Distribution by Scientific Domains
Distribution within Medical Sciences

Terms modified by IGFBP-3

  • igfbp-3 level

  • Selected Abstracts

    Adipokine genes and prostate cancer risk

    Steven C. Moore
    Abstract Adiposity and adipocyte-derived cytokines have been implicated in prostate carcinogenesis. However, the relationship of adipokine gene variants with prostate cancer risk has not been thoroughly investigated. We therefore examined common variants of the IL6, LEP, LEPR, TNF and ADIPOQ genes in relation to prostate cancer in a case-control study nested within a large cohort of Finnish men. The study sample consisted of 1,053 cases of prostate cancer, diagnosed over an average 11 years of follow up, and 1,053 controls matched to the cases on age, intervention group and date of baseline blood draw. Logistic regression was used to model the relative odds of prostate cancer. We also examined genotypes in relation to serum insulin, IGF-1 and IGF-1:IGFBP-3 among 196 controls. Variant alleles at three loci (,14858A>G, ,13973A>C, ,13736C>A) in a potential regulatory region of the LEP gene conferred a statistically significant 20% reduced risk of prostate cancer. For example, at the ,14858A>G locus, heterozygotes and homozygotes for the A allele had an odds ratio (OR) of prostate cancer of 0.76 [95% confidence interval (CI) 0.62, 0.93] and 0.79 (95% CI 0.60, 1.04), respectively. At 13288G>A, relative to the GG genotype, the AA genotype was associated with a suggestive increased risk of prostate cancer (OR = 1.29; 95% CI 0.99,1.67; ptrend = 0.05). Polymorphisms in the IL6, LEPR, TNF and ADIPOQ genes were not associated with prostate cancer. Allelic variants in the LEP gene are related to prostate cancer risk, supporting a role for leptin in prostate carcinogenesis. 2008 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 patients

    Judith 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]

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

    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]

    Long term consequences of the 1944,1945 Dutch famine on the insulin-like growth factor axis

    Sjoerd G. Elias
    Abstract The insulin-like growth factor axis is highly responsive to nutritional status and may be involved as one of the underlying mechanisms through which caloric restriction could affect cancer risk. High levels of circulating insulin-like growth factor (IGF)-I, or IGF-I relative to IGF binding protein (IGFBP)-3 have been related to various human cancer types. In a group of 87 postmenopausal women, we found that childhood exposure to the 1944,1945 Dutch famine was associated with increased plasma levels of IGF-I and IGFBP-3, whereas IGFBP-1 and -2 levels were weakly decreased. These results are opposite to immediate responses seen under starvation and we hypothesize that this could indicate a permanent overshoot upon improvement of nutritional status after the famine. 2003 Wiley-Liss, Inc. [source]

    Prediagnostic levels of C-peptide, IGF-I, IGFBP -1, -2 and -3 and risk of endometrial cancer,

    Annekatrin Lukanova
    Abstract Conditions related to chronic hyperinsulinemia, such as obesity, noninsulin dependent diabetes mellitus and polycystic ovary syndrome, are associated with an increased risk of endometrial cancer. Elevated plasma IGF-I and decreased levels of IGF-binding proteins have been shown to be associated with increased risk of several cancer types that are frequent in affluent societies. We investigated for the first time in a prospective study the association of pre-diagnostic blood concentrations of C-peptide (a marker of pancreatic insulin production), IGF-I, IGFBP-1, -2 and -3 with endometrial cancer risk. A case-control study was nested within 3 cohorts in New York (USA), Ume (Sweden) and Milan (Italy). It included 166 women with primary invasive endometrial cancer and 315 matched controls, of which 44 case and 78 control subjects were premenopausal at recruitment. Endometrial cancer risk increased with increasing levels of C-peptide (ptrend = 0.0002), up to an odds ratio (OR) of 4.76 [95% confidence interval (CI) = 1.91,11.8] for the highest quintile. This association remained after adjustment for BMI and other confounders [OR for the top quintile = 4.40 (1.65,11.7)]. IGFBP-1 levels were inversely related to endometrial cancer [ptrend = 0.002; OR in the upper quintile = 0.30 (0.15,0.62)], but the association was weakened and lost statistical significance after adjustment for confounders [ptrend = 0.06; OR in the upper quintile = 0.49 (0.22,1.07)]. Risk was unrelated to levels of IGF-I, IGFBP-2 and IGFBP-3. Chronic hyperinsulinemia, as reflected by increased circulating C-peptide, is associated with increased endometrial cancer risk. Decrease in the prevalence of chronic hyperinsulinemia, through changes in lifestyle or medication, is expected to prevent endometrial cancer. 2003 Wiley-Liss, Inc. [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,

