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Insulin-like Growth Factor Binding (insulin-like + growth_factor_binding)

Distribution by Scientific Domains

Medical Sciences	85%

Distribution within Medical Sciences

Oncology & Radiotherapy	29%
8 Other Subdomains	42%

Terms modified by Insulin-like Growth Factor Binding

insulin-like growth factor binding protein

Selected Abstracts

Aberrant promoter methylation of insulin-like growth factor binding protein-3 gene in human cancers

INTERNATIONAL JOURNAL OF CANCER, Issue 3 2007
Kunitoshi Tomii
Abstract Insulin-like growth factor binding protein-3 (IGFBP-3) is postulated to be a mediator of growth suppression signals. Here, we examined the methylation status of IGFBP-3 to correlate to clinicopathological factors in human cancers. The methylation status of IGFBP-3 was determined by bisulfite DNA sequencing and was correlated with expression semi-quantified by real-time RT-PCR to develop a methylation-specific PCR (MSP) assay for IGFBP-3. Using the MSP assay, we examined the methylation status of IGFBP-3 in gastric cancer (GC), colorectal cancer (CRC), breast cancer (BC) and malignant mesothelioma (MM). IGFBP-3 methylation was detected in 6 of 13 (46%) and 16 of 24 (67%) GC cell lines and tumors, respectively; 4 of 8 (50%) and 15 of 26 (58%) CRC cell lines and tumors, respectively; 3 of 11 (27%) and 7 of 39 (18%) BC cell lines and tumors, respectively and 1 of 5 (20%) and 18 of 56 (32%) MM cell lines and tumors, respectively. Interestingly, the methylation status of MM specimens from Japanese patients (75%, 12 out of 16 patients) was significantly higher than those from the USA (15%, 6 out of 40 patients) (p < 0.0001), suggesting the presence of ethnic differences in the IGFBP-3 methylation status. We also found that IGFBP-3 methylation was preferentially present in GCs arising in the lower-third of the stomach (p = 0.079). In summary, our results showed that IGFBP-3 methylation played an important role in the silencing of its expression, suggesting that IGFBP-3 may act as a tumor suppressor gene in several human cancers examined. © 2006 Wiley-Liss, Inc. [source]

Stimulatory Effect of Insulin-Like Growth Factor Binding Protein-5 on Mouse Osteoclast Formation and Osteoclastic Bone-Resorbing Activity

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 5 2000
Masanori Kanatani
Abstract Insulin-like growth factor binding protein-5 (IGFBP-5) stimulates osteoblast proliferation directly or indirectly through IGF-I action, but its effects on osteoclast formation and osteoclastic activity are unknown. We tested the effects of IGFBP-5 on osteoclastic activity and osteoclast formation. IGFBP-5 significantly stimulated pit formation by pre-existent osteoclasts in mouse bone cell cultures and its stimulatory effect was completely blocked by IGF-I antibody (Ab). However, IGFBP-5 did not affect the bone-resorbing activity of isolated rabbit osteoclasts. When IGFBP-5 was added to unfractionated bone cells after degeneration of pre-existent osteoclasts, IGFBP-5 (77 pM,7.7 nM) dose-dependently stimulated osteoclast-like cell formation, irrespective of the presence of IGF-I Ab. Moreover, osteoclast-like cells newly formed by IGFBP-5 from unfractionated bone cells possessed the ability to form pits on dentine slices. We next examined the direct effect of IGFBP-5 on osteoclast precursors in the absence of stromal cells, using hemopoietic blast cells derived from spleen cells. IGFBP-5 dose-dependently stimulated osteoclast-like cell formation from osteoclast precursors, irrespective of the presence of IGF-I Ab. Growth hormone (GH) as well as IGF-I significantly stimulated bone resorption by pre-existent osteoclasts in mouse bone cell cultures and these stimulatory effects were completely blocked by IGF-I Ab. GH as well as IGF-I stimulated osteoclast-like cell formation from unfractionated bone cells and this stimulatory effect of GH was significantly but partially blocked by IGF-I Ab. The direct stimulatory effect of GH on osteoclast-like cell formation from hemopoietic blast cells was not affected by IGF-I Ab. The present data indicate that IGFBP-5 stimulates bone resorption both by stimulation of osteoclast formation in an IGF-I,independent fashion and by IGF-I,dependent activation of mature osteoclasts, possibly via osteoblasts, in vitro. (J Bone Miner Res 2000;15:902,910) [source]

