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vous system function has only recently been recognized. This is also the case for children with childhood-onset GH deficiency (GHD) where GH has been used to stimulate bone growth and enhance final adult height. Circulating IGF1 is transported across the blood-brain barrier and IGF1 and its receptors are also synthesized in the brain by neurons and glial and endothelial cells. Nevertheless, the relationship between circulating IGF1 and brain IGF1 remains unclear. This study, using a GH-deficient dwarf rat model and peripheral GH replacement, investigated the effects of circulating IGF1 during adolescence on IGF1 levels in the brain. Our results demonstrated that hippocampal IGF1 protein concentrations during adolescence are highly regulated by circulating IGF1, which were reduced by GHD and restored by systematic GH replacement. Importantly, IGF1 levels in the cerebrospinal fluid were decreased by GHD but not restored by GH replacement. Furthermore, analysis of gene expression using microarrays and RT-PCR indicated that circulating IGF1 levels did not modify the transcription of Igf1 or its receptor in the hippocampus but did regulate genes that are involved in microvascular structure and function, brain development, and synaptic plasticity, which potentially support brain structures involved in cognitive function during this important developmental period.

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ween serum IGF1 levels and the main characteristics of Graves' disease (GD): severity of hyperthyroidism, goiter size, presence of active Graves' ophthalmopathy (GO), antythyroid antibodies status and titer. DESIGN AND METHODS: This cross-sectional study included 98 newly diagnosed hyperthyroid patients with GD who presented consecutively at our clinic. The main measured parameters were: TSH, FT4, FT3, TT3, thyroglobulin,anti-thyroid peroxidase antibodies (TPOAb), anti-thyroglobulin antibodies (ATA), thyrotropin receptor antibodies (TRAb), IGF1. Patients were considered IGF deficient if IGF1 z score was ≤-2SD from mean for age. RESULTS: In GD patients, men had higher IGF1 levels (p=0.023) and IGF1 z scores (p=0.013) than women. 18.4% of GD patients were, at diagnosis, IGF1 deficient. Compared to patients without IGF1 deficiency, these patients presented higher thyroglobulin (median=72.55, IQR=116.02 vs median=11.40, IQR=80.74 ng/ml, p=0.002) and FT3 (median=11.30, IQR=7.64 vs median=7.33, IQR=5.72 pg/ml, p=0.027), and lower ATA (median=20, IQR=0 vs median=34.05, IQR=161 iu/ml, p<0.001) levels. Thyroglobulin was independently associated with IGF1 deficiency (AUROC=0.732, 95% CI: 0.620-0.844, p=0.002; cut-off for thyroglobulin=50.40 ng/ml, Se=77.8%, Sp=70%). IGF1 status was not influenced by gender (p=0.084), current smoking (p=0.558), goiter size (p=0.533), active ophthalmopathy (p=0.334), TRAb (p=0.239) or TPOAb status (p=0.367). CONCLUSIONS: Nearly one fifth of newly diagnosed GD patients had IGF1 deficiency. IGF1 deficiency was associated with lower ATA titers, higher thyroglobulin levels and more severe FT3 hyperthyroidism at diagnosis.

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scription factor, leading to production of IGF-I mRNAs and proteins. However, the precise mechanisms by which GH-activated Stat5b promotes IGF-I gene transcription have not been defined. Unlike other GH-regulated genes, there are no Stat5b sites near either of the two IGF-I gene promoters. Although dispersed GH-activated Stat5b binding elements have been mapped in rodent Igf1 gene chromatin, it is unknown how these distal sites might function as potential transcriptional enhancers. Here we have addressed mechanisms of regulation of IGF-I gene transcription by GH by generating cell lines in which the rat Igf1 chromosomal locus has been incorporated into the mouse genome. Using these cells we find that physiological levels of GH rapidly and potently activate Igf1 gene transcription while stimulating physical interactions in chromatin between inducible Stat5b-binding elements and the Igf1 promoters. We have thus developed a robust experimental platform for elucidating how dispersed transcriptional enhancers control Igf1 gene expression under different biological conditions.

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icipants with high myopia (-8.00 diopters or less) and 300 emmetropic controls (within +/-1.00 diopter). Twenty-one tag SNPs were selected from these candidate genes and were genotyped. Genotype data were analyzed by logistic regression. Multiple comparisons were corrected by running 15 000 permutations of case-control status. RESULTS: Although we did not find any significant association for IGF1 SNPs using single-marker analysis, we identified many windows with haplotype frequencies significantly different between case participants and control participants using a variable-sized sliding-window strategy. In particular, the most significant association was shown by a 3-SNP window consisting of rs12423791, rs7956547, and rs5742632 (omnibus test: asymptotic P(asym) = 3.70 x 10(-9) and empirical P(emp) = 6.67 x 10(-5)). There were 3 high-risk haplotypes: CAC (P(asym) = 2.35 x 10(-6); odds ratio [OR], 5.06), GAT (P(asym) = 3.56 x 10(-4); OR, 3.18), and GGC (P(asym) = 2.25 x 10(-3); OR, 25.10). There was 1 protective haplotype: GAC (P(asym) = 8.43 x 10(-4); OR, 0.63). On the other hand, our single-marker and haplotype analyses did not show any significant association for IGFBP3 and IGFBP4. CONCLUSIONS: IGF1 haplotypes are associated with genetic susceptibility to high myopia in Chinese adults, whereas IGFBP3 and IGFBP4 are unlikely to be important in the genetic predisposition to high myopia. CLINICAL RELEVANCE: IGF1 is associated with high myopia, and identifying the causal variants is important for understanding the underlying mechanisms.