    Joan 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]

    Systemic Regulation of Distraction Osteogenesis: A Cascade of Biochemical Factors,,

    S. Weiss M.D.
    Abstract This study investigates the systemic biochemical regulation of fracture healing in distraction osteogenesis compared with rigid osteotomy in a prospective in vivo study in humans. To further clarify the influence of mechanical strain on the regulation of bone formation, bone growth factors (insulin-like growth factor [IGF] I, IGF binding protein [IGFBP] 3, transforming growth factor [TGF] ,1, and basic FGF [bFGF]), bone matrix degrading enzymes (matrix-metalloproteinases [MMPs] 1, 2, and 3), human growth hormone (hGH), and bone formation markers (ALP, bone-specific ALP [BAP], and osteocalcin [OC]) have been analyzed in serum samples from 10 patients in each group pre- and postoperatively. In the distraction group, a significant postoperative increase in MMP-1, bFGF, ALP, and BAP could be observed during the lengthening and the consolidation period when compared with the baseline levels. Osteotomy fracture healing without the traction stimulus failed to induce a corresponding increase in these factors. In addition, comparison of both groups revealed a significantly higher increase in TGF-,1, IGF-I, IGFBP-3, and hGH in the lengthening group during the distraction period, indicating key regulatory functions in mechanotransduction. The time courses of changes in MMP-1, bone growth factors (TGF-,1 and bFGF), and hGH, respectively, correlated significantly during the lengthening phase, indicating common regulatory pathways for these factors in distraction osteogenesis. Significant correlation between the osteoblastic marker BAP, TGF-,1, and bFGF suggests strain-activated osteoblastic cells as a major source of systemically increased bone growth factors during callus distraction. The systemic increase in bFGF and MMP-1 might reflect an increased local stimulation of angiogenesis during distraction osteogenesis. [source]

    TGF-, control of cell proliferation

    Shuan S. Huang
    Abstract This article focuses on recent findings that the type V TGF-, receptor (T,R-V), which co-expresses with other TGF-, receptors (T,R-I, T,R-II, and T,R-III) in all normal cell types studied, is involved in growth inhibition by IGFBP-3 and TGF-, and that TGF-, activity is regulated by two distinct endocytic pathways (clathrin- and caveolar/lipid-raft-mediated). TGF-, is a potent growth inhibitor for most cell types, including epithelial and endothelial cells. The signaling by which TGF-, controls cell proliferation is not well understood. Many lines of evidence indicate that other signaling pathways, in addition to the prominent T,R-I/T,R-II/Smad2/3/4 signaling cascade, are required for mediating TGF-,-induced growth inhibition. Recent studies revealed that T,R-V, which is identical to LRP-1, mediates IGF-independent growth inhibition by IGFBP-3 and mediates TGF-,-induced growth inhibition in concert with T,R-I and T,R-II. In addition, IRS proteins and a Ser/Thr-specific protein phosphatase(s) are involved in the T,R-V-mediated growth inhibitory signaling cascade. The T,R-V signaling cascade appears to cross-talk with the T,R-I/T,R-II, insulin receptor (IR), IGF-I receptor (IGF-IR), integrin and c-Met signaling cascades. Attenuation or loss of the T,R-V signaling cascade may enable carcinoma cells to escape from TGF-, growth control and may contribute to the aggressiveness and invasiveness of these cells via promoting epithelial-to-mesenchymal transdifferentiation (EMT). Finally, the ratio of TGF-, binding to T,R-II and T,R-I is a signal controlling TGF-, partitioning between two distinct endocytosis pathways and resultant TGF-, responsiveness. These recent studies have provided new insights into the molecular mechanisms underlying TGF-,-induced cellular growth inhibition, cross-talk between the T,R-V and other signaling cascades, the signal that controls TGF-, responsiveness and the role of T,R-V in tumorigenesis. 2005 Wiley-Liss, Inc. [source]

    Insulin-like growth factor (IGF) binding protein-3 regulation of IGF-I is altered in an acidic extracellular environment

