Insulin-like Growth Factor Type 1 Receptor Expression Research Articles

Differential expression of insulin-like growth factor type 1 receptor identifies heterogeneous intrahepatic regulatory T subsets in mouse hepatocellular carcinoma.

Understanding regulatory T-cell (Treg)-mediated tumor tolerance is critical for designing immunotherapy against hepatocellular carcinoma (HCC). In this study, we characterized the expression of insulin-like growth factor type 1 receptor (IGF1R) in intrahepatic Tregs in a chemical-induced mouse HCC model. We found two intrahepatic Treg subsets with differential IGF1R expression: IGF1Rhi Tregs and IGF1Rlo/- Tregs. Functional assays indicated that compared with IGF1Rlo/- Tregs, IGF1Rhi Tregs produced more TGF-β and IL-10 and were more proliferative in vivo. Furthermore, IGF1Rhi Tregs exhibited higher phosphorylation of the mammalian target of the rapamycin complex 1 (mTORC1) in vivo. However, in vitro stimulation and immunosuppression assay revealed that the immunosuppressive capacity of the two Treg subsets was equivalent, as evidenced by comparable cytokine production and immunosuppressive effect over conventional T cells. The transcriptome sequencing analysis revealed up-regulation of genes that encode proteins essential for glycolysis, oxidative phosphorylation, and electron transport chain in IGF1Rhi Tregs. Consistently, IGF1Rhi Tregs produces more adenosine triphosphate (ATP), lactate, and reactive oxygen species (ROS). Furthermore, malignant cells in the tumor nodules induced IGF1R down-regulation in Tregs at the mRNA level. In summary, we identified the heterogeneity of intrahepatic Tregs in HCC which might play significant roles in tumor immunity.

Expression of Insulin-Like Growth Factor Type 1 Receptor Is Linked to Inflammation in Adamantinomatous Craniopharyngioma

Introduction: Insulin-like growth factor type 1 receptor (IGF1R) is overexpressed in various malignant tumors, which relates to their transformation and recurrence. Craniopharyngioma is a benign tumor with malignant results, often accompanied by a severe inflammatory reaction. However, the relationship between IGF1R expression and the inflammatory response of craniopharyngioma is unclear. Methods: We enrolled 85 patients with adamantinomatous craniopharyngioma (ACP) in a study to explore the relationship between IGF1R expression and clinical features of this disease. Results: Patients in the IGF1R high-expression group had a significantly higher incidence of hypopituitarism, higher recurrence rate, and lower progression-free survival. β-Catenin can further regulate expression of the stem cell marker, CD44, by regulating IGF1R. Using immunofluorescence, we found that tumor stem cell-like cells did not express phosphorylated (p)-ERK, although p-ERK activation was evident in the surrounding cells. Picropodophyllin, a specific inhibitor of IGF1R, increased the expression of p-ERK protein and decreased the transcription level of interleukin-6. Conclusions: High expression of IGF1R might promote inflammation of ACP, which might be an unfavorable factor for pituitary function and prognosis. The high expression of IGF1R in tumor stem cell-like cells might inhibit the expression of p-ERK and promote the generation of inflammatory factors. IGF1R plays a stemness maintenance role in ACP and regulates the production of inflammatory factors through a p-ERK pathway, which suggests that targeting IGF1R and p-ERK might provide a new direction for alleviating tumor inflammation.

RETRACTED ARTICLE: Circular RNA circ_0000517 regulates hepatocellular carcinoma development via miR-326/IGF1R axis

BackgroundCircular RNAs (circRNAs) play vital roles in hepatocellular carcinoma development. However, the role and mechanism of circRNA hsa_circ_0000517 (circ_0000517) in hepatocellular carcinoma development were largely unknown.Methods45 paired tumor and adjacent nontumor samples were collected from hepatocellular carcinoma patients. The levels of circ_0000517, miR-326 and insulin-like growth factor type 1 receptor (IGF1R) were detected via quantitative reverse transcription polymerase chain reaction or western blot. Cell viability, colony ability, migration, invasion and glycolysis were assessed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, western blot, transwell assay, glucose consumption, lactate production or adenosine triphosphate (ATP) production. The target correlation between miR-326 and circ_0000517 or IGF1R was analyzed via dual-luciferase reporter analysis. The function of circ_0000517 in vivo was assessed via xenograft model.Resultscirc_0000517 expression was elevated in hepatocellular carcinoma tissues and cell lines. circ_0000517 knockdown suppressed cell viability, colony formation, migration, invasion and glycolysis. miR-326 was sponged via circ_0000517 and miR-326 knockdown reversed the effect of circ_0000517 silence on hepatocellular carcinoma development. miR-326 overexpression inhibited hepatocellular carcinoma development through targeting IGF1R. circ_0000517 knockdown decreased IGF1R expression by modulating miR-326. circ_0000517 downregulation reduced xenograft tumor growth.Conclusioncirc_0000517 knockdown repressed hepatocellular carcinoma development in vitro and in vivo by modulating miR-326 and IGF1R.

