OBJECTIVE

To investigate the role of N-cadherin and hepatocyte growth factor (HGF) in the invasion of collagen type I by human retinal pigment epithelial (RPE) cells.

METHODS

RPE sheets from eight human eyes were used for characterization through Western blot analysis of the expression of cadherin in total lysates or after immunoprecipitation with anti beta-catenin antibody. First-passage primary cultures of RPE sheets were successfully established from 28 of 56 human eyes. First-passage primary RPE cell cultures on glass substrate, consisting of patches of cells, were used for immunocytochemistry. Fifteen first-passage primary RPE cell cultures in culture vessels were grown to confluence. Four of the 15 first-passage primary RPE cell cultures were investigated for cadherin expression by immunocytochemistry, and the other 11 were further subcultured for two to six passages. These 11 cultures were used for functional assays and investigated for expression of cadherin at regular time intervals. Cells from passage-3 to -4 primary RPE cell cultures were tested for invasion into collagen type I gels, with or without neutralizing antibodies for HGF and N-cadherin, respectively. Activation of the c-Met receptor for HGF and of focal adhesion kinase (FAK) was investigated by immunoprecipitation with anti-phosphotyrosine antibody, gel electrophoresis, and immunostaining on Western blot. Levels of HGF in conditioned medium (CM) of RPE cells were determined by ELISA.

RESULTS

RPE cells in culture displayed two phenotypes: Both fibroblast-like and epithelioid cells were present in all 15 first-passage primary cultures and in further passaged cultures derived therefrom. When seeded on collagen, all RPE cells acquired a fibroblast-like phenotype and invaded the collagen type I gel. RPE cells also stimulated branching morphogenesis of MDCK/AZ epithelial canine kidney cell colonies inside collagen. HGF was found in RPE CM, suggesting an autocrine loop for invasion through its c-Met receptor. HGF-neutralizing antibody inhibited invasion of collagen. The major cadherin expressed by RPE cells in culture was N(euronal)-cadherin. Invasion of collagen by RPE cells was also inhibited by an N-cadherin-neutralizing antibody. N-cadherin and c-Met coimmunoprecipitated in RPE cells. FAK and c-Met were both phosphorylated in RPE cells in culture, and phosphorylation was inhibited by antibodies neutralizing either N-cadherin or HGF.

CONCLUSIONS

The present investigation provides evidence for an autocrine HGF/c-Met loop that stimulates RPE cell invasion into collagen through FAK. The invasion-stimulatory molecule N-cadherin also activates FAK in invasive RPE cells.

OBJECTIVE

To determine the dose response of human recombinant basic fibroblast growth factor (bFGF) on mitogenic activity, and the supplementary role of serum in cultured bovine and human corneal endothelial cells (BCECs, HCECs). To investigate the effect of bFGF on endothelial wound healing of human corneas in vitro.

METHODS

In cell culture, DNA synthesis was assessed by 3H-thymidine incorporation. Wound healing was studied using paired human corneas after mechanical damaging of the endothelium. One cornea was treated with bFGF, and the mate served as control. Wound closure was determined after staining with trypan blue. Endothelial cell density (ECD) was assessed in the closed wound area after alizarin red staining. DNA synthesis was assessed using 3H-thymidine autoradiography.

RESULTS

In cell culture, bFGF induced a dose-dependent mitogenic response on BCECs and HCECs. Addition of serum to the culture medium shifted the dose-response curve to considerably lower bFGF concentrations. In organ culture, the time of complete wound closure shortened only marginally (0.5 day) after bFGF treatment (P < 0.01). In the closed wound center, ECD was significantly higher in 1 ng/ml bFGF-treated corneas (686 +/- 134 cells/mm2) than in controls (554 +/- 117 cells/mm2), an increase of +25%. Doses of 0.1 and 10 ng/ml also were effective, but less so than with 1 ng/ml (+11% and +15%, respectively), whereas a dose of 100 ng/ml even had a negative effect (-11%). DNA synthesis was marginally enhanced in bFGF-treated (1 ng/ml) corneas.

CONCLUSIONS

The maximal effective dose of bFGF producing a BCEC mitogenic response is dependent on serum. In human senior donor corneas, bFGF promotes endothelial wound healing predominantly by stimulation of cell migration.

