Serum insulin‐like growth factor‐I concentrations in late middle age: no association with birthweight in three UK cohorts

Background: Small body size at birth and during infancy is associated with an increased risk of adult osteoporosis and cardiovascular disease. Fetal programming of the growth hormone–insulin‐like growth factor (GH‐IGF) axis may provide a mechanism for these epidemiological findings. Aims: To determine whether measurements of GH and IGF‐I in late middle age were related to size at birth and in infancy. Methods: Overnight urinary GH excretion and fasting serum IGF‐I were measured in 309 men and 193 women from Hertfordshire (born 1920–1930) for whom birthweight and weight at 1 year were recorded. Serum IGF‐I was measured in men and women from Preston (n = 254, born 1935–1943) and Sheffield (n = 215, born 1939–1940) whose birthweight and other birth measurements were recorded. Results: Urinary GH and serum IGF‐I were not related to birthweight, other measurements at birth, or weight at 1 year. Conclusion: In contrast to previous studies in children or young adults, these data do not support the hypothesis that IGF‐I concentrations are programmed by intra‐uterine events, as assessed by birthweight, in late middle age.     

The insulin‐like growth factor system and sarcomas

Sarcomas are a diverse group of malignant mesenchymal tumours arising from bone and soft tissues. The identification of critical cellular signalling pathways in sarcomas is an important issue for the development of new targeted therapies. This review highlights the experimental and clinical evidence supporting the role of the insulin‐like growth factor (IGF) signalling system in the cellular transformation and progression of several types of sarcoma, including rhabdomyosarcoma, synovial sarcoma, leiomyosarcoma, Ewing's sarcoma and osteosarcoma. Preclinical data suggest that the IGF system could be a promising target for therapy in these sarcomas. Currently, therapies interrupting IGF signalling have been or are being developed. In recent phase 1 clinical studies with humanized monoclonal antibodies directed against IGF receptor type 1 (IGF‐1R), objective tumour responses were observed in several patients with Ewing's sarcoma, encouraging further clinical testing in Ewing's sarcoma and other sarcoma (sub)types. Moreover, the occasional occurrence of paraneoplastic hypoglycaemia as a result of the secretion of incompletely processed forms of pro‐IGF‐II by sarcomas is discussed. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Methylthioadenosine phosphorylase and activated insulin‐like growth factor‐1 receptor/insulin receptor: potential therapeutic targets in chordoma

Currently there is no effective chemotherapy for chordoma. Recent studies report co‐expression of insulin‐like growth factor‐1 receptor (IGF1R) and its cognate ligand in chordoma, but it is unknown whether this receptor tyrosine kinase is activated in these tumours. Additionally, genetic studies have confirmed frequent deletions of chromosome 9p in chordomas, which encompasses the cyclin‐dependent kinase inhibitor 2A (CDKN2A) locus. Another gene in this region, methylthioadenosine phosphorylase (MTAP), is an essential enzyme of the purine salvage pathway and has therapeutic relevance because MTAP‐deficient cells are particularly sensitive to inhibitors of de novo purine synthesis. We investigated whether these pathways might be potential therapeutic targets for chordoma. Paraffin‐embedded tissue samples from 30 chordomas were analysed by immunohistochemistry for expression of the phosphorylated isoforms of IGF1R or the insulin receptor (pIGF1R/pIR) and selected downstream signalling molecules, including BCL2‐associated agonist of cell death protein (BAD). Expression of CDKN2A and MTAP proteins was also assessed. Skeletal chondrosarcomas, benign notochordal cell tumours, and fetal notochord were studied for comparison. Phosphorylated IGF1R/IR was detected in 41% of chordomas, together with activated downstream signalling molecules, and pIGF1R/pIR was absent in benign notochordal cell tumours and fetal notochord. Thirty‐nine per cent of chordomas were negative for MTAP immunoreactivity. Patients with pIGF1R/pIR‐positive tumours showed significantly decreased median disease‐free survival in multivariate survival analysis (p = 0.036), whereas phosphorylation of BAD at serine‐99 was found to be associated with a favourable prognosis (p = 0.002). Approximately 40% of chordomas demonstrate evidence of activation of the IGF1R/IR signalling pathway or loss of a key enzyme in the purine salvage pathway. Aberrant signalling cascades and disrupted metabolic pathways such as these may represent opportunities for novel targeted therapeutic approaches for the treatment of chordoma. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

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

Chang MH, Lee J, Han J, Park YH, Ahn JS, Park K, Ahn M‐J. Prognostic role of insulin‐like growth factor receptor‐1 expression in small cell lung cancer. APMIS 2009; 117: 861–9. 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.     