SAT-LB26 A Dual Role for IGF-1R in Mammary Tumorigenesis

The insulin-like growth factor type 1 receptor (IGF-1R) is now thought to have a dual function in breast cancer. Several studies have shown overexpression of the IGF-1R pathway results in increased tumor cell proliferation and survival. Recent loss-of-function models have shown decreased mammary tumorigenesis latency and increased metastasis. These recent studies correlate with analyses of human patient datasets identifying worse overall survival with low IGF-1R expression. Similarly, inhibition of IGF-1R in the clinic has had no affect or has led to worse outcomes supporting the hypothesis that the IGF-1R may have tumor suppressive properties. Our prior published studies revealed loss of IGF-1R function results in heightened tumor epithelial stress, which alters the tumor microenvironment to be permissive for metastasis. Therefore, we asked does the loss of IGF-1R inherently change the tumor epithelium or is it simply the alterations of the microenvironment that lead to a metastatic primary tumor? We first analyzed cell invasion of primary tumor epithelial cells from a mouse tumor model driven by the Wnt1 oncogene (MMTV-Wnt1) and with reduced IGF-1R signaling by expression of a dominant-negative transgene (MMTV-dnIGF-1R). Epithelial cells from the MMTV-Wnt1/dnIGF-1R (bigenic) tumors invaded at the same rate as MMTV-Wnt1 tumor epithelial cells by tail vein injection suggesting invasive capacity is unchanged with reduced IGF-1R signaling. Interestingly, size of lung micrometastases from tail vein injected bigenic tumor epithelial cells was significantly reduced and the number also decreased over time in part due to a proliferative defect determined by immunostaining for pH3. Similarly, bigenic primary tumor epithelial cells injected into the mammary gland fat pad failed to form tumors suggesting alterations in cell adhesion. Consistent with this observation, E-cadherin gene and protein expression were decreased in the bigenic tumor epithelium compared to MMTV-Wnt1 tumors. In vitro analysis of cell adhesion in MMTV-Wnt1 primary epithelial cells resulted in both K8+ (luminal) and K14+ (basal) tumor epithelial cells adherence, while only K14+ cells from bigenic tumors adhered to collagen. Similarly, the lung micrometastases from tail vein injections exhibited predominantly K14+ cells. Analysis of MMTV-Wnt1 and bigenic primary tumors using single cell RNAseq revealed alterations in both stromal and epithelial populations that may contribute to bigenic primary tumor growth and metastasis. These data support the conclusion that inhibiting IGF-1R signaling results in both alterations to the tumor epithelium (partial EMT) and microenvironment that result in metastasis, but also, that the IGF-1R deficient metastatic cells need a niche or paracine signaling to proliferate.

Efficacy of the Antibody-Drug Conjugate W0101 in Preclinical Models of IGF-1 Receptor Overexpressing Solid Tumors.

The insulin-like growth factor type 1 receptor (IGF-1R) is important in tumorigenesis, and its overexpression occurs in numerous tumor tissues. To date, therapeutic approaches based on mAbs and tyrosine kinase inhibitors targeting IGF-1R have only shown clinical benefit in specific patient populations. We report a unique IGF-1R-targeted antibody-drug conjugate (ADC), W0101, designed to deliver a highly potent cytotoxic auristatin derivative selectively to IGF-1R overexpressing tumor cells. The mAb (hz208F2-4) used to prepare the ADC was selected for its specific binding properties to IGF-1R compared with the insulin receptor, and for its internalization properties. Conjugation of a novel auristatin derivative drug linker to hz208F2-4 did not alter its binding and internalization properties. W0101 induced receptor-dependent cell cytotoxicity in vitro when applied to various cell lines overexpressing IGF-1R, but it did not affect normal cells. Efficacy studies were conducted in several mouse models expressing different levels of IGF-1R to determine the sensitivity of the tumors to W0101. W0101 induced potent tumor regression in certain mouse models. Interestingly, the potency of W0101 correlated with the expression level of IGF-1R evaluated by IHC. In an MCF-7 breast cancer model with high-level IGF-1R expression, a single injection of W0101 3 mg/kg led to strong inhibition of tumor growth. W0101 provides a potential new therapeutic option for patients overexpressing IGF-1R. A first-in-human trial of W0101 is currently ongoing to address clinical safety.