Cardiac <em>fibroblasts</em> constitute greater than 90% of the non-myocyte cells in the heart. Previously, it was established that cardiac <em>fibroblasts</em> are predisposed to transformation into a phenotype with muscle-specific features and that transforming <em>growth</em> <em>factor</em>-beta 1 (TGF-beta 1) is a specific inducer of this event. In this study the hypothesis that TGF-beta 1-induced phenotypic modulation of cardiac <em>fibroblasts</em> is associated with their altered proliferative capacity is tested. Therefore the effects of TGF-beta 1 on DNA synthesis in cardiac <em>fibroblasts</em> under normal conditions of cell culture and in response to a potent mitogen, basic <em>fibroblasts</em> <em>growth</em> <em>factor</em> (bFGF) were determined. The results showed that TGF-beta 1 at <em>15</em> ng/ml (a concentration that induces <em>fibroblast</em> "transformation") had a regulatory effect on proliferative capacity of cardiac <em>fibroblasts</em> which varied as the function of cell density in culture. In subconfluent and confluent cultures, pre-treatment of cardiac <em>fibroblasts</em> with TGF-beta 1 for 24 h resulted in a dramatic shift in the bFGF-induced stimulation of DNA synthesis. TGF-beta 1-induced inhibition of DNA synthesis in cardiac <em>fibroblasts</em> coincided with their phenotypic modulation as evidenced by the expression of sarcomeric actin mRNA and morphological changes. Cross-linking studies with [125I]-labeled TGF-beta 1 showed the presence of conventional types I, II and III TGF-beta 1 receptor complexes on cardiac <em>fibroblasts</em> and their binding to TGF-beta 1 under the experimental conditions. In summary, these data indicate that the proliferative capacity of cardiac <em>fibroblasts</em> is controlled by TGF-beta 1. They further suggest that the TGF-beta 1-induced phenotypic modulation of cardiac <em>fibroblasts</em> may be extended to include their altered proliferative capacity.

We investigated the mitogenic effect of continuous intrathecal infusion of epidermal <em>growth</em> <em>factor</em> (EGF) or <em>fibroblast</em> <em>growth</em> <em>factor</em> 2 (FGF2) on ependymal precursor cells of the adult rat spinal cord in vivo. Either EGF, FGF2, EGF plus FGF2, or artificial cerebrospinal fluid (aCSF) was infused at a flow rate of 0.5 microl/h (<em>15</em> ng/h of EGF or FGF2) for 3 or 14 days into the intrathecal space at T1 through a catheter attached to an osmotic minipump. To assess proliferation, the bromodeoxyuridine (BrdU) labeling index (LI) in the ependyma at T1 was calculated at 3 or 14 days. At 3 days there was no statistical difference in LI between these groups, but at 14 days the LI was significantly higher in the EGF plus FGF2 group (27.2% = 16.0%) than in the aCSF group (5.4% +/- 4.7%; p < 0.05). With EGF alone or FGF2 alone, the LI increases were not significantly different from the aCSF group. With EGF plus FGF2 for 14 days, some BrdU-positive cells in the ependyma also expressed nestin. These results suggest that the intrathecal infusion of EGF plus FGF2 has a mitogenic effect on precursor cells in the ependyma of the adult rat spinal cord.

We have evaluated the effect of X irradiation on the mesenchymal tissue <em>growth</em> (blood capillaries and stromal cells) in an angiogenesis system in the mouse. This was accomplished by implanting a polyvinyl alcohol sponge disc in the subcutis of the thorax, and quantifying the extent of <em>growth</em> reduction of capillaries and stromal cells following graded doses of X rays. The sponge disc contained a centrally located pellet impregnated with 20 micrograms of epidermal <em>growth</em> <em>factor</em> and coated with a thin film of slow-releasing compound. Total <em>growth</em> of vessels and <em>fibroblasts</em> was determined by morphometric analysis of histologic sections. The incorporation of [3H]TdR was measured during a 24-h period. A dose-response relationship was observed when X irradiation was given on Day 11 after implantation, with the disc removed on Day 20. A single dose of <em>15</em> Gy reduced both the rate of incorporation of [3H]TdR and the total <em>growth</em> area. These and previous observations point to endothelial cells as important targets of ionizing radiation in the stroma, especially during the period of active proliferation of these cells, induced by <em>growth</em> <em>factors</em>.

BACKGROUND

Malignant tumors of the testis are among the most common cancers in men between the ages of <em>15</em> and 30 years. The sensitivity of detection of known tumor markers depends upon the tumor histology and stage. In other cancers, increased serum concentrations of various angiogenic <em>growth</em> <em>factors</em> have been described as potential markers for tumor progression and metastasis. One main histological feature of testicular cancer is profound angiogenesis.

METHODS

In this study, we investigated by sensitive enzyme-linked immunosorbent assays (ELISAs) the levels of various growth and angiogenesis factors in the serum of testicular cancer patients as compared with normal control subjects. For the most profoundly increased growth factors, pleiotrophin (PTN) and fibroblast growth factor-2 (FGF-2), we furthermore analyzed tumor lysates by northern blotting, RT-PCR and ELISA.