    Kimberly E. Forsten
    While extracellular acidification within solid tumors is well-documented, how reduced pH impacts regulation of insulin-like growth factor-I (IGF-I) has not been studied extensively. Because IGF-I receptor binding is affected by IGF binding proteins (IGFBPs), we examined how pH impacted IGFBP-3 regulation of IGF-I. IGF-I binding in the absence of IGFBP-3 was diminished at reduced pH. Addition of IGFBP-3 reduced IGF-I cell binding at pH 7.4 but increased surface association at pH 5.8. This increase in IGF-I binding at pH 5.8 corresponded with an increase in IGFBP-3 cell association. This, however, was not due to an increase in affinity of IGFBP-3 for heparin at reduced pH although both heparinase III treatment and heparin addition reduced IGFBP-3 enhancement of IGF-I binding. An increase in IGF-I binding to IGFBP-3, though, was seen at reduced pH using a cell-free assay. We hypothesize that the enhanced binding of IGF-I at pH 5.8 is facilitated by increased association of IGFBP-3 at this pH and that the resulting cell associated IGF-I is IGFBP-3 and not IGF-IR bound. Increased internalization and nuclear association of IGF-I at pH 5.8 in the presence of IGFBP-3 was evident, yet cell proliferation was reduced by IGFBP-3 at both pH 5.8 and 7.4 indicating that IGFBP-3-cell associated IGF-I does not signal the cell to proliferate and that the resulting transfer of bound IGF-I from IGF-IR to IGFBP-3 results in diminished proliferation. Solution binding of IGF-I by IGFBP-3 is one means by which IGF-I-induced proliferation is inhibited. Our work suggests that an alternative pathway exists by which IGF-I and IGFBP-3 both associate with the cell surface and that this association inhibits IGF-I-induced proliferation. 2001 Wiley-Liss, Inc. [source]

    Insulin-like growth factors in patients with liver cysts

    Olgica Nedi
    Abstract Insulin-like growth factors (IGFs) play an important role in cell growth and differentiation, and the liver is the main source of IGFs and IGF-binding proteins (IGFBPs) that appear in the circulation. The effect of liver cysts on the circulating IGF system was studied in this work. Serum concentrations of IGF-I and -II were measured by radioimmunoassay, IGFBP patterns were characterised by ligand-affinity and immunoblotting, and a lectin-binding assay was used to investigate the glyco component of IGFBP-3 complexes. IGF-I and -II concentrations in patients with cysts were significantly lower compared to those in healthy individuals (P<0.0001 and P<0.01, respectively), and the decrease was related to age but not sex. The overall mean concentrations of IGF-I and -II were not significantly different whether the cysts were caused by Echinococcus granulosus, cross-reactive pathologies, or some other factor. IGFBP profiles correlated with the amount of IGF present: patients with lower IGF-I concentrations expressed decreased IGFBP-3 and elevated IGFBP-2 levels. Increased IGFBP-3 proteolytic activity in the patients' blood was not detected by immunoblotting. In the lectin-binding assay, IGFBP-3 complexes in the circulation of patients demonstrated reactivity similar to that in healthy persons, suggesting that the overall structure of the saccharide moieties of the IGFBP-3 complexes was not significantly altered due to liver cyst formation. J. Clin. Lab. Anal. 18:299,304, 2004. 2004 Wiley-Liss, Inc. [source]

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

    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]

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

    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]

    Microarray analysis reveals that leptin induces autocrine/paracrine cascades to promote survival and proliferation of colon epithelial cells in an Apc genotype-dependent fashion

    Jenifer I. Fenton
    Abstract The imbalance in systemic mediators of inflammation, such as leptin, is thought to be involved in obesity-associated cancers. In addition, systemic endocrine signals can influence the local autocrine/paracrine factors produced within this microenvironment to influence epithelial cell fate. We previously demonstrated that leptin preferentially promotes the survival and proliferation of colon epithelial cells possessing an Apc mutation (IMCE) but not model normal cells (YAMC). Therefore, the purpose of this study was to identify leptin-induced functional gene family changes which characterize the response of colon epithelial cells possessing an Apc mutation but not normal cells. Consistent with our knowledge of colon carcinogenesis, genes regulating the Wnt/,-catenin-mediated pathway including Mdm2, Pik3r1, and Rb1 were upregulated by leptin. Importantly, leptin induced IGF-mediated pathway gene expression changes and their protein products in IMCE cells. In the IMCE cells IGFBP-6, IGF-1, and Crim1 expression was upregulated, while IGFBP-2, IGFBP-3, IGFBP-4, IGFBP-5, and Nov expression was downregulated by leptin treatment. These data establish a biologically plausible mechanistic link between the elevated levels of growth factors and the increased risk of colon cancer associated with obesity. 2007 Wiley-Liss, Inc. [source]