Decreased Amino Acid Concentrations are Involved in Congenital Heart Disease

Objective: Congenital heart disease (CHD) is the most common malformation in China. In this study, we determined whether amino acids (AAs) in the amniotic fluid (AF) of patients with CHD changed and clarified whether AAs would affect the insulin-like growth factor type 1 receptor (IGF1R). Method: Fifty-seven AF samples from pregnant women carrying CHD-affected (n = 17) or normal (n = 40) fetuses were collected. The AA concentrations were measured in AF by liquid chromatography-tandem mass spectrometry. The IGF axis-related and epigenetic marker proteins in AF after serial treatments were quantified using a multiple reaction monitoring approach. IGF1R and P300 were also confirmed by Western blot in AF without any treatment. Results: Most AAs decreased in the AF of patients with CHD. P300 and IGF1R decreased significantly in the CHD group. When H9C2 cells were cultured in one-half AA concentrations, the expression of P300 and IGF1R was reduced. Histone acetylation of the IGF1R promoter also decreased. Conclusion: Our data suggest that AAs decreased in the AF of patients with CHD. AAs may partly regulate the IGF1R through P300, which may be involved in heart development.

Insulin-like growth factor receptor signaling in breast tumor epithelium protects cells from endoplasmic reticulum stress and regulates the tumor microenvironment

BackgroundEarly analyses of human breast cancer identified high expression of the insulin-like growth factor type 1 receptor (IGF-1R) correlated with hormone receptor positive breast cancer and associated with a favorable prognosis, whereas low expression of IGF-1R correlated with triple negative breast cancer (TNBC). We previously demonstrated that the IGF-1R acts as a tumor and metastasis suppressor in the Wnt1 mouse model of TNBC. The mechanisms for how reduced IGF-1R contributes to TNBC phenotypes is unknown.MethodsWe analyzed the METABRIC dataset to further stratify IGF-1R expression with patient survival and specific parameters of TNBC. To investigate molecular events associated with the loss of IGF-1R function in breast tumor cells, we inhibited IGF-1R in human cell lines using an IGF-1R blocking antibody and analyzed MMTV-Wnt1-mediated mouse tumors with reduced IGF-1R function through expression of a dominant-negative transgene.ResultsOur analysis of the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) dataset revealed association between low IGF-1R and reduced overall patient survival. IGF-1R expression was inversely correlated with patient survival even within hormone receptor-positive breast cancers, indicating reduced overall patient survival with low IGF-1R was not due simply to low IGF-1R expression within TNBCs. Inhibiting IGF-1R in either mouse or human tumor epithelial cells increased reactive oxygen species (ROS) production and activation of the endoplasmic reticulum stress response. IGF-1R inhibition in tumor epithelial cells elevated interleukin (IL)-6 and C-C motif chemokine ligand 2 (CCL2) expression, which was reversed by ROS scavenging. Moreover, the Wnt1/dnIGF-1R primary tumors displayed a tumor-promoting immune phenotype. The increased CCL2 promoted an influx of CD11b+ monocytes into the primary tumor that also had increased matrix metalloproteinase (MMP)-2, MMP-3, and MMP-9 expression. Increased MMP activity in the tumor stroma was associated with enhanced matrix remodeling and collagen deposition. Further analysis of the METABRIC dataset revealed an increase in IL-6, CCL2, and MMP-9 expression in patients with low IGF-1R, consistent with our mouse tumor model and data in human breast cancer cell lines.ConclusionsOur data support the hypothesis that reduction of IGF-1R function increases cellular stress and cytokine production to promote an aggressive tumor microenvironment through infiltration of immune cells and matrix remodeling.