RESULTS

We demonstrate a marked elevation of average serum levels of PTN ( approximately 20-fold) and of FGF-2 ( approximately 7-fold) in patients and expression of both growth factors in tumor biopsies. To a lesser extent, vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) serum levels were increased, whereas FGF-4 and transforming growth factor-beta levels were similar to those in normal control subjects. Elevation of PTN, FGF-2, EGF and VEGF was detected in seminomatous as well as non-seminatous tumors, and even in early stages.

CONCLUSIONS

PTN and FGF-2 may represent promising new diagnostic markers for testicular cancer with high sensitivity even in early-stage testicular cancer. Further studies are warranted to extend our analyses.

Inflammation enables human cancers and is a critical promoter of hepatocellular carcinoma (HCC). TIMP3 (Tissue inhibitor of metalloproteinase 3), a natural metalloproteinase inhibitor, controls cytokine and <em>growth</em> <em>factor</em> bioavailability to keep inflammation in check and regulate cell survival in the liver. TIMP3 is also found silenced in human cancers. We therefore tested whether Timp3 affects HCC predisposition. Remarkably, genetic loss of Timp3 protected from carcinogen-induced HCC through the immediate engagement of several tumor suppressor pathways, while tumor necrosis <em>factor</em> (TNF) signaling was dispensable for this protection. All wild-type mice developed HCC by 12 months, whereas HCC incidence was reduced to 33% at 12 months and 57% at <em>15</em> months in Timp3 null mice. Upon acute carcinogen treatment the deficient livers exhibited greater cytokine expression, but lower cell death and higher hepatocyte senescence. We found that precocious activation of p53, p38 and Notch preceded senescence and hepatic cell differentiation, and these events were conserved throughout tumorigenesis. Timp3-deficient mouse embryo <em>fibroblasts</em> also responded to carcinogen by favoring senescence over apoptosis. We conclude that Timp3 status determines p53, p38 and Notch coactivation to instruct hepatic cell fate and transformation and uncover mechanisms that are protective even within a pro-inflammatory microenvironment.

In chronic inflammatory conditions, mononuclear cells infiltrate the connective tissue attracted by <em>fibroblast</em>-secreted chemokines. The role of <em>fibroblasts</em> in sustaining the lymphocyte immune response upon cellular infiltration is so far unresolved. We here report that, upon prolonged stimulation with tumor necrosis <em>factor</em>-alpha, dermal <em>fibroblasts</em> enhance proliferation of activated T cells whereas unstimulated <em>fibroblasts</em> do not. T cell <em>growth</em> stimulation requires cell contact of tumor necrosis <em>factor</em>-alpha stimulated <em>fibroblasts</em> to T cells and is not due to soluble <em>factors</em>. <em>Growth</em> stimulation is substantially blocked by neutralizing antibodies to interleukin-<em>15</em>. Fluorescence-activated cell sorter analyses revealed that tumor necrosis <em>factor</em> alpha stimulated <em>fibroblasts</em> expose interleukin-<em>15</em> in a membrane-bound form on the cell surface whereas nonstimulated <em>fibroblasts</em> and interferon-gamma treated <em>fibroblasts</em> do not. The amount of membrane interleukin-<em>15</em> increases with the duration of tumor necrosis <em>factor</em>-alpha stimulation for at least 3 d. Unstimulated <em>fibroblasts</em>, however, accumulate interleukin-<em>15</em> in the cytoplasm. No interleukin-<em>15</em> could be detected in the culture supernatant. Immunohistochemical analyses confirmed membrane interleukin-<em>15</em> on dermal <em>fibroblasts</em> in discoid lupus erythematosus skin lesions whereas no membrane interleukin-<em>15</em> was found on the surface of <em>fibroblasts</em> in healthy skin. We conclude that dermal <em>fibroblasts</em> upon long-term tumor necrosis <em>factor</em>-alpha stimulation during chronic inflammation are involved via membrane-bound interleukin-<em>15</em> in stimulating proliferation of accumulated, activated T cells.

OBJECTIVE

To evaluate the inflammatory status and the cartilage regenerative potential of pathological synovial fibroblasts from patients with osteoarthritis (OA) compared with non-inflamed synovium (NS)-derived cells from patients with chondropathy.

METHODS

The inflammatory cell phenotype was investigated based on the constitutive and inducible surface expression and secretion of various effector molecules using flow cytometry or ELISA assays. The capacity of cells to produce cartilage-like extracellular matrix was assessed using acid Alcian blue staining and type II collagen immunostaining after treatment with transforming growth factor beta1 (TGF-beta1).

