Insulin-like Growth Factor Binding Research Articles

Serum phosphate: Does it more closely reflect the true state of acromegaly?

An increased serum phosphate (P) level is common in acromegaly patients, however, the relationships among P, growth hormone (GH), insulin-like growth factor 1 (IGF-1) and disease status remain unknown. To reveal these relationships, we examined the association of P with comprehensive clinical data. We measured the serum P, calcium, GH, oral glucose tolerance test-GH (OGTT-GH), IGF-1, and insulin-like growth factor binding protein-3 (IGBP-3) levels in 103 acromegaly patients. SAGIT® was used to assess the disease status comprehensively. Spearman’s rank correlation coefficient was obtained to evaluate the associations among the above parameters. Stepwise multiple linear regression analysis was performed to investigate factors independently associated factors with the SAGIT scores. The area under the receiver operating characteristic curve (AUCROC) was used to evaluate the efficacy of the percentage change in the serum phosphate level in predicting remission in patients with postoperatively discordant GH and IGF-1 levels. Hyperphosphatemia was found in 68.9% of patients at baseline. The serum P level was higher in the non-remission group, but no correlation was found between hyperphosphatemia and remission. We revealed a significant correlation between the P level and SAGIT® score in patients both preoperatively (r = 0.659, p = 0.000) and 1-year postoperatively without remission patients (r = 0.534, p = 0.027). All biochemical levels decreased significantly postoperatively, and the GH and OGTT-GH levels achieved early stability (1 month); however, the P, IGF-1 and IGBP-3 levels showed a gradual decline. A percentage change in P of −8.12% is recommended as a cut-off value for predicting remission in patients with postoperatively discordant GH and IGF-1 levels. As a metabolic product which affected by the GH/IGF-1 axis, serum P appears to more closely reflect the comprehensive disease status in acromegaly. When the GH and IGF-1 levels are discordant during follow-up, perioperative change in the P level may be a potential predictor of remission.

Pathogenic/likely pathogenic variants in the SHOX, GHR and IGFALS genes among Indian children with idiopathic short stature.

Background Our objective was to estimate the prevalence of pathogenic/likely pathogenic variants in the SHOX, GHR, and IGFALS genes among Indian children with idiopathic short stature (ISS), and assess the genotype-phenotype correlation. Methods We recruited 61 children with short stature, who were born appropriate for gestational age, had no obvious dysmorphism or disproportion, and in whom step-wise investigative work-up (including provocative growth hormone test) was normal. Multiplex ligation-dependent probe amplification was undertaken for identifying deletions/duplications in the SHOX gene. Bidirectional sequencing was performed for identifying variants in the SHOX and GHR genes in all, and for the IGFALS gene in those with serum insulin-like growth factor-1 (IGF-1) <-1 standard deviation. The genotype-phenotype correlation was studied. Results Four children (6.5%) had pathogenic heterozygous variants in the SHOX gene, with one child each having duplication of exon 5, splice site point variant c.278-1G > C in exon 3, partial deletion and complete deletion. None of the patients had pathogenic variants in the GHR gene. Of the 39 patients in whom the IGFALS gene was sequenced, novel heterozygous likely pathogenic variants were found in two children. One had the frameshift variant c.764_765insT, p.A265Gfs*114. The second had the missense variant c.1793G > A, p.R598H predicted by MutationTaster as 'disease causing', and indicated by the protein-modelling study as having compromised binding with IGF-1 and insulin-like growth factor binding protein-3 (IGFBP-3) due to altered conformation of the interacting loop. Conclusions Pathogenic variants in the SHOX and IGFALS genes account for a significant proportion of Indian children with ISS. Further molecular studies using next generation sequencing are needed to gain insight into pathophysiological mechanisms and effective treatment strategies for ISS.