Abstract 3617: A paradigm shift for insulin-like growth factor 1 receptor function in triple negative breast cancers

Abstract Signaling through the insulin-like growth factor type 1 receptor (IGF-1R) is complex in breast cancers. Early studies reported that expression of the IGF-1R correlated with estrogen receptor (ER) expression and predicted a favorable phenotype. Moreover, loss of IGF-1R has been associated with breast tumor progression into a more undifferentiated phenotype. We have generated and characterized a mouse line containing both MMTV-Wnt1 and MMTV-dnIGF-1R (kinase dead-IGF-1R) transgenes (referred to subsequently as bigenic mice) that leads to increased mammary tumor initiation and metastasis. These data support the hypothesis that the IGF-1R functions in suppressing metastasis in certain contexts and subtypes of triple negative breast cancers (TNBCs). Recent analyses of TCGA human datasets support the relevance of our model in human TNBCs that have reduced IGF-1R expression and increased expression of Wnt1 and the Frizzled co-receptor Lrp6. We have identified alterations in a number of target genes that potentially regulate metastasis in the bigenic primary tumors including increases in interleukin-6 (IL-6), Slug, Vimentin, Zeb 1/2 and decreases in E-cadherin expression as assessed by Qiagen specific qPCR and single gene qPCR. Furthermore, a subset of anti-inflammatory chemokines and cytokines were assessed by a targeted qPCR array revealing increases in interleukin-4, interleukin-10, and C-C motif chemokine ligand-2 and decreases in tumor necrosis factor-alpha in the bigenic tumors indicating a tumor associated macrophage phenotype. By flow cytometry analysis, the ratio of CD4+ T cells to CD8+ T cells is increased in the bigenic tumors suggesting a tumor promoting immune microenvironment. However, increased expression of IL-6 in the bigenic tumors is specific to the luminal tumor cells, and inhibition of IGF-1R in the MCF7 human breast cancer cell line results in increases in IL-6, Slug, and Zeb 1/2 expression suggesting the tumor cells activate EMT and a pro-tumorigenic microenvironment in response to decreased IGF-1R. Moreover, inhibition of IGF-1R in human breast cancer cells and MMTV-Wnt1 mouse tumor cells results in increased cell motility and invasion as assessed by the xCELLigence motility assay. Taken together, our data support the hypothesis that IGF-1R acts as a negative regulator of mediators that promote migration, invasion, and metastasis in TNBCs. Citation Format: Alison Obr, Sushil Kumar, Raymond Birge, Teresa Wood. A paradigm shift for insulin-like growth factor 1 receptor function in triple negative breast cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3617. doi:10.1158/1538-7445.AM2017-3617

Functional antagonism of \u03b2-arrestin isoforms balance IGF-1R expression and signalling with distinct cancer-related biological outcomes

With very similar 3D structures, the widely expressed β-arrestin isoforms 1 and 2 play at times identical, distinct or even opposing roles in regulating various aspects of G protein-coupled receptors (GPCR) expression and signalling. Recent evidence recognizes the β-arrestin system as a key regulator of not only GPCRs, but also receptor tyrosine kinases, including the highly cancer relevant insulin-like growth factor type 1 receptor (IGF-1R). Binding of β-arrestin1 to IGF-1R leads to ligand-dependent degradation of the receptor and generates additional MAPK/ERK signalling, protecting cancer cells against anti-IGF-1R therapy. Because the interplay between β-arrestin isoforms governs the biological effects for most GPCRs, as yet unexplored for the IGF-1R, we sought to investigate specifically the regulatory roles of the β-arrestin2 isoform on expression and function of the IGF-1R. Results from controlled expression of either β-arrestin isoform demonstrate that β-arrestin2 acts in an opposite manner to β-arrestin1 by promoting degradation of an unstimulated IGF-1R, but protecting the receptor against agonist-induced degradation. Although both isoforms co-immunoprecipitate with IGF-1R, the ligand-occupied receptor has greater affinity for β-arrestin1; this association lasts longer, sustains MAPK/ERK signalling and mitigates p53 activation. Conversely, β-arrestin2 has greater affinity for the ligand-unoccupied receptor; this interaction is transient, triggers receptor ubiquitination and degradation without signalling activation, and leads to a lack of responsiveness to IGF-1, cell cycle arrest and decreased viability of cancer cells. This study reveals contrasting abilities of IGF-1R to interact with each β-arrestin isoform, depending on the presence of the ligand and demonstrates the antagonism between the two β-arrestin isoforms in controlling IGF-1R expression and function, which could be developed into a practical anti-IGF-1R strategy for cancer therapy.

