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Growth Factor Binding Protein (growth + factor_binding_protein)
Kinds of Growth Factor Binding Protein Selected AbstractsSuppression of liver regeneration and hepatocyte proliferation in hepatocyte-targeted glypican 3 transgenic mice,HEPATOLOGY, Issue 3 2010Bowen Liu Glypican 3 (GPC3) belongs to a family of glycosylphosphatidylinositol-anchored, cell-surface heparan sulfate proteoglycans. GPC3 is overexpressed in hepatocellular carcinoma. Loss-of-function mutations of GPC3 result in Simpson-Golabi-Behmel syndrome, an X-linked disorder characterized by overgrowth of multiple organs, including the liver. Our previous study showed that GPC3 plays a negative regulatory role in hepatocyte proliferation, and this effect may involve CD81, a cell membrane tetraspanin. To further investigate GPC3 in vivo, we engineered transgenic (TG) mice overexpressing GPC3 in the liver under the control of the albumin promoter. GPC3 TG mice with hepatocyte-targeted, overexpressed GPC3 developed normally in comparison with their nontransgenic littermates but had a suppressed rate of hepatocyte proliferation and liver regeneration after partial hepatectomy. Moreover, gene array analysis revealed a series of changes in the gene expression profiles in TG mice (both in normal mice and during liver regeneration). In unoperated GPC3 TG mice, there was overexpression of runt related transcription factor 3 (7.6-fold), CCAAT/enhancer binding protein alpha (2.5-fold), GABA A receptor (2.9-fold), and wingless-related MMTV integration site 7B (2.8-fold). There was down-regulation of insulin-like growth factor binding protein 1 (8.4-fold), Rab2 (5.6-fold), beta-catenin (1.7-fold), transforming growth factor beta type I (3.1-fold), nodal (1.8-fold), and yes-associated protein (1.4-fold). Changes after hepatectomy included decreased expression in several cell cycle,related genes. Conclusion: Our results indicate that in GPC3 TG mice, hepatocyte overexpression of GPC3 suppresses hepatocyte proliferation and liver regeneration and alters gene expression profiles, and potential cell cycle,related proteins and multiple other pathways are involved and affected. (HEPATOLOGY 2010;52:1060,1067) [source] Positive Linear Growth and Bone Responses to Growth Hormone Treatment in Children With Types III and IV Osteogenesis Imperfecta: High Predictive Value of the Carboxyterminal Propeptide of Type I Procollagen,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2003Joan C Marini MD Abstract Extreme short stature is a cardinal feature of severe osteogenesis imperfecta (OI), types III and IV. We conducted a treatment trial of growth hormone in children with OI and followed linear growth velocity, bone metabolism markers, histomorphometrics, and vertebral bone density. Twenty-six children with types III and IV OI, ages 4.5,12 years, were treated with recombinant growth hormone (rGH), 0.1,0.2 IU/kg per day for 6 days/week, for at least 1 year. Length, insulin-like growth factor (IGF-I), insulin-like growth factor binding protein (IGFBP-3), bone metabolic markers, and vertebral bone density by DXA were evaluated at 6-month intervals. An iliac crest biopsy was obtained at baseline and 12 months. Approximately one-half of the treated OI children sustained a 50% or more increase in linear growth over their baseline growth rate. Most responders (10 of 14) had moderate type IV OI. All participants had positive IGF-I, IGFBP-3, osteocalcin, and bone-specific alkaline phosphatase responses. Only the linear growth responders had a significant increase in vertebral DXA z-score and a significant decrease in long bone fractures. After 1 year of treatment, responders' iliac crest biopsy showed significant increases in cancellous bone volume, trabecular number, and bone formation rate. Responders were distinguished from nonresponders by higher baseline carboxyterminal propeptide (PICP) values (p < 0.05), suggesting they have an intrinsically higher capacity for collagen production. The results show that growth hormone can cause a sustained increase in the linear growth rate of children with OI, despite the abnormal collagen in their bone matrix. In the first year of treatment, growth responders achieve increased bone formation rate and density, and decreased fracture rates. The baseline plasma concentration of PICP was an excellent predictor of positive response. [source] Insulin-like growth factor binding protein-3 induces angiogenesis through IGF-I- and SphK1-dependent mechanismsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 4 2007R. GRANATA Summary. Angiogenesis is critical for development and repair, and is a prominent feature of many pathological conditions. Based on evidence that insulin-like growth factor binding protein (IGFBP)-3 enhances cell motility and activates sphingosine kinase (SphK) in human endothelial cells, we have investigated whether IGFBP-3 plays a role in promoting angiogenesis. IGFBP-3 potently induced network formation by human endothelial cells on Matrigel. Moreover, it up-regulated proangiogenic genes, such as vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP)-2 and -9. IGFBP-3 even induced membrane-type 1 MMP (MT1-MMP), which regulates MMP-2 activation. Decreasing SphK1 expression by small interfering RNA (siRNA), blocked IGFBP-3-induced network formation and inhibited VEGF, MT1-MMP but not IGF-I up-regulation. IGF-I activated SphK, leading to sphingosine-1-phosphate (S1P) formation. The IGF-I effect on SphK activity was blocked by specific