The liver and intestine play crucial roles in maintaining bile acid homeostasis. Here, we demonstrate that <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>15</em> (FGF<em>15</em>) signals from intestine to liver to repress the gene encoding cholesterol 7alpha-hydroxylase (CYP7A1), which catalyzes the first and rate-limiting step in the classical bile acid synthetic pathway. FGF<em>15</em> expression is stimulated in the small intestine by the nuclear bile acid receptor FXR and represses Cyp7a1 in liver through a mechanism that involves FGF receptor 4 (FGFR4) and the orphan nuclear receptor SHP. Mice lacking FGF<em>15</em> have increased hepatic CYP7A1 mRNA and protein levels and corresponding increases in CYP7A1 enzyme activity and fecal bile acid excretion. These studies define FGF<em>15</em> and FGFR4 as components of a gut-liver signaling pathway that synergizes with SHP to regulate bile acid synthesis.

Bile acids are synthesized from cholesterol in the liver and further metabolized by the gut microbiota into secondary bile acids. Bile acid synthesis is under negative feedback control through activation of the nuclear receptor farnesoid X receptor (FXR) in the ileum and liver. Here we profiled the bile acid composition throughout the enterohepatic system in germ-free (GF) and conventionally raised (CONV-R) mice. We confirmed a dramatic reduction in muricholic acid, but not cholic acid, levels in CONV-R mice. Rederivation of Fxr-deficient mice as GF demonstrated that the gut microbiota regulated expression of <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>15</em> in the ileum and cholesterol 7α-hydroxylase (CYP7A1) in the liver by FXR-dependent mechanisms. Importantly, we identified tauro-conjugated beta- and alpha-muricholic acids as FXR antagonists. These studies suggest that the gut microbiota not only regulates secondary bile acid metabolism but also inhibits bile acid synthesis in the liver by alleviating FXR inhibition in the ileum.

Bile acids are physiological detergents that generate bile flow and facilitate intestinal absorption and transport of lipids, nutrients, and vitamins. Bile acids also are signaling molecules and inflammatory agents that rapidly activate nuclear receptors and cell signaling pathways that regulate lipid, glucose, and energy metabolism. The enterohepatic circulation of bile acids exerts important physiological functions not only in feedback inhibition of bile acid synthesis but also in control of whole-body lipid homeostasis. In the liver, bile acids activate a nuclear receptor, farnesoid X receptor (FXR), that induces an atypical nuclear receptor small heterodimer partner, which subsequently inhibits nuclear receptors, liver-related homolog-1, and hepatocyte nuclear <em>factor</em> 4alpha and results in inhibiting transcription of the critical regulatory gene in bile acid synthesis, cholesterol 7alpha-hydroxylase (CYP7A1). In the intestine, FXR induces an intestinal hormone, <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>15</em> (FGF<em>15</em>; or FGF19 in human), which activates hepatic FGF receptor 4 (FGFR4) signaling to inhibit bile acid synthesis. However, the mechanism by which FXR/FGF19/FGFR4 signaling inhibits CYP7A1 remains unknown. Bile acids are able to induce FGF19 in human hepatocytes, and the FGF19 autocrine pathway may exist in the human livers. Bile acids and bile acid receptors are therapeutic targets for development of drugs for treatment of cholestatic liver diseases, fatty liver diseases, diabetes, obesity, and metabolic syndrome.

Dendritic cells, the professional antigen-presenting cells (APC) involved in T cell priming, express CD40, a molecule which triggering plays a key role in B cell <em>growth</em> and differentiation as well as monocyte activation. Herein we demonstrate that dendritic Langerhans cells (D-Lc) generated by culturing cord blood CD34+ progenitor cells with granulocyte/macrophage colony-stimulating and tumor necrosis <em>factor</em> alpha (TNF-alpha) express functional CD40 at a density higher than that found on B cells. Culturing D-Lc on CD40-ligand (CD40L) transfected L cells allowed D-Lc survival as 50 +/- <em>15</em>% of seeded cells were recovered after 4 d while only 5% survived over control L cells. CD40 activation induced important morphological changes with a reduction of cytoplasmic content and a remarkable increase of dendrite development as well as an altered phenotype. In particular, CD40 triggering induced maintenance of high levels of major histocompatibility complex class II antigens and upregulation of accessory molecules such as CD58, CD80 (B7-1) and CD86 (B7-2). CD40 engagement also seems to turn on D-Lc maturation as illustrated by upregulation of CD25, a molecule usually expressed on interdigitating dendritic cells of secondary lymphoid organs. Finally, CD40 activated D-Lc secreted a limited set of cytokines (TNF-alpha, IL-8, and macrophage inflammatory protein 1 alpha [MIP-1 alpha]) whereas a similar activation induced elutriated monocytes to secrete IL-1 alpha, IL-1 beta, IL-6, IL-8, IL-10, TNF-alpha, and MIP-1 alpha. As D-Lc activated T cells upregulated CD40L, it is likely that CD40 activation of D-Lc observed herein with a <em>fibroblast</em> cell line stably expressing CD40L, mimics physiological interactions between dendritic cells and T cells.