The influence of insulin-like Growth Factor-1-Receptor expression and endocrine treatment on clinical outcome of postmenopausal hormone receptor positive breast cancer patients: A Dutch TEAM substudy analysis

BackgroundSignaling via the Insulin-like Growth Factor type 1 Receptor (IGF1R) plays a crucial role in cancer development. In breast cancer (BC), IGF1R and estrogen receptor expression are correlated. In this current study we explored the hypothesis that postmenopausal hormone receptor positive (HR+ve) BC patients with high IGF1R tumor expression still have estrogen driven IGF1R stimulated tumor growth when treated with tamoxifen, resulting in detrimental clinical outcome compared to patients treated with exemestane. Additionally, we assessed the added value of metformin as this drug may lower IGF1R stimulation. MethodsOf 2,446 Dutch TEAM patients, randomized to either exemestane for 5 years or sequential treatment (tamoxifen for 2–3 years followed by exemestane for another 3–2 years) tumor tissue microarray sections were immunohistochemically stained for IGF1R. Overall Survival (OS), Breast Cancer specific Survival (BCSS) and Relapse-Free Survival (RFS) were assessed in patient subgroups with low and high IGF1R expression, and in patients with or without metformin use. ResultsHigh IGF1R tumor expression was significantly associated with exemestane therapy for RFS (Hazard Ratio (HR) 0.74, 95% Confidence Interval (CI) 0.58–0.95, p = 0.02). In addition, the combination of metformin with exemestane resulted in improved efficacy, yielding a 5-yrs RFS of 95% (HR 0.32, 95% CI 0.10–1.00, p = 0.02, compared to sequential treatment). No relation was observed in tumors with low IGF-1R expression. ConclusionThis study suggests IGF1R as a potential biomarker of improved clinical outcome in HR+ve BC patients treated with exemestane. Adding metformin to exemestane treatment may add to this effect.

The dog as a naturally-occurring model for insulin-like growth factor type 1 receptor-overexpressing breast cancer: an observational cohort study.

BackgroundDogs spontaneously develop invasive mammary carcinoma with a high prevalence of the triple-negative (TN) subtype (lack of ER-Estrogen Receptor and PR-Progesterone Receptor expression, lack of HER2-Human Epidermal Growth Factor Receptor 2 overexpression), making this animal model relevant for investigating new therapeutic pathways. Insulin-like growth factor Type-1 receptor (IGF1R) is frequently overexpressed in primary human breast cancers, with a growing role in the TN phenotype. The purpose of this study was to investigate the Dog as a candidate model for IGF1R-overexpressing mammary carcinoma.Methods150 bitches with canine mammary carcinoma (CMC) and a known 2-year follow-up were retrospectively included. IGF1R expression was assessed by immunohistochemistry (IHC) using a similar scoring system as for HER2 in breast cancer. The prognostic value of the IGF1R expression was assessed in terms of overall and specific survival as well as disease-free interval (DFI).Results47 CMC (31 %) were classified as luminal and 103 (69 %) as triple-negative (TN-CMC). 41 % of CMC overexpressed IGF1R (IHC score 3+) of which 76 % were TN-CMC and 62 % grade III. IGF1R overexpression was associated with aggressive features including lymphovascular invasion, histological grade III, low ER expression and the TN phenotype. Univariate and multivariate analyses revealed that IGF1R overexpression was associated with shorter overall and specific survivals and shorter DFI in TN-CMC.ConclusionsIGF1R overexpression is common and related to a poor outcome in canine invasive mammary carcinoma, particularly in the triple negative subtype, as in human breast cancer. Preclinical studies using the Dog as a spontaneous animal model could be considered to investigate new therapies targeting IGF1R in triple-negative breast cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-015-1670-6) contains supplementary material, which is available to authorized users.

Role of the Insulin-Like Growth Factor Type 1 Receptor in the Pathogenesis of Diabetic Encephalopathy.

Defective cognitive function is common in patients with diabetes, suggesting that insulin normally exerts anabolic actions in neuron, namely, diabetic encephalopathy. However, because insulin can cross-activate the insulin-like growth factor type 1 receptor (IGF-1R), which also functions in most of tissues, such as muscle and bone, it has been difficult to establish the direct (IGF-1-independent) actions of insulin in the pathogenesis of diabetic encephalopathy. To overcome this problem, we examined insulin signaling and action in primary PC-12 cells engineered for conditional disruption of the IGF-1 receptor (ΔIGF-1R). The results showed that the lower glucose metabolism and high expression of IGF-1R occurred in the brain of the DE rat model. The results also showed the defect of IGF-1R could significantly improve the ability of glucose consumption and enhance sensitivity to insulin-induced IR and Akt phosphorylation in PC12 cells. And meanwhile, IGF-1R allele gene knockout (IGF-1Rneo) mice treated with HFD/STZ had better cognitive abilities than those of wild mice. Those results indicate that insulin exerts direct anabolic actions in neuron-like cells by activation of its cognate receptor and prove that IGF-1R plays an important role in the pathogenesis of diabetic encephalopathy.