Insulin-like growth factor binding protein-3 induces angiogenesis through IGF-I- and SphK1-dependent mechanisms

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 4 2007
R. 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]

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 interaction

THE PROSTATE, Issue 11 2008
Petra 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]

Regulation of global gene expression in the bone marrow microenvironment by androgen: Androgen ablation increases insulin-like growth factor binding protein-5 expression

THE PROSTATE, Issue 15 2007
Chang Xu
Abstract BACKGROUND Prostate cancer frequently metastasizes to bone. Androgen suppression treatment is initially highly effective, but eventually results in resistant cancer cells. This study evaluates the effects of androgen suppression on the bone and bone marrow (BM). In particular we questioned whether the androgen therapy could adversely facilitate prostate cancer progression through an increase growth factor secretion by the bone microenvironment. METHODS Global gene expression is analyzed on mPEDB DNA microarrays. Insulin-like growth factor binding protein-5 (IGFBP5) is detected by immunohistochemistry in mouse tissues and its regulation measured by qPCR and Western blotting in human BM stromal cells. Effects of extracellular matrix-associated IGFBP5 on human prostate epithelial cells are tested in an MTS cell-growth assay. RESULTS Castration increases expression of 159 genes (including 4 secreted cytokines) and suppresses expression of 84 genes. IGFBP5 is most consistently increased and the increase in expression is reversed by testosterone administration. IGFBP5 protein is detected in vivo in osteoblasts, BM stromal cells, and endothelial cells. Primary human stromal cell cultures secrete IGFBP5. In vitro, treatment of immortalized human marrow stromal cells with charcoal-stripped serum increases IGFBP5 mRNA expression, which is reversed by androgen supplementation. IGFBP5 is incorporated into the extracellular matrix. Further, IGFBP5 immobilized on extracellular matrices of stromal cells enhances the growth of immortalized prostate epithelial cells. CONCLUSIONS Androgen suppressive therapy increases IGFBP5 in the BM microenvironment and thereby may facilitate the progression of prostate cancer. Prostate 67: 1621,1629, 2007. © 2007 Wiley-Liss, Inc. [source]

Strong suppression of tumor growth by insulin-like growth factor-binding protein-related protein 1/tumor-derived cell adhesion factor/mac25

CANCER SCIENCE, Issue 7 2007
Yuichiro Sato
Insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) has been shown to induce cellular senescence or apoptosis of breast and prostate cancer cell lines in vitro. To examine whether IGFBP-rP1 acts as a tumor-suppressive protein in vivo, we established two model systems. Expression of IGFBP-rP1 in the human bladder carcinoma cell line EJ-1 was blocked by RNA interference. Human colon cancer cell line DLD-1, which did not express endogenous IGFBP-rP1, was transfected with an IGFBP-rP1 expression vector. When injected intraperitoneally or subcutaneously into nude mice, the IGFBP-rP1-expressing EJ-1 and DLD-1 cell lines grew poorly, whereas the IGFBP-rP1 non-producers grew rapidly and produced large tumors. In monolayer culture the IGFBP-rP1 producers and non-producers grew similarly in each model, whereas in soft agar culture the former produced far less colonies than the latter. The IGFBP-rP1 producers had IGFBP-rP1 bound to the cell surface, and adhered more efficiently to fibronectin and laminin-5 than the respective non-producers. Expression of IGFBP-rP1 did not affect the efficiency of insulin signaling. These results demonstrate that IGFBP-rP1 strongly suppresses tumor growth by an insulin-independent or insulin-like growth factor-independent mechanism. Cell surface IGFBP-rP1 may reduce the anchorage-independent growth ability, leading to the marked loss of tumorigenicity. (Cancer Sci 2007; 98: 1055,1063) [source]

Identification of membrane-bound serine proteinase matriptase as processing enzyme of insulin-like growth factor binding protein-related protein-1 (IGFBP-rP1/angiomodulin/mac25)