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adult T-ALL patients. Since aberrant IGFBP7 expression was observed in a variety of neoplasia and was relevant for prognosis in T-ALL, we investigated the functional role of IGFBP7 in Jurkat and Molt-4 cells as in vitro models for T-ALL. METHODS: Jurkat and Molt-4 cells were stably transfected with an IGFBP7 over-expression vector or the empty vector as control. Proliferation of the cells was assessed by WST-1 assays and cell cycle status was measured by flow-cytometry after BrDU/7-AAD staining. The effect of IGFBP7 over-expression on sensitivity to cytostatic drugs was determined in AnnexinV/7-AAD assays. IGF1-R protein expression was measured by Western Blot and flow-cytometric analysis. IGF1-R associated gene expression profiles were generated from microarray gene expression data of 86 T-ALL patients from the Microarrays Innovations in Leukemia (MILE) multicenter study. RESULTS: IGFBP7-transfected Jurkat cells proliferated less, leading to a longer survival in a nutrient-limited environment. Both IGFBP7-transfected Jurkat and Molt-4 cells showed an arrest in the G0/G1 cell cycle phase. Furthermore, Jurkat IGFBP7-transfected cells were resistant to vincristine and asparaginase treatment. Surface expression and whole protein measurement of IGF1-R protein expression showed a reduced abundance of the receptor after IGFBP7 transfection in Jurkat cells. Interestingly, combination of the IGF1-R inhibitor NPV-AEW541 restored sensitivity to vincristine in IGFBP7-transfected cells. Additionally, IGF1-R associated GEP revealed an up-regulation of important drivers of T-ALL pathogenesis and regulators of chemo-resistance and apoptosis such as NOTCH1, BCL-2, PRKCI, and TP53. CONCLUSION: This study revealed a proliferation inhibiting effect of IGFBP7 by G0/G1 arrest and a drug resistance-inducing effect of IGFBP7 against vincristine and asparaginase in T-ALL. These results provide a model for the previously observed association between high IGFBP7 expression and chemotherapy failure in T-ALL patients. Since the resistance against vincristine was abolished by IGF1-R inhibition, IGFBP7 could serve as biomarker for patients who may benefit from therapies including IGF1-R inhibitors in combination with chemotherapy.

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mice to light induces a gene program in cortical vasoactive intestinal peptide (VIP)-expressing neurons that is markedly distinct from that induced in excitatory neurons and other subtypes of inhibitory neuron. We identify Igf1 as one of several activity-regulated genes that are specific to VIP neurons, and demonstrate that IGF1 functions cell-autonomously in VIP neurons to increase inhibitory synaptic input onto these neurons. Our findings further suggest that in cortical VIP neurons, experience-dependent gene transcription regulates visual acuity by activating the expression of IGF1, thus promoting the inhibition of disinhibitory neurons and affecting inhibition onto cortical pyramidal neurons.

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00;'>IGF1) promoted a lineage bias towards CD31(-)/34(+)/146(-) cells at the expense of CD31(-)/34(+)/146(+) cells. IGF1 was microencapsulated in poly(lactic-co-glycolic acid) scaffolds and implanted in the inguinal fat pad of C57Bl6 mice. Control-released IGF1 induced remarkable adipogenesis in vivo by recruiting endogenous cells. In comparison with the CD31(-)/34(+)/146(+) cells, CD31(-)/34(+)/146(-) cells had a weaker Wnt/beta-catenin signal. IGF1 attenuated Wnt/beta-catenin signaling by activating Axin2/PPARgamma pathways in SVF cells, suggesting IGF1 promotes CD31(-)/34(+)/146(-) bias through tuning Wnt signal. PPARgamma response element (PPRE) in Axin2 promoter was crucial for Axin2 upregulation, suggesting that PPARgamma transcriptionally activates Axin2. Together, these findings illustrate an Axin2/PPARgamma axis in adipogenesis that is particularly attributable to a lineage bias towards CD31(-)/34(+)/146(-) cells, with implications in adipose regeneration.

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poptosis/proliferation of hepatocytes and cholangiocytes. Primary cultures of rat hepatocytes and cholangiocytes were exposed to glycochenodeoxycholate or tauro-CDC in the presence or absence of insulin-like growth factor 1 receptor blocking antibody (alphaIR3), small interfering RNA for insulin-like growth factor 1, 17beta-estradiol or estrogen receptor antagonist (ICI 182,780). Proliferation was evaluated by proliferating cell nuclear antigen Western blot and apoptosis by measuring caspase-3 activity or annexin-V. RESULTS: In hepatocytes, the insulin-like growth factor 1 receptor blocker enhanced glycochenodeoxycholate-induced apoptosis and caused tauro-CDC to promote apoptosis. 17Beta-estradiol or the estrogen receptor antagonist (ICI 182,780) did not influence the apoptotic effect of glycochenodeoxycholate. In cholangiocytes, both glycochenodeoxycholate and tauro-CDC induced proliferation at 100microM, while they induced apoptosis at 1mM with a more pronounced effect of glycochenodeoxycholate. Apoptosis induced by 1mM glycochenodeoxycholate or tauro-CDC in cholangiocytes was enhanced by blocking insulin-like growth factor 1 receptor or by silencing insulin-like growth factor 1. 17Beta-estradiol counteracts glycochenodeoxycholate-induced cholangiocyte apoptosis by enhancing insulin-like growth factor 1 secretion and activating the insulin-like growth factor 1 system. CONCLUSIONS: Modulation of the IGF1 system could represent a potential strategy for the management of bile salts-induced liver injury.

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was described in 2004, only 16 mutations have been reported since. Moreover, the phenotype of affected patients as a consequence of ALS deficiency is still highly variable. We assessed whether children with idiopathic short stature (ISS) harbour mutations in IGFALS and characterized affected patients' phenotype.
DESIGN: Sixty-five children with ISS were enrolled in the study. Serum ALS levels were measured by ELISA, and IGFALS was sequenced.
RESULTS: A novel homozygous mutation in IGFALS, c.380T>C (p.L127P), was identified in two siblings of a consanguineous family. The proband, a 17·75-year-old male, was -1·9 SDS in height and -4·5 SDS in weight. Exaggerated stimulated GH (38 ng/ml) and extremely low IGF1 and IGFBP3 (<25 and <500 ng/ml, respectively) indicated GH insensitivity. Both affected siblings had low or no ALS (43 and 0 mU/ml, respectively). They were also mildly small for gestational age, severely underweight and showed osteopenia, insulin insensitivity and delayed and slow puberty progression.
CONCLUSIONS: Acid-labile subunit deficiency due to IGFALS mutations is a rare cause of growth retardation in children. The unique combination of features presented by the two affected siblings emphasizes the important role of IGF1 in bone formation, insulin regulation and the pubertal process, in addition to its crucial effect on growth. Long-term follow-up is indicated since the clinical outcome with respect to osteoporosis, diabetes mellitus and fertility has not been recognized.