RESULTS

OA and NS fibroblasts consistently expressed CD29, CD44, CD49e, CD54, CD90 and CD106. Expression of high-affinity receptors for IL-4, IL-15, CXCL8 and CXCL12 was also detected but only intracellularly. All types of fibroblasts spontaneously released abundant amounts of CXCL12, CCL2, IL-6 and tissue inhibitor of metalloproteinase 1, while the production of IL-11, TGF-beta1, matrix metalloproteinase 1 (MMP-1) and MMP-9 was detected at moderate levels. Several other secreted factors remained undetectable. No statistically significant differences were noted between the two groups of fibroblasts. Treatment with the proinflammatory cytokine tumour necrosis factor alpha (TNF-alpha) up-regulated the same set of surface and secreted molecules, including CD54, CD106, membrane IL-15, CCL2 and CCL5. Under TGF-beta1 treatment and adipogenic culture conditions, both OA and NS fibroblasts displayed chondrogenic and adipocytic activities that were reduced in OA compared with NS cells.

CONCLUSIONS

OA synovial fibroblasts did not display a distinct activated inflammatory phenotype compared with NS cells. However, they did differ in their reduced ability to produce cartilage-like matrix. This difference may be an additional important factor contributing to OA pathogenesis.

It was determined whether the expression level of several genes that regulate different steps of metastasis in formalin-fixed paraffin-embedded archival specimens of human gastric cancers correlated with disease recurrence and metastasis. The steady-state mRNA expression level for epidermal <em>growth</em> <em>factor</em> receptor (EGF-R), basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF), E-cadherin, type IV collagenase and multidrug resistance (MDR-1) were examined by a colorimetric in situ hybridisation (ISH) technique, concentrating on reactivity at the periphery of the lesions. All patients were operated on for cure. <em>15</em> cases were disease-free and 10 had disease recurrence by 4.5 years after resection of the primary tumours. The expression of EGF-R and bFGF type IV collagenase was higher and expression of E-cadherin was lower in the disease-recurrence cases than in the disease-free cases. The ratio between the expression level of collagenase type IV and E-cadherin at the periphery of the surgical specimens differed significantly between the disease-free cases and the recurrent-metastatic cases. These data show that multiparametric ISH analysis for several metastasis-related genes may allow prediction of disease recurrence of gastric cancer.

BACKGROUND

Von Hippel Lindau disease (VHL) is a rare autosomal dominant inherited disorder characterized by highly vascularized tumors in various organs. The abundant presence of endothelial cells in VHL tumors strongly suggest a role of the VHL tumor suppressor gene in the regulation of angiogenesis. Recently, in vitro studies have shown that the VHL tumor suppressor gene regulates the expression of vascular endothelial growth factor (VEGF). We investigated whether VHL patiens have increased levels of VEGF in their body fluids.

METHODS

The concentration of VEGF was measured in fluid of the anterior chamber of the eye, serum, urine, and fluid from renal cysts of VHL patients and unaffected individuals by ELISA. In addition, levels of basic fibroblast growth factor (bFGF), interleukin-8 (IL-8) and endothelin-1 (ET-1) were measured in urine and serum of VHL patients and control subjects.

RESULTS

In 80% of the VHL patients VEGF was detectable in aqueous fluid of the anterior chamber of their eyes. A strong positive correlation (r = 0.90) was found between the age of VHL patients and ocular VEGF concentrations. At comparable age, VEGF levels in ocular fluid of VHL patients were significantly higher (P < 0.001) than in unaffected subjects. No correlation was found between VEGF concentration and the presence of retinal angiomas. A 10 and 16 fold increase of VEGF concentration was seen in fluid from two independent VHL-related cysts as compared with VEGF serum levels of the same patient. The mean concentration of VEGF in serum of VHL patients (n = 15) (319 +/- 84 pg/ml) was higher than in matched controls (238 +/- 68 pg/ml; P = NS). The mean concentration of VEGF in urine of VHL patients (128 +/- 36 pg/ml) was lower than in matched controls (183 +/- 25 pg/ml; P = NS). Concentrations of VEGF did not correlate with the presence of VHL-related tumors. No differences were observed between concentrations of bFGF, IL-8 and ET-1 in serum and urine of VHL patients and matched controls.

CONCLUSIONS

These findings support a role for the VHL tumor suppressor gene in the in vivo regulation of VEGF.

BACKGROUND

Small-cell lung cancer (SCLC) accounts for <em>15</em>% of all lung cancers and has been understudied for novel therapies. Signaling through <em>fibroblast</em> <em>growth</em> <em>factors</em> (FGF2, FGF9) and their high-affinity receptor has recently emerged as a contributing <em>factor</em> in the pathogenesis and progression of non-small-cell lung cancer. In this study, we evaluated <em>fibroblast</em> <em>growth</em> <em>factor</em> receptor 1 (FGFR1) and ligand expression in primary SCLC samples.