FEBS JOURNAL, Issue 3 2006
Sanjida Ahmed
Insulin-like growth factor (IGF) binding protein-related protein-1 (IGFBP-rP1) modulates cellular adhesion and growth in an IGF/insulin-dependent or independent manner. It also shows tumor-suppressive activity in vivo. We recently found that a single-chain IGFB-rP1 is proteolytically cleaved to a two-chain form by a trypsin-like, endogenous serine proteinase, changing its biological activities. In this study, we attempted to identify the IGFBP-rP1-processing enzyme. Of nine human cell lines tested, seven cell lines secreted IGFBP-rP1 at high levels, and two of them, ovarian clear cell adenocarcinoma (OVISE) and gastric carcinoma (MKN-45), highly produced the cleaved IGFBP-rP1. Serine proteinase inhibitors effectively blocked the IGFBP-rP1 cleavage in the OVISE cell culture. The conditioned medium of OVISE cells did not cleave purified IGFBP-rP1, but their membrane fraction had an IGFBP-rP1-cleaving activity. The membrane fraction contained an 80-kDa gelatinolytic enzyme, which was identified as the membrane-type serine proteinase matriptase (MT-SP1) by immunoblotting. When the membrane fraction was separated by SDS/PAGE, the IGFBP-rP1-cleaving activity comigrated with matriptase. A soluble form of matriptase purified in an inhibitor-free form efficiently cleaved IGFBP-rP1 at the same site as that found in a naturally cleaved IGFBP-rP1. Furthermore, small interfering RNAs for matriptase efficiently blocked both the matriptase expression and the cleavage of IGBP-rP1 in OVISE cells. These results demonstrate that IGFBP-rP1 is processed to the two-chain form by matriptase on the cell surface. [source]

Aberrant promoter methylation of insulin-like growth factor binding protein-3 gene in human cancers

IGFBP-1 levels in adult women born small for gestational age suggest insulin resistance in spite of normal BMI

JOURNAL OF INTERNAL MEDICINE, Issue 1 2004
A. Kistner
Abstract. Objective., Impaired fetal development may contribute to decreased insulin sensitivity. This study was designed to characterize serum markers of insulin resistance in adults born small for date or born prematurely. Study design., Fifty subjects, all women, were evaluated at a mean age ± SD of 26 ± 2 years (range: 23,30 years). They were allocated to three groups: (i) born fullterm with birth weight <2600 g (n = 18) (small for gestational age, SGA), (ii) born before gestational week 32 (n = 15) (ex-preterm), and (iii) controls, born fullterm with appropriate birth weight (n = 17). Anthropometric data as well as fasting serum samples of plasma B-glucose, serum lipids, insulin, insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-1 (IGFBP-1) levels were determined. Results., In the SGA group final height was lower and they weighed less compared with the controls. Fasting insulin and glucose levels did not differ amongst the groups. Triglycerides were lower in the SGA group and in the ex-preterm group compared with the controls (P < 0.05). The SGA group showed lower IGFBP-1 levels compared with the controls median 17 (range 3,121) vs. 26 (7,67) ,g L,1; P < 0.05]. The IGF-I levels in the SGA, ex-preterm and control groups were 212 ± 58, 259 ± 37 and 216 ± 32 ,g L,1, respectively, corresponding to a mean SD score of ,0.8 ± 1.0, 0.1 ± 0.6 and ,0.6 ± 0.6. Conclusion., As IGFBP-1 is a marker of insulin sensitivity, the low levels observed in adult women with normal BMI, born small for date, suggest relative insulin resistance in spite of normal BMI. [source]

Localization of insulin-like growth factor binding protein-2 in chondrocytes of bovine articular cartilage

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2003
Teresa I. Morales
Purpose: Previous work indicated that transforming growth factor (TGF-,) treatment of bovine articular cartilage resulted in an accumulation of insulin-like growth factor binding protein-2 (IGF-BP-2). The purpose of the work presented in this paper was to define the localization of the IGF-BP-2 in freshly excised articular cartilage and in slices cultured in the presence and absence of TGF-,. Method: Newborn calf articular cartilage was dissected and immediately fixed or maintained in organ culture for five days under basal conditions (media without added serum or growth factors) or with basal media containing 15 ng/ml of TGF-,1. Frozen or paraffin embedded sections were prepared, and immunohistochemistry using anti-IGF-BP-2 performed. Results: The paraffin sections provided the best preservation of morphology and consistency of immunohistochemical staining patterns. In fresh cartilage slices, IGF-BP-2 was associated with most of the chondrocytes. The basal cultured cartilage showed positive immunostaining in some areas, but not others: the most consistently stained area was the upper radial zone. In all cases where a positive reaction was observed, it was associated mostly with chondrocytes. On the other hand, all the TGF-, treated samples that were examined in this study were evenly stained, and most chondrocytes were positive in all areas from superficial to deep zones, thus closely resembling the pattern of fresh tissue. Conclusions: It is concluded that IGF-BP-2 is closely cell associated in bovine articular cartilage. Following culture of cartilage slices, TGF-, increases the number of cells with positive immunostaining. These data help to support the postulate that TGF-, exerts at least some of its actions in articular cartilage via cross-talk mechanisms involving the IGF-BP-2 system. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source]