    A pilot study to determine the short-term effects of a low glycemic load diet on hormonal markers of acne: A nonrandomized, parallel, controlled feeding trial

    Robyn Smith
    Abstract Observational evidence suggests that dietary glycemic load may be one environmental factor contributing to the variation in acne prevalence worldwide. To investigate the effect of a low glycemic load (LGL) diet on endocrine aspects of acne vulgaris, 12 male acne sufferers (17.0 0.4 years) completed a parallel, controlled feeding trial involving a 7-day admission to a housing facility. Subjects consumed either an LGL diet (n = 7; 25% energy from protein and 45% from carbohydrates) or a high glycemic load (HGL) diet (n = 5; 15% energy from protein, 55% energy from carbohydrate). Study outcomes included changes in the homeostasis model assessment of insulin resistance (HOMA-IR), sex hormone binding globulin (SHBG), free androgen index (FAI), insulin-like growth factor-I (IGF-I), and its binding proteins (IGFBP-I and IGFBP-3). Changes in HOMA-IR were significantly different between groups at day 7 (,0.57 for LGL vs. 0.14 for HGL, p = 0.03). SHBG levels decreased significantly from baseline in the HGL group (p = 0.03), while IGFBP-I and IGFBP-3 significantly increased (p = 0.03 and 0.03, respectively) in the LGL group. These results suggest that increases in dietary glycemic load may augment the biological activity of sex hormones and IGF-I, suggesting that these diets may aggravate potential factors involved in acne development. [source]

    Expression of insulin-like growth factors systems in cloned cattle dead within hours after birth

    Shijie Li
    Abstract Cloning by somatic nuclear transfer is an inefficient process in which many of the cloned animals die shortly after birth and display organ abnormalities. In an effort to determine the possible roles IGFs played in neonatal death and organ abnormalities, we have examined expression patterns of eight genes in insulin-like growth factor (IGF) systems (IGF1, IGF2, IGF1R, IGF2R, IGFBP-1, IGFBP-2, IGFBP-3, and IGFBP-4) in six organs (heart, liver, spleen, lung, kidney, and brain) of both neonatal death cloned bovines (n,=,9) and normal control calves (n,=,3) produced by artificial insemination (AI) using real-time quantitative RT-PCR. The effect of the age of the fibroblast donor cell on the gene expression profiles was also investigated. Aberrant expressions of six genes (IGF2, IGF1R, IGF2R, IGFBP-2, IGFBP-3, and IGFBP-4) were found in some studied tissues, but the expression of two genes (IGF1 and IGFBP-1) had similar levels with the normal controls. For the studied genes, kidney was the organ that was most affected (five genes) by gene downregulation, whereas spleen was the organ that was not affected. The two upregulation genes were in brain, but both of downregulation and upregulation were found in the heart, liver, and lung. The expression of three genes (IGF2R, IGFBP-4, and IGF2) in some tissues showed significant differences between AF cell-derived and FF cell-derived clones. Our results suggest that aberrations in gene expression within IGF systems were found in most cloned bovine tissues of neonatal death. Because IGF systems play an important role in embryo development and organogenesis, the aberrant transcription patterns detected in these clones may contribute to the defects of organs reported in neonatal death of clones. Mol. Reprod. Dev. 74: 397,402, 2007. 2006 Wiley-Liss, Inc. [source]

    ADAM12: a novel first-trimester maternal serum marker for Down syndrome

    PRENATAL DIAGNOSIS, Issue 13 2003
    Jennie 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 g/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 g/L at week 8 of pregnancy to 670 g/L at 16 weeks, and reached 12 000 g/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]

    Premenopausal Breast Cancer: Estrogen Receptor Status and Insulin-Like Growth Factor-I (IGF-I), Insulin-Like Growth Factor Binding Protein-3 (IGFBP-3), and Leptin

    THE BREAST JOURNAL, Issue 4 2009
    Jennifer Eng-Wong MD
    No abstract is available for this article. [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]

    Carbohydrate restriction, prostate cancer growth, and the insulin-like growth factor axis,