OBJECTIVE

To compare selected immunohistological features of inflammation in synovial tissue from patients with early and late osteoarthritis (OA).

METHODS

Synovial tissue samples were obtained from 10 patients with knee pain, normal radiographs, and arthroscopic manifestations of OA (early OA), and from <em>15</em> patients with OA undergoing knee joint arthroplasty (late OA). Conventional immunohistochemical techniques were used to measure microscopic manifestations of inflammation. The inflammatory cell infiltrate, blood vessel formation, and angiogenic <em>factors</em>, NF-kappaB activation, expression of tumour necrosis <em>factor</em> alpha (TNFalpha) and interleukin 1beta (IL1beta), and the presence of cyclo-oxygenase (COX)-1 and COX-2 were quantified. <em>Fibroblast</em>-like synoviocytes (FLS) were isolated from early and late OA tissue samples to compare in vitro production of prostaglandin E2 (PGE2)

RESULTS

Synovial tissue from patients with early OA demonstrated significantly greater CD4+ (p = 0.017) and CD68+ (p<0.001) cell infiltration, blood vessel formation (p = 0.01), vascular endothelial growth <em>factor</em> (p = 0.001), and intercellular adhesion molecule-1 expression (p<0.001). Numbers of cells producing TNFalpha and IL1beta were also significantly greater in early OA (p<0.001). Manifestations of inflammation in early OA were associated with increased expression of the NF-kappaB1 (p<0.001) and RelA (p = 0.0<em>15</em>) subunits, and with increased COX-2 expression (p = 0.04). Cytokine-induced PGE2 production by cultured FLS was similar in both groups.

CONCLUSIONS

Increased mononuclear cell infiltration and overexpression of mediators of inflammation were seen in early OA, compared with late OA. Isolated FLS were functionally similar in both groups, consistent with microenvironmental differences in the synovial tissue during different phases of OA. These observations may have important therapeutic implications for some patients during the early evolution of OA.

Achondroplasia (ACH) is the most common genetic form of dwarfism. This disorder is inherited as an autosomal dominant trait, although the majority of cases are sporadic. A gene for ACH was recently localized to 4p16.3 by linkage analyses. The ACH candidate region includes the gene encoding <em>fibroblast</em> <em>growth</em> <em>factor</em> receptor 3 (FGFR3), which was originally considered as a candidate for the Huntington's disease gene. DNA studies revealed point mutations in the FGFR3 gene in ACH heterozygotes and homozygotes. The mutation on <em>15</em> of the 16 ACH-affected chromosomes was the same, a G->>A transition, at nucleotide 1138 of the cDNA. The mutation on the only ACH-affected chromosome 4 without the G->>A transition at nucleotide 1138 had a G->>C transversion at this same position. Both mutations result in the substitution of an arginine residue for a glycine at position 380 of the mature protein, which is in the transmembrane domain of FGFR3.

OBJECTIVE

Glioblastoma is an incurable solid tumor characterized by increased expression of vascular endothelial growth factor (VEGF). We performed a phase II study of cediranib in patients with recurrent glioblastoma.

METHODS

Cediranib, an oral pan-VEGF receptor tyrosine kinase inhibitor, was administered (45 mg/d) until progression or unacceptable toxicity to patients with recurrent glioblastoma. The primary end point was the proportion of patients alive and progression free at 6 months (APF6). We performed magnetic resonance imaging (MRI) and plasma and urinary biomarker evaluations at multiple time points.