inhibitors of IGF-IR, PI3K/Akt and ERK1/2 phosphorylation. The disruption of IGF-I signaling prevented the IGFBP-3 effect on tube formation, SphK activity and VEGF release. Blocking ERK1/2 signaling caused the loss of SphK activation and VEGF and IGF-I up-regulation. Finally, IGFBP-3 dose-dependently stimulated neovessel formation into subcutaneous implants of Matrigel in vivo. Thus, IGFBP-3 positively regulates angiogenesis through involvement of IGF-IR signaling and subsequent SphK/S1P activation. [source] Gene expression changes following androgen receptor elimination in LNCaP prostate cancer cellsMOLECULAR CARCINOGENESIS, Issue 4 2003Iris E. Eder Abstract We have shown recently that inhibition of androgen receptor (AR) expression with an antisense AR oligonucleotide (ODN) inhibits LNCaP prostate tumor cells in vitro as well as in vivo. In this study, we investigated gene expression changes that occur after AR signaling blockade, either through AR elimination by antisense treatment or through complete androgen receptor inhibition by androgen deprivation combined with the antiandrogen bicalutamide, in order to search for genes that are directly or indirectly regulated through the AR. Gene expression changes were investigated with cDNA NIH 10K gene microarrays in response to treatment over 48 h. Expression of selected genes was further analyzed by real-time reverse transcriptase (RT)-polymerase chain reaction (PCR), Western blotting, and radioimmunoassay. A comparison of antisense-treated and androgen-deprived cells revealed several concordances such as significant downregulation of prostate-specific genes, cell-cycle regulatory genes, genes of the cholesterol biosynthesis pathway, and several cytoskeletal genes. However, there were also several genes that were differentially regulated. Among the genes that were exclusively changed by treatment with the antisense AR ODN were the insulin-like growth factor binding protein 2 (IGFBP2) and the phosphatidylinositol-4-phosphate 5-kinase type I alpha (PIP5KIA). On the other hand, complete androgen receptor blockade induced changes in the expression of the prostate overexpressed gene 1 and the S100 calcium binding protein P. In summary, we identified a cohort of interesting genes whose expression was highly affected by elimination of the AR in LNCaP prostate cancer cells. Further investigations are warranted to clarify their role in the AR signaling pathway and their susceptibility as a target for the treatment of prostate cancer. © 2003 Wiley-Liss, Inc. [source] Transcriptosome and serum cytokine profiling of an atypical case of myelodysplastic syndrome with progression to acute myelogenous leukemiaAMERICAN JOURNAL OF HEMATOLOGY, Issue 10 2006Daruka Mahadevan Abstract A Native American-Indian female presenting with anemia and thrombocytosis was diagnosed with myelodysplastic syndrome (MDS, refractory anemia). Over the course of 5 years she developed cytopenias and periods of leukocytosis with normal bone marrow (BM) blast counts, features of an unclassifiable MDS/MPS syndrome. The patient ultimately progressed to acute myelogenous leukemia (AML, FAB M2) and had a normal karyotype throughout her course. The episodes of leukocytosis were associated with infectious complications. Transformation to AML was characterized by a BM blast percentage of 49%. Peripheral blood and BM samples were obtained for serum protein analysis and gene expression profiling (GEP) to elucidate her disease process. An ELISA assay of the serum analyzed ,80 cytokines, which demonstrated that hepatocyte growth factor/scatter factor and insulin-like growth factor binding protein 1 were markedly elevated compared to normal. GEP demonstrated a unique "tumor molecular profile," which included overexpression of oncogenes (HOXA9, N-MYC, KOC1), proliferative genes (PAWR, DLG5, AKR1C3), invasion/metastatic genes (FN1, N-CAM-1, ITGB5), pro-angiogenesis genes (c-Kit), and down regulation of tumor suppressor genes (SUI1, BARD1) and anti-apoptotic genes (PGLYRP, SERPINB2, MPO). Hence, a biomics approach has provided insight into elucidating disease mechanisms, molecular prognostic factors, and discovery of novel targets for therapeutic intervention. Am. J. Hematol., 2006. © 2006 Wiley-Liss, Inc. [source] Altered levels of insulin-like growth factor binding protein proteases in preeclampsia and intrauterine growth restrictionPRENATAL DIAGNOSIS, Issue 9 2010Julian K. Christians Abstract Intrauterine growth restriction (IUGR) and preeclampsia (PE) are leading causes of perinatal and maternal morbidity and mortality. Many studies have found association between low levels of insulin-like growth factor binding protein (IGFBP) proteases in the first trimester maternal circulation and the risk of subsequent development of PE and/or IUGR. These results are generally interpreted to reflect decreased production of the proteases by the placenta, leading to reduced proteolysis of IGFBPs and lower free levels of insulin-like growth factor (IGF), resulting in diminished feto-placental development. However, the association between low circulating levels of placental proteins early in pregnancy and the subsequent development of IUGR and/or PE could be due to low exchange in the placenta and not due to reduced production. In contrast, late in pregnancy, the circulating levels of these proteins and their expression in the placenta are often elevated in PE, which may reflect upregulation to compensate for abnormal placental development, that is an adaptive mechanism to increase IGFBP