Increased miR‐223 expression in T cells from patients with rheumatoid arthritis leads to decreased insulin‐like growth factor‐1‐mediated interleukin‐10 production

We hypothesized that the aberrant expression of microRNAs (miRNAs) in rheumatoid arthritis (RA) T cells was involved in the pathogenesis of RA. The expression profile of 270 human miRNAs in T cells from the first five RA patients and five controls were analysed by real‐time polymerase chain reaction. Twelve miRNAs exhibited potentially aberrant expression in RA T cells compared to normal T cells. After validation with another 22 RA patients and 19 controls, miR‐223 and miR‐34b were over‐expressed in RA T cells. The expression levels of miR‐223 were correlated positively with the titre of rheumatoid factor (RF) in RA patients. Transfection of Jurkat cells with miR‐223 mimic suppressed insulin‐like growth factor‐1 receptor (IGF‐1R) and transfection with miR‐34b mimic suppressed cAMP response element binding protein (CREB) protein expression by Western blotting. The protein expression of IGF‐1R but not CREB was decreased in RA T cells. The addition of recombinant IGF‐1‐stimulated interleukin (IL)‐10 production by activated normal T cells, but not RA T cells. The transfection of miR‐223 mimic impaired IGF‐1‐mediated IL‐10 production in activated normal T cells. The expression levels of SCD5, targeted by miR‐34b, were decreased in RA T cells after microarray analysis. In conclusion, both miR‐223 and miR‐34b were over‐expressed in RA T cells, but only the miR‐223 expression levels were correlated positively with RF titre in RA patients. Functionally, the increased miR‐223 expression could impair the IGF‐1‐mediated IL‐10 production in activated RA T cells in vivo, which might contribute to the imbalance between proinflammatory and anti‐inflammatory cytokines.     

Inhibited anabolic effect of insulin‐like growth factor‐I on stromal bone marrow cells in endothelial nitric oxide synthase‐knockout mice

Aims: Insulin‐like growth factor‐I (IGF‐I), parathyroid hormone (PTH) and PTH‐related protein (PTHrP) are hormones that have anabolic effects on bone formation. The aim of this study was to investigate whether production of nitric oxide (NO) is involved in the effect of IGF‐I and PTH/PTHrP on osteoblast‐like cells. Methods: Bone marrow stromal cells from adult endothelial nitric oxide synthase (eNOS)‐knockout (eNOSKO) mice and wild type (WT) counterparts were cultivated with osteogenic substances. The cells showed an osteoblastic phenotype measured as osteocalcin production and alkaline phosphatase activity. DNA synthesis was measured as [³H] thymidine incorporation in the bone marrow cells and in a human osteosarcoma cell‐line (SaOS‐2). Results: The stimulatory effect of IGF‐I on thymidine incorporation seen in WT animals was absent in eNOSKO mice. Addition of a NO donor to eNOSKO cells recovered the effect of IGF‐I on thymidine incorporation. PTH/PTHrP stimulated cell proliferation in both WT and eNOSKO mice. In SaOS‐2 cells, incubation with IGF‐I together with a NOS inhibitor resulted in an inhibition of the anabolic effect of IGF‐I on cell proliferation. Conclusions: The stimulatory effect of IGF‐I on WT cell proliferation was abolished in eNOSKO cells, recovered by an NO donor and inhibited in osteosarcoma cells by a NOS inhibitor. The results indicate that the effect of IGF‐I is dependent on NO production. The impaired IGF‐I response may contribute to the bone defect formation seen in eNOSKO animals.     