    THE PROSTATE, Issue 1 2008
    Stephen J. Freedland
    Abstract BACKGROUND Recent evidence suggests carbohydrate intake may influence prostate cancer biology. We tested whether a no-carbohydrate ketogenic diet (NCKD) would delay prostate cancer growth relative to Western and low-fat diets in a xenograft model. METHODS Seventy-five male SCID mice were fed a NCKD (84% fat,0% carbohydrate,16% protein kcal), low-fat (12% fat,72% carbohydrate,16% protein kcal), or Western diet (40% fat,44% carbohydrate,16% protein kcal). Low-fat mice were fed ad libitum and the other arms fed via a modified-paired feeding protocol. After 24 days, all mice were injected with LAPC-4 cells and sacrificed when tumors approached 1,000 mm3. RESULTS Despite consuming equal calories, NCKD-fed mice lost weight (up to 15% body weight) relative to low-fat and Western diet-fed mice and required additional kcal to equalize body weight. Fifty-one days after injection, NCKD mice tumor volumes were 33% smaller than Western mice (rank-sum, P,=,0.009). There were no differences in tumor volume between low-fat and NCKD mice. Dietary treatment was significantly associated with survival (log-rank, P,=,0.006), with the longest survival among the NCKD mice, followed by the low-fat mice. Serum IGFBP-3 was highest and IGF-1:IGFBP-3 ratio was lowest among NCKD mice while serum insulin and IGF-1 levels were highest in Western mice. NCKD mice had significantly decreased hepatic fatty infiltration relative to the other arms. CONCLUSIONS In this xenograft model, despite consuming more calories, NCKD-fed mice had significantly reduced tumor growth and prolonged survival relative to Western mice and was associated with favorable changes in serum insulin and IGF axis hormones relative to low-fat or Western diet. Prostate 68: 11,19, 2008. 2007 Wiley-Liss, Inc. [source]

    Role of insulin-like growth factor binding proteins in 1,,25-dihydroxyvitamin D3 -induced growth inhibition of human prostate cancer cells

    THE PROSTATE, Issue 1 2005
    LaMonica 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]

    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]


    ANZ JOURNAL OF SURGERY, Issue 11 2003
    Ian M. Holdaway
    Background: Insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) appear to influence the growth of breast cancer cells in vitro, and epidemiological studies suggest higher serum IGF-I levels increase the risk of breast cancer. IGF-I and IGFBP-3 have therefore been measured in women with advanced breast cancer to determine if changes in serum levels predict the response to treatment by chemotherapy. Methods: Serum IGF-I and IGFBP-3 levels were measured in 14 patients before and after 1 week of chemotherapy. Changes in serum levels were compared with duration of survival. Results: Mean basal serum levels of IGF-I and IGFBP-3 were not significantly different between patients with advanced breast cancer and controls or women with early breast cancer. Serum IGFBP-3 fell significantly 1 week after initiation of chemotherapy. Patient survival was not significantly related to baseline IGF-I or IGFBP-3 levels, but when the fall in serum levels 1 week after starting treatment was expressed either as absolute change or as a percentage of baseline, those individuals with a decrease in IGFBP-3 greater than the median had significantly poorer survival (median survival 5.5 months vs 18 months). These results were independent of other prognostic variables such as previous disease-free survival, and were also unaffected by the change in serum albumin with treatment. The fall in IGF-I and IGFBP-3 with chemotherapy mainly occurred in those with hepatic metastases, but prediction of survival was explained solely by the extent of the fall in IGFBP-3. Conclusions: This preliminary study has shown that serum IGFBP-3 falls significantly following initiation of chemotherapy and the extent of reduction significantly predicts the response to treatment. [source]

    Prognostic role of insulin-like growth factor receptor-1 expression in small cell lung cancer