proteolysis, increase local IGF levels and promote feto-placental growth. Further research into the biological mechanisms underlying these associations will aid the identification of high-risk pregnancies and the development of therapeutic targets for diseases for which there are presently no preventative measures. Copyright © 2010 John Wiley & Sons, Ltd. [source] Insulin-like growth factor binding protein-3 (IGFBP-3) in the prostate and in prostate cancer: Local production, distribution and secretion pattern indicate a role in stromal-epithelial interactionTHE PROSTATE, Issue 11 2008Petra Massoner Abstract Background Insulin-like growth factor binding protein 3 (IGFBP-3) exerts inhibitory and proapoptotic effects on prostate cancer cells. Serum levels of IGFBP-3 were found to be associated with the risk of prostate cancer, but the data are still inconclusive. We present a detailed analysis of the expression and localization of IGFBP-3 in the prostate and a comparison with its expression pattern in tumors. Methods Expression and localization of IGFBP-3 were analyzed in cellular models and tissue by real-time RT-PCR, ELISA, immunohistochemistry, and immunofluorescence. Results All cell types of a panel of benign epithelial, stromal and tumor prostate cells expressed IGFBP-3. Significantly higher expression levels were registered in stromal cells. TGF-, stimulation boosted IGFBP-3 levels 60-fold in stromal cells. The pattern of expression was confirmed in microdissected tissue samples. Protein levels measured by ELISA paralleled the mRNA levels and more than 80% of IGFBP-3 was secreted. On tissue immunostaining, IGFBP-3 was found to be mainly located in the epithelium. The pattern suggested secretion of IGFBP-3, which was confirmed in prostate tissue cultured ex vivo and the ejaculate of vasectomized men. IGFBP-3 levels were increased in primary tumors but did not differ from benign epithelium in metastases and local recurrent tumors. Conclusions We registered a significant local production of IGFBP-3 in the prostate, which may well override the effect of protein entering from blood. The stroma,particularly reactivated stroma,is the main source of IGFBP-3 in the prostate, suggesting that this peptide acts as a mediator of stromal-epithelial interactions. Prostate 68: 1165,1178, 2008. © 2008 Wiley-Liss, Inc. [source] Latent transforming growth factor binding protein 4 (LTBP-4) is downregulated in human mammary adenocarcinomas in vitro and in vivo,APMIS, Issue 6 2007SUSANNE MAUEL Transforming growth factor beta (TGF-ß) is able to inhibit proliferation of epithelial cells and is involved in the carcinogenesis of human mammary tumours. Three latent transforming growth factor-ß binding proteins (LTBP-1, -3 and -4) are involved in TGF-ß function. The aim of the study was to analyze the expression profiles of TGF-ß 1 and 2 and LTBP-4 in human mammary carcinoma cell lines as well as in human mammary tumours. Expression analysis was performed at the transcription and protein level under in vivo and in vitro conditions. LTBP-4 expression was quantitatively analysed in human carcinomas of the mammary gland and in healthy mammary tissues of the same patients. Downregulation of LTBP-4 in all investigated human mammary tumours compared to normal tissues could be demonstrated. Results also revealed that protein levels of TGF-ß 1 are downregulated and of TGF-ß 2 are upregulated in human mammary carcinoma cell lines compared to primary (normal) human mammary epithelial cells. LTBP-4 reduction in neoplasms leads to a possible decrease of TGF-ß 1 extracellular deposition with reduced TGF-ß 1 bioavailability. TGF-ß 2 was upregulated, which indicates a possible compensatory mechanism. This study demonstrated a possible functional role of LTBP-4 for TGF-ß bioavailability with respect to carcinogenesis of human mammary tumours in vivo and in vitro. [source] Synthesis of insulin-like growth factor binding protein 3 in vitro in human articular cartilage culturesARTHRITIS & RHEUMATISM, Issue 2 2003Tamar Eviatar Objective To quantify the rate of synthesis of insulin-like growth factor binding protein 3 (IGFBP-3) and insulin-like growth factor 1 (IGF-1) by in vitro cultures of normal and osteoarthritic (OA) human articular cartilage. Methods Levels of IGF-1 and IGFBP-3 in media from in vitro cultures of human cartilage were determined by radioimmunoassay (RIA). IGFBPs were characterized by immunoblots and ligand blots. Ultrafiltration and RIA analysis of synovial fluid (SF) samples and washings of cartilage samples ex vivo were used to calculate partition coefficients and to estimate the amount of IGF-1 and IGFBP-3 in cartilage in vivo. Results OA cartilage synthesized 150 ng of IGFBP-3 per gm of cartilage per day, compared with 50 ng synthesized by normal cartilage. The surface zone of normal cartilage produced more IGFBP-3 than did the deep zone. Immunoblots and ligand blots confirmed the presence of IGFBP-3. IGFBP-3 synthesis was stimulated by exogenous IGF-1. No freshly synthesized IGF-1 was detected. The quantities of IGF-1 and IGFBP-3 present ex vivo were 11.3 and 78.7 ng/gm of cartilage in normal cartilage and 21.6 and 225.4 ng/gm in OA cartilage. Conclusion The results show that while IGFBP-3 is synthesized in explant cultures, IGF-1 is not. The rate of IGFBP-3 synthesis is 3 times higher in OA than in normal cartilage. Both IGFBP-3 and IGF-1 penetrate into cartilage from SF in vivo. We estimate that the quantities of IGFBP-3 produced in culture by human cartilage are small compared with the amount