Role of insulin-like growth factor binding protein-3 in breast cancer cell growth

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 1 2002
Lynette 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]

Differential expression of insulin-like growth factor binding protein-5 in pancreatic adenocarcinomas: Identification using DNA microarray

MOLECULAR CARCINOGENESIS, Issue 11 2006
Sarah K. Johnson
Abstract Pancreatic ductal adenocarcinoma (PDAC) is characterized by its aggressiveness and resistance to both radiation and chemotherapeutic treatment. To better understand the molecular pathogenesis of pancreatic cancer, DNA array technology was employed to identify genes differentially expressed in pancreatic tumors when compared to non-malignant pancreatic tissues. RNA isolated from 11 PDACs and 14 non-malignant bulk pancreatic duct specimens was used to probe Affymetrix U95A DNA arrays. Genes that displayed at least a fourfold differential expression were identified and real-time quantitative PCR was used to verify the differential expression of selected upregulated genes. Interrogation of the DNA array revealed that 73 genes were upregulated in PDACs and 77 genes were downregulated. The majority of the 150 genes identified have not been previously reported to be differentially expressed in pancreatic tumors, although a number of the upregulated transcripts have been reported previously. Immunohistochemistry was used to correlate calponin and insulin-like growth factor binding protein-5 (IGFBP-5) RNA levels with protein expression in PDACs and revealed peritumoral calponin staining in the reactive stroma and intense focal staining of islets cells expressing IGFBP-5 at the edge of tumors; thus implicating the interplay of various cell types to promote neoplastic cell growth within pancreatic carcinomas. As a potential modulator of cell proliferation, the overexpression of IGFBP-5 may, therefore, play a significant role in the malignant transformation of normal pancreatic epithelial cells. © 2006 Wiley-Liss, Inc. [source]

Regulation of global gene expression in the bone marrow microenvironment by androgen: Androgen ablation increases insulin-like growth factor binding protein-5 expression

Analysis of vitamin D-regulated gene expression in LNCaP human prostate cancer cells using cDNA microarrays

THE PROSTATE, Issue 3 2004
Aruna V. Krishnan
Abstract BACKGROUND 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] exerts growth inhibitory, pro-differentiating, and pro-apoptotic effects on prostate cells. To better understand the molecular mechanisms underlying these actions, we employed cDNA microarrays to study 1,25(OH)2D3 -regulated gene expression in the LNCaP human prostate cancer cells. METHODS mRNA isolated from LNCaP cells treated with vehicle or 50 nM 1,25(OH)2D3 for various lengths of time were hybridized to microarrays carrying approximately 23,000 genes. Some of the putative target genes revealed by the microarray analysis were verified by real-time PCR assays. RESULTS 1,25(OH)2D3 most substantially increased the expression of the insulin-like growth factor binding protein-3 (IGFBP-3) gene. Our analysis also revealed several novel 1,25(OH)2D3 -responsive genes. Interestingly, some of the key genes regulated by 1,25(OH)2D3 are also androgen-responsive genes. 1,25(OH)2D3 also down-regulated genes that mediate androgen catabolism. CONCLUSIONS The putative 1,25(OH)2D3 target genes appear to be involved in a variety of cellular functions including growth regulation, differentiation, membrane transport, cell,cell and cell,matrix interactions, DNA repair, and inhibition of metastasis. The up-regulation of IGFBP-3 gene has been shown to be crucial in 1,25(OH)2D3 -mediated inhibition of LNCaP cell growth. 1,25(OH)2D3 regulation of androgen-responsive genes as well as genes involved in androgen catabolism suggests that there are interactions between 1,25(OH)2D3 and androgen signaling pathways in LNCaP cells. Further studies on the role of these genes and others in mediating the anti-cancer effects of 1,25(OH)2D3 may lead to better approaches to the prevention and treatment of prostate cancer. © 2004 Wiley-Liss, Inc. [source]