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vation of a signaling pathway that causes an increased production of amyloid beta-peptide, the principal event in the pathogenesis of Alzheimer's disease. Here, by using long-term neuronal cultures as a model of aging, we show that astroglial cells are required to upregulate the expression of IGF1-R in neurons during in vitro senescence. Moreover, evidence is provided that the cross-talk between astrocytes and neurons is independent of cell-to-cell contact, and it is mediated by low molecular weight soluble factor(s) released by astrocytes in culture medium. These results suggest that astrocytes could play an important role in aging and age-related pathological processes.

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a current model, "ligand occupancy" of alphavbeta3 (i.e. the binding of extracellular matrix proteins) enhances signaling induced by IGF1 binding to IGF1R. We recently reported that IGF1 directly binds to alphavbeta3 and induces alphavbeta3-IGF1-IGF1R ternary complex formation. Consistently, the integrin binding-defective IGF1 mutant (R36E/R37E) is defective in inducing ternary complex formation and IGF signaling, but it still binds to IGF1R. Like alphavbeta3, integrin alpha6beta4 is overexpressed in many cancers and is implicated in cancer progression. Here, we discovered that alpha6beta4 directly bound to IGF1, but not to R36E/R37E. Grafting the beta4 sequence WPNSDP (residues 167-172), which corresponds to the specificity loop of beta3, to integrin beta1 markedly enhanced IGF1 binding to beta1, suggesting that the WPNSDP sequence is involved in IGF1 recognition. WT IGF1 induced alpha6beta4-IGF1-IGF1R ternary complex formation, whereas R36E/R37E did not. When cells were attached to matrix, exogenous IGF1 or alpha6beta4 expression had little or no effect on intracellular signaling. When cell-matrix adhesion was reduced (in poly(2-hydroxyethyl methacrylate-coated plates), IGF1 induced intracellular signaling and enhanced cell survival in an alpha6beta4-dependent manner. Also IGF1 enhanced colony formation in soft agar in an alpha6beta4-dependent manner. These results suggest that IGF binding to alpha6beta4 plays a major role in IGF signaling in anchorage-independent conditions, which mimic the in vivo environment, and is a novel therapeutic target.

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occlusion. A total of 40 male and 40 female rats were used, and malocclusion was created by moving the first molars mesially and the third molars distally in the experimental group. Animals were killed at the end of the second and fourth weeks. Haematoxylin and eosin (HE) staining was performed to monitor the changes in cartilage morphology and thickness. Immunohistochemistry and real-time PCR were used to detect the expression of IGF1, IGFR1 and IGFBP3. Osteoarthritis (OA)-like changes were observed in the experimental groups, with 2-week females showing larger OA-like regions than 2-week males (P < 0.05). Compared to their age- and sex-matched controls, both 2- and 4-week males in the experimental groups displayed increased cartilage thickness in the posterior regions (P < 0.05). Compared to their age- and sex-matched controls, the expression of IGF1 was lower in 2-week female group (P < 0.05), but higher in 4-week female, 2- and 4-week male experimental groups (P < 0.05). Similarly, the expression of IGFR1 was lower in 2-week female experimental group (P < 0.05), but higher in 2-week male experimental group (P < 0.05). The higher expression of IGFBP3 was observed in 2-week female, 2- and 4-week male experimental groups (P < 0.05). These results indicate that condylar cartilage from male and female rats respond differently to the malocclusion in early stage of OA, with more serious degeneration in females.

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nation that enhances the risk of osteoporotic fracture. INTRODUCTION: Osteoporosis is a complex disease with strong genetic influence, but the genes involved are ill-defined. We examined estrogen receptor beta (ESR2) polymorphisms in interaction with estrogen receptor alpha (ESR1) and insulin-like growth factor I (IGF1) variants in relation to the risk of osteoporotic fracture, BMD, and bone geometry. MATERIALS AND METHODS: In the Rotterdam study, a prospective population-based cohort of elderly white individuals, we studied six single nucleotide polymorphisms (SNPs) in ESR2 (n = 6343, 60% women). We analyzed the genetic variants in the form of haplotypes reconstructed by a statistical method. Results refer to the most frequent ESR2 haplotype 1 estimated from two SNPs in intron 2 and the 3'-untranslated region (UTR). Outcomes included vertebral and incident nonvertebral fractures, BMD, and hip structural analysis (HSA). We also studied the interaction with (the most frequent) ESR1 haplotype 1 estimated from the PvuII and XbaI polymorphisms and an IGF1 promoter CA-repeat. RESULTS: Compared with ESR2 haplotype 1 noncarriers, female homozygous carriers had a 1.8- and 1.4-fold increased risk of vertebral and fragility fractures. HSA showed that ESR2 haplotype 1 homozygote women had 2.6% thinner cortices, 1.0% increased neck width, and 4.3% higher bone instability (buckling ratios). For testing the gene interaction, we assumed a recessive model of ESR2 haplotype 1. Female homozygous carriers of ESR2 haplotype 1 and noncarriers of ESR1 haplotype 1 had a 3.5- and 1.8-fold increased risk of vertebral and fragility fractures (p(interaction) = 0.10). Such effects and interactions were stronger in women homozygous for the IGF1 192-bp allele, with 9.3-fold increased risk (p(interaction) = 0.002) for vertebral and 4.0-fold increased risk (p(interaction) = 0.01) for fragility fractures. Multilocus interaction analyses of fracture endured correction for multiple testing using Monte-Carlo simulations (p(interaction) = 0.02 for vertebral and p(interaction) = 0.03 for fragility fractures). Similar patterns of interaction were observed for BMD, cortical thickness, bone strength (section modulus), and instability (buckling ratio). In men, no such effects were observed. CONCLUSIONS: Variants of ESR2 alone and in interaction with ESR1 and IGF1 influence the risk of fracture in postmenopausal women. These findings reinforce the polygenic and complex character of osteoporosis.