RESULTS

Thirty-one patients with recurrent glioblastoma were accrued. APF6 after cediranib was 25.8%. Radiographic partial responses were observed by MRI in 17 (56.7%) of 30 evaluable patients using three-dimensional measurements and in eight (27%) of 30 evaluable patients using two-dimensional measurements. For the 15 patients who entered the study taking corticosteroids, the dose was reduced (n = 10) or discontinued (n = 5). Toxicities were manageable. Grade 3/4 toxicities included hypertension (four of 31; 12.9%); diarrhea (two of 31; 6.4%); and fatigue (six of 31; 19.4%). Fifteen (48.4%) of 31 patients required at least one dose reduction and 15 patients required temporary drug interruptions due to toxicity. Drug interruptions were not associated with outcome. Changes in plasma placental growth factor, basic fibroblast growth factor, matrix metalloproteinase (MMP) -2, soluble VEGF receptor 1, stromal cell-derived factor-1alpha, and soluble Tek/Tie2 receptor and in urinary MMP-9/neutrophil gelatinase-associated lipocalin activity after cediranib were associated with radiographic response or survival.

CONCLUSIONS

Cediranib monotherapy for recurrent glioblastoma is associated with encouraging proportions of radiographic response, 6-month progression-free survival, and a steroid-sparing effect with manageable toxicity. We identified early changes in circulating molecules as potential biomarkers of response to cediranib. The efficacy of cediranib and the predictive value of these candidate biomarkers will be explored in prospective trials.

Cellular senescence, a stress induced <em>growth</em> arrest of somatic cells, was first documented in cell cultures over 40 years ago, however its physiological significance has only recently been demonstrated. Using novel biomarkers of cellular senescence we examined whether senescent cells accumulate in tissues from baboons of ages encompassing the entire lifespan of this species. We show that dermal <em>fibroblasts</em>, displaying markers of senescence such as telomere damage, active checkpoint kinase ATM, high levels of heterochromatin proteins and elevated levels of p16, accumulate in skin biopsies from baboons with advancing age. The number of dermal <em>fibroblasts</em> containing damaged telomeres reaches a value of over <em>15</em>% of total <em>fibroblasts</em>, whereas 80% of cells contain high levels of the heterochromatin protein HIRA. In skeletal muscle, a postmitotic tissue, only a small percentage of myonuclei containing damaged telomeres were detected regardless of animal age. The presence of senescent cells in mitotic tissues might therefore be a contributing <em>factor</em> to aging and age related pathology and provides further evidence that cellular senescence is a physiological event.

OBJECTIVE

Brivanib is a dual inhibitor of vascular-endothelial growth factor and fibroblast growth factor receptors that are implicated in the pathogenesis of hepatocellular carcinoma (HCC). Our multinational, randomized, double-blind, phase III trial compared brivanib with sorafenib as first-line treatment for HCC.

METHODS

Advanced HCC patients who had no prior systemic therapy were randomly assigned (ratio, 1:1) to receive sorafenib 400 mg twice daily orally (n = 578) or brivanib 800 mg once daily orally (n = 577). Primary end point was overall survival (OS). Secondary end points included time to progression (TTP), objective response rate (ORR), disease control rate (DCR) based on modified Response Evaluation Criteria in Solid Tumors (mRECIST), and safety.

RESULTS

The primary end point of OS noninferiority for brivanib versus sorafenib in the per-protocol population (n = 1,150) was not met (hazard ratio [HR], 1.06; 95.8% CI, 0.93 to 1.22), based on the prespecified margin (upper CI limit for HR ≤ 1.08). Median OS was 9.9 months for sorafenib and 9.5 months for brivanib. TTP, ORR, and DCR were similar between the study arms. Most frequent grade 3/4 adverse events for sorafenib and brivanib were hyponatremia (9% and 23%, respectively), AST elevation (17% and 14%), fatigue (7% and 15%), hand-foot-skin reaction (15% and 2%), and hypertension (5% and 13%). Discontinuation as a result of adverse events was 33% for sorafenib and 43% for brivanib; rates for dose reduction were 50% and 49%, respectively.

CONCLUSIONS

Our study did not meet its primary end point of OS noninferiority for brivanib versus sorafenib. However, both agents had similar antitumor activity, based on secondary efficacy end points. Brivanib had an acceptable safety profile, but was less well-tolerated than sorafenib.