A polymorphism in the growth hormone receptor is associated with height in children with Prader-Willi syndrome

The exon‐3 deletion polymorphism (d3, Database of Genomic Variants ID: Variation_64191) in the growth hormone receptor (GHR) gene is associated with increased growth response to growth hormone (GH) therapy in GH‐deficient patients. However, an association of the GHR genotype with height has not yet been reported in Prader–Willi syndrome (PWS). The aim of this study was to assess the association of GHR alleles with height before starting GH therapy in patients with PWS. Seventy‐four patients with PWS were genotyped and their medical records were retrospectively reviewed (45 males and 29 females, median age 8.7 years). One hundred normal controls, with known final height, were also genotyped. The GH‐exon 3 locus was genotyped using a PCR multiplex assay. The distribution of alleles in the patients with PWS was not different from controls [(fl/fl n = 53 (72%), fl/d3 n = 21 (28%)) in PWS vs. (fl/fl n = 72(72%), fl/d3 n = 26(26%), and d3/d3 n = 2(2%)]. However, patients with PWS carrying a d3 allele had significantly greater height standard deviation scores (SDS) (P = 0.025) and higher insulin‐like growth factor I (IGF‐I) level (P = 0.041), although the age at the start of GH therapy, weight, BMI, and body fat were not different. The d3 allele was associated with height and IGF‐I levels before GH therapy and suggests that even before GH therapy, d3 allele may influence height through GH secretion. © 2011 Wiley Periodicals, Inc.     

Genetic association and sequencing of the insulin‐like growth factor 1 gene in bipolar affective disorder

Insulin‐like growth factor 1 (IGF1) has been shown to have an important role in brain development and function. Studies of IGF1 administration in rodents have shown that it has an anxiolytic and antidepressant effect. A genome‐wide association study (GWAS) of the first University College London (UCL) cohort of 506 bipolar affective disorder subjects and 510 controls was carried out. The exons and flanking regions of IGF1 were resequenced, any new polymorphisms found were genotyped in an enlarged UCL sample of 937 cases and 941 controls. GWAS data gave good evidence of allelic and haplotypic association between multiple IGF1 SNP's and bipolar disorder (BD). New polymorphisms were found by resequencing IGF1 region. Data from GWAS and the new markers showed that twelve out of 43 SNPs showed association with BD with the four most significant SNPs having values of 3.7 × 10^?5, 8.4 × 10^?4, 2.6 × 10^?4, and 2.5 × 10^?4. A 5′ promoter microsatellite polymorphism previously correlated with plasma lipoprotein concentration was also associated with BD (P = 0.013). Haplotypic association confirmed association with BD with significance values similar to the single marker SNP values. The marker rs12426318 has also been found to be associated with BD in a second sample. A test of gene wide significance with permutation testing for all markers genotyped at IGF1 was also significant. These data implicate IGF1 as a candidate gene to cause genetic susceptibility to BD. © 2011 Wiley‐Liss, Inc.     

Induction of insulin‐like growth factor‐I by interleukin‐17F in bronchial epithelial cells

Cite this as: M. Kawaguchi, J. Fujita, F. Kokubu, G. Ohara, S‐K Huang, S. Matsukura, Y. Ishii, M. Adachi, H. Satoh and N. Hizawa, Clinical & Experimental Allergy, 2010 (40) 1036–1043. Background Increased expression of IL‐17F has been noted in the airway of asthmatic patients, but its role in asthma has not been fully elucidated. Insulin‐like growth factor‐I (IGF‐I) is known to be involved in airway remodelling and inflammation, while its regulatory mechanisms remain to be defined. Objective To further clarify the biological function of IL‐17F, we investigated whether IL‐17F is able to regulate the expression of IGF‐I in bronchial epithelial cells. Methods Bronchial epithelial cells were stimulated with IL‐17F in the presence or absence of T‐helper type 2 cytokines. Various kinase inhibitors were added to the culture to identify the key signalling events leading to the expression of IGF‐I, in conjunction with the use of short interfering RNAs (siRNAs) targeting mitogen‐ and stress‐activated protein kinase (MSK) 1, p90 ribosomal S6 kinase (p90RSK), and cyclic AMP response element‐binding protein (CREB). Results IL‐17F significantly induced IGF‐I gene and protein expression, and co‐stimulation with IL‐4 and IL‐13 augmented its production. MAP kinase kinase (MEK) inhibitors and the Raf1 kinase inhibitor significantly inhibited IGF‐I production, and the combination of PD98059 and Raf1 kinase inhibitor showed further inhibition. Overexpression of Raf1 and Ras dominant‐negative mutants inhibited its expression. MSK1 inhibitors significantly blocked IL17F‐induced IGF‐I expression. Moreover, transfection of the siRNAs targeting MSK1, p90RSK, and CREB blocked its expression. Conclusions In bronchial epithelial cells, IL‐17F is able to induce the expression of IGF‐I via the Raf1–MEK1/2–ERK1/2–MSK1/p90RSK–CREB pathway in vitro.     