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d age of female sexual maturation, measured by vaginal patency (VP). Among strains with normal lifespans (mean lifespan >600 d), delayed age of VP associated with greater longevity (P = 0.015), suggesting a genetically regulated tradeoff at least partly mediated by IGF1. Supporting this hypothesis, C57BL/6J females had 9% lower IGF1, 6% delayed age of VP, and 24% extended lifespan compared with C57BL/6J.C3H/HeJ-Igf1, which carries a C3H/HeJ allele on chromosome (Chr) 10 that increases IGF1. To identify genetic loci/genes that regulate female sexual maturation, including loci that mediate lifespan tradeoffs, we performed haplotype association mapping for age of VP and identified significant loci on Chrs 4 (Vpq1) and 16 (Vpq2 and 3). At each locus, wild-derived strains share a unique haplotype that associates with delayed VP. Substitution of Chr 16 of C57BL/6J with Chr 16 from a wild-derived strain significantly reduced IGF1 and delayed VP. Strains with a wild-derived allele at Vpq3 have significantly extended longevity compared with strains with other alleles. Bioinformatic analysis identified Nrip1 at Vpq3 as a candidate gene. Nrip1(-/-) females have significantly reduced IGF1 and delayed age of VP compared with Nrip1(+/+) females. We conclude that IGF1 may coregulate female sexual maturation and longevity; wild-derived strains carry specific alleles that delay sexual maturation; and Nrip1 is involved in regulating sexual maturation and may affect longevity by regulating IGF1 level.

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lso has been associated with lower serum levels of the binding protein. However, the association between this variant and prostate cancer is inconsistent. To test the hypothesis that inconsistencies are partly due to cancer grade-specific differences in strength and direction of associations, we reanalyzed data from our previous Durham Veterans Administration Hospital study of blacks and whites comprising 47 cases (19 African Americans) with Gleason sum > or = 7, 50 cases (30 African Americans) with Gleason sum < 7 and 93 controls (49 African Americans). Compared to controls, the association between carrying the IGFBP3 C allele and prostate cancer risk was in OR(Low-Gleason) = 4.0; 95% CI: 1.4-12.3 compared to OR(High-Gleason) = 1.0; 95% CI: 0.4-2.2. Association patterns were similar in African Americans (OR(Low-Gleason) = 3.6; 95% CI: 1.0-13.2 vs. OR(High-Gleason) = 1.4; 95% CI: 0.4-2.3) and whites (OR(Low-Gleason) = 5.6; 95% CI: 0.6-49.0 vs. OR(High-Gleason) = 0.6; 95% CI: 0.2-2.2). The inverse association between carrying the IGF1 (CA)19 repeat variant did not vary by grade or ethnicity. If confirmed in larger studies, these findings support the hypothesis that the association between IGFBP3 C allele and prostate cancer is grade specific in both ethnic groups.

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ional region (3'UTR) of IGF1 mRNA in angiogenic activity in osteosarcomas is still unknown. In the present study, we performed gain-of-function assays to investigate the role of IGF1-3'UTR in angiogenesis. For the first time, we demonstrated that IGF1 3'UTR increased VEGF expression and promotes angiogenesis in osteosarcoma cells. In addition, RNA-immunoprecipitation and luciferase reporter assays showed that IGF1 3'UTR was a direct target of miR-29s. Our data also demonstrated that there existed a competition of miR-29s between IGF1-3'UTR and VEGF mRNA, and IGF1-3'UTR promoted angiogenesis at least in part via sponging miR-29s. Taken together, our study suggests that IGF1-3'UTR functions as a ceRNA in promoting angiogenesis by sponging miR-29s in osteosarcoma.

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of lipid efflux from cells to apolipoproteins and plays an important role on formation of FL. In this study, we determined the effects of IGF1 on ABCA1 expression in GH-deficient mice to clarify its effects on FL. Western blotting, real-time PCR, and a luciferase assay were employed to examine the effect of IGF1. The binding of FoxO1 to the ABCA1 promoter was assessed by chromatin immunoprecipitation (ChIP) assay. Cholesterol accumulation was analyzed by Oil Red O stain and cholesterol content measurement. We confirmed that IGF1 upregulated the ABCA1 expression. The activity of a reporter construct containing the ABCA1 promoter was induced by IGF1, and this effect was blocked by LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K). Constitutively active Akt stimulated the ABCA1 promoter activity, and a dominant-negative mutant of Akt or mutagenesis of the FoxO1 response element abolished the effect of IGF1. A ChIP assay indicated that FoxO1 mediated IGF1 transcriptional activity by directly binding to the ABCA1 promoter region. For in vivo experiments, we used an inhibitor for the GH receptor (Pegvisomant) to reduce the IGF1 level. A high-fat diet induced FL in mice (C57BL/6J) given Pegvisomant treatment. IGF1 treatment stimulated ABCA1 expression to improve cholesterol accumulation in these mice. These results show that the PI3K/Akt/FoxO1 pathway contributes to the regulation of ABCA1 expression in response to IGF1 stimulation that suppressed FL in GH-deficient mice.

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sured the levels of IGF-IR mRNA in normal kidney and in Wilms tumor samples using solution hybridization/RNase protection assays. IGF-IR mRNA levels in the tumors were 5.8-fold higher than in adjacent normal kidney tissue. Among the tumors themselves, the levels of IGF-IR mRNA in those containing heterologous stromal elements were 2-fold higher (P < 0.01) than in tumors without these elements. IGF-IR gene (designated IGF1R) expression in the tumors was inversely correlated with the expression of the Wilms tumor suppressor gene WT1, whose inactivation appears to be a key step in the etiology of Wilms tumor. Cotransfection of Chinese hamster ovary cells with rat and human IGF-IR gene promoter constructs driving luciferase reporter genes and with WT1 expression vectors showed that the active WT1 gene product represses IGF-IR promoter activity in a dose-dependent manner. These results suggest that underexpression, deletion, or mutation of WT1 may result in increased expression of the IGF-IR, whose activation by IGF-II may be an important aspect of the biology of Wilms tumor.

