factor (bFGF) is a heparin-binding growth factor that is accumulated in human dysplastic and cystic renal diseases. Previous studies have shown that bFGF can modulate the growth of developing renal tubules; however, its role in the pathogenesis of renal cyst formation is not clearly understood. Here, we tested the hypothesis that overexpression of bFGF in developing rodent kidneys induces cyst formation in vivo. We used two different adenoviral-mediated gene-transferring approaches to overexpress bFGF in developing rodent kidneys. Initially, metanephric kidney (MK) explants harvested from embryonic day 15 Sprague-Dawley rats were infected with adenoviral vectors (rAd) encoding human bFGF or LacZ genes and transplanted under the renal capsule of adult female rats. Subsequently, to determine whether bFGF could induce renal cysts in developing kidneys with an intact renal collecting system, we injected rAd-bFGF or LacZ vectors in the retroorbital plexus of newborn mice. Basic FGF induced a more efficient integration of the MK explants into the host kidneys and increased the vascularization and proliferation of developing tubules, leading to tubular dilatation and rapid formation of renal cysts. In addition, we successfully expressed human bFGF in the kidney of newborn mice in vivo and induced tubular dilatation and renal cysts. In contrast, mice injected with rAd-lacZ did not develop tubular dilatation or renal cysts. To the best of our knowledge, these experiments show for the first time that overexpression of bFGF in developing rodent kidneys can induce the formation of renal cysts in vivo.

Increased expression of basic fibroblast growth factor in skin of patients with systemic sclerosis

Increased collagen deposition is a hallmark of systemic sclerosis (SSc). Several fibrogenic cytokines play a role in this sclerosis. The role of basic fibroblast growth factor (bFGF), the most potent fibrogenic cytokine, is poorly understood in SSc. Skin biopsies from forearm of 13 patients with SSc and 3 normal individuals were analyzed by immunohistochemistry using avidin biotin-system to amplify the signal. In addition serum levels of bFGF were also measured in 30 patients including these 13 and 23 healthy controls. Thirteen patients with SSc were all females and had a median age of 26.5 years, median disease duration of 2.25 years. Of these thirteen, seven had diffuse and six had limited disease. The skin biopsies from patients showed increased expression of bFGF in the basal layer of epidermis, dermis (periappendageal, perivascular, matrix tissue) as compared to normal tissues. The expression of bFGF did not correlate with duration of disease or skin score. In contrast, only low levels of bFGF were detectable in 4/30 sera from SSc patients as compared to 3/23 from healthy controls (p = ns). Overexpression of bFGF in skin of patients with SSc along with normal serum levels suggests that bFGF probably acts in an autocrine or paracrine manner in fibrogenesis.

Chondrocyte cluster formation in agarose cultures as a functional assay to identify genes expressed in osteoarthritis

Understanding altered gene expression in osteoarthritic cartilage can lead to new targets for drug intervention. We established a functional assay based on chondrocyte cluster formation, a phenotype associated with osteoarthritis (OA), to screen an OA cartilage gene library. Previous reports have demonstrated that normal chondrocytes grown in suspension culture maintain their chondrocytic phenotype, however, certain growth factors such as basic fibroblast growth factor (bFGF) will induce the cells to proliferate in tight clusters similar to those seen in osteoarthritic cartilage. In this study we validate that overexpression of bFGF by retrovirally transduced normal chondrocytes would similarly induce the proliferation of tight cell clusters. We then used this approach as a basis to set up a functional screen where an entire OA cartilage cDNA library was tranduced into normal chondrocytes to search for other genes that would also induce cluster formation. Seven potential genes were isolated from the OA gene library, including BPOZ, IL-17 receptor C, NADH ubiquinone oxidoreductase, COMP, Soluble carrier 16 (MCT 3), C1r, and bFGF itself. None of the identified genes were upregulated by bFGF, however, all of them upregulated the expression of bFGF suggesting a common pathway. Although cluster formation is not considered to be destructive in OA cartilage, it is consistent with the disease and could yield answers to the altered phenotype. Further studies are needed to elucidate how these genes are linked to the disease state.