Mitogen-activated protein kinases (p42mapk and p44mapk) are serine/threonine kinases that are activated rapidly in cells stimulated with various extracellular signals. This activation is mediated via MAP kinase kinase (p45mapkk), a dual specificity kinase which phosphorylates two key regulatory threonine and tyrosine residues of MAP kinases. We reported previously that the persistent phase of MAP kinase activation is essential for mitogenically stimulated cells to pass the "restriction point" of the cell cycle. Here, using specific polyclonal antibodies and transfection of epitope-tagged recombinant MAP kinases we demonstrate that these signaling protein kinases undergo distinct spatio-temporal localization in <em>growth</em> <em>factor</em>-stimulated cells. In G0-arrested hamster <em>fibroblasts</em> the activator p45mapkk and MAP kinases (p42mapk, p44mapk) are mainly cytoplasmic. Subsequent to mitogenic stimulation by serum or alpha-thrombin both MAP kinase isoforms translocate into the nucleus. This translocation is rapid (seen in <em>15</em> min), persistent (at least during the entire G1 period up to 6 h), reversible (by removal of the mitogenic stimulus) and apparently 'coupled' to the mitogenic potential; it does not occur in response to nonmitogenic agents such as alpha-thrombin-receptor synthetic peptides and phorbol esters that fail to activate MAP kinases persistently. When p42mapk and p44mapk are expressed stably at high levels, they are found in the nucleus of resting cells; this nuclear localization is also apparent with kinase-deficient mutants (p44mapk T192A or Y194F). In marked contrast the p45mapkk activator remains cytoplasmic even during prolonged <em>growth</em> <em>factor</em> stimulation and even after high expression levels achieved by transfection. We propose that the rapid and persistent nuclear transfer of p42mapk and p44mapk during the entire G0-G1 period is crucial for the function of these kinases in mediating the <em>growth</em> response.

Non-small cell lung cancer (NSCLC), which is comprised mainly of adenocarcinoma and squamous cell carcinoma (SCC), is the cause of 80% of all lung cancer deaths in the United States. NSCLC is also associated with a high rate of relapse after clinical treatment and, therefore, requires robust prognostic markers to better manage therapy options. The aim of this study was to identify microRNA (miRNA) expression profiles in SCC of the lung that would better predict prognosis. Total RNA from 61 SCC samples and 10 matched normal lung samples was processed for small RNA species and profiled on MirVana miRNA Bioarrays (version 2, Ambion). We identified <em>15</em> miRNAs that were differentially expressed between normal lung and SCC, including members of the miR-17-92 cluster and its paralogues. We also identified miRNAs, including miR-<em>15</em>5 and let-7, which had previously been shown to have prognostic value in adenocarcinoma. Based on cross-fold validation analyses, miR-146b alone was found to have the strongest prediction accuracy for stratifying prognostic groups at approximately 78%. The miRNA signatures were superior in predicting overall survival than a previously described 50-gene prognostic signature. Whereas there was no overlap between the mRNAs targeted by the prognostic miRNAs and the 50-gene expression signature, there was a significant overlap in the corresponding biological pathways, including <em>fibroblast</em> <em>growth</em> <em>factor</em> and interleukin-6 signaling. Our data indicate that miRNAs may have greater clinical utility in predicting the prognosis of patients with squamous cell lung carcinomas than mRNA-based signatures.

OBJECTIVE

SPARC (secreted protein acidic and rich in cysteine) is a protein involved in cell matrix interactions, wound repair, and cell migration, and has been reported to inhibit cancer growth. SPARC undergoes epigenetic silencing in many pancreatic cancers, but stromal fibroblasts adjacent to infiltrating pancreatic adenocarcinomas frequently express SPARC. We evaluated the prognostic significance of tumor and peritumoral SPARC expression in patients with pancreatic adenocarcinoma.

METHODS

The expression patterns of SPARC were characterized by immunohistochemistry in 299 primary pancreatic ductal adenocarcinoma resection specimens from patients who underwent pancreaticoduodenectomy at Johns Hopkins Hospital (Baltimore, MD) between 1998 and 2003. Kaplan-Meier analysis and Cox proportional hazards regression modeling were used to assess the mortality risk associated with the presence or absence of tumor SPARC and peritumoral SPARC status.

RESULTS

By Kaplan-Meier analysis, patients whose pancreatic cancer stromal fibroblasts expressed SPARC (median survival, 15 months) had a significantly worse prognosis than patients whose tumor stroma did not express SPARC (median survival, 30 months; log-rank P < .001). In contrast, the expression of SPARC in pancreatic cancer cells was not associated with prognosis (log-rank P = .13). Controlling for other prognostic factors (tumor size, positive lymph nodes, margin status, tumor grade, and age), the relative hazard for patients whose stroma expressed SPARC compared with those whose stroma did not was 1.89 (95% CI, 1.31 to 2.74); the expression of SPARC in pancreatic cancer cells remained unrelated to prognosis (relative hazard, 1.02; 95% CI, 0.73 to 1.42).

CONCLUSIONS

The expression of SPARC by peritumoral fibroblasts portends a poorer prognosis for patients with pancreatic cancer.