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but IIS in astrocytes remains poorly understood. We therefore examined the IIS pathway in human astrocytes and developed models to reduce IIS at the level of the insulin or the IGF1 receptor (IGF1R). RESULTS: We determined IIS was present and functional in human astrocytes by immunoblotting and showed astrocytes express the insulin receptor (IR)-B isoform of Ir. Immunocytochemistry and cell fractionation followed by western blotting revealed the phosphorylation status of insulin receptor substrate (IRS1) affects its subcellular localisation. To validate IRS1 expression patterns observed in culture, expression of key pathway components was assessed on post-mortem AD and control tissue using immunohistochemistry. Insulin signalling was impaired in cultured astrocytes by treatment with insulin + fructose and resulted in decreased IR and Akt phosphorylation (pAkt S473). A monoclonal antibody against IGF1R (MAB391) induced degradation of IGF1R receptor with an associated decrease in downstream pAkt S473. Neither treatment affected cell growth or viability as measured by MTT and Cyquant(R) assays or GFAP immunoreactivity. DISCUSSION: IIS is functional in astrocytes. IR-B is expressed in astrocytes which differs from the pattern in neurons, and may be important in differential susceptibility of astrocytes and neurons to insulin resistance. The variable presence of IRS1 in the nucleus, dependent on phosphorylation pattern, suggests the function of signalling molecules is not confined to cytoplasmic cascades. Down-regulation of IR and IGF1R, achieved by insulin + fructose and monoclonal antibody treatments, results in decreased downstream signalling, though the lack of effect on viability suggests that astrocytes can compensate for changes in single pathways. Changes in signalling in astrocytes, as well as in neurons, may be important in ageing and neurodegeneration.

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e='font-weight:700;'>IGF1 3'UTR region and the risk of childhood acute lymphoblastic leukemia (ALL). METHODS: Questionnaires were applied to collect epidemiological data. The genotypes of IGF1 polymorphisms were tested in a population of 744 ALL patients and 1088 cancer-free controls utilizing Taqman. Cell functional studies included real-time PCR, cell culture and transfection and luciferase assays. RESULTS: We found that rs6214 homozygous AA genotype and rs6218 homozygous CC genotype were significantly associated with increased risk of childhood ALL. In addition, rs6218 CC genotype was associated with increased level of IGF1 mRNA in bone marrow, and the mutation in rs6218 led to aberrant binding capacity of hsa-miR-603 and hsa-miR-3941 in the 3'UTR of IGF1. CONCLUSION: Polymorphisms of rs6214 and rs6218 in the 3'UTR of IGF1 are associated with childhood ALL susceptibility, and the polymorphism of rs6218 is related with IGF1 expression at mRNA level.

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matrilin 1 (MATN1), melatonin receptor 1B (MTNR1B), tryptophan hydroxylase 1 (TPH1), and insulin-like growth factor 1 (IGF1) are reported to be associated with AIS in Chinese. However, these associations have not been replicated so far. To confirm the associations, we compared these SNPs with AIS predisposition and curve severity in a population of Japanese females consisting of 798 AIS patients and 1,239 controls. All the subjects were genotyped using the PCR-based Invader assay. We found no association of any of the SNPs with AIS predisposition or curve severity. Considering the statistical power and sample size of the present study, we concluded that these SNPs are not associated with either AIS predisposition or curve severity in Japanese.

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ects of IGF1 on cardiomyopathy have been described, but its potential role in improving DCM is less well characterized. We investigated the consequences of expressing a cardiac-specific transgene encoding locally acting IGF1 propeptide (muscle-produced IGF1; mIGF1) on disease progression in a mouse model of DCM [cardiac-specific and inducible serum response factor (SRF) gene disruption] that mimics some forms of human DCM. Cardiac-specific mIGF1 expression substantially extended the lifespan of SRF mutant mice, markedly improved cardiac functions, and delayed both DCM and HF. These protective effects were accompanied by an overall improvement in cardiomyocyte architecture and a massive reduction of myocardial fibrosis with a concomitant amelioration of inflammation. At least some of the beneficial effects of mIGF1 transgene expression were due to mIGF1 counteracting the strong increase in CTGF expression within cardiomyocytes caused by SRF deficiency, resulting in the blockade of fibroblast proliferation and related myocardial fibrosis. These findings demonstrate that SRF plays a key role in the modulation of cardiac fibrosis through repression of cardiomyocyte CTGF expression in a paracrine fashion. They also explain how impaired SRF function observed in human HF promotes fibrosis and adverse cardiac remodeling. Locally acting mIGF1 efficiently protects the myocardium from these adverse processes, and might thus represent a therapeutic avenue to counter DCM.

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d so far. In this study rs6218 located in the 3'UTR of IGF-1 was selected to evaluate its relationship with the risk of GC among Chinese population. METHODS: Questionnaire, SNaPshot genotype assay, real time PCR assay, cell transfection and the dual luciferase reporter assay were used in our study. RESULTS: SNP rs6218 in IGF-1 3'-UTR was involved in the occurrence of GC by acting as a tumor promotion factor while rs6128 acting as a risk factor. SNP rs6128 was also could be regulated by miR-603 which caused an up-regulation of IGF-1 in patients with UC and CC genotype. Furthermore, the carriers of UC and CC genotype presented a big tumor size as well as the high probability of metastasis. CONCLUSION: In conclusion, our findings have shown that the SNP rs6218 in IGF-1 3'-UTR, through disrupting the regulatory role of miR-603 in IGF-1 expression, rs16128 in IGF-1 might act as a promotion factor in the pathogenesis of GC.