METHODS

FGFR1 protein expression, messenger RNA (mRNA) levels, and gene copy number were determined by immunohistochemistry (IHC), mRNA in situ hybridization, and silver in situ hybridization, respectively, in primary tumors from 90 patients with SCLC. Protein and mRNA expression of the FGF2 and FGF9 ligands were determined by IHC and mRNA in situ hybridization, respectively. In addition, a second cohort of 24 SCLC biopsy samples with known FGFR1 amplification by fluorescence in situ hybridization was assessed for FGFR1 protein expression by IHC. Spearman correlation analysis was performed to evaluate associations of FGFR1, FGF2 and FGF9 protein levels, respective mRNA levels, and FGFR1 gene copy number.

RESULTS

FGFR1 protein expression by IHC demonstrated a significant correlation with FGFR1 mRNA levels (p < 0.0001) and FGFR1 gene copy number (p = 0.03). The prevalence of FGFR1 mRNA positivity was 19.7%. FGFR1 mRNA expression correlated with both FGF2 (p = 0.0001) and FGF9 (p = 0.002) mRNA levels, as well as with FGF2 (p = 0.01) and FGF9 (p = 0.001) protein levels. There was no significant association between FGFR1 and ligands with clinical characteristics or prognosis. In the second cohort of specimens with known FGFR1 amplification by fluorescence in situ hybridization, 23 of 24 had adequate tumor by IHC, and 73.9% (17 of 23) were positive for FGFR1 protein expression.

CONCLUSIONS

A subset of SCLCs is characterized by potentially activated FGF/FGFR1 pathways, as evidenced by positive FGF2, FGF9, and FGFR1 protein and/or mRNA expression. FGFR1 protein expression is correlated with FGFR1 mRNA levels and FGFR1 gene copy number. Combined analysis of FGFR1 and ligand expression may allow selection of patients with SCLC to FGFR1 inhibitor therapy.

Basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF) is a potent mitogen and angiogenic <em>factor</em>. bFGF is expressed by a variety of solid human tumors and has been implicated as an autocrine regulator of tumor <em>growth</em>. Different solid tumor lines including glioma, colon carcinoma and melanoma were examined for intracellular immunoreactive bFGF, high- and low-affinity bFGF receptors and mitogenic response to bFGF when grown in chemically defined medium. All tumor lines contained significant levels of bFGF. In addition, all tumor lines contained subsets of five forms of immunoreactive bFGF, as well as 0.68-20 x 10(6) low affinity bFGF binding sites (Kd = <em>15</em>-300 nM). Most, but not all lines exhibited high affinity bFGF receptors (Kd = 25-40 pM). Glioma cell lines were distinguished by expressing the highest levels of bFGF protein as well as the most high-affinity receptors for bFGF. Furthermore, glioma cell lines were the only tumor type mitogenically responsive to bFGF. These results indicate that glioma cells express high levels of this potent mitogen and angiogenic <em>factor</em> relative to human colon carcinoma and melanoma cells. The expression of bFGF and bFGF receptors by glioma cells may be related to abnormal <em>growth</em> and neoplastic progression in these tumors.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> (FGF) has been purified 333,000-fold from human placenta by a combination of salt precipitation, cation-exchange chromatography, and Heparin-Sepharose affinity chromatography. Molecular weight (<em>15</em>-16 kDaltons), amino acid composition, bioactivity and immunological crossreactivity with bovine pituitary FGF indicate that the mitogens from the two species are closely related molecules.

Delays in wound healing often result in infection, chronic ulceration, and possible amputation of extremities. Impaired wound healing is a major complication of the 23 million people in the USA with diabetes, and financial and medical burdens are demanding new treatments for wound healing. Previous studies have demonstrated that topical application of the opioid antagonist naltrexone (NTX) dissolved in moisturizing cream reverses delays in wound closure in rats with streptozotocin-induced type 1 diabetes. A target of NTX's action is DNA synthesis and cell proliferation. In this study, granulation tissue was evaluated to ascertain the specific cellular targets that were impaired in diabetic wounds, as well as those that were enhanced following NTX application. Mast cell number as well as the number of new blood vessels immunoreactive to <em>fibroblast</em> <em>growth</em> <em>factor</em>-2 (FGF-2), vascular endothelial <em>growth</em> <em>factor</em> (VEGF), and alpha smooth muscle actin (α-SMA) antibodies were recorded at 3, 5, 8, 10, <em>15</em>, and 20 days following creation of full-thickness dorsal cutaneous wounds in normal and type 1 diabetic rats. Diabetic rats displayed delays in wound closure as well as a reduction in the number of mast cells responding to the injury, and delays in the spatial and temporal expression of FGF-2, VEGF, and α-SMA in capillaries. Topical NTX accelerated the rate of wound closure and stimulated expression of angiogenic <em>factors</em> within granulation tissue of diabetic rats relative to control animals receiving saline in moisturizing cream. These data support observations that a novel biological pathway is impaired under diabetic conditions and can be modulated by topical NTX to enhance proliferative events in wound healing.