    APMIS, Issue 12 2009
    Insulin-like growth factor receptor-1 (IGFR-1) is a cellular membrane receptor which is overexpressed in many tumors and seems to play a critical role in anti-apoptosis. The insulin-like growth factor binding protein-3 (IGFBP-3) is known as a growth suppressor in multiple signaling pathways. The aim of this study was to determine IGFR-1 and IGFBP-3 expression in small-cell lung cancer (SCLC) and analyze the prognostic value in patients with SCLC. We analyzed IGFR-1 and IGFBP-3 expression in 194 SCLC tissues by immunohistochemical staining. Correlative analyses between IGFR-1 and IGFBP-3 expression in SCLC and clinicopathologic factors were performed. A total of 117 patients had extensive disease (ED) (60.3%) and 77 had limited disease (39.7%). With the median follow-up duration of 49.5 months (24,82 months), the median progression-free survival (PFS) and overall survival (OS) were 7.2 months [95% confidence interval (CI): 6.4,8.0 months] and 14.4 months (95% CI: 12.7,16 months), respectively. IGFR-1 expression was observed in 154 of the 190 tumor tissues, whereas there was no IGFBP-3 expression. Multivariate analysis showed that stage (p < 0.001), response rate (p < 0.001), and lactate dehydrogenase (LDH) levels (p < 0.001) were the independent prognostic factors for PFS, and age (p = 0.014), LDH level (p < 0.001), and stage (p < 0.001) for OS. The IGFR-1 positivity was not associated with PFS or OS in the entire cohort. Subgroup analysis revealed that OS was significantly longer in patients with IGFR-1-positive tissue than IGFR-1-negative tissue in SCLC-ED (p = 0.034). These results suggest that IGFR-1 expression may be useful as a prognostic marker in patients with SCLC-ED. [source]

    Synthesis of insulin-like growth factor binding protein 3 in vitro in human articular cartilage cultures

    ARTHRITIS & RHEUMATISM, Issue 2 2003
    Tamar 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 osteoarthritis

    ARTHRITIS & RHEUMATISM, Issue 3 2002
    David 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]

    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]

    High-risk colorectal adenomas and serum insulin-like growth factors

    A. G. Renehan
    Background: This study investigated the hypothesis that circulating levels of insulin-like growth factor (IGF) I and its main binding protein (IGFBP-3) predict for the presence of colorectal adenomas, surrogate markers of colorectal cancer risk. Methods: Within the Flexi-Scope Trial (healthy volunteers aged 55,64 years), at one study centre, IGF-I and IGFBP-3 levels in serum samples collected prospectively from 442 attendants were measured. Of these, 100 individuals underwent a complete screening colonoscopy. There were 47 normal examinations, while in 11 examinations low-risk adenomas and in 42 examinations high-risk adenomas were identified. Estimates of relative risk (RR) for the adenomatous stages were calculated by means of unconditional logistic regression, adjusting for known risk factors. Results: Mean serum IGF-I and IGFBP-3 levels were similar in individuals with a normal colonoscopy finding and in those with low-risk adenomas. By contrast, the mean(s.d.) serum IGF-I level was increased (190(53) versus 169(54) g/l; P = 006) and the serum IGFBP-3 concentration was significantly decreased (322(060) versus 347(062) mg/l; P = 005) in individuals with high-risk adenomas compared with levels in those with normal colonoscopy and low-risk adenomas combined. Levels were unaffected by removal of the adenomas. With high-risk adenoma as the dependent factor, regression models demonstrated a significant positive association with IGF-I after controlling for IGFBP-3 (RR per one standard deviation (1s.d.) change 439 (95 per cent confidence interval (c.i.) 131,147); P = 002) and, independently, an inverse association with IGFBP-3 after adjustment for IGF-I (RR per 1s.d. change 041 (95 per cent c.i. 020,082); P = 001). Conclusion: These findings suggest that circulating IGF-I and IGFBP-3 levels are related to future colorectal cancer risk and, specifically, may predict adenoma progression. 2001 British Journal of Surgery Society Ltd [source]

    Serum Insulin-like Growth Factors, Insulin-like Growth Factor-binding Protein-3, and Risk of Lung Cancer Death: A Case-control Study Nested in the Japan Collaborative Cohort (JACC) Study