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he precise molecular mechanisms which link between PCOS and EC remain unclear. It has been suggested that insulin resistance may contribute to the increased risk of EC in PCOS. The specific expression of genes related to the insulin-signalling pathway including the IGF system in the endometrium of women with PCOS has however never been measured and compared to that in women with EC without PCOS and control women without EC or PCOS. .
OBJECTIVES: To test the hypothesis that insulin signalling plays a key role in the development of EC in women with PCOS by measuring and comparing the expression of three key genes involved in the insulin signalling pathway (IGF1, PTEN and IGFBP1) in endometrial tissue obtained from three groups of women; PCOS without EC, women with EC without PCOS and non-PCOS women without EC (controls). We also aimed to determine the correlation between the gene expressions to various clinical variables among participants.
METHODS: This was a cross-sectional study of 102 women in 3 groups (PCOS, EC and controls) at a University teaching hospital in the United Kingdom. Clinical assessment (blood pressure, body mass index (BMI) and waist-hip-circumference ratio), venepuntures (fasting blood sugar, insulin, lipid profile, hormones) and endometrial tissue biopsies were taken in all participants. Endometrial tissue RNA extraction was performed before real time polymerase-chain-reaction for the genes of interest (IGF1, IGFBP1 and PTEN) was carried out. To compare the baseline characteristics of the study population, One-Way-ANOVA test or the Independent t-test was used. For variables that were not normally distributed, the Spearman correlation test was used to calculate the r value. A "p" value of <0.05 was considered statistically significant.
RESULTS: IGF1, IGFBP1 and PTEN gene expression were significantly up-regulated in the endometrium of PCOS and EC women compared to controls. However there was no significant difference in the expression of these genes in PCOS compared to EC endometrium. The BMI of women with PCOS and controls, were not significantly different (29.28 (± 2.91) vs 28.58 (± 2.62) kg/m(2)) respectively, women with EC however had a higher mean BMI (32.22 (± 5.70) kg/m(2)). PCOS women were younger (31.8 (± 5.97) years) than women with EC (63.44 (± 10.07) years) and controls (43.68 (± 13.12) years). The changes in gene expression were independent of BMI, waist hip ratio, estradiol and androgen levels. Protein validation test in the serum samples in the three groups were consistent with the gene findings.
CONCLUSION: Women with PCOS and EC have an increased endometrial expression of genes (IGF1, IGFBP1 and PTEN) involved in the insulin signalling pathway compared with control women. This may explain the increased risk of EC in PCOS women. This study provides a strong basis for clinical trials aiming to prevent EC in women with PCOS by investigating drugs targeting the insulin signalling pathway. This panel of genes may also serve as clinically useful early biomarkers which predict which women with PCOS will go on to develop EC.

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at miR-217 expression was downregulated in EOC tissue and inversely correlated with advanced FIGO stage, high histological grading and lymph node metastasis (P<0.01). Function analysis revealed that the ectopic expression of miR-217 in EOC cells inhibited cell proliferation, migration and invasion in vitro, as well as suppressed tumor growth in vivo. Bioinformatics analysis and dual luciferase assays identified insulin-like growth factor 1 receptor (IGF1R) as a direct target of miR-217 in EOC cells. Western blot assay showed that overexpression of miR-217 in EOC cells inhibited IGF1R expression. In addition, downregulation of IGF1R mimicked the tumor-suppressive effects of miR-217 in EOC cells, whereas the reintroduction of IGF1R partially abrogated the suppression effect induced by miR-217 on EOC cells. Collectively, these results demonstrated that miR-217 plays a tumor suppressor role in human epithelial ovarian cancer by directly targeting IGF1R gene, suggesting a new potential therapeutic target in EOC.

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ient as expected. METHODS: In order to anticipate potential molecular mechanisms of resistance to the p110alpha isoform-selective inhibitor BYL719, we developed resistant breast cancer cell lines, assessed the concomitant changes in cellular signaling pathways using unbiased phosphotyrosine proteomics and characterized the mechanism of resistance using pharmacological inhibitors. RESULTS: We found an increase in IGF1R, IRS1/IRS2 and p85 phosphorylation in the resistant lines. Co-immunoprecipitation experiments identified an IGF1R/IRS/p85/p110beta complex that causes the activation of AKT/mTOR/S6K and stifles the effects of BYL719. Pharmacological inhibition of members of this complex reduced mTOR/S6K activation and restored sensitivity to BYL719. CONCLUSION: Our study demonstrates that the IGF1R/p110beta/AKT/mTOR axis confers resistance to BYL719 in PIK3CA mutant breast cancers. This provides a rationale for the combined targeting of p110alpha with IGF1R or p110beta in patients with breast tumors harboring PIK3CA mutations.

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study, a total of 498 individuals including 173 HBV related cirrhosis patients, 171 HBV-related HCC patients, and 154 healthy controls were enrolled. Sixteen single nucleotide polymorphisms (SNPs) in IGF1, IGF2, IGF1R and IGF2R have been genotyped by employing SNaPshot assays. We found A/A genotype at rs3743251 of IGF1R was negatively associated with HBV related HCC [odds ratio (OR) = 0.38, 95% confidence interval (CI) = 0.20-0.72, P = 0.037]; A/G genotype decreased the risk of portal vein thrombosis (OR = 0.38, 95%CI = 0.18-0.82, P = 0.01). These results indicate that rs3743251 polymorphism in IGF1R is associated with the susceptibility of HBV-related HCC.

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ihydroxycoumarin (78DC) is a coumarin derivative that possesses diversified and favorable pharmacology profile to be considered in anticancer research against various malignancies. The present study was intended to investigate the antiproliferative and chemotherapeutic potentials of 78DC (20, 40, and 80 mg/kg BW) against DMBA (20 mg in olive oil)-induced mammary carcinoma Sprague-Dawley rats. We established the in silico approach for evaluation of the effect of 78DC on hormonal (estrogen receptor-α (ERα), progesterone receptor (PR)), growth factor receptors (EGFR and IGFR), 17ß-hydroxysteroid dehydrogenase type 1 (17ß-HD1), and aromatase. Effect of 78DC on estrogen synthesis, tumor growth, proliferation markers (Ki-67 and PCNA), cytokines (IL-10, IL-1ß, IL-12), chemokine (MCP-1), and cellular expressions of ERα, PR, EGFR, IGF1R, p-MAPK1/2, p-JNK1/2, p-Akt, 17ß-HD1, and aromatase was evaluated in mammary carcinoma bearing SD rats. DMBA induces large tumor burden and histological alterations in mammary gland with a subsequent increase in ERα, PR, EGFR, IGF1R, Ki-67, proliferating cell nuclear antigen (PCNA ), cytokines, and chemokine expressions. This was also correlated with the changes in rapid cell differentiation and proliferation. In contrast, 78DC treatment to the cancer-bearing animals abbreviated these changes and revealed to possess antitumorigenic and antiproliferative potentials. Further, a significant decrease in expressions of ERα, PR, EGFR, IGFR, p-MAPK1/2, p-JNK1/2, p-Akt, 17ß-HD1, and aromatase signifies a reduction in estrogen sensitivity and secondary signaling pathways that may contribute to the prevention of tumor growth. The current findings revealed that 78DC potentially reduce cancer cell proliferation and reverted mammary cancer-induced changes in experimental animals in a dose-dependent manner.