138 ASAS-EAAP Exchange Speaker Talk: Immediate and long-term consequences of methylating micronutrient supplementation during pregnancy on the offspring’s phenotype

Abstract Environmental factors including maternal diet during periconception and pregnancy can immediately impact fetal growth and development and have long-term consequences on phenotypic outcomes of the offspring, a phenomenon known as “fetal programming” by which the in utero environmental cues regulate specific gene functions via epigenetic modifications. This prompted us to investigate the effects of a methylating micronutrient-rich maternal diet in pregnant Pietrain sows fed either a standard (CON) or supplemented diet with methionine, folate, choline, B6, B12, and zinc (MET). Our results showed an association between increased fetal weight and MET. Microarray-based transcriptional responses of the liver were analyzed at 35, 63, and 91-days post-conception (dpc). Altered insulin-like growth factor (IGF) signaling led us to investigate IGF-2 and insulin-like growth factor binding proteins (IGFBPs) in the muscle and liver. Indeed, weight differences and modulated IGF pathways reflected increased and decreased levels of the muscle IGF-2 and IGFBP-2 in MET, respectively. We extended the study to further investigate the effects of MET on transcriptome and DNA-methylation of the liver at two ontogenetic stages (91-dpc (fetal) and 150-days post-natal (adult)) and breeds (German-Landrace and Pietrain) using RNA-Seq and bisulfite-sequencing (RRBS). The results showed numerous differentially expressed genes (DEGs) depending on stage, sex, breed and maternal diet. Ingenuity Pathway Analysis of DEGs (MET vs CON) highlighted regulations of genes related to nucleic acid metabolisms including DOT1L, SLBP, TCF3 and RPA1 in the fetuses, while genes involved in lipid metabolisms including PON3, ACSM2B, CYP4F2 and LDHB were altered by MET in the adults. Several genes showed an inverse relationship between gene expression and DNA-methylation state of the promoter including CBFA2T3, CPEB4 and TUBB4B. Altogether, our results provide evidence demonstrating immediate and long-term consequences of methylating micronutrient supplementation during pregnancy on phenotypic outcomes of the pig offspring reinforcing epigenetic modulation via intervening maternal diet.

IGF1R undergoes active and directed centripetal transport on filopodia upon receptor activation.

Filopodia are thin, actin-based membrane protrusions with roles in sensing external mechanical and chemical cues, such as growth factor gradients in tissues. It was proposed that the chemical sensing role of filopodia is achieved through clearance of activated signaling receptors from filopodia. Type I insulin-like growth factor receptor (IGF1R) is a key regulator of normal development and growth, as well as tumor development and progression. Its biological roles depend on its activation upon IGF1 binding at the cell membrane. IGF1R behavior at the cell membrane and in particular in filopodia, has not been established. We found that IGF1 activation led to a gradual reduction in IGF1R puncta in filopodia, and that this clearance depended on actin, non-muscle myosin II, and IGF1R kinase activity. Using single particle tracking of filopodial IGF1R, we established that ligand-free IGF1R undergoes non-directional unidimensional diffusion along the filopodium. Moreover, after initial diffusion, the ligand-bound IGF1R is actively transported along the filopodium towards the filopodium base, and consequently cleared from the filopodium. Our results show that IGF1R can move directionally on the plasma membrane protrusions, supporting a sensory role for filopodia in interpreting local IGF1 gradients.

Gonadotropin versus Follicle-Stimulating Hormone for Ovarian Response in Patients Undergoing in vitro Fertilization: A Retrospective Cohort Comparison

Poor ovarian responders generally refer to patients who respond poorly to ovarian stimulation for assisted reproductive techniques (ART) such as in-vitro fertilization (IVF) and hence experience low live birth rate. Various controlled ovarian stimulation (COS) protocols have been developed during the past 3 decades for IVF/ICSI to improve oocyte quality and ultimately live birth rate, to increase ovarian response in POR patients, and to reduce the risk of ovarian hyperstimulation syndrome. Both highly puri?ed human menopausal gonadotropin (hp-hMG) and recombinant follicle-stimulating hormone (rFSH) have been widely used for COS during IVF/ICSI. Their in?uence on treatment outcome in women undergoing IVF/ICSI hasbeen actively debated. To compare highly purified human menopausal gonadotropin (hp-hMG) and recombinant follicle-stimulating hormone (rFSH) in patients with poor ovarian response undergoing in vitro fertilization/intracytoplasmic sperm injection with a gonadotropin-releasing hormone antagonist protocol. This retrospective cohort study included 60 patients with poor ovarian response (30 received hp-hMG and 30 received rFSH) undergoing in vitro fertilization/intracytoplasmic sperm injection with a gonadotropin-releasing hormone antagonist protocol. Pregnancy-related outcomes, ovarian response, oocyte, and embryo parameters were compared between the 2 groups. Additionally, serum insulin-like growth factor-1 and insulin-like growth factor binding protein-1 levels on the day of oocyte retrieval were compared between the 2 groups. The 2 treatments resulted in comparable numbers of oocytes retrieved and embryos, comparable oocyte retrieval rate, mature oocyte rate, and fertilization rate, and also comparable clinical pregnancy rates, implantation rates, and miscarriage rate. However, hp-hMG led to statistically insignificant higher viable embryo rate (54.0% vs 44.8%; P = 0.174) and live birth rate per pregnancy (16.7% vs 10%) versus rFSH. Finally, statistically significantly higher serum insulin-like growth factor-1 level (178.53 [13.70] ng/mL vs 164.93 [12.17] ng/mL; P = 0.01) and statistically insignificantly lower serum insulin-like growth factor binding protein-1 level (19.53 [3.56] ng/mL vs the lower insulin-like growth factor binding protein-1 level SD is (2.76 [20.83] ng/mL; P > 0.05) on the day of oocyte retrieval were associated with hp-hMG versus rFSH. hp-HMG and rFSH did not lead to significantly different treatment outcomes in patients with poor ovarian response undergoing in vitro fertilization/intracytoplasmic sperm injection with a gonadotropin-releasing hormone antagonist protocol, although significantly higher serum insulin-like growth factor-1 level and insignificantly lower serum insulin-like growth factor binding protein-1 level on the day of oocyte retrieval associated with hp-HMG might suggest a beneficial endocrine environment. (Curr Ther Res Clin Exp. 2020; 81:XXX-XXX).

