Distribution of fibroblast growth factors in cultured tumor cells and their transplants

Fibroblast Growth Factor (FGF-2) and Its Receptors FGFR-2 and FGFR-3 May Be Putative Biomarkers of Malignant Transformation of Potentially Malignant Oral Lesions into Oral Squamous Cell Carcinoma

There are several factors like angiogenesis, lymphangiogenesis, genetic alterations, mutational factors that are involved in malignant transformation of potentially malignant oral lesions (PMOLs) to oral squamous cell carcinoma (OSCC). Fibroblast growth factor-2 (FGF-2) is one of the prototypes of the large family of growth factors that bind heparin. FGF-2 induces angiogenesis and its receptors may play a role in synthesis of collagen. FGFs are involved in transmission of signals between the epithelium and connective tissue, and influence growth and differentiation of a wide variety of tissue including epithelia. The present study was undertaken to analyze expression of FGF-2 and its receptors FGFR-2 and FGFR-3 in 72 PMOLs, 108 OSCC and 52 healthy controls, and their role in risk assessment for malignant transformation of Leukoplakia (LKP) and Oral submucous fibrosis (OSMF) to OSCC. Immunohistochemistry was performed using antibodies against FGF-2, FGFR-2 and FGFR-3. IHC results were validated by Real Time PCR. Expression of FGF-2, FGFR-2 and FGFR-3 was upregulated from PMOLs to OSCC. While 90% (9/10) of PMOLs which showed malignant transformation (transformed) expressed FGF-2, only 24.19% cases (15/62) of PMOLs which were not transformed (untransformed) to OSCC expressed FGF-2. Similarly, FGFR-2 expression was seen in 16/62 (25.81%) of untransformed PMOLs and 8/10 (80%) cases of transformed PMOLs. FGFR-3 expression was observed in 23/62 (37.10%) cases of untransformed PMOLs and 6/10 (60%) cases of transformed PMOLs. A significant association of FGF-2 and FGFR-2 expression with malignant transformation from PMOLs to OSCC was observed both at phenotypic and molecular level. The results suggest that FGF-2 and FGFR-2 may be useful as biomarkers of malignant transformation in patients with OSMF and LKP.

Saffold virus type 3 (SAFV-3) persists in HeLa cells

Saffold virus (SAFV) was identified as a human cardiovirus in 2007. Although several epidemiological studies have been reported, they have failed to provide a clear picture of the relationship between SAFV and human diseases. SAFV genotype 3 has been isolated from the cerebrospinal fluid specimen of patient with aseptic meningitis. This finding is of interest since Theiler’s murine encephalomyelitis virus (TMEV), which is the closely related virus, is known to cause a multiple sclerosis-like syndrome in mice. TMEV persistently infects in mouse macrophage cells in vivo and in vitro, and the viral persistence is essential in TMEV-induced demyelinating disease. The precise mechanism(s) of SAFV infection still remain unclear. In order to clarify the SAFV pathogenicity, in the present study, we studied the possibilities of the in vitro persistent infection of SAFV. The two distinct phenotypes of HeLa cells, HeLa-N and HeLa-R, were identified. In these cells, the type of SAFV-3 infection was clearly different. HeLa-N cells were lyticly infected with SAFV-3 and the host suitable for the efficient growth. On the other hand, HeLa-R cells were persistently infected with SAFV-3. In addition, the SAFV persistence in HeLa-R cells is independent of type I IFN response of host cells although the TMEV persistence in mouse macrophage cells depends on the response. Furthermore, it was suggested that SAFV persistence may be influenced by the expression of receptor(s) for SAFV infection on the host cells. The present findings on SAFV persistence will provide the important information to encourage the research of SAFV pathogenicity.

Fibroblast growth factor-2 expression during experimental oral carcinogenesis. Its possible role in the induction of pre-malignant fibrosis

BACKGROUND

The fibroblastic growth factor (FGF)-2 has been shown to induce angiogenesis in several tumor types. To date, the activity of FGF during the development of oral pre-cancerous lesions has not been analyzed. We herein evaluated the role of FGF-2 in the pre-cancerous and cancerous lesions in the hamster cheek pouch oral cancer model.