The aim of this study was to evaluate the effect of silk sericin, a protein from silkworm cocoon, on scratch wound healing in vitro. For applicable result in clinical use, we also study the efficacy of sericin added to a standard antimicrobial cream, silver zinc sulfadiazine, for open wound care in the treatment of second-degree burn wounds. In vitro scratch assays show that sericin at concentration 100 μg/mL can promote the migration of <em>fibroblast</em> L929 cells similar to epidermal <em>growth</em> <em>factor</em> (positive control) at 100 μg/mL. After 1 day of treatment, the length of scratch in wounds treated with sericin was significantly shorter than the length of negative control wounds (culture medium without sericin). For clinical study, a total of 29 patients with 65 burn wounds which covered no less than <em>15</em> % of total body surface area were randomly assigned to either control (wounds treated with silver zinc sulfadiazine cream) or treatment (wounds treated with silver zinc sulfadiazine with added sericin cream) group in this randomized, double-blind, standard-controlled study. The results showed that the average time to reach 70 % re-epithelialization of the burned surface and complete healing in the treatment group was significantly shorter, approximately 5-7 days, than in the control group. Regarding time for complete healing, control wounds took approximately 29.28 ± 9.27 days, while wounds treated with silver zinc sulfadiazine with added sericin cream took approximately 22.42 ± 6.33 days, (p = 0.001). No infection or severe reaction was found in any wounds. This is the first clinical study to show that silk sericin is safe and beneficial for burn wound treatment when it is added to silver sulfadiazine cream.

The regulation of cell function by <em>fibroblast</em> <em>growth</em> <em>factors</em> (FGFs) classically occurs through a dual receptor system of a tyrosine kinase receptor (FGFR) and a heparan sulfate proteoglycan co-receptor. Mutations in some consensus N-glycosylation sites in human FGFR result in skeletal disorders and craniosynostosis syndromes, and biophysical studies in vitro suggest that N-glycosylation of FGFR alters ligand and heparan sulfate binding properties. The evolutionarily conserved FGFR signaling system of Caenorhabditis elegans has been used to assess the role of N-glycosylation in the regulation of FGFR signaling in vivo. The C. elegans FGF receptor, EGL-<em>15</em>, is N-glycosylated in vivo, and genetic substitution of specific consensus N-glycosylation sites leads to defects in the maintenance of fluid homeostasis and differentiation of sex muscles, both of which are phenotypes previously associated with hyperactive EGL-<em>15</em> signaling. These phenotypes are suppressed by hypoactive mutations in EGL-<em>15</em> downstream signaling components or activating mutations in the phosphatidylinositol 3-kinase pathway, respectively. The results show that N-glycans negatively regulate FGFR activity in vivo supporting the notion that mutation of N-glycosylation sites in human FGFR may lead to inappropriate activation of the receptor.

Mouse oocytes produce members of the transforming <em>growth</em> <em>factor</em> beta (TGFbeta) superfamily, including bone morphogenetic protein <em>15</em> (BMP<em>15</em>) and <em>growth</em> differentiation <em>factor</em> 9 (GDF9), as well as <em>fibroblast</em> <em>growth</em> <em>factors</em> (FGFs). These <em>growth</em> <em>factors</em> cooperate to regulate cumulus cell function. To identify potential mechanisms involved in these interactions, the ability of fully grown oocytes to regulate expression of BMP or FGF antagonists in cumulus cells was examined. Oocytes promoted cumulus cell expression of transcripts encoding antagonists to TGFbeta superfamily members, including Grem2, Htra1, Htra3, and Nog mRNAs. In contrast, oocytes suppressed cumulus cell expression of Spry2 mRNA, which encodes a regulator of receptor tyrosine kinase signals, such as FGF and epidermal <em>growth</em> <em>factor</em> (EGF) receptor signals. The regulation of Spry2 mRNA levels in cumulus cells was studied further as a model for analysis of potential mechanisms for cooperativity of FGF/EGF signaling with oocyte-derived members of the TGFbeta superfamily. Oocytes suppressed basal and FGF-stimulated Spry2 mRNA levels in cumulus cells but promoted EGF-stimulated levels. Furthermore, recombinant TGFbeta superfamily proteins, including BMP<em>15</em> and GDF9, mimicked these effects of oocytes. Elevated expression of Spry2 mRNA in cumulus and mural granulosa cells correlated with human chorionic gonadotropin-induced expression of mRNAs encoding EGF-like peptides. Therefore, oocyte-derived members of the TGFbeta superfamily suppress FGF-stimulated Spry2 mRNA levels before the luteinizing hormone surge but promote Spry2 mRNA levels stimulated by EGF receptor-mediated signals after the surge.