We review the physiology and pharmacology of two atypical fibroblast growth factors (FGFs)-FGF15/19 and FGF21-that can function as hormones. Both FGF15/19 and FGF21 act on multiple tissues to coordinate carbohydrate and lipid metabolism in response to nutritional status. Whereas FGF15/19 is secreted from the small intestine in response to feeding and has insulin-like actions, FGF21 is secreted from the liver in response to extended fasting and has glucagon-like effects. FGF21 also acts in an autocrine fashion in several tissues, including adipose. The pharmacological actions of FGF15/19 and FGF21 make them attractive drug candidates for treating metabolic disease.

There appear to be 2 pathways involved in the early pathogenesis of premalignant monoclonal gammopathy of undetermined significance (MGUS) and malignant multiple myeloma (MM) tumors. Nearly half of these tumors are nonhyperdiploid and mostly have immunoglobulin H (IgH) translocations that involve 5 recurrent chromosomal loci, including 11q13 (cyclin D1), 6p21 (cyclin D3), 4p16 (<em>fibroblast</em> <em>growth</em> <em>factor</em> receptor 3 [FGFR3] and multiple myeloma SET domain [MMSET]), 16q23 (c-maf), and 20q11 (mafB). The remaining tumors are hyperdiploid and contain multiple trisomies involving chromosomes 3, 5, 7, 9, 11, <em>15</em>, 19, and 21, but infrequently have IgH translocations involving the 5 recurrent loci. Dysregulated expression of cyclin D1, D2, or D3 appears to occur as an early event in virtually all of these tumors. This may render the cells more susceptible to proliferative stimuli, resulting in selective expansion as a result of interaction with bone marrow stromal cells that produce interleukin-6 (IL-6) and other cytokines. There are 5 proposed tumor groups, defined by IgH translocations and/or cyclin D expression, that appear to have differences in biologic properties, including interaction with stromal cells, prognosis, and response to specific therapies. Delineation of the mechanisms mediating MM cell proliferation, survival, and migration in the bone marrow (BM) microenvironment may both enhance understanding of pathogenesis and provide the framework for identification and validation of novel molecular targets.

Pathological processes involved in the initiation of rheumatoid synovitis remain unclear. We undertook the present study to identify immune and stromal processes that are present soon after the clinical onset of rheumatoid arthritis (RA) by assessing a panel of T cell, macrophage, and stromal cell related cytokines and chemokines in the synovial fluid of patients with early synovitis. Synovial fluid was aspirated from inflamed joints of patients with inflammatory arthritis of duration 3 months or less, whose outcomes were subsequently determined by follow up. For comparison, synovial fluid was aspirated from patients with acute crystal arthritis, established RA and osteoarthritis. Rheumatoid <em>factor</em> activity was blocked in the synovial fluid samples, and a panel of 23 cytokines and chemokines measured using a multiplex based system. Patients with early inflammatory arthritis who subsequently developed RA had a distinct but transient synovial fluid cytokine profile. The levels of a range of T cell, macrophage and stromal cell related cytokines (e.g. IL-2, IL-4, IL-13, IL-17, IL-<em>15</em>, basic <em>fibroblast</em> <em>growth</em> <em>factor</em> and epidermal <em>growth</em> <em>factor</em>) were significantly elevated in these patients within 3 months after symptom onset, as compared with early arthritis patients who did not develop RA. In addition, this profile was no longer present in established RA. In contrast, patients with non-rheumatoid persistent synovitis exhibited elevated levels of interferon-gamma at initiation. Early synovitis destined to develop into RA is thus characterized by a distinct and transient synovial fluid cytokine profile. The cytokines present in the early rheumatoid lesion suggest that this response is likely to influence the microenvironment required for persistent RA.

OBJECTIVE

Loss of intercellular adhesion and increased cell motility promote tumor cell invasion. In the present study, E- and N-cadherin, members of the classical cadherin family, are investigated as inducers of epithelial-to-mesenchymal transition (EMT) that is thought to play a fundamental role during the early steps of invasion and metastasis of carcinomas. Cell growth factors are known to regulate cell adhesion molecules. The purpose of the study presented here was to investigate whether a gain in N-cadherin in pancreatic cancer is involved in the process of metastasis via EMT and whether its expression is affected by growth factors.

METHODS

We immunohistochemically examined the expression of N- and E-cadherins and vimentin, a mesenchymal marker, in pancreatic primary and metastatic tumors. Correlations among the expressions of N-cadherin, transforming growth factor (TGF)beta, and fibroblast growth factor 2 was evaluated in both tumors, and the induction of cadherin and vimentin by growth factors was examined in cultured cell lines.