Growth hormone deficiency in megalencephaly-capillary malformation syndrome: An association with activating mutations in PIK3CA.

Megalencephaly-capillary malformation syndrome (MCAP) is a brain overgrowth disorder characterized by cortical malformations (specifically polymicrogyria), vascular anomalies, and segmental overgrowth secondary to somatic activating mutations in the PI3K-AKT-MTOR pathway (PIK3CA). Cases of growth failure and hypoglycemia have been reported in patients with MCAP, raising the suspicion for unappreciated growth hormone (GH) deficiency. Here we report an observational multicenter study of children with MCAP and GH deficiency. Eleven participants were confirmed to have GH deficiency, all with very low or undetectable circulating concentrations of insulin-like growth factor-1 and insulin-like growth factor binding protein-3. Seven underwent GH stimulation testing and all had insufficient responses with a median GH peak of 3.7 ng/ml (range 1.1-8.6). Growth patterns revealed a drastic decline in length z-scores within the first year of life but then stabilized afterward. Five were treated with GH; one discontinued due to inconsolability. The other four participants continued on GH with improvement in linear growth velocity. Other endocrinopathies were identified in 7 of the 11 participants in this cohort. This study indicates that GH deficiency is associated with MCAP and that children with MCAP and hypoglycemia and/or postnatal growth failure should be evaluated for GH deficiency and other endocrinopathies.

Effects of food deprivation on plasma insulin-like growth factor-1 (Igf1) and Igf binding protein (Igfbp) gene transcription in juvenile cabezon (Scorpaenichthys marmoratus)

The growth hormone (GH)/insulin-like growth factor (Igf) endocrine axis regulates somatic growth in the face of changing environmental conditions. In actinopterygian fishes, food availability is a key modulator of the somatotropic axis, with lower food intake generally depressing liver Igf1 release to diminish growth. Igf1 signaling, however, also involves several distinct IGF binding proteins (Igfbps), and the functional roles of many of these Igfbps in affecting growth during shifting food availability remain uncertain. Here, we tested how complete food deprivation (fasting) affected gene transcription for paralogs of all six types of Igfbps in the liver and fast-twitch skeletal muscle of cabezon (Scorpaenichthys marmoratus), a nearshore marine fish important for recreational fisheries in the eastern North Pacific Ocean. Juvenile cabezon were maintained as either fed (6% mass food⋅g fish wet mass−1⋅d−1) or fasted for 14 d. Fasted fish exhibited a lower body condition (K), a depressed mass-specific growth rate (SGR), and reduced plasma concentrations of Igf1. In the liver, fasting reduced the relative abundance of gene transcripts encoding Igfbps igfbp2a and igfbp2b, while significantly elevating mRNA levels for igfbp1a, igfbp1b, igfbp3b, and igfbp4. Fasting also reduced hepatic mRNA levels of GH receptor-1 (ghr1) – but not GH receptor-2 (ghr2) – supporting the idea that changes in liver sensitivity to GH may underlie the decline in plasma Igf1 during food deprivation. In skeletal muscle, fasting downregulated gene transcripts encoding igf1, igfbp2b, igfbp5b, and igfbp6b, while also upregulating mRNAs for igf2 and ghr2. These data demonstrate isoform-specific regulation of Igfbps in liver and skeletal muscle in cabezon experiencing food deprivation and reinforce the idea that the repertoire of duplicated Igfbp genes that evolved in actinopterygian fishes supports a diverse scope of endocrine and paracrine functions.