Polymerase chain reaction analysis revealed an mRNA in rat prostate that results from alternate splicing of exon 16 in the heparin-binding <em>fibroblast</em> <em>growth</em> <em>factor</em> receptor kinase type 2 gene (FGFR2). The absence of exon 16 and the shift in reading frame at the exon <em>15</em>-17 junction predicts an expression product (FGFR2-2) with a unique COOH-terminus that does not exhibit the major autophosphorylation site (tyrosine 789) required for interaction of phospholipase C gamma 1 with the full-length FGFR2-1 isoform. Nuclease protection analysis revealed that the FGFR-2 splice variant is expressed in quantities equal to or greater than the FGFR2-1 isoform in normal prostate tissue. When combined with the same FGFR2 extracellular domain, co-expression of the two COOH-terminal variants may mediate effect of the same FGF ligand on different signal transduction pathways.

In this study, we assessed the changes and prognostic relevance of syndecan-1 (SDC1) tissue and serum levels in bladder cancer (BC). SDC1 levels were analyzed in 213 samples (119 paraffin-embedded and 79 serum samples of BC patients and <em>15</em> controls) using immunohistochemistry and enzyme-linked immunosorbent assay. Results were correlated with clinicopathological characteristics and follow-up data, as well as previously determined serum levels of angiogenic <em>factors</em> (basic <em>fibroblast</em> <em>growth</em> <em>factor</em>, endostatin, angiostatin, angiopoietin, vascular endothelial <em>growth</em> <em>factor</em>, Tie2 and MMP-7). SDC1 staining was present in the cell membrane of normal bladder epithelium and non-muscle-invasive BC cells but was absent in a significant proportion of muscle-invasive carcinomas (P < .001). In contrast, stromal SDC1 expression was enhanced in muscle-invasive compared to non-muscle-invasive BCs (P = .001). Serum concentrations of the SDC1 ectodomain were higher in muscle-invasive BCs compared to controls or non-muscle-invasive carcinomas (P < .001 each). Lymph node-positive cases had the highest SDC1 serum concentrations (P < .001). SDC1 expression in stromal cells was independently associated with survival (hazard ratio = 2.034, 95% confidence interval 1.176-3.519, P = .011). SDC1 serum concentrations correlated with those of endostatin and matrix metalloproteinase 7. Loss of SDC1 in tumor cells and the parallel increase of serum SDC1 ectodomain concentration in high-stage, high-grade BCs suggest the involvement of SDC1 shedding in BC progression. In addition, high preoperative SDC1 serum levels may help to identify patients with lymph node metastases, supporting therapeutic decision-making. Presence of SDC1 in tumor stroma is an independent risk <em>factor</em> for patient survival and may therefore be used to select patients for more aggressive therapy.

In an attempt to improve the resistance of seeded endothelial cell (EC) to desquamation due to shear stress, we evaluated the effect of coating expanded polytetrafluoroethylene (ePTFE) grafts with fibrin glue (FG) containing <em>fibroblast</em> <em>growth</em> <em>factor</em> 1 (FGF1) and heparin on the retention of EC exposed to pulsatile flow ex vivo. Five pairs of ePTFE grafts (30 microm internodal distance, 4 mm internal diameter, 7 cm long) were coated with either FG/FGF-1/heparin (fibrinogen 32.1 mg/ml, thrombin 0.32 U/ml, FGF-1 11 ng/ml, heparin 250 U/ml) or fibronectin (FN) (20 microgram/ml). Canine jugular vein endothelial cells (<em>Factor</em> VIII, passages 5-7), were radiolabeled with indium-111 (100 microCi/1 million cells). Cell seeding (3 x 10(5) cells/cm2) was achieved by four successive inoculations of cells separated by 90 degree graft rotations. After overnight incubation (37 degrees C), pairs of FG and FN grafts (5 cm long) were simultaneously perfused ex vivo with culture media containing 10% fetal bovine serum (120/80 mm Hg, 90 cc/min, 60 pulsations/min). During the 1-hr perfusion, perfusate samples were taken at 0, 5, <em>15</em>, 30, and 60 min to determine radioactivity loss. Pre- and postperfusion whole graft radioactivity data were compared to estimate cell retention and confirmed by histologic evaluation. Mean adherent radioactivity on FG-coated grafts (96 +/- 5%) was significantly higher (P = 0.0029, Student's t test) than on FN-coated grafts (85 +/- 3%). Maximum radioactivity loss in perfusate was seen after 5 min, with lower sustained loss thereafter. The improved retention of seeded EC on ePTFE grafts coated with FG containing FGF-1 and heparin compared to FN will need to be confirmed for longer durations of perfusion and using in vivo models.