RESULTS

N-cadherin expression was observed in 13 of 30 primary tumors and in 8 of 15 metastatic tumors. N-cadherin expression correlated with neural invasion (P = 0.008), histological type (P = 0.043), fibroblast growth factor expression in primary tumors (P = 0.007), and TGF expression (P = 0.004) and vimentin (P = 0.01) in metastatic tumors. Vimentin, a mesenchymal marker, was observed in a few cancer cells of primary tumor but was substantially expressed in liver metastasis. TGF stimulated N-cadherin and vimentin protein expression and decreased E-cadherin expression of Panc-1 cells with morphological change.

CONCLUSIONS

This study provided the morphological evidence of EMT in pancreatic carcinoma and revealed that overexpression of N-cadherin is involved in EMT and is affected by growth factors.

Oncogenic osteomalacia (OO) is a rare paraneoplastic syndrome of osteomalacia due to phosphate wasting. The phosphaturic mesenchymal tumor (mixed connective tissue variant) (PMTMCT) is an extremely rare, distinctive tumor that is frequently associated with OO. Despite its association with OO, many PMTMCTs go unrecognized because they are erroneously diagnosed as other mesenchymal tumors. Expression of <em>fibroblast</em> <em>growth</em> <em>factor</em>-23 (FGF-23), a recently described protein putatively implicated in renal tubular phosphate loss, has been shown in a small number of mesenchymal tumors with known OO. The clinicopathological features of 32 mesenchymal tumors either with known OO (29) or with features suggestive of PMTMCT (3) were studied. Immunohistochemistry for cytokeratin, S-100, actin, desmin, CD34, and FGF-23 was performed. The patients (13 male, 19 female) ranged from 9 to 80 years in age (median 53 years). A long history of OO was common. The cases had been originally diagnosed as PMTMCT (<em>15</em>), hemangiopericytoma (HPC) (3), osteosarcoma (3), giant cell tumor (2), and other (9). The tumors occurred in a variety of soft tissue (21) and bone sites (11) and ranged from 1.7 to 14 cm. Twenty-four cases were classic PMTMCT with low cellularity, myxoid change, bland spindled cells, distinctive "grungy" calcified matrix, fat, HPC-like vessels, microcysts, hemorrhage, osteoclasts, and an incomplete rim of membranous ossification. Four of these benign-appearing PMTMCTs contained osteoid-like matrix. Three other PMTMCTs were hypercellular and cytologically atypical and were considered malignant. The 3 cases without known OO were histologically identical to the typical PMTMCT. Four cases did not resemble PMTMCT: 2 sinonasal HPC, 1 conventional HPC, and 1 sclerosing osteosarcoma. Three cases expressed actin; all other markers were negative. Expression of FGF-23 was seen in 17 of 21 cases by immunohistochemistry and in 2 of 2 cases by RT-PCR. Follow-up (25 cases, 6-348 months) indicated the following: 21 alive with no evidence of disease and with normal serum chemistry, 4 alive with disease (1 malignant PMTMCT with lung metastases). We conclude that most cases of mesenchymal tumor-associated OO, both in the present series and in the reported literature, are due to PMTMCT. Improved recognition of their histologic spectrum, including the presence of bone or osteoid-like matrix in otherwise typical cases and the existence of malignant forms, should allow distinction from other mesenchymal tumors. Recognition of PMTMCT is critical, as complete resection cures intractable OO. Immunohistochemistry and RT-PCR for FGF-23 confirm the role of this protein in PMTMCT-associated OO.

Experimentally, peripheral nerve repair can be enhanced by Schwann cell transplantation but the clinical application is limited by donor site morbidity and the inability to generate a sufficient number of cells quickly. We have investigated whether adult stem cells, isolated from adipose tissue, can be differentiated into functional Schwann cells. Rat visceral fat was enzymatically digested to yield rapidly proliferating <em>fibroblast</em>-like cells, a proportion of which expressed the mesenchymal stem cell marker, stro-1, and nestin, a neural progenitor protein. Cells treated with a mixture of glial <em>growth</em> <em>factors</em> (GGF-2, bFGF, PDGF and forskolin) adopted a spindle-like morphology similar to Schwann cells. Immunocytochemical staining and western blotting indicated that the treated cells expressed the glial markers, GFAP, S100 and p75, indicative of differentiation. When co-cultured with NG108-<em>15</em> motor neuron-like cells, the differentiated stem cells enhanced the number of NG108-<em>15</em> cells expressing neurites, the number of neurites per cell and the mean length of the longest neurite extended. Schwann cells evoked a similar response whilst undifferentiated stem cells had no effect. These results indicate adipose tissue contains a pool of regenerative stem cells which can be differentiated to a Schwann cell phenotype and may be of benefit for treatment of peripheral nerve injuries.