Management of growth failure and growth hormone deficiency after pediatric allogeneic HSCT: Endocrinologists are of importance for further guidelines and studies

Growth failure (GF) is a frequent problem after pediatric allogeneic hematopoietic stem cell transplantation (HSCT). Growth hormone deficiency (GHD) occurs in 20 to 85%, but published data on the efficacy of growth hormone treatment (GHT) are conflicting. Currently, there are no recommendations on screening for and treatment of GHD after HSCT. We aimed to describe the management of endocrine follow-up (FU)and details of GHT within European Society for Blood and Marrow Transplantation (EBMT) centers.In a retrospective questionnaire study, all EBMT centers performing pediatric HSCT were invited. Results were evaluated in correlation with the structure of endocrine aftercare (HSCT-clinicians and endocrinologists).The majority of centers (80%) reported endocrine FU by an endocrinologist – either within the HSCT-center or in a separate endocrine clinic. Fifty-four percent reported FU outside of the HSCT-center. As diagnostic tests the insulin-like growth factor IGF-I and insulin-like growth factor binding protein IGFBP3, insulin tolerance test and arginine stimulation test were most frequently used. Sixty-four percent of centers performed GHT and endocrinologists were more likely to prescribe GH (74%) compared to HSCT-clinicians (33%). The most frequent indication for GHT was GHD in 60%, with a distinct different approach of endocrinologists in comparison with HSCT-clinicians.Our study reveals substantial variation in practice and emphasizes the need for endocrine aftercare performed by dedicated endocrinologists in close collaboration with the HSCT-center. Our results indicate that the management of GHT depends on the structure of endocrine aftercare, which is important for the future development and distribution of studies and guidelines.

Structural basis of the activation of type 1 insulin-like growth factor receptor

Type 1 insulin-like growth factor receptor (IGF1R) is a receptor tyrosine kinase that regulates cell growth and proliferation, and can be activated by IGF1, IGF2, and insulin. Here, we report the cryo-EM structure of full-length IGF1R–IGF1 complex in the active state. This structure reveals that only one IGF1 molecule binds the Γ-shaped asymmetric IGF1R dimer. The IGF1-binding site is formed by the L1 and CR domains of one IGF1R protomer and the α-CT and FnIII-1 domains of the other. The liganded α-CT forms a rigid beam-like structure with the unliganded α-CT, which hinders the conformational change of the unliganded α-CT required for binding of a second IGF1 molecule. We further identify an L1–FnIII-2 interaction that mediates the dimerization of membrane-proximal domains of IGF1R. This interaction is required for optimal receptor activation. Our study identifies a source of the negative cooperativity in IGF1 binding to IGF1R and reveals the structural basis of IGF1R activation.

Enhanced Platelet Sensitivity to IGF-1 in Patients with Type 2 Diabetes Mellitus.

Diabetes mellitus is characterized by increased platelet activation which is determined by many factors including changes in the expression of membrane proteins. The aim of this study was to investigate the sensitivity of human platelets to the insulin-like growth factor (IGF) system in patients with poorly controlled type 2 diabetes mellitus (DM2). Ligand binding was analyzed using 125I-labelled IGF-1 and insulin, and relative expression of insulin-like growth factor 1 receptor (IGF-1R) and insulin receptor (IR) was evaluated by Western blotting. Platelet aggregation in the presence of IGF-1 was studied by the plate aggregometry assay. We found that platelets from DM2 patients exhibited significantly higher IGF-1 binding and upregulation of IGF-1R expression in comparison with healthy individuals. Both insulin binding and IR expression were lower in the DM2 group, but the differences with the healthy control were statistically insignificant. The potentiating effect of IGF-1 on the thrombin-induced activation of platelets was detected in both groups but was significantly more pronounced in the DM2 patients. The initial rate of platelet activation in the presence of IGF-1 positively correlated with the concentration of glycated hemoglobin. Platelets isolated from DM2 patients displayed elevated expression of the IGF-1R subunits, which might have contributed to the higher sensitivity of these cells to IGF-1 in thrombin-initiated aggregation by increasing the rate of platelet activation. However, further experiments are needed to investigate the role of IGF-1 in thrombotic complications that usually accompany diabetes.