    CANCER SCIENCE, Issue 12 2002
    Kenji Wakai
    To elucidate the roles of insulin-like growth factors (IGFs) in the development of lung cancer, we conducted a case-control study nested within the Japan Collaborative Cohort Study. Serum samples were collected at baseline from 39 140 men and women between 1988 and 1990. We measured serum IGF-I, IGF-II, and IGF-binding protein-3 (IGFBP-3) in 194 case subjects who subsequently died from lung cancer during an 8-year follow-up and in 9351 controls. The odds ratios (ORs), adjusted for smoking and other covariates, were smaller with higher levels of IGF-II and IGFBP-3. The ORs across quartiles were 0.41 (95% confidence interval [CI], 0.27,0.63), 0.47 (0.31,0.71), and 0.67 (0.46,0.98) for IGF-II (trend P=0.018), and 0.55 (95% CI, 0.37,0.81), 0.54 (0.36,0.82), and 0.67 (0.45,1.01) for IGFBP-3 (trend P=0.037). These peptides were not independently related to lung cancer risk when mutually adjusted. The risk was increased in the highest vs. the lowest quartile of IGF-I only after controlling for IGFBP-3 (OR, 1.74; 95% CI, 1.08,2.81). Limiting subjects to those followed for ,3 years strengthened the negative associations of IGF-II and IGFBP-3, whereas the ORs for IGF-I generally decreased. A higher level of circulating IGFBP-3 and/or IGF-II may decrease lung cancer risk. Elevated serum IGF-I may increase the risk, but this could partly be attributable to latent tumors. [source]

    Insulin-like Growth Factor (IGF)-I, IGF-binding Protein-3 and Colorectal Adenomas in Japanese Men

    CANCER SCIENCE, Issue 11 2002
    Satoshi Teramukai
    Several epidemiological studies have found that high levels of plasma insulin-like growth factor (IGF)-I and low levels of IGF-binding protein (IGFBP)-3 are related to an increased risk of colorectal cancer or late-stage adenomas. We examined the relation of body mass index, fasting and 2-h postload plasma glucose levels and plasma concentrations of IGF-I and IGFBP-3 to colorectal adenomas in middle-aged Japanese men. The study subjects comprised 157 cases of histologically diagnosed colorectal adenomas and 311 controls with normal colonoscopy or non-polyp benign lesions in a consecutive series of 803 men receiving a preretirement health examination at two hospitals of the Self Defense Forces (SDF). After adjustment for rank in the SDF, hospital, smoking and IGFBP-3, a statistically nonsignificant modest increase in the prevalence odds of colorectal adenomas was observed for the highest versus the lowest quartile level of IGF-I. The increase was slightly greater with further adjustment for 2-h glucose concentrations (adjusted odds ratio 1.8, 95% confidence interval 1.0,4.5, trend P=0.06). Men with high levels of IGFBP-3 showed only a minimal decrease in risk after adjustment for IGF-I. The association with IGF-I was less evident for advanced adenomas (,5 mm in size or tubulovillous/villous). Fasting and 2-h glucose and body mass index were more strongly positively associated with colorectal adenomas than IGF-I, especially with advanced adenomas, independently of IGF-I and IGFBP-3. The findings suggest that plasma IGF-I and IGFBP-3 may be involved in colorectal tumorigenesis regardless of the stage in growth of adenoma, but not as a mediator for the effects of being overweight or of hyperglycemia. [source]

    Circulating IGF-I levels are associated with increased biventricular contractility in top-level rowers

    Giovanni Vitale
    Summary Background, The intensive physical activity is often associated with cardiac changes. Objectives, (i) To evaluate the IGF-I system and myocardial structure and function by standard Doppler echocardiography and Tissue Doppler in athletes and sedentary controls; and (ii) to determine any relationship between IGF-I system and echocardiographic parameters. Methods, Nineteen male top-level rowers and 19 age-matched healthy sedentary male controls underwent blood determination of fasting serum IGF-I, IGFBP-3 and acid-labile subunit levels and standard Doppler echocardiography combined with pulsed Tissue Doppler of posterior septal wall, left ventricular (LV) lateral mitral annulus and right ventricular (RV) tricuspid annulus. Myocardial presystolic (PSm), systolic (Sm), the ratio of early diastolic (Em) to atrial (Am) velocities as well as myocardial time intervals were calculated. Results, Rowers had higher serum IGF-I levels (P = 004), higher biventricular cavity dimensions and wall thicknesses compared to controls. They also had better LV and RV myocardial function than controls. In the rowers, IGF-I was associated with LV ejection fraction (r = 050, P = 003), RV PSm velocity (r = 055, P = 001) and with RV myocardial precontraction time (r = ,057, P = 001). These associations remained significant after adjusting for age and heart rate. Conclusions, Top-level athletes showed higher IGF-I levels and a better myocardial performance than controls, particularly for the RV systolic activity. The independent correlations between IGF-I and systolic parameters of the left (ejection fraction) and right (PSm velocity and precontraction time) ventricles may possibly indicate a role of IGF-I system in the modulation of myocardial inotropism in athletes. Further studies are needed to confirm this hypothesis. [source]