Altered expression of type I insulin-like growth factor receptor in Crohn's disease

The fibrotic and antiapoptotic effects of insulin-like growth factors (IGF) are mediated by type I IGF receptor (IGF-1R). IGFs could play a role in intestinal stricturing and in the maintenance of inflammation in Crohn's disease (CD). We aimed to describe IGF-1R expression in CD intestinal lesions, to compare it to other intestinal inflammatory diseases and to correlate it with fibrosis and apoptosis. IGF-1R expression and apoptosis (active caspase-3) were studied by immunohistochemistry. Surgical intestinal specimens [17 CD, nine controls, six diverticulitis and four ulcerative colitis (UC)] were used. IGF-1R was expressed transmurally mainly by inflammatory cells (IC) and smooth muscle cells, both in diseased intestine and controls. IGF-1R positive IC were increased in the mucosa and the submucosa of CD (P < 0.007), and in involved areas compared to uninvolved areas (P = 0.03). In UC, the number of IGF-1R positive IC was only increased in the mucosa, and was not different from controls in the submucosa. In diverticulitis, the number of IGF-1R positive IC did not differ from controls. In CD submucosa, IGF-1R expression in IC was inversely correlated with apoptosis in uninvolved areas (P = 0.01). Expression of IGF-1R in submucosal fibroblast-like cells, subserosal adipocytes and hypertrophic nervous plexi was specific for CD. We have shown a transmural altered expression of IGF-1R in CD. This may suggest a role for IGF-1R in the maintenance of chronic inflammation and stricture formation in CD.     

Sustained low‐dose growth hormone therapy optimizes bioactive insulin‐like growth factor‐I level and may enhance CD4 T‐cell number in HIV infection

High‐dose recombinant human growth hormone (rhGH) (2–6 mg/day) regimes may facilitate T‐cell restoration in patients infected with human immunodeficiency virus (HIV) on highly active antiretroviral therapy (HAART). However, high‐dose rhGH regimens increase insulin‐like growth factor‐I (IGF‐I) to supra‐physiological levels associated with severe side effects. The present study investigated whether lower doses of rhGH may improve T‐cell restoration in patients infected with HIV following an expedient response of total and bioactive (i.e., free) IGF‐I. A previous 16‐week pilot‐study included six HIV‐infected patients on stable HAART to receive rhGH 0.7 mg/day, which increased total (+117%, P < 0.01) and free (+155%, P < 0.01) IGF‐I levels. The study was extended to examine whether continuous use of low‐dose rhGH (0.7 mg/day until week 60; 0.4 mg/day from week 60 to week 140) would maintain expedient IGF‐I levels and improve CD4 T‐cell response. Total and free IGF‐I increased at week 36 (+97%, P < 0.01 and +125%, P < 0.01, respectively) and week 60 (+77%, P = 0.01 and +125%, P < 0.01) compared to baseline levels (161 ± 15 and 0.75 ± 0.11 µg/L). CD4 T‐cell number increased at week 36 (+15%, P < 0.05) and week 60 (+31%, P = 0.01) compared to baseline levels (456 ± 55 cells/µL). Following rhGH dose reduction, total IGF‐I and CD4 T‐cell number remained increased at week 88 (+44%, P = 0.01 and +33%, P < 0.01) and week 140 (+46%, P = 0.07 and +36%, P = 0.02) compared to baseline levels. These data support the notion that low‐dose rhGH regimens may increase expediently total and bioactive IGF‐I and improve T‐cell restoration in patients infected with HIV on HAART. J. Med. Virol. 82:197–205, 2010. © 2009 Wiley‐Liss, Inc.     

High expression of insulin receptor on tumour‐associated blood vessels in invasive bladder cancer predicts poor overall and progression‐free survival