Assessing the bioactivity of the codon optimized sfGFP-IGF1 fusion protein via interaction with IGFBP3 and induction of cell proliferation

BackgroundHuman insulin like growth factor-1 (IGF1) is a hormonal peptide associated with growth and development in mammalian. It has become a particularly attractive therapeutic target because of its role in various physiological processes. IGF1 binding to its receptor IGF1R on the surface of the cell triggers a signaling cascade leading to proliferative and anti-apoptotic events. ResultsWe constructed an adapter of codon optimized IGF1 gene with two different linkers; rigid: EAAAK (E) and flexible: GSGSG (G), which was cloned in the plasmid pRSET-sfGFP as a fusion partner to the superfolder form of green fluorescent protein (sfGFP), resulting in the constructs pRSET-sfGFP-IGF1-(E or G). The expressed 6× His tagged sfGFP-IGF1-E protein (36 kDa) was purified from the cytoplasm of E. coli by metal affinity chromatography. Its purity was confirmed by SDS-PAGE blue staining and immunoblotting with anti-His or anti-GFP antibodies. Proper folding of sfGFP-IGF1-E was confirmed by indirect ELISA that revealed the ability of the sfGFP-IGF1-E but not the sfGFP, to bind to the immobilized IGF binding protein 3 (IGFBP3), and the ability of IGFBP3 to bind to the immobilized sfGFP-IGF1-E. Both interactions were able to be detected by anti-GFP and anti-IGFBP3, respectively. XTT test confirmed the bioactivity of sfGFP-IGF1-E after MCF-7 and HepG2 cancer cell lines treatment with increased concentrations of sfGFP-IGF1-E. ConclusionsThe procedure described in this study facilitates the production of effectively sfGFP-IGF1-E fusion protein in sufficiently large amounts, which provides a promising curative compound for many disorders.

Active recovery shows favorable IGF-I and IGF binding protein responses following heavy resistance exercise compared to passive recovery

IGF-I and IGFBPs have important physiological modulatory effects and this study sought to examine the influence of active vs. passive recovery following a heavy resistance exercise on IGF-I and IGF binding protein (IGFBP) recovery responses. It was hypothesized that increased IGF-I and decreased inhibitory IGFBPs during active recovery may be reflective of cascades promoting physiological recovery. 18 untrained men ((AR n = 7, PR n = 11), age: 26 ± 4 years, height: 174 ± 8 cm, body mass: 75 ± 13 kg) performed either a protocol-specific 10 × 10 × 30% 1RM active (AR) or passive recovery (PR) session following a heavy resistance exercise session performed on a leg press device (10 × 10 1RM). Maximal isometric force production (MVC) and IGF- and IGFBPs were measured pre, post, 1-hr post, and next morning. A significantly greater relative response in IGF-I was observed in AR than in PR at post recovery and next morning (p < .01 and statistical trend, respectively) while absolute concentrations of IGFBP-1 at next morning were significantly higher in PR than AR (p < .05), and relative IGFBP-1 response from control to next morning in PR was significantly greater than in AR (p < .001). IGFBP-1 may be inhibitory to IGF-I biological action, thus the lower concentration of IGFBP-1 after AR may be considered favorable in terms of recovery due to its positive relationship with glucose metabolism and maintaining metabolic homeostasis. These results suggest that some of the benefits of an active recovery bout may be mediated by favorable IGF-I system responses (increased IGF-I and decreased IGFBP-1) in the hormonal milieu that may assist facilitating the cascade of physiological recovery processes following acute heavy resistance loading exercise.

Proline-containing peptides-New insight and implications: A Review.