Mesenchymal stem cells (MSCs) are multipotent cells that differentiate into a variety of lineages including myocytes and vascular endothelial cells. However, little information is available regarding the therapeutic potential of MSCs in patients with atrioventricular block (AVB). We investigated whether local implantation of MSCs improves AV conduction in a rat model of complete AVB. Complete AVB was achieved by injection of ethanol into the AV nodal region of Lewis rats. Five days after ethanol injection, 2 x 10(6) of MSCs (MSC group) or vehicle (Control group) were injected into the AV nodal region. Animals were monitored by electrocardiograms for 14 days, and physiological and histological examinations were performed. The 1:1 AV conduction was recovered in 5 of <em>15</em> rats (33%) in the MSC group during the followup period, whereas no improvement was observed in the control group. MSC transplantation significantly decreased collagen deposition in the AV node, which was associated with a marked decrease in transforming <em>growth</em> <em>factor</em>-beta1 expression. In vitro experiments demonstrated that MSCs secreted a large amount of antifibrotic <em>factors</em> such as hepatocyte <em>growth</em> <em>factor</em> and interleukin-10, and MSC conditioned medium inhibited the <em>growth</em> of adult cardiac <em>fibroblasts</em>. In addition, local injection of MSC conditioned medium recovered AV conduction in 2 of <em>15</em> rats (13%). MSC transplantation improved AV conduction in a rat model of complete AVB, at least in part through antifibrotic paracrine effects.

BACKGROUND

A subset of follicular lesions of the thyroid is encapsulated similar to follicular adenomas but with partial nuclear features suggestive of papillary thyroid carcinoma (PTC), raising the possibility of biologically borderline tumors.

METHODS

Gene expression profiling and advanced significance analyses were performed on 50 histologically unequivocal benign and malignant tumors, and a list of 61 differentially expressed genes was generated. By using this 61-gene list, unsupervised hierarchical and K-means cluster analyses were performed on 40 additional tumors, including <em>15</em> histologically borderline tumors, 11 benign tumors, and 14 PTCs.

RESULTS

Analysis revealed 3 distinct tumor groups-benign, malignant, and intermediate. Tumors in the intermediate group (n = <em>15</em>) were mostly histologic borderline tumors and had an expression profile overlapping with the benign and malignant groups. Twenty-seven genes were expressed differentially between the benign and intermediate groups, including the cyclic AMP response element-binding protein/p300-interactivator with glutamic acid/aspartic acid-rich carboxy-terminal domain 1 or CITED1 gene and the fibroblast growth factor receptor 2 or FGFR2 gene. Fourteen genes were expressed differentially between the intermediate group and malignant tumors, notably overexpression of the met proto-oncogene and of the high-mobility group adenine/thymine-hook 2 or HMGA2 gene in malignancies. Mutations of the v-raf murine sarcoma viral oncogene homolog B1 or BRAF gene were identified in 4 of 14 malignant tumors but not in benign or intermediate tumors. Patients who had either histologically or molecularly borderline tumors did not have metastasis or recurrences.

CONCLUSIONS

Gene expression profiling supported the finding that encapsulated thyroid follicular lesions with partial nuclear features of PTC are biologically borderline tumors that are distinct molecularly from benign and malignant tumors.

By screening cDNA expression libraries derived from fresh leukemic cells of adult T-cell leukemia for the potential to transform murine <em>fibroblasts</em>, NIH3T3, we have identified a novel transforming gene, designated Tgat. Expression of Tgat in NIH3T3 resulted in the loss of contact inhibition, increase of saturation density, anchorage-independent <em>growth</em> in a semisolid medium, tumorigenicity in nude mice, and increased invasiveness. Sequence comparison revealed that an alternative RNA splicing of the Trio gene was involved in the generation of Tgat. The Tgat cDNA encoded a protein product consisting of the Rho-guanosine nucleotide exchange <em>factor</em> (GEF) domain of a multifunctional protein, TRIO, and a unique C-terminal <em>15</em>-amino acid sequence, which were derived from the exons 38-46 of the Trio gene and a novel exon located downstream of its last exon (exon 58), respectively. A Tgat mutant cDNA lacking the C-terminal coding region preserved Rho-GEF activity but lost the transforming potential, indicating an indispensable role of the unique sequence. On the other hand, treatment of Tgat-transformed NIH3T3 cells with Y-27632, a pharmacological inhibitor of Rho-associated kinase, abrogated their transforming phenotypes, suggesting the coinvolvement of Rho-GEF activity. Thus, alternative RNA splicing, resulting in the fusion protein with the Rho-GEF domain and the unique <em>15</em> amino acids, is the mechanism generating the novel oncogene, Tgat.