Bladder cancer is a frequently recurring disease with a very poor prognosis once progressed to invasive stages, and tumour‐associated blood vessels play a crucial role in this process. In order to identify novel biomarkers associated with progression, we isolated blood vascular endothelial cells (BECs) from human invasive bladder cancers and matched normal bladder tissue, and found that tumour‐associated BECs greatly up‐regulated the expression of insulin receptor (INSR). High expression of INSR on BECs of invasive bladder cancers was significantly associated with shorter progression‐free and overall survival. Furthermore, increased expression of the INSR ligand IGF‐2 in invasive bladder cancers was associated with reduced overall survival. INSR may therefore represent a novel biomarker to predict cancer progression. Mechanistically, we observed pronounced hypoxia in human bladder cancer tissue, and found a positive correlation between the expression of the hypoxia marker gene GLUT1 and vascular INSR expression, indicating that hypoxia drives INSR expression in tumour‐associated blood vessels. In line with this, exposure of cultured BECs and human bladder cancer cell lines to hypoxia led to increased expression of INSR and IGF‐2, respectively, and IGF‐2 increased BEC migration through the activation of INSR in vitro. Taken together, we identified vascular INSR expression as a potential biomarker for progression in bladder cancer. Furthermore, our data suggest that IGF‐2/INSR mediated paracrine crosstalk between bladder cancer cells and endothelial cells is functionally involved in tumour angiogenesis and may thus represent a new therapeutic target. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

胰岛素、胰岛素样生长因子Ⅰ及其受体在PCOS患者子宫内膜的表达

目的探讨胰岛素及其受体、胰岛素样生长因子I及其受体在多囊卵巢综合征患者子宫内膜的表达特点。方法利用免疫组化实验技术分析INS、INS-R、IGF-I和IGF-IR在多囊卵巢综合征和非多囊卵巢综合征不孕症患者子宫内膜中的表达情况,对结果进行图像分析,并利用SPSS10.0软件进行统计学分析,比较各组间的差异。结果1.多囊卵巢综合征患者子宫内膜IGF-I和INS-R表达水平明显高于对照组,差异有显著性(P<0.01)。其中多囊卵巢综合征中子宫内膜增生症患者的IGF-I和INS-R表达水平高于多囊卵巢综合征组增殖期患者,差异有显著性(P<0.05)。2.IGF-IR和INS在多囊卵巢综合征患者与对照组子宫内膜的表达水平无明显差异(P>0.05)。结论多囊卵巢综合征患者子宫内膜异常增生可能与局部IGF-I和INS-R表达异常有关。     

Practical utility of insulin‐like growth factor II mRNA‐binding protein 3, glucose transporter 1, and epithelial membrane antigen for distinguishing malignant mesotheliomas from benign mesothelial proliferations

The differentiation of malignant mesotheliomas and benign mesothelial proliferations is crucial in determining patient care and prognosis. But, this distinction can be extremely difficult, particularly in small biopsies. Recently, insulin‐like growth factor II mRNA‐binding protein 3 (IMP3) and glucose transporter 1 (GLUT‐1) have been reported as specific and sensitive markers in the distinction of mesotheliomas from benign mesothelial proliferations. The purpose of this study is to evaluate the utility of IMP3, GLUT‐1, and epithelial membrane antigen (EMA) immunohistochemistry for distinguishing mesotheliomas from benign mesothelial proliferations. Immunoexpression of IMP3, GLUT‐1, and EMA was evaluated in 88 malignant mesotheliomas, 35 adenomatoid tumors, and 20 benign lung tissues with reactive mesothelial cells. The sensitivity for IMP3, GLUT‐1, and EMA was 37%, 21%, and 41%, respectively. The specificity for IMP3, GLUT‐1, and EMA was 100%. When IMP3, GLUT1, and EMA combined, the sensitivity was 66% for IMP3/EMA staining, 53% for GLUT‐1/EMA staining, and 45% for IMP3/GLUT‐1. Use of IMP3 and EMA together is more helpful to distinguish malignant mesotheliomas from benign mesothelial proliferations than the use of IMP3 or EMA alone.     

RNA干扰沉默IGF—IR基因治疗卵巢癌的实验研究

目的研究RNA干扰技术沉默IGF—IR在卵巢癌靶向治疗中的意义。方法以IGF—IR为目的基因,设计合成siRNA重组质粒;利用Real—timePCR和Westernblot方法,分别从mRNA水平及蛋白水平检测IGF—IR的表达;通过MTF实验检测细胞增殖情况。结果本实验成功构建了三个表达载体pSihIGF—IR-1、pSihIGF—IR-2和pSihIGF—IR-3,转染卵巢癌OVCAR3细胞,48h后,IGF—IR的mRNA及蛋白水平均明显降低,并且显著抑制了OVCAR3细胞的体外增殖。结论应用RNA干扰技术,能够高效、特异的沉默IGF—IR基因的表达,抑制肿瘤生长。针对卵巢癌IGF—IR的RNAi技术,可能为卵巢癌的临床治疗开拓-条新的途径。