Nutritional Effect of Dialysis Therapy

ARTIFICIAL ORGANS, Issue 3 2003
Tsutomu Sanaka
Abstract: The prognosis of patients with end-stage renal disease has been improved by the recent remarkable advances in medical and engineering technology. However, there are still many unsolved problems in the clinical field. One of the problems is an intractable malnutrition characterized by clinical manifestations including hypoproteinemia and decrease in muscular volume, which is associated with deterioration in the quality of the patient's life. Malnutrition in hemodialysis patients involves abnormal energy metabolism and aberrant amino acid metabolism. In the most malnourished patients, immunodefense mechanisms and homeostasis are disrupted, greatly influencing the prognosis. Moreover, when the performance of dialyzer used is too high, the dialysis treatment might remove a necessary nutrient for the patient. There is also a possibility that the protein catabolism is accelerated when the biocompatibility is inferior. On the other hand, in malnutri-tion, the circulating level of insulin-like growth factor-1 (IGF-1) falls while the level of insulin-like growth factor binding protein-1 (IGFBP-1) is remarkably increased. It has been recognized that IGF-1 and IGFBP-1 are indicators reflecting the initiation of a malnutritional state in patients with chronic renal failure, although there are many indicators such as albumin, prealbumin, and anthropometric measurement for nutritional assessment. We have suggested that r-hGH and IGF-1 improve the malnutritional state by alleviating hypoproteinemia and abnormality of serum amino acid profile in uremic patients on hemodialysis. The serum IGF-1/IGFBP-1 ratio is useful not only as a nutritional parameter but also as a predicting index of responsiveness to r-hGH. It is necessary to examine the problem from various angles to improve malnutrition in the dialysis patient, while considering the above mentioned. [source]

Prognostic significance of insulin-like growth factor (IGF) binding protein-2 to IGF-binding protein-3 ratio in patients undergoing radical cystectomy for invasive transitional cell carcinoma of the bladder

BJU INTERNATIONAL, Issue 7 2005
Hideaki Miyake
OBJECTIVES To analyse the prognostic significance of insulin-like growth factor binding protein-2 (IGFBP-2) and IGFBP-3 in patients having a radical cystectomy for invasive bladder cancer. PATIENTS AND METHODS Tissue samples of invasive bladder cancer were obtained from 97 patients who had radical cystectomy. The expression of IGFBP-2 and IGFBP-3 mRNAs in these samples was measured by real-time reverse transcription-polymerase chain reaction (RT-PCR), and the findings analysed in relation to clinicopathological factors. RESULTS During the observation period, 31 patients (group A) developed disease recurrence, while the remaining 66 (group B) had no evidence of recurrence. The expression level of IGFBP-2 mRNA was significantly higher in group A than in B, while IGFBP-3 mRNA expression was significantly lower in group A than in B, and there was a significant difference in the relative expression ratio of IGFBP-2 to IGFBP-3 (BP-2/BP-3 ratio) between the groups. Recurrence-free survival in patients with an elevated BP-2/BP-3 ratio was significantly lower than in those with a normal ratio. Multivariate analysis indicated that an elevated BP-2/BP-3 ratio, but not IGFBP-2 and IGFBP-3 mRNA levels, was an independent predictor of disease recurrence. CONCLUSIONS These findings suggest that the BP-2/BP-3 ratio measured by real-time RT-PCR could be useful for predicting disease recurrence in patients who have had a radical cystectomy for invasive bladder cancer. [source]

Absence of hypoglycemia in response to varying doses of recombinant human insulin-like growth factor-I (rhIGF-I) in children and adolescents with low serum concentrations of IGF-I