In addition to their contribution to the research on early human development, human embryonic stem (hES) cells may also be used for cell-based therapies. Traditionally, these cells have been cultured on mouse embryonic <em>fibroblast</em> feeder layers, which allow their continuous <em>growth</em> in an undifferentiated state. However, the use of hES cells in human therapy requires an animal-free culture system, in which exposure to mouse retroviruses is avoided. In this study we present a novel feeder layer-free culture system for hES cells, based on medium supplemented with <em>15</em>% serum replacement, a combination of <em>growth</em> <em>factors</em> including transforming <em>growth</em> <em>factor</em> beta1 (TGFbeta1), leukemia inhibitory <em>factor</em>, basic <em>fibroblast</em> <em>growth</em> <em>factor</em>, and fibronectin matrix. Human ES cells grown in these conditions maintain all ES cell features after prolonged culture, including the developmental potential to differentiate into representative tissues of the three embryonic germ layers, unlimited and undifferentiated proliferative ability, and maintenance of normal karyotype. The culture system presented here has two major advantages: 1) application of a well-defined culture system for hES cells and 2) reduced exposure of hES cells to animal pathogens. The feeder layer-free culture system reported here aims at facilitating research practices and providing a safer alternative for future clinical applications of hES cells.

OBJECTIVE

Effective systemic therapy for advanced carcinoid is lacking. The combination of bevacizumab (BEV) and pegylated (PEG) interferon alpha-2b was evaluated among patients with metastatic or unresectable carcinoid tumors.

METHODS

Forty-four patients on stable doses of octreotide were randomly assigned to 18 weeks of treatment with bevacizumab or PEG interferon alpha-2b. At disease progression (PD) or at the end of 18 weeks (whichever occurred earlier), patients received bevacizumab plus PEG interferon until progression. Functional computer tomography (CT) scans were performed to measure effect on tumor blood flow.

RESULTS

In the bevacizumab arm, four patients (18%) achieved confirmed partial response (PR), 17 patients (77%) had stable disease (SD), and one patient (5%) had PD. In the PEG interferon arm, <em>15</em> patients (68%) had SD and six patients (27%) had PD. Progression-free survival (PFS) rates after 18 weeks of monotherapy were 95% in bevacizumab versus 68% on the PEG interferon arm. The overall median PFS for all 44 patients is 63 weeks. Compared with paired baseline measurements on functional CT scans, we observed a 49% (P < .01) and 28% (P < .01) decrease in tumor blood flow at day 2 and week 18 among patients treated with bevacizumab. No significant changes in tumor blood flow were observed following PEG interferon. PEG interferon alpha-2b treatment was associated with decrease in plasma basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF; P = .04) and increase in plasma interleukin-18 (IL-18; P < .01). No significant changes in bFGF or IL-18 following treatment with bevacizumab were observed.

CONCLUSIONS

Bevacizumab therapy resulted in objective responses, reduction of tumor blood flow, and longer PFS in patients with carcinoid than PEG interferon treatment.

Mouse <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>15</em> (FGF<em>15</em>) and human ortholog FGF19 have been identified as the bile acid-induced intestinal <em>factors</em> that mediate bile acid feedback inhibition of cholesterol 7alpha-hydroxylase gene (C YP7A1) transcription in mouse liver. The mechanism underlying FGF<em>15</em>/FGF19 inhibition of bile acid synthesis in hepatocytes remains unclear. Chenodeoxycholic acid (CDCA) and the farnesoid X receptor (FXR)-specific agonist GW4064 strongly induced FGF19 but inhibited CYP7A1 messenger RNA (mRNA) levels in primary human hepatocytes. FGF19 strongly and rapidly repressed CYP7A1 but not small heterodimer partner (SHP) mRNA levels. Kinase inhibition and phosphorylation assays revealed that the mitogen-activated protein kinase/extracellular signal-regulated kinase 1/2 (MAPK/Erk1/2) pathway played a major role in mediating FGF19 inhibition of CYP7A1. However, small interfering RNA (siRNA) knockdown of SHP did not affect FGF19 inhibition of CYP7A1. Interestingly, CDCA stimulated tyrosine phosphorylation of the FGF receptor 4 (FGFR4) in hepatocytes. FGF19 antibody and siRNA specific to FGFR4 abrogated GW4064 inhibition of CYP7A1. These results suggest that bile acid-activated FXR is able to induce FGF19 in hepatocytes to inhibit CYP7A1 by an autocrine/paracrine mechanism.