METHODS

Expression of FGF-2 and its receptors FGFR-2 and FGFR-3 was assessed by immunohistochemistry at different stages of the carcinogenesis protocol. Activity of FGF-2 isoforms was analyzed by Western blots.

RESULTS

Increase and abnormal localization of FGF-2 expression was evident in cancerized epithelium before it was possible to detect morphologic alterations. The changes in FGF-2 are concomitant with the evolution of subepithelial fibrosis. Immunolabeling of carcinomas was faint or completely negative. Increases of FGF-2 activity are mainly due to the increase in the 18 kDa isoform. Receptors 2 and 3 of FGF are present in epithelium, fibroblasts, and vascular endothelia of control samples and in all stages of malignant transformation.

CONCLUSIONS

Our results would suggest a role for FGF-2 in the epithelium-connective interactions and a deregulation of its expression in the early stages of oral cancerization. In pre-cancerous tissue FGF-2 would play a central role in the development of fibrosis and a more collateral role in the induction of angiogenesis. The data would indicate its involvement in the process via the 18 kDa isoform.

Levels of fibroblast growth factor 2 in synovial fluids in human patients with internal derangement of the temporomandibular joint

OBJECTIVE

We sought to elucidate the levels of fibroblast growth factor 2 (FGF-2) in synovial fluid taken from internally deranged human temporomandibular joints (TMJs) and to discuss the role of FGF-2 in the pathogenesis of internal derangement.

STUDY DESIGN

Through the use of a pumping procedure, diluted synovial fluid was collected from the upper joint compartment of 22 TMJs with evidence of internal derangement (21 patients) and 8 TMJs with no such evidence (5 control subjects). Two of the control subjects were patients who had habitual dislocation, and three were healthy volunteers. The level of FGF-2 in the synovial fluid was assessed by means of an enzyme-linked immunosorbent assay.

RESULTS

FGF-2 levels were at detectable levels in 15 of the 22 TMJs (68%) with internal derangement. The mean concentration of FGF-2 was 24 pg/mL. In the control group, FGF-2 levels were detectable in only 1 of 8 joints (13%), for a concentration of 3 pg/mL. The mean concentration of FGF-2 in the synovial fluid was significantly higher in the internal derangement group than in the control group (P =.02).

CONCLUSIONS

FGF-2 levels are elevated in the human synovial fluid of TMJs with internal derangement.

Fibroblast growth factor-1 stimulation of quiescent NIH 3T3 cells increases G/T mismatch-binding protein expression

Polypeptide growth factors promote cell-cycle progression in part by the transcriptional activation of a diverse group of specific genes. We have used an mRNA differential-display approach to identify several fibroblast growth factor (FGF)-1 (acidic FGF)-inducible genes in NIH 3T3 cells. Here we report that one of these genes, called FGF-regulated (FR)-3, is predicted to encode G/T mismatch-binding protein (GTBP), a component of the mammalian DNA mismatch correction system. The murine GTBP gene is transiently expressed after FGF-1 or calf serum treatment, with maximal mRNA levels detected at 12 and 18 h post-stimulation. FGF-1-stimulated NIH 3T3 cells also express an increased amount of GTBP as determined by immunoblot analysis. These results indicate that elevated levels of GTBP may be required during the DNA synthesis phase of the cell cycle for efficient G/T mismatch recognition and repair.

Basic fibroblast growth factor within endothelial cells during vascularization of the anterior pituitary

BACKGROUND

Basic fibroblast growth factor (FGF-2), a potent angiogenic peptide, is known to be present in gonadotropes of the anterior pituitary parenchyma of rats and mice, and has been isolated from endothelial cells of many organs. Its localization within endothelial cells has not been determined, nor the mechanisms by which it might be released from endothelial cells during normal organogenesis.

METHODS

Localization of FGF within endothelial cells of the anterior pituitary was accomplished by immunocytochemistry and studied by light- and electron microscopy. Capillaries within the anterior pituitary were studied in fetal rats from day 15 to term, and in adult rats.