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studies (GWAS) involving 114,223 adults from six ethnic groups. The present study aimed to examine associations between these SNPs and height in Brazilian children. METHODS: Cross-sectional heights of 1,008 healthy unrelated 4.4- to 9.7-year-old children were evaluated. All genotypes were determined by allele-specific polymerase chain reactions. Height standard deviation scores (SDS) were generated for this population and regressed on allele counts. Linear regressions were performed to estimate the effect of individual SNPs or a polygenic allelic score on height. RESULTS: The T allele of rs8081612 (MAP3K3), the C allele of rs2871865 (IGF1R) and the G allele of rs2425019 (MMP24) were significantly associated with a 0.091-SDS greater height (95% CI 0.089-0.093, p = 0.001) by polygenic analysis. The mean height SDS difference between children with 2 'tall' alleles and children with 4 'tall' alleles was 0.24 SDS (95% CI 0.05-0.43, p = 0.01). The observed allelic effect is consistent with that found in previous GWAS. CONCLUSIONS: Polymorphisms in MAP3K3, MMP24 and IGF1R act additively on height in children of an admixed population. These results demonstrate the importance of these loci for children's height.

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network in cancer models. We highlight the oncogenic effects controlled by IGF1R and INSR in prostate cancer cells and show similarities as well as differences after receptor knockdown (KD). In PC3 prostate cancer cells stably transduced with inducible short hairpin RNAs, targeting IGF1R or INSR attenuated cell growth and proliferation ultimately driving cells into apoptosis. IGF1R KD triggered rapid and strong antiproliferative and proapoptotic responses, whereas these effects were less pronounced and delayed after INSR KD. Down-regulation of the antiapoptotic proteins myeloid cell leukemia-1 and survivin was observed in both KDs, whereas IGF1R KD also attenuated expression of prosurvival proteins B cell lymphoma-2 and B cell lymphoma-xL. Receptor KD induced cell death involved autophagy in particular upon IGF1R KD; however, no difference in mitochondrial energy metabolism was observed. In a mouse xenograft model, induction of IGF1R or INSR KD after tumor establishment eradicated most of the tumors. After 20 days of receptor KD, tumor cells were found only in 1/14 IGF1R and 3/14 INSR KD tumor remnants. Collectively, our data underline the oncogenic functions of IGF1R and INSR in prostate cancer namely growth, proliferation, and survival in vitro as well as in vivo and identify myeloid cell leukemia-1 and survivin as important mediators of inhibitory and apoptotic effects.

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c GK rat. To test this, we evaluated during pancreatic organogenesis: (1) the beta cell development in GK rats on embryonic day (E) 13.5 and E18.5; (2) IGF2 and IGF1 receptor (IGF1R) pancreatic protein production on E13.5 and E18.5; (3) the in vitro development of GK pancreatic rudiment on E13.5; and (4) the in vitro effect of IGF2 addition on beta cell mass. MATERIALS AND METHODS: Beta cell quantitative analyses were determined by immunohistochemistry and morphometry. IGF2 and IGF1R pancreatic protein production was evaluated using western blot analyses. Dorsal pancreatic rudiments were dissected on E13.5, separated from surrounding mesenchyme and cultured for 7 days without or with recombinant IGF2. RESULTS: While beta cell mass was already decreased on E18.5, the differentiation of the first beta cells was in fact normal in E13.5 GK pancreas. Moreover, defective IGF2 and IGF1R protein production was detected in GK pancreatic rudiment as early as E13.5. The isolated GK pancreatic rudiment as maintained in vitro mimics the GK beta cell deficiency observed in vivo. This last approach enabled us to show that GK beta cells were fully responsive to IGF2 as far as their net growth is concerned. CONCLUSIONS/INTERPRETATION: In diabetic GK rat, defective IGF2 and IGF1R protein production in embryonic pancreas precedes beta cell mass anomaly. IGF2 supplementation expands the pool of beta cells.

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in the treatment of PAH. Real-time PCR and western blot analysis were performed to evaluate the expression of H19, miR-200a, miR-675, insulin-like growth factor-1 receptor (IGF1R), and programmed cell death 4 (PDCD4). The value of systolic pulmonary artery pressure (SPAP) and the ratio of medial thickening in the monocrotaline (MCT) group were increased, whereas the melatonin treatment could decrease these values to some extent. The weights of RV (right ventricle), LV (left ventricle) + IVS (interventricular septal), and RV/(LV + IVS) in the MCT group were much higher than those in the MCT + melatonin and control groups. In addition, the expression of H19, miR-675, IGF1R mRNA, and IGF1R protein in the MCT group was the highest, whereas their expression in the control group was the lowest. The expression of miR-200, PDCD4 mRNA, and PDCD4 protein in the MCT group was the lowest, whereas their expression in the control group was the highest. Furthermore, H19 directly suppressed the expression of miR-200a, whereas miR-675-3p and miR-200a directly inhibited the expression of IGF1R and PDCD4, respectively. Finally, melatonin treatment inhibited cell proliferation; upregulated the expression of H19, miR-675-3p, and PDCD4; and downregulated the expression of miR-200a and IGF1R. This study demonstrated the role of H19-miR-675-3p-IGF1R- and H19-miR-200a-PDCD4-signaling pathways in the melatonin treatment of PAH.

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and BRAF(V600E) enhance PDEC proliferation and increase survival after exposure to apoptotic stimuli in a manner dependent on MEK/ERK and PI3K/AKT signaling. Interestingly, we find that activation of PI3K/AKT signaling occurs downstream of MAP-ERK kinase (MEK), and is dependent on the autocrine activation of the insulin-like growth factor (IGF) receptor (IGF1R) by IGF2. Importantly, IGF1R inhibition impairs KRAS(G12D)- and BRAF(V600E)-induced survival, whereas ectopic IGF2 expression rescues KRAS(G12D)- and BRAF(V600E)-mediated survival downstream of MEK inhibition. Moreover, we show that KRAS(G12D)- and BRAF(V600E)-induced tumor formation in an orthotopic model requires IGF1R. Interestingly, we show that while individual inhibition of MEK or IGF1R does not sensitize PDAC cells to apoptosis, their concomitant inhibition reduces survival. Our findings identify a novel mechanism of PI3K/AKT activation downstream of activated KRAS, illustrate the importance of MEK/ERK, PI3K/AKT, and IGF1R signaling in pancreatic tumor initiation, and suggest potential therapeutic strategies for this malignancy.