The family of regulatory proline-containing peptides (PCPs), also known as glyprolines, exhibit significant biological activity. The group of glyprolines includes Gly-Pro (GP), Pro-Gly-Pro (PGP), cyclic Gly-Pro (cGP), as well as PGP derivatives, for example, N-acetylated PGP (N-a-PGP) and N-methylated PGP (N-m-PGP). PCPs are engaged in various biological processes including the proinflammatory neutrophil chemoattraction in lung diseases, inflammatory bowel diseases or ischemic stroke. Glyprolines have been also postulated to play an important role as atheroprotective and anticoagulant agents, exhibit neuroprotective effects in Parkinson's disease, as well as regulate insulin-like growth factor (IGF) homeostasis. It was also noticed that PCPs inhibit proliferation and migration of keratinocytes in wound healing, protection of the gastric mucosa and stimulation of its regeneration. The regulatory glyprolines are derived from endogenous and exogenous sources. Most PCPs are derived from collagen or diet protein degradation. Recently, great interest is concentrated on short proline-rich oligopeptides derived from IGF-1 degradation. The mechanism of PCPs biological activity is not fully explained. It involves receptor-mediated mechanisms, for example, N-a-PGP acts as CXCR1/2 receptor ligand, whereas cGP regulates IGF-1 bioavailability by modifying the IGF-1 binding to the IGF-1 binding protein-3. PGP has been observed to interact with collagen-specific receptors. The data suggest a promising role of PGP as a target of various diseases therapy. This review is focused on the effect of PCPs on metabolic processes in different tissues and the molecular mechanism of their action as an approach to pharmacotherapy of PCPs-dependent diseases.

Maternal transmission of an Igf2r domain 11: IGF2 binding mutant allele (Igf2rI1565A) results in partial lethality, overgrowth and intestinal adenoma progression

The cation-independent mannose 6-phosphate/insulin-like growth factor-2 receptor (M6P/IGF2R or IGF2R) traffics IGF2 and M6P ligands between pre-lysosomal and extra-cellular compartments. Specific IGF2 and M6P high-affinity binding occurs via domain-11 and domains-3-5-9, respectively. Mammalian maternal Igf2r allele expression exceeds the paternal allele due to imprinting (silencing). Igf2r null-allele maternal transmission results in placenta and heart over-growth and perinatal lethality (>90%) due to raised extra-cellular IGF2 secondary to impaired ligand clearance. It remains unknown if the phenotype is due to either ligand alone, or to both ligands. Here, we evaluate Igf2r specific loss-of-function of the domain-11 IGF2 binding site by replacing isoleucine with alanine in the CD loop (exon 34, I1565A), a mutation also detected in cancers. Igf2rI1565A/+p maternal transmission (heterozygote), resulted in placental and embryonic over-growth with reduced neonatal lethality (<60%), and long-term survival. The perinatal mortality (>80%) observed in homozygotes (Igf2rI1565A/I1565A) suggested that wild-type paternal allele expression attenuates the heterozygote phenotype. To evaluate Igf2r tumour suppressor function, we utilised intestinal adenoma models known to be Igf2 dependent. Bi-allelic Igf2r expression suppressed intestinal adenoma (ApcMin). Igf2rI1565A/+p in a conditional model (Lgr5-Cre, Apcloxp/loxp) resulted in worse survival and increased adenoma proliferation. Growth, survival and intestinal adenoma appear dependent on IGF2R-domain-11 IGF2 binding.

MiR-4429 prevented gastric cancer progression through targeting METTL3 to inhibit m6A-caused stabilization of SEC62

Gastric cancer (GC) has been recognized as the major reason for global cancer-associated mortality. SEC62 homolog, preprotein translocation factor (SEC62) has been documented to possess carcinogenic functions in cancers, but its influence on GC remains elusive. Present study aimed to uncover the impact and mechanism of SEC62 in GC. We validated the upregulation of SEC62 in GC samples by GEPIA, and revealed its high level in GC cell lines. Functionally, depletion of SEC62 hindered proliferation and encouraged apoptosis in GC cells. Furthermore, we found through Starbase 3.0 and validated that methyltransferase like 3 (METTL3) interacted with SEC62 to induce the m6A on SEC62 mRNA, therefore facilitated the stabilizing effect of IGF2 binding protein 1 (IGF2BP1) on SEC62 mRNA. Moreover, we predicted through miRmap and validated that miR-4429 targeted and inhibited METTL3 to repress SEC62. Rescue assays demonstrated that miR-4429 inhibited GC progression through METTL3/SEC62 axis. Together, our study firstly revealed that miR-4429 prevented gastric cancer progression through targeting METTL3 to inhibit m6A-caused stabilization of SEC62, indicating miR-4429 as a promising target for treatment improvement for GC.