supplied in the form of "small complexes" from the circulation. The high value of the partition coefficient of IGFBP-3 implies binding to the matrix. [source] Inhibition of insulin-like growth factor binding protein 5 proteolysis in articular cartilage and joint fluid results in enhanced concentrations of insulin-like growth factor 1 and is associated with improved osteoarthritisARTHRITIS & RHEUMATISM, Issue 3 2002David R. Clemmons Objective The complement component C1s is present in dog joint fluid in an activated state. Since C1s degrades insulin-like growth factor binding protein 5 (IGFBP-5), we undertook to determine whether inhibiting C1s in joint fluid would result in an increase in the amount of intact IGFBP-5 and IGF-1 in cartilage and joint fluid, and whether C1s inhibition would be associated with a reduction in cartilage destruction during the development of osteoarthritis (OA). Methods Twenty-two dogs were randomized to 3 treatment groups. All dogs underwent anterior cruciate ligament transection and were exercised. Dogs received 1 of 3 treatments: buffer alone (controls; n = 6); PB-145, a peptide derived from the sequence of antithrombin III (n = 9); and pentosan polysulfate (PPS; n = 7). PB-145 or saline was injected into the joint space 3 times per week for 3 weeks. PPS was injected intramuscularly weekly for 3 weeks. Results Joint histology showed preservation of chondrocytes and a smooth joint surface in the animals treated with PB-145 and PPS. Mankin scoring showed statistically significant reductions in joint destruction with PB-145 and PPS treatments (P < 0.01) compared with buffer control. Mean active collagenase concentrations were decreased by these two treatments. Immunoblotting of joint fluid showed that both treatments increased concentrations of intact IGFBP-5. Direct analysis of IGFBP-3 and IGFBP-5 protease activity showed that IGFBP-5 was degraded more rapidly and that PB-145 and PPS inhibited the degradation of both proteins. Total IGF-1 concentrations in joint fluid were increased 5.6,5.8-fold by these two treatments. Analysis showed that C1s was being activated in joint fluid and that its activation was inhibited by the addition of PB-145 or PPS. Conclusion The findings suggest that direct inhibition of the serine protease C1s results in increased concentrations of intact IGFBP-5 and that proteolysis of IGFBP-3 is also inhibited, probably by the inhibition of some other protease. This increase in concentrations of intact IGFBP-3 and IGFBP-5 leads to an increase in IGF-1 which is associated with an improvement in joint architecture during the development of OA. [source] Matrix metalloproteinase-7 triggers the matricrine action of insulin-like growth factor-II via proteinase activity on insulin-like growth factor binding protein 2 in the extracellular matrixCANCER SCIENCE, Issue 5 2007Shin'ichi Miyamoto Many growth factors and cytokines are immobilized on the extracellular matrix (ECM) by binding to glycosaminoglycans and are stored in an inactive form in the cellular microenvironment. However, the mechanisms of ECM-bound growth factor or cytokine activation have not been well documented. We showed that the insulin-like growth factor type-1 receptor (IGF-1R) was rapidly phosphorylated after the addition of matrix metalloproteinase (MMP)-7 to a serum-starved human colon cancer cell line (HT29) and that phosphorylation was completely inhibited by an IGF-II neutralizing antibody. In the ECM of this cell line, IGF-II and IGF binding protein (BP)-2 coexisted, but IGFBP-2 disappeared from the ECM fraction after treatment with MMP-7 or heparinase III. On the other hand, in a cell line in which IGF-1R was overexpressed, IGF-1R was phosphorylated by supernatant from the MMP-7-treated ECM fraction of HT29 but not by that from a heparinase-III-treated ECM fraction. We also demonstrated that MMP-7 degrades IGFBP-2 in vitro at three cleavage sites (peptide bonds E151,L152, G175,L176 and K181,L182), which have not been documented previously. Taken together, these results demonstrate that MMP-7 generates bioactive IGF-II by degrading the IGF-II/IGFBP-2 complex binding to heparan sulfate proteoglycan in the ECM, resulting in IGF-II-induced signal transduction. This evidence indicates that some ECM-associated growth factors enhance their ability to bind to their receptors by some proteases in the tumor microenvironment. This mechanism of action (,protease-triggered matricrine') represents an attractive model for understanding ECM,tumor interactions. (Cancer Sci 2007; 98: 685,691) [source] Energy substrate production in infants born small for gestational ageACTA PAEDIATRICA, Issue 1 2007Barbro Diderholm Abstract Aim: To investigate energy substrate production and its hormonal regulation in infants born small for gestational age. Methods: Eleven infants, aged 24.4 ± 5.3 hour, were studied following a fast of 4.0 ± 0.6 hour. Gestational age was 35.4 ± 2.8 weeks and birth weight 1804 ± 472 g (<,2 SD). Rates of glucose production and lipolysis were analyzed using [6,6- 2H2]-glucose and [2- 13C]-glycerol. Results: Plasma levels of glucose and glycerol were 4.1 ± 1.1 mmol . L,1 and 224 ± 79 ,mol . L,1, respectively. Glucose appearance averaged 30.3 ± 8.2 and glucose production rate 21.1 ± 6.1 ,mol . kg,1 . minutes,1. Glycerol production rate was 5.6 ± 1.6 ,mol . kg,1 . minutes,1, correlating strongly to birth weight (r = 0.904, p < 0.001). Of the glycerol produced, 55 ± 22% was converted to glucose, corresponding to 8 ± 3% of the glucose production. Conclusions: Even though the infants could produce energy substrates, lipolysis was reduced and the glucose production was in the low end of the normal range compared with infants born appropriate for gestational age. The correlation between glycerol production and birth weight indicates that lipolysis depends on the amount of stored fat. Data on insulin and insulin-like growth factor binding protein 1 support the view that insulin sensitivity in these infants is reduced in the liver but increased peripherally. [source] Insulin, adiponectin, IGFBP-1 levels and body composition in small for gestational age born non-obese children during prepubertal agesCLINICAL ENDOCRINOLOGY, Issue 1 2008Ozlem Sancakli Summary Background, Being small for gestational age (SGA) at birth and postnatal growth pattern may have an impact on insulin resistance and body composition in later life. Adiponectin is a strong determinant of insulin sensitivity. Objective, The aim of this study was to evaluate insulin resistance and adiponectin levels in SGA born children with catch-up growth (CUG) in the absence of obesity in prepubertal ages and relations with body composition and insulin-like growth factor binding protein (IGFBP)-1. Methods, Twenty-four (15F, 9M) SGA born children with CUG but without obesity were evaluated at age 6·3 ± 0·5 years with respect to glucose, insulin, IGFBP-1, leptin and adiponectin levels, and body composition by dual-energy X-ray absorptiometry (DEXA). Their data were compared to that of 62 (27F, 35M) appropriate for gestational age (AGA) children. Results, SGA and AGA children had similar height standard deviation score (SDS) corrected for parental height and body mass index (BMI) SDS. Homeostasis model for insulin resistance (HOMA-IR) was significantly high in SGA (0·7 ± 0·6) than in AGA children (0·4 ± 0·2) (P = 0·029). There were no significant differences in leptin, IGFBP-1, adiponectin, and total and truncal fat between SGA and AGA children. However, being born SGA and having higher BMI in the upper half for the distribution in the sample, although within normal ranges, was associated with lower adiponectin levels (estimated means of log adiponectin levels 3·8 ± 0·3 vs. 4·4 ± 0·1 µg/ml, P = 0·040). Conclusions, SGA children with CUG and with no obesity have higher insulin levels compared to AGA children. Both SGA birth and recent size seem to have an effect on serum adiponectin levels in childhood. [source] OBSL1 mutations in 3-M syndrome are associated with a modulation of IGFBP2 and IGFBP5 expression levels,HUMAN MUTATION, Issue 1 2010Celine Huber Abstract 3-M syndrome is an autosomal recessive disorder characterized by severe pre- and postnatal growth retardation and minor skeletal changes. We have previously identified CUL7 as a disease-causing gene but we have also provided evidence of genetic heterogeneity in the 3-M syndrome. By homozygosity mapping in two inbred families, we found a second disease locus on chromosome 2q35,36.1 in a 5.2-Mb interval that encompasses 60 genes. To select candidate genes, we performed microarray analysis of cultured skin fibroblast RNA from one patient, looking for genes with altered expression; we found decreased expression of IGFBP2 and increased expression of IGFBP5. However, direct sequencing of these two genes failed to detect any anomaly. We then considered other candidate genes by their function/location and found nine distinct mutations in the OBSL1 gene in 13 families including eight nonsense and one missense mutations. To further understand the links between OBSL1, CUL7, and insulin-like growth factor binding proteins (IGFBPs), we performed real-time quantitative PCR (RT-PCR) analysis for OBSL1, CUL7, IGFBP2, and IGFBP5, using cultured fibroblast RNAs from two patients with distinct OBSL1 mutations (p.F697G; p.H814RfsX15). We found normal CUL7 mRNA levels but abnormal IGFBP2 and IGFBP5 mRNA levels in the two patients, suggesting that OBSL1 modulates the expression of IGFBP proteins. Hum Mutat 30:1,7, 2009. © 2009 Wiley-Liss, Inc. [source] Various components of the insulin-like growth factor system in tumor tissue, cerebrospinal fluid and peripheral blood of pediatric medulloblastoma and ependymoma patientsINTERNATIONAL JOURNAL OF CANCER, Issue 3 2008Judith M. de Bont Abstract The insulin-like growth factor (IGF) system plays an important role in neuronal development and may contribute to the development of brain tumors. In this study, we studied mRNA expression levels of IGFs, insulin-like growth factor binding proteins (IGFBPs) and insulin-like growth factor receptors (IGFRs) in 27 pediatric medulloblastomas, 13 pediatric ependymomas and 5 control cerebella. Compared to normal cerebellum, mRNA levels of IGFBP-2 and IGFBP-3 were significantly increased in medulloblastomas and ependymomas. IGFBP-2 expression was indicative of poor prognosis in medulloblastomas, whereas IGFBP-3 mRNA levels were especially high in anaplastic ependymomas. IGFBP-5 and IGF-II mRNA levels were significantly increased in ependymomas compared to control cerebellum. Protein expression levels of IGFs and IGFBPs were analyzed in the cerebrospinal fluid (CSF) of 16 medulloblastoma, 4 ependymoma and 23 control patients by radioimmuno assay to determine whether they could be used as markers for residual disease after surgery. No aberrant CSF protein expression levels were found for ependymoma patients. In medulloblastoma patients, the IGFBP-3 protein levels were significantly higher than in ependymoma patients and controls. Moreover, enhanced levels of