CONCLUSIONS

The hepatic FGF19/FGFR4/Erk1/2 pathway may inhibit CYP7A1 independent of SHP. In addition to inducing FGF19 in the intestine, bile acids in hepatocytes may activate the liver FGF19/FGFR4 signaling pathway to inhibit bile acid synthesis and prevent accumulation of toxic bile acid in human livers.

The systemic expression of the bile acid (BA) sensor farnesoid X receptor (FXR) has led to promising new therapies targeting cholesterol metabolism, triglyceride production, hepatic steatosis and biliary cholestasis. In contrast to systemic therapy, bile acid release during a meal selectively activates intestinal FXR. By mimicking this tissue-selective effect, the gut-restricted FXR agonist fexaramine (Fex) robustly induces enteric <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>15</em> (FGF<em>15</em>), leading to alterations in BA composition, but does so without activating FXR target genes in the liver. However, unlike systemic agonism, we find that Fex reduces diet-induced weight gain, body-wide inflammation and hepatic glucose production, while enhancing thermogenesis and browning of white adipose tissue (WAT). These pronounced metabolic improvements suggest tissue-restricted FXR activation as a new approach in the treatment of obesity and metabolic syndrome.

Basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF) was immobilized to hydrogel scaffolds with retention of mitogenic and chemotactic activity. The bFGF was functionalized in order to incorporate it covalently within polyethylene glycol (PEG) hydrogel scaffolds by reaction with acryloyl-PEG-NHS. Hydrogels were formed by exposing aqueous solutions of PEG diacrylate, acryloyl-PEG-RGDS, and acryloyl-PEG-bFGF to long-wavelength ultraviolet light in the presence of a photoinitiator. These bFGF-modified hydrogels with RGD adhesion sites were evaluated for their effect on vascular smooth muscle cell (SMC) behavior, increasing SMC proliferation by approximately 41% and migration by approximately <em>15</em>%. A covalently immobilized bFGF gradient was formed using a gradient maker to pour the hydrogel precursor solutions and then photopolymerizing to lock in the concentration gradient. Silver staining was used to detect the bFGF gradient, which increased linearly along the hydrogel's length. Cells were observed to align on hydrogels modified with a bFGF gradient in the direction of increasing tethered bFGF concentration as early as 24 h after seeding. SMCs also migrated differentially, up the concentration gradient, on bFGF-gradient hydrogels compared to control hydrogels with and without a constant bFGF concentration. These hydrogel scaffolds may be useful for studying protein gradient effects on cell behavior and for directing cell migration in tissue-engineering applications.

An elevated level of <em>fibroblast</em> <em>growth</em> <em>factor</em>-23 (FGF-23) is the earliest abnormality of mineral metabolism in CKD. High FGF-23 levels promote left ventricular hypertrophy but not coronary artery calcification. We used survival analysis to determine whether elevated FGF-23 is associated with greater risk of adjudicated congestive heart failure (CHF) and atherosclerotic events (myocardial infarction, stroke, and peripheral vascular disease) in a prospective cohort of 3860 participants with CKD stages 2-4 (baseline estimated GFR [eGFR], 44±<em>15</em> ml/min per 1.73 m(2)). During a median follow-up of 3.7 years, 360 participants were hospitalized for CHF (27 events/1000 person-years) and 287 had an atherosclerotic event (22 events/1000 person-years). After adjustment for demographic characteristics, kidney function, traditional cardiovascular risk <em>factors</em>, and medications, higher FGF-23 was independently associated with graded risk of CHF (hazard ratio [HR], 1.45 per doubling [95% confidence interval (CI), 1.28 to 1.65]; HR for highest versus lowest quartile, 2.98 [95% CI, 1.97 to 4.52]) and atherosclerotic events (HR per doubling, 1.24 [95% CI, 1.09 to 1.40]; HR for highest versus lowest quartile, 1.76 [95% CI, 1.20 to 2.59]). Elevated FGF-23 was associated more strongly with CHF than with atherosclerotic events (P=0.02), and uniformly was associated with greater risk of CHF events across subgroups stratified by eGFR, proteinuria, prior heart disease, diabetes, BP control, anemia, sodium intake, income, fat-free mass, left ventricular mass index, and ejection fraction. Thus, higher FGF-23 is independently associated with greater risk of cardiovascular events, particularly CHF, in patients with CKD stages 2-4.