Linear growth failure induced by systemic inflammation inhibiting IGF-1/IGFBP axis in rats with asymptomatic colitis

BackgroundChildren in poor areas show significant growth retardation that does not improve with an adequate supply of energy and nutrients, which may be related to asymptomatic intestinal infection caused by poor sanitation. Our objective was to explore the mechanism of intestinal inflammation inhibiting growth in the setting of asymptomatic colitis.MethodsForty-eight 3-week-old Wistar rats were randomly divided into three groups: the control group, colitis group (with asymptomatic colitis induced by 2.5% trinitrobenzenesulphonic acid) and pair-fed group (daily food intake matched to the pair in the colitis group). The linear growth was assessed, and the plasma levels of hormone and systemic cytokines were detected and compared by independent two-sample t-test or one-way ANOVA among groups.ResultsAt d5, the increases in the body length of the control, colitis and pair-fed groups were 1.65 ± 0.34 cm, 1.10 ± 0.30 cm and 1.38 ± 0.26 cm, respectively, and the increase in the body length in the colitis group was significantly less than that in the control group (P < 0.05). There were significant differences in the levels of hormone and cytokines among three groups (P < 0.05). Compared with the control group, rats in the colitis group exhibited linear growth failure, as well as higher expression of calprotectin, tumour necrosis factor-α, interleukin-6 and insulin-like growth factor binding protein 2, lower insulin-like growth factor-1 and insulin-like growth factor binding protein 3, and lower expression of nuclear factor kappa B in hepatocytes.ConclusionsIn addition to undernutrition, the systemic inflammatory response caused by asymptomatic colitis may inhibit the linear growth of rats by its influence on the insulin-like growth factor/insulin-like growth factor binding protein axis.

Fibroblast deficiency of insulin-like growth factor 1 receptor type 1 (IGF1R) impairs initial steps of murine pheochromocytoma development

Insulin-like growth factor 1 (IGF1) has a critical role in maintaining tumor phenotype and survival of already transformed murine pheochromocytoma (pheo) cells (MPC4/30) and it is required for the initial establishment of these tumors. However, the role of local IGF1/IGF1R system in tumor microenvironment has not been fully understood. In vivo, by subcutaneous injection of pheo cells in heterozygous IGF1R knockout mice (L/n), we found that the time of noticeable tumor appearance was delayed, and incidence was decreased in L/n group compared to control (L/L) mice. Once established, tumor proliferation, vascularization or growth rate did not differ between groups. In vitro, fibroblast from L/n and L/L mice were cultured to generate conditioned media (CM) and differential matrixes on which pheo cells were seeded. Proliferation rate was higher when pheo cells were cultured with CM, or in differential matrix generated by L/L murine fibroblasts. A diminished fibronectin (FN) expression and secretion from L/n fibroblast was associated with decreased expression of integrin subunits in tumor cells. Also, soluble factors as IGF1 and insulin-like growth factor binding protein 2 (IGFBP2) were reduced. Our data suggest that IGF1 signaling through IGF1R may contribute to tumor cells anchorage and survival by interaction with both matrix and soluble factors produced by tumor microenvironment fibroblasts.

1559-P: Differential Effects of Type 1 (T1D) and Type 2 Diabetes (T2D) on the Growth Hormone (GH)-Insulin-Like Growth Factor (IGF) Axis in Youth

T1D and T2D are characterized by hyperglycemia and insulin resistance (IR), but in T1D the IR occurs even in the absence of metabolic syndrome features. The loss of β-cell insulin secretion in T1D results in lower portal and thus hepatic insulin concentrations in T1D than in T2D or nondiabetic (non-DM) individuals, affecting the GH-IGF axis, as exogenous insulin is subcutaneously delivered in T1D. In this study, we examined how the GH-IGF axis differs by diabetes type, and how it relates to IR. This study included youth (mean age 15±2 years, 37% female) with T1D (n=16), T2D (n=27) and non-DM controls (n=38). A morning fasting blood sample was obtained to measure GH, IGF-1, and IGF binding proteins (IGF BP-1, 2 and 3). Hyperinsulinemic euglycemic clamps were performed to measure glucose infusion rate (GIR), an estimate of skeletal muscle IR, and serum free fatty acid (FFA) suppression. GH, IGF BP-1 and IGF BP-2 were higher in T1D compared to non-DM youth (Figure). Higher IGF BP-3 was associated with lower GIR (more muscle IR) in all youth, but lower IGF BP-1 and 2 were associated with lower GIR in non-DM youth only. Higher GH, IGF BP-1 and IGF BP-3 were associated with less FFA suppression (more adipose IR) in T1D youth only. The GH-IGF-1 axis is altered and is differentially correlated to IR in T1D versus T2D. These data provide clues regarding the unique phenotype of IR in T1D. Disclosure J.K. Snell-Bergeon: None. J.E.B. Reusch: Board Member; Self; American Diabetes Association. Other Relationship; Self; Merck &amp; Co., Inc. A.D. Baumgartner: None. M. Cree-Green: None. K.J. Nadeau: None. Funding American Diabetes Association (7-13-CD-10 to J.K.S-B.)