RESULTS

At the onset stages of vascularization (15-18 days fetal), the cytoplasm of the endothelial cells of many of the invading, immature capillaries (thick-walled with few or no fenestrations) was intensely immunopositive for FGF. Immunoprecipitate-filled blebs and slender cytoplasmic processes projected from the endothelial cells into the presumptive pericapillary space and toward the parenchymal cells. As gestation progressed (19-20 day fetal), and an increasing number of capillaries acquired the features characteristic of capillaries in the anterior pituitary of adult animals, i.e., thin-walled and fenestrated, there were fewer capillaries demonstrating immunopositivity for FGF. Foci of released FGF, i.e., extracellular, were occasionally evident within the presumptive pericapillary spaces throughout gestation. By comparison, capillaries of the anterior pituitary of adult rats did not contain immunostainable FGF in their cytoplasm, nor were any blebs and/or processes filled with immunoprecipitate evident. However capillaries did reveal an immunopositive enhancement of their lumenal and ablumenal surfaces.

CONCLUSIONS

During vascularization of the anterior pituitary, FGF within the cytoplasm of endothelial cells is released from blebs and/or processes of endothelial cells, and after the capillary bed is stabilized postnatally, these characteristics of vascularization are absent.

Expression and localization of basic fibroblast growth factor (bFGF) in the repair process of rat liver injury

BACKGROUND/AIMS

To clarify the expression and localization of basic fibroblast growth factor in the repair process of liver injury, acute liver injury was induced by administration of carbon tetrachloride, D-glactosamine hydrochloride, or dimethylnitrosamine to rats.

METHODS

We measured basic fibroblast growth factor protein in the liver tissue by radioimmunoassay, evaluated the expression of basic fibroblast growth factor mRNA by the reverse transcriptase polymerase chain reaction, and identified basic fibroblast growth factor-positive cells by immunostaining.

RESULTS

In the carbon tetrachloride injured liver, the basic fibroblast growth factor protein contents began to increase 2 days after administration when liver injury was most marked, and reached a peak after 4 days, decreasing thereafter. In the carbon tetrachloride-injured liver, basic fibroblast growth factor mRNA expression was observed from 12 h after administration, prior to an increase in the protein content. In the D-galactosamine hydrochloride-injured liver, basic fibroblast growth factor protein also increased. On the other hand, in the dimethylnitrosamine-injured liver, the basic fibroblast growth factor protein content decreased 2 days after administration when liver injury was marked, but increased after 7 days. In the regenerating liver after partial hepatectomy, the basic fibroblast growth factor protein content did not increase. Among cell fractions, the Ito cell fraction obtained from the carbon tetrachloride-injured liver after 4 days showed expression of basic fibroblast growth factor mRNA. In cells cultured for 24 h, this fraction was immunopositive for basic fibroblast growth factor. Ito cells in the liver tissue markedly increased in the carbon tetrachloride-injured liver and increased after 7 days in the dimethylnitrosamine-injured liver.

CONCLUSIONS

This study confirmed basic fibroblast growth factor production in the liver tissue in the repair process of liver injury. Our results suggest that basic fibroblast growth factor is primarily produced in Ito cells, acts on sinusoidal wall cells including Ito cells by the autocrine and paracrine mechanisms, and promotes extracellular matrix production and vascularization, involving the repair process of liver injury.

Basic fibroblast growth factor in rat salivary glands

We studied the occurrence and localization of basic fibroblast growth factor (bFGF) in rat salivary glands using a specific monoclonal antibody. It was shown that the extract of rat salivary glands has a pronounced stimulatory activity on the growth of bovine capillary endothelial cells, which is blocked by the addition of an antibody against bFGF. The concentration of bFGF in the submandibular/sublingual gland, as determined by radioimmunoassay, was approximately 80% that in the brain. Immunocytochemistry revealed bFGF-immunoreactivity localized primarily in the epithelial cells lining the striated ducts and excretory ducts of the parotid, sublingual and submandibular glands. In addition, intense bFGF-immunoreactivity was observed in the granular convoluted tubule of the submandibular gland, localized predominantly in the agranular pillar cells, which lay in small numbers among the majority of weakly immunostained cells containing many apical secretory granules. At the electron-microscopic level, the immunoreactive material was distributed diffusely in the cytoplasmic matrix and nuclei of all immunoreactive cells, whereas it was absent from all cytoplasmic organelles including the secretory granules. These results indicate that bFGF is localized in different cellular and subcellular compartments from those of other growth factors in the duct system of rat salivary glands.