Herniated and Spondylotic Intervertebral Discs of the Human Cervical Spine: Histological and Immunohistochemical Observations

We investigated the histological and immunohistochemical changes within and around the cervical intervertebral discs in symptomatic myeloradiculopathy and myelopathy patients. A total of 163 cervical intervertebral discs, 100 herniated discs and 63 spondylotic discs, were harvested en bloc during anterior decompressive surgeries and histological examination was performed, focusing on nucleus pulposus, annulus fibrosus, cartilaginous endplate, and ligamentous enthesis. There was a close relationship between MRI grade and histological degenerative changes. Histological features of the herniated intervertebral discs were the presence of granulation tissue, newly-developed blood vessels and infiltration of CD68-positive cells, which surrounded the herniated tissue in the outer layer of the annulus fibrosus. Marked vascular invasion was detected in 67% of herniated discs and 54% of spondylotic discs. Immunohistochemically, chondrocytes positive for matrix metalloproteinase (MMP)-3, tumor necrosis factor (TNF)-α, basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) were detected in both herniated and spondylotic discs. Our results indicate that the neoangiogenesis process is associated with overexpression of bFGF and VEGF, and suggest that intervertebral disc degradation is enhanced by macrophage infiltration, which is regulated by MMP-3 and TNF-α. The expression of these proteins may be enhanced by the tear of annulus fibrosus.

526. Adenovirus- Mediated Overexpression of bFGF Induces Hypertropy in Skeletal Muscles

526. Adenovirus- Mediated Overexpression of bFGF Induces Hypertropy in Skeletal Muscles

Bone marrow immunohistochemical studies of angiogenic cytokines and their receptors in myelofibrosis with myeloid metaplasia

Bone marrow specimens from 11 patients with myelofibrosis with myeloid metaplasia (MMM) and seven normal controls were studied immunohistochemically to determine expression of transforming growth factor β (TGF-β), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and corresponding receptors. Staining distribution and intensity for TGF-β, PDGF, VEGF, TGF-β type II receptor, a receptor for PDGF, and receptors for VEGF and bFGF were similar in patients and controls. Bone marrow from 10 MMM patients showed increased TGF-β type I receptor (TGF-βRI) expression in small vessel endothelial cells. Eight patient specimens had bFGF overexpression in megakaryocytes. Increased microvessel density and decreased concentration of bFGF-staining stromal cells accompanied these changes. Microvascular TGF-βRI upregulation and bFGF overexpression by megakaryocytes may cause bone marrow microenvironmental changes in MMM patients.

Fibroblast growth factor receptor 1 (FGFR1) is over-expressed in benign prostatic hyperplasia whereas FGFR2-IIIc and FGFR3 are not.

Benign prostatic hyperplasia (BPH) is one of the major public health problems among men: 50% of men over 55 are concerned with this disease. Prostate growth is under the control of androgens which act by means of several growth factors such as fibroblast growth factors (FGFs), epidermal growth factor and transforming growth factor beta. Basic FGF (bFGF) has been shown to stimulate prostatic stromal growth. In BPH, bFGF concentration is two- to threefold higher than in normal prostate. In this work, the bFGF receptors (FGFR1, FGFR2-IIIc and FGFR3) genes expression was evaluated to study the correlation between the expression of bFGF receptors and induction of BPH. The expression of FGFRs was analyzed by RT-PCR, FGFR1 was localized by immunohistochemistry and protein expression was evaluated by Western blot. A two- to eightfold over-expression of FGFR1 was observed in BPH compared with normal prostates. FGFR1 was localized in the stroma both in BPH and in normal prostates and 1.5- to 2.5-fold over-expression of the protein was observed. The expression of FGFR2-IIIc and FGFR3, more secondary receptors, was not significantly different between BPH and normal prostates. bFGF receptors and particularly FGFR1 seem to be involved in the induction and evolution of BPH and probably potentiate bFGF over-expression effects in BPH.

Basic Fibroblast Growth Factor and Ultraviolet B Transform Melanocytes in Human Skin

Ultraviolet (UV) light is an epidemiological risk factor for melanoma, but its specific contribution to melanoma induction is not known. The first critical step of melanoma development, ie, the uncontrolled proliferation of melanocytes, may be induced by a combination of UV damage and an imbalance of growth factor production by cells in the immediate area of the melanocyte. Among several candidates, basic fibroblast growth factor (bFGF) is the major autocrine growth factor in melanoma and associated with tumor progression. Overexpression of bFGF via adenoviral gene transfer in human skin xenografted to severe combined immunodeficiency mice led to black-pigmented macules within 3 weeks of treatment. Immunofluorescence analysis demonstrated pathological hyperpigmentation, proliferation and hyperplasia of activated melanocytes, but no malignant transformation. Similar changes were observed in skin reconstructs. When bFGF was combined with UVB, pigmented lesions with hyperplastic melanocytic cells were detected, including a lesion with high-grade atypia resembling lentiginous forms of malignant melanoma. Donor-matched control grafts revealed no melanocytic changes. bFGF was overexpressed in dermal fibroblasts demonstrating the co-carcinogenic influence of paracrine-acting growth factors by cells of the microenvironment. This is the first report suggesting that an imbalance of physiological growth factor production in the skin may cause melanoma in combination with UVB.