ACTA PAEDIATRICA, Issue 2 2006
Jaime Guevara-Aguirre
Abstract Aim: To determine whether recombinant human insulin-like growth factor-I (rhIGF-I) administration to children with low IGF-I and relatively low insulin-like growth factor binding protein-3 (IGFBP3) serum concentrations would result in hypoglycemia. Methods: Eighteen children age 11,19 y with serum levels of IGF-I,<,,,2 SDS and IGFBP3,<,0 SDS were randomly assigned to receive rhIGF-I at 80 µg/kg body weight daily (n=6), 40 µg/kg twice daily (n=6), or 80 µg/kg twice daily (n=6). After a 10-d dose escalation and 15 d of treatment at the specified dosage, a 25-h pharmacokinetic/pharmacodynamic profile was obtained, which included 22 blood glucose measurements. Regular meals and snacks were provided. Results: No signs or symptoms of hypoglycemia were noted throughout the study. There were no differences in mean blood glucose concentrations among the three dosage groups. The lowest glucose value recorded, 3.44 mmol/l, was 15 min after a morning injection of 80 µg/kg IGF-I, and promptly rose. Although subjects were selected on the basis of low concentrations of IGF-I to represent proposed candidates for rhIGF-I therapy, the mean and range of SDS for height were not different from those of previously studied normal Ecuadorian controls. Conclusion: In normal individuals with low serum concentrations of IGF-I and relatively low concentrations of IGFBP3, the administration of therapeutic doses of rhIGF-I, while maintaining reasonable food intake, does not result in hypoglycemia. [source]

Increased levels of insulin-like growth factor binding protein-2 in sera and tumours from patients with colonic neoplasia with and without acromegaly

CLINICAL ENDOCRINOLOGY, Issue 4 2001
F. Miraki-Moud
OBJECTIVE Patients with acromegaly are at increased risk of developing colorectal carcinoma and premalignant tubulovillous adenoma. The pathogenesis of these neoplasms could involve a stimulatory effect of serum growth factors on colonic epithelial cell proliferation. The aim of this study was to evaluate changes in (1) serum IGF-I, IGF-II, IGFBP-3 and IGFBP-2 and (2) changes in local expression of IGFBPs and p53 in colonic epithelium in patients with colonic neoplasia with and without acromegaly. DESIGN A cross-sectional retrospective study was performed. Fasting serum samples were obtained at the time of colonoscopy for patients with acromegaly and at the time of surgery for patients with colonic neoplasia without acromegaly. MEASUREMENTS Serum IGF-I, IGF-II, IGFBP-2 and IGFBP,3 were measured using specific immunoassays. Tissue expression of IGFBP-2, IGFBP-3 and p53 status were determined by immunohistochemistry. PATIENTS Group 1: 26 age- and sex-matched control subjects (range 40,69 years); group 2: 18 patients with acromegaly without colonic neoplasia (range 39,68 years); group 3: 18 patients with acromegaly and colonic neoplasia (range 41,74 years, 11 = adenoma, seven = carcinoma); group 4: 19 patients with colonic neoplasia without endocrine disease (range 43,91 years, four = adenoma, 15 = carcinoma). Immunohistochemical staining of colonic biopsies was performed for IGFBP-2, IGFBP-3 and p53 in groups 3 and 4. RESULTS Mean serum IGF-I and IGFBP-3 levels were significantly elevated in group 2 (371 ± 131 µg/l and 6·5 ± 1·8 mg/l, respectively) and group 3 (379 ± 174 µg/l and 5·8 ± 1·6 mg/l, respectively), and significantly reduced in group 4 (103 ± 36 µg/l and 2·4 ± 1 mg/l) compared to controls (165 ± 40 µg/l and 4·7 ± 1 mg/l; P < 0·0001, P < 0·001, respectively). However, median serum IGFBP-2 levels were significantly elevated in group 3 (P < 0·01) and group 4 (P < 0·0001). Immunostaining for IGFBP-2 showed strong areas of immunoreactivity in the cytoplasm of malignant colonic epithelium compared to benign epithelium. IGFBP-3 immunostaining showed strong areas of immunoreactivity in the cytoplasm and in the nucleus of malignant and benign colonic epithelium compared to the normal epithelium. Nuclear staining for p53 was observed in three patients from group 3 (two carcinoma, one adenoma) and four patients from group 4 (all carcinoma). CONCLUSION Our results describe changes in IGFBP-2 expression in colonic neoplasia in patients with and without acromegaly, which suggest that this binding protein may regulate local bioavailability of IGF, which in turn could modulate colonic cell proliferation and/or differentiation. [source]