proteolytic fragments of IGFBP-3 were found in the CSF of medulloblastoma patients, being in concordance with a significantly increased IGFBP-3 proteolytic activity in the CSF of these patients. In conclusion, our data suggest that the IGF system is of importance in pediatric medulloblastomas and ependymomas. Larger studies should be conducted to validate the predictive values of the levels of intact IGFBP-3 and proteolytic fragments in CSF in the follow-up of medulloblastomas. © 2008 Wiley-Liss, Inc. [source] Growth hormone and insulin-like growth factor 1 levels and their relation to survival in children with bacterial sepsis and septic shockJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 4 2004N Önenli-Mungan Objectives: Despite improved supportive care, the mortality of sepsis and septic shock is still high. Multiple changes in the neuroendocrine systems, at least in part, are responsible for the high morbidity and mortality. A reduced circulating level of insulin-like growth factor and an elevated level of growth hormone are the reported characteristic findings early in the course of sepsis and septic shock in adults. The aim of this study was to evaluate the changes of growth hormone/insulin-like growth factor 1 axis in sepsis and septic shock and investigate the relationship between these hormones and survival. Methods: Fifty-one children with sepsis (S), 21 children with septic shock (SS) and 30 healthy, age- and sex-matched children (C) were enrolled in this study. Growth hormone, insulin-like growth factor 1 and cortisol levels of the sepsis and septic shock groups were obtained before administration of any inotropic agent. Results: Growth hormone levels were 32.3 ± 1.5 µIU/mL (range 4,56), 15.9 ± 0.6 µIU/mL (range 11,28) and 55.7 ± 2.7 µIU/mL (range 20,70) in S, C and SS groups, respectively. The difference between the growth hormone levels of the S and C groups, S and SS groups, and C and SS groups were significant (P < 0.001). Non-survivors (54.7 ± 1.6 µIU/mL) had significantly higher growth hormone levels than survivors (29.4 ± 1.5 µIU/mL) (P < 0.001). Insulin-like growth factor 1 levels were 38.1 ± 2.1 ng/mL (range 19,100), 122.9 ± 9.6 ng/mL (range 48,250) and 22.2 ± 1.9 ng/mL (range 10,46) in the S, C and SS groups, respectively, and the difference between the insulin-like growth factor 1 levels of the S and C, S and SS, and C and SS groups were significant (P < 0.001). Non-survivors (8.8 ± 1.1 µg/dL) had significantly lower cortisol levels than survivors (40.9 ± 2.1 µg/dL) (P < 0.001). We detected a significant difference between the levels of cortisol in non-survivors (19.7 ± 1.8 µg/dL) and survivors (33.9 ± 0.9 µg/dL) (P < 0.01). Conclusions: There were elevated levels of growth hormone with decreased levels of insulin-like growth factor 1 in children during sepsis and septic shock compared to healthy subjects. In addition, there were even higher levels of growth hormone and lower levels of insulin-like growth factor 1 in non-survivors than in survivors. We think that both growth hormone and insulin-like growth factor 1 may have potential prognostic value to serve as a marker in bacterial sepsis and septic shock in children. As there is insufficient data in the paediatric age group, more studies including large numbers of patients and additionally evaluating cytokines and insulin-like growth factor binding proteins are needed. [source] Growth factors and proliferation of cultured rat gingival cells in response to cyclosporin AJOURNAL OF PERIODONTAL RESEARCH, Issue 1 2005Takumasa Yoshida Objective:, The prominent side-effect of cyclosporin A, an immunosuppressive drug, in oral tissues is gingival outgrowth, although the exact mechanism underlying this side-effect is unclear. The main purposes of the present study were to determine whether cyclosporin A induced the gingival outgrowth by promoting proliferation of gingival cells and whether growth factors such as transforming growth factor-,s (TGF-,s), fibroblast growth factor-2 (FGF-2), platelet-derived growth factors (PDGFs), and insulin-like growth factors (IGFs) are involved in the possible changes in the proliferation of gingival cells induced by cyclosporin A. Methods:, Cells isolated from rat gingival tissues were cultured with cyclosporin A or IGF-I for 3 days. The effects of cyclosporin A or IGF-I on the proliferation of cultured rat gingival cells were analyzed with a CellTiter 96 proliferation assay kit. The mRNA expression levels for TGF-,s, FGF-2, PDGFs, IGFs, insulin-like growth factor receptors (IGFRs), and insulin-like growth factor binding proteins (IGFBPs) in the rat gingival cells treated with cyclosporin A were measured using competitive reverse transcription,polymerase chain reaction (RT,PCR). Results:, Cyclosporin A induced 23,25% (p < 0.001) increases in the proliferation of rat gingival cells and approximately 130% (p < 0.05) and 60% (p < 0.05) elevations in the mRNA expression levels for TGF-,1 and FGF-2, respectively. On the other hand, exogenous IGF-I induced 8,11% (p < 0.05) increases in the proliferation, but cyclosporin A induced 30,80% (p < 0.05,0.01) reductions in the mRNA expression levels for endogenous IGF-I, IGFR1, IGFBP2, IGFBP3, IGFBP5, and IGFBP6. Conclusions:, Cyclosporin A stimulates the proliferation of rat gingival cells. TGF-,1 and FGF-2 could be involved, but IGFs, IGFRs and IGFBPs could not be directly involved in this cyclosporin A induced-stimulation of the gingival cell proliferation. [source] Role of insulin-like growth factor binding protein-3 in breast