Sex hormone, insulin, and insulin-like growth factor signaling in recurrence of high stage endometrial cancer: Results from the NRG Oncology/Gynecologic Oncology Group 210 trial.

5509 Background: Sex hormone and insulin/insulin-like growth factor (IGF) axis signaling pathways play an important role in endometrial cancer development but their role in endometrial cancer recurrence is unknown. In this study GOG-8015 we evaluated these pathways in a prospective cohort of patients diagnosed with the most common type of endometrial cancer, endometrioid adenocarcinoma. Methods: Stage II-IV endometrioid endometrial adenocarcinoma patients (N = 816) enrolled in the GOG-210 study with pre-treatment specimens were tested for tumor mRNA and protein expression levels of IGF1, IGF2, IGF binding proteins ( IGFBP) -1and -3, the insulin (IR) and IGF-I receptors (IGF1R), and phosphorylated (activated) IR/IGF1R as well as estrogen (ER) and progesterone receptors (PR) using quantitative PCR and immunohistochemistry (IHC). Serum concentrations of insulin, IGF-I, IGFBP-3, estradiol, estrone and sex hormone binding globulin were measured using ELISAs. Hazard ratios (HR) and 95% confidence intervals (CI) for risk of recurrence were obtained from multivariable Cox proportional hazard’s models with adjustment for age, stage and grade. Results: Recurrence occurred in 280 (34%) cases during a mean of 5.4 years of follow-up. ER-positivity (HR 0.67, 95% CI 0.47-0.95), IR-positivity (HR 0.53, 95% CI 0.29-0.98) and serum IGF-I levels (highest versus lowest quartile, HR 0.66, 95% CI 0.47-0.92) were inversely associated with recurrence risk. Conversely, circulating estradiol (highest versus lowest tertile, HR 1.55, 95% CI 1.02-2.36) and insulin (per 10 uU/ml, HR 1.52, 95% CI 1.12-2.06) and phosphorylated IGF1R/pIR expression (HR 1.40, 95% CI 1.02-1.92) were associated with increased risk of recurrence. Conclusions: We identified novel sex hormone and insulin/IGF axis tissue and circulating biomarkers of recurrence in a prospective study of high stage endometrioid endometrial cancer. Circulating insulin and estradiol, and tissue phosphorylated (activated) IGR1R/IR were independently associated with recurrence. These findings support prioritizing studies to establish their clinical utility as prognostic biomarkers and to investigate new strategies that target these pathways for prevention and treatment of endometrial cancer recurrence.

SUN-267 Relationship between Height Velocity and Change of Serum Insulin-Like Growth Factor-1 and Insulin-Like Growth Factor Binding Protein-3 Concentrations during Gonadotropin-Releasing Hormone Agonist Treatment in Korean Girls with Idiopathic Central Precocious Puberty

Purpose : This study aims to investigate the effect of gonadotropin-releasing hormone agonist (GnRHa) on the growth velocity during treatment in Korean girls with idiopathic central precocious puberty (ICPP). Methods : Data was collected from 97 girls, diagnosed under 9 year of age and treated by GnRHa for at least 1 year between 2014 and 2015. Their body height, weight, ∆ Height standard deviation score (SDS), serum insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) concentrations and bone age were measured at the start and after a year of GnRHa treatment. Possible correlations between the variables were calculated. Results : During the treatment, height SDS, IGF-1 SDS, IGFBP-3 SDS and IGF-1/IGFBP-3 ratio significantly decreased. There were significant correlations between serum IGF-1 level and ∆ Height SDS (r=0.405, p=0.000), and between serum IGFBP-3 level and ∆ Height SDS (r=0.228, p=0.025). C allele had significant correlation with IGFBP-3 level (p=0.004) but had no significant correlation with ∆ Height SDS (p=0.947). Conclusions : The results suggest that the height velocity during GnRHa treatment may be related to serum IGF-1 and IGFBP-3 concentration thus GnRHa may affect GH-IGF-1 axis.