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ssion and role of miR—30a in human NSCLC. The expression of miR—30a is significantly decreased in clinical NSCLC tissues and cell lines. Overexpression of miR—30a inhibited NSCLC cell proliferation, G1/S and S/G2 transition in vitro, whereas suppression of miR—30a facilitated NSCLC cell proliferation, G1/S and S/G2 transition. Using a luciferase reporter assay, insulin—like growth factor 1 receptor (IGF1R) was determined to be a direct target of miR—30a. Furthermore, silencing IGF1R resulted in the same biologic effects of miR—30a overexpression in NSCLC cells, which included suppressed NSCLC cell proliferation and trigering cell cycle arrest through PI3K/AKT signaling pathway by inhibiting cell cycle regulators (CDK2, CDK4, Cyclin A2 , Cyclin D1). These results demonstrate that miR—30a influences NSCLC progression through PI3K/AKT signaling pathway by targeting IGF1R in A549 cells, which suggest miR—30a as a novel strategy for NSCLC diagnosis and treatment.

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is defect remains unclear. In this study, IGF1 signaling during fracture healing was investigated in an osteoblast-specific IGF1 receptor (IGF1R) conditional knockout (KO) mouse model. A closed tibial fracture was induced in IGF1R(flox/flox) /2.3-kb alpha1(1)-collagen-Cre (KO) and IGF1R(flox/flox) (control) mice aged 12 weeks. Fracture callus samples and nonfractured tibial diaphysis were collected and analyzed by muCT, histology, immunohistochemistry, histomorphometry, and gene expression analysis at 10, 15, 21, and 28 days after fracture. A smaller size callus, lower bone volume accompanied by a defect in mineralization, bone microarchitectural abnormalities, and a higher cartilage volume were observed in the callus of these KO mice. The levels of osteoblast differentiation markers (osteocalcin, alkaline phosphatase, collagen 1alpha1) were significantly reduced, but the early osteoblast transcription factor runx2, as well as chondrocyte differentiation markers (collagen 2alpha1 and collagen 10alpha1) were significantly increased in the KO callus. Moreover, increased numbers of osteoclasts and impaired angiogenesis were observed during the first 15 days of fracture repair, but decreased numbers of osteoclasts were found in the later stages of fracture repair in the KO mice. Although baseline nonfractured tibias of KO mice had decreased trabecular and cortical bone compared to control mice, subsequent studies with mice expressing the 2.3-kb alpha1(1)-collagen-Cre ERT2 construct and given tamoxifen at the time of fracture and so starting with comparable bone levels showed similar impairment in fracture repair at least initially. Our data indicate that not only is the IGF1R in osteoblasts involved in osteoblast differentiation during fracture repair, but it plays an important role in coordinating chondrocyte, osteoclast, and endothelial responses that all contribute to the endochondral bone formation required for normal fracture repair.

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r suggest that inhibition of the pathway might yield clinically effective therapeutics. METHODS: We describe A-928605, a novel pyrazolo [3,4-d]pyrimidine small molecule inhibitor of the receptor tyrosine kinases (IGF1R and IR) responsible for IGF signal transduction. This compound was first tested for its activity and selectivity via conventional in vitro kinome profiling and cellular IGF1R autophosphorylation. Additionally, cellular selectivity and efficacy of A-928605 were analyzed in an IGF1R oncogene-addicted cell line by proliferation, signaling and microarray studies. Finally, in vivo efficacy of A-928605 was assessed in the oncogene-addicted cell line and in a neuroblastoma model as a single agent as well as in combination with clinically approved therapeutics targeting EGFR in models of pancreatic and non-small cell lung cancers. RESULTS: A-928605 is a selective IGF1R inhibitor that is able to abrogate activation of the pathway both in vitro and in vivo. This novel compound dosed as a single agent is able to produce significant growth inhibition of neuroblastoma xenografts in vivo. A-928605 is also able to provide additive effects when used in combination with clinically approved agents directed against EGFR in non-small cell lung and human pancreatic tumor models. CONCLUSION: These results suggest that a selective IGF1R inhibitor such as A-928605 may provide a useful clinical therapeutic for IGF pathway affected tumors and warrants further investigation.

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type 4 (CXCR-4) and its ligand, stromal cell-derived factor-1 (SDF-1), plays an important role in cancer progression and metastasis. However, the molecular mechanism underling the CRCR4-mediated CRC metastasis has not been well characterized. In this study, we aimed to investigate the roles of CXCR4 in colorectal cancer using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-based genomic editing technique.
MATERIALS AND METHODS: We knocked-down CXCR4 using specific guide-RNA linked CRISPR/Cas9 in HT115 and COLO201 colon cancer cell lines which exhibited high levels of endogenous CXCR4 gene expression. Stable HT115 cells with CXCR4 knock-down were established by CRISPR plasmid transfection and validation was confirmed using T7 endonuclease 1 (T7EN1), flow cytometry (FACS) and western blotting assays.
RESULTS: Knock-down of CXCR4 did not decrease proliferation of HT115 cells, but decreased the adhesion potential of cells to the human umbilical vein endothelial cells (HUVEC) and extracellular matrix. We further demonstrated that the AKT and type 1 insulin-like growth factor receptor (IGF1R) signalling pathways may be involved in the alteration of adhesion in CRC cells when CXCR4 is knocked down.
CONCLUSION: Our data suggest that CXCR4 plays a key role in colorectal cancer progression via the mediation of tumor cell adhesion.

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efining the minimal critical region for this duplication syndrome. In both families the duplication (albeit a complex copy number gain in one family) is associated with tall stature, early speech delay and variable cognitive problems. Neither familial copy number gains encompass the gene encoding for the insulin-like growth factor 1 receptor (IGF1R), the most-cited candidate for the overgrowth phenotype. In one family, whole genome sequence data and break point mapping excludes disruption of known IGF1R regulatory elements due to potential insertion within these elements. These cases highlight the possibility that the distal region of 15q contains another gene regulating human growth, with LRRK1 being a potential candidate.