cancer cell growthMICROSCOPY RESEARCH AND TECHNIQUE, Issue 1 2002Lynette J. Schedlich Abstract The mitogenic effects of insulin-like growth factors (IGFs) are regulated by a family of insulin-like growth factor binding proteins (IGFBPs). One member of this family, IGFBP-3, mediates the growth-inhibitory and apoptosis-inducing effects of a number of growth factors and hormones such as transforming growth factor-,, retinoic acid, and 1,25-dihydroxyvitamin D3. IGFBP-3 may act in an IGF-dependent manner by attenuating the interaction of pericellular IGFs with the type-I IGF receptor. It may also act in an IGF-independent manner by initiating intracellular signaling from a cell surface receptor, or by direct nuclear action, or both. The possibility of a membrane-bound receptor is strengthened by recent studies which have identified members of the transforming growth factor-, receptor family as having a role, either directly or indirectly, in signaling from the cell surface by IGFBP-3. A number of growth factors and hormones stimulate the expression and secretion of cellular IGFBP-3, which then signals from the cell surface to bring about some of the effects attributed to the primary agents. Within the cell, the apoptosis-inducing tumor suppressor, p53, can also induce IGFBP-3 expression and secretion. Since IGFBP-3 upregulates the cell cycle inhibitor, p21Waf1, and increases the ratio of proapoptotic to antiapoptotic members of the Bcl family, it appears to exert the same effects on major downstream targets of cell signaling as p53 does. The nuclear localization of IGFBP-3 has been described in a number of cell types. IGFBP-3 may act to import IGFs or other nuclear localization signal-deficient signaling molecules into the nucleus. It may also act directly in the nucleus by enhancing the activity of retinoid X receptor-, and thereby promote apoptosis. All of the above phenomena will be discussed with particular emphasis on the growth of breast cancer cells. Microsc. Res. Tech. 59:12,22, 2002. © 2002 Wiley-Liss, Inc. [source] ADAM12: a novel first-trimester maternal serum marker for Down syndromePRENATAL DIAGNOSIS, Issue 13 2003Jennie Laigaard Abstract Objectives The concentration of bioavailable insulin-like growth factor (IGF) I and II is important to foetal growth. It is regulated by insulin-like growth factor binding proteins (IGFBP) 1 through 6. Proteolytic cleavage of IGFBP-3 takes place in human pregnancy serum; accordingly, IGFBP-3 serum levels decrease markedly during pregnancy. ADAM12 (A disintegrin and metalloprotease) is an IGFBP-3 and IGFBP-5 protease and is present in human pregnancy serum. The goal of this study was to determine whether ADAM12 concentration in maternal serum is a useful indicator of foetal health. Methods We developed an enzyme-linked immunosorbent assay (ELISA) for the quantification of ADAM12 in serum. The assay range was 42 to 667 µg/L. Recombinant ADAM12 was used as the standard for calibration. Results We found that ADAM12 was highly stable in serum. Serum concentration increased from 180 µg/L at week 8 of pregnancy to 670 µg/L at 16 weeks, and reached 12 000 µg/L at term. In 18 first-trimester Down syndrome pregnancies, the concentration of ADAM12 was decreased, thus the median multiple of mean (MoM) value was 0.14 (0.01,0.76). A detection rate for foetal Down syndrome of 82% for a screen-positive rate of 3.2% and a 1:400 risk cut-off was found by Monte Carlo estimation using ADAM12 and maternal age as screening markers. Conclusion ADAM12 is a promising marker for Down syndrome. Copyright © 2003 John Wiley & Sons, Ltd. [source] Molecular characterization of tumour heterogeneity and malignant mesothelioma cell differentiation by gene profilingTHE JOURNAL OF PATHOLOGY, Issue 1 2005Xiaojuan Sun Abstract Malignant mesothelioma is an aggressive tumour, characterized by a variable differentiation pattern and poor prognosis. At present, the clinical outcome in patients with malignant mesothelioma is mainly predicted by the morphological phenotype of the tumour. However, this conventional clinicopathological parameter is of limited value, partly because of the biological heterogeneity of this tumour and poor understanding of the regulatory mechanisms underlying the various patterns of growth. To elucidate the intrinsic molecular programmes that determine tumour differentiation, oligonucleotide arrays were used in an in vitro model of mesothelioma differentiation. The analysis of 2059 genes detected 102 genes that were significantly deregulated. Clustering of these genes into functional categories showed distinctive patterns for the two phenotypes, namely epithelioid and sarcomatoid. The molecular fingerprint of the sarcomatoid tumour component indicates overrepresentation of growth factor receptors and growth factor binding proteins, whereas epithelioid mesothelioma cells express other tumour-promoting factors involved in differentiation, metabolism, and regulation of apoptosis. These differences in the molecular phenotype may give a better basis for diagnosis and for designing novel therapies. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Genetic and plasma variation of insulin-like growth factor binding proteins in relation to prostate cancer incidence and survivalTHE PROSTATE, Issue 12 2009Mattias Johansson Abstract BACKGROUND Binding proteins regulate bioavailability of insulin-like growth factor-I (IGF-I) in the circulation and affect apoptosis of tumor cells in the prostate. We analyzed genetic variation within genes coding for IGF binding proteins in relation to prostate cancer incidence and survival. We also investigated if circulating IGFBP3 affects prostate cancer-specific survival. MATERIALS AND METHODS Eleven haplotype tagging SNPs and two single SNPs in the IGFBP1, IGFBP3, and IGFALS genes were genotyped within the CAncer Prostate in Sweden (CAPS) study including 2,774 cases and 1,736 controls. Plasma samples for analyses of total- and intact IGFBP3 levels were available for 1,521 cases and 909 controls. Complete follow-up of vital status was achieved by linkage to the Swedish Cause of Death Register. RESULTS We found no clear association between the genetic variants and prostate cancer incidence or survival. The rare allele of the IGFBP3 SNP rs2854744 was associated with elevated plasma levels of total IGFBP3 (Ptrend,=,9,×,10,8), but not intact IGFBP3 (Ptrend,=,0.16). Elevated levels of total- (Ptrend,=,0.03) and intact IGFBP3 (Ptrend,=,6,×,10,14) were associated with increased risk of prostate cancer specific death. Treatment and tumor characteristics accounted for the association with total IGFBP3, whereas the association with intact IGFBP3 was attenuated, but still statistically significant in adjusted analysis (Ptrend-adjusted,=,0.0004). Elevated intact IGFBP3 was also significantly associated with increased risk of prostate cancer-specific death among patients who were chemically or surgically castrated (Ptrend-adjusted,=,0.0003), and among patients who had not been treated (Ptrend-adjusted,=,0.02). CONCLUSIONS Circulating levels of intact IGFBP3 measured after diagnosis is associated with increased risk of prostate cancer-specific death. Prostate 69:1281,1291, 2009. © 2009 Wiley-Liss, Inc. [source] Role of insulin-like growth factor binding proteins in 1,,25-dihydroxyvitamin D3 -induced growth inhibition of human prostate cancer cellsTHE PROSTATE, Issue 1 2005LaMonica V. Stewart Abstract BACKGROUND The mechanisms underlying 1,,25-dihydroxyvitamin D3 (1,25D)-induced growth inhibition of human prostate cancer cells have not been fully elucidated. To determine whether alterations in the insulin-like growth factor (IGF) signaling axis are associated with 1,25D-induced growth inhibition, we examined the ability of 1,25D to regulate expression of IGF binding proteins (IGFBPs) in human prostate cancer cell lines. METHODS Northern and Western blot analyses were used to detect 1,25D-induced alterations in IGFBP expression. Additional in vitro studies were performed to determine the role of IGFBP-3 in 1,25D-induced growth inhibition. RESULTS 1,25D decreased mRNA levels of the growth stimulatory IGFBP-2 and induced IGFBP-3 mRNA in LNCaP and C4-2 cells. 1,25D treatment also increased secreted IGFBP-3 protein levels in prostate cancer cell lines sensitive to 1,25D growth inhibition but had little effect on IGFBP-3 expression in 1,25D-resistant DU145 cells. However, recombinant IGFBP-3 had only a minor effect on LNCaP cell growth in the presence of serum. Furthermore, siRNA duplexes that reduced IGFBP-3 expression did not alter 1,25D growth inhibition in either LNCaP or PC-3 cell lines grown in serum-containing media. CONCLUSIONS Our studies indicate 1,25D-induced up-regulation of IGFBP-3 is not required for the growth inhibitory effects of 1,25D in prostate cancer cells grown in serum-containing media. © 2005 Wiley-Liss, Inc. [source] Insulin like growth factor-1 and insulin like growth factor binding proteins in the cerebrospinal fluid and serum from patients with Alzheimer's diseaseBIOFACTORS, Issue 2 2008Zivar Salehi Insulin like growth factor-1 (IGF-1) is ubiquitously expressed growth factor that has profound effects on the growth and differentiation of many cell types and tissues, including cells of the central nervous system (CNS). IGF-1 is produced by a wide variety of cells and is found in many biological fluids including cerebrospinal fluid (CSF). IGF-1 plays important role during CNS development and repair. IGF-1 has broad range neuroprotective effects and is a therapeutic candidate for Huntington's disease (HD). IGF-1 protects striatal neurons from the toxicity of mutated Huntington in vitro and improves neuronal survival in vivo in a phenotypic model of HD. Alzheimer's disease (AD) is an age-dependent dementia characterized by progressive loss of cognitive functions and by characteristic pathological changes in the brain: the formation of aggregates extracellularly by ß-amyloid (AB) peptide and intracellularly by tau proteins. Since cerebrospinal fluid (CSF) is in contact with the extracellular space of the brain, biochemical brain modifications could be reflected in the CSF. IGFs in circulation and other physiological fluids are associated with a group of high-affinity binding proteins insulin like growth factor binding proteins (IGFBPs) that specifically bind and modulate their bioactivity at the cellular level. The aim of this study was to determine the level of CSF and serum IGF-1 and IGFBPs concentrations in the patients with AD. CSF was obtained by lumbar puncture. The presence of IGF-1 and IGFBPs in the CSF and serum samples was confirmed by Western blot using anti-IGF-1 and IGFBPs antibodies. Using enzyme linked immunosorbent assay (ELISA), it was shown that the concentration of CSF and serum IGF-1 and IGFBPs in the patients with AD is higher than in normal control. The data from this study indicate that IGF-1 is a constant component of human CSF. It is also concluded that high levels of CSF IGF-1 may be partly related to AD pathophysiology. [source] | |||||||||||||||||||||||||