Comparative Evaluation of Strategies for Quantifying Signaling Pathway Proteins in Ewing Sarcoma

Targeted therapies are increasingly being evaluated for patients with Ewing sarcoma (EWS). Optimal strategies for quantifying key signaling proteins in EWS remain unclear. We sought to quantify tumor expression of signaling pathway proteins in EWS using 3 methodologies. A total of 46 blocks of formalin-fixed paraffin-embedded tissue were obtained from 40 patients with EWS. Tumor was evaluated for the expression of proteins in the insulin-like growth factor type 1 receptor (IGF-1R), epithelial growth factor receptor (EGFR), and mTOR pathways using standard immunohistochemical analysis (IHC), automated quantitative analysis (AQUA) immunohistochemical analysis, and mass spectrometry quantification. The mean age at diagnosis was 14 years (range, 1 to 49 y). About 67.5% were male and 57.5% had localized disease. Samples displayed a wide range of expression by AQUA: mean (range) IGF-1R=10,702 (393 to 14,424); EGFR=2750 (672 to 9798); and phosphatase and tensin homolog (PTEN)=2250 (251 to 6557). Mean IGF-1R expression by AQUA did not differ between standard IHC expression categories (low IHC=11,255; medium IHC=11,070; high IHC=11,023; P=0.98). Mean PTEN expression by AQUA was higher in the medium and high IHC categories (low IHC=1229; medium IHC=2715; high IHC=2940; P=0.064). Only 2 samples expressed EGFR by standard IHC. Mass spectrometry trended toward correlation with standard IHC but did not yield interpretable results in the majority of samples. This study demonstrates that the relative quantification of signaling protein expression in EWS is dependent on the methodology used. Optimization and validation of these tools are necessary before clinical application for risk stratification of patients or measurement of biomarker expression.

99mTc(CO)3]+-(HE)3-ZIGF1R:4551, a new Affibody conjugate for visualization of insulin-like growth factor-1 receptor expression in malignant tumours

Radionuclide imaging of insulin-like growth factor type 1 receptor (IGF-1R) expression in tumours might be used for selection of patients who would benefit from IGF-1R-targeted therapy. We have previously shown the feasibility of IGF-1R imaging using the Affibody molecule (111)In-DOTA-His(6)-Z(IGF1R:4551). The use of (99m)Tc instead of (111)In should improve sensitivity and resolution of imaging, and reduce the dose burden to patients. We hypothesized that inclusion of a HEHEHE tag instead of a His(6) tag in Z(IGF1R:4551) would permit its convenient purification using IMAC, enable labelling with [(99m)Tc(CO)(3)](+), and improve its biodistribution. Z(IGF1R:4551) was expressed with a HEHEHE tag in the N terminus. The resulting (HE)(3)-Z(IGF1R:4551) construct was labelled with [(99m)Tc(CO)(3)](+). Targeting of IGF-1R-expressing cells using [(99m)Tc(CO)(3)](+)-(HE)(3)-Z(IGF1R:4551) was evaluated in vitro and in vivo. (HE)(3)-Z(IGF1R:4551) was stably labelled with (99m)Tc with preserved specific binding to IGF-1R-expressing DU-145 prostate cancer cells in vitro. In mice, [(99m)Tc(CO)(3)](+)-(HE)(3)-Z(IGF1R:4551) accumulated in IGF-1R-expressing organs (pancreas, stomach, lung and salivary gland). [(99m)Tc(CO)(3)](+)-(HE)(3)-Z(IGF1R:4551) demonstrated 3.6-fold lower accumulation in the liver and spleen than (111)In-DOTA-Z(IGF1R:4551). In NMRI nu/nu mice with DU-145 prostate cancer xenografts, the tumour uptake was 1.32 ± 0.11 %ID/g and the tumour-to-blood ratio was 4.4 ± 0.3 at 8h after injection. The xenografts were visualized using a gamma camera 6h after injection. (99m)Tc(CO)(3)](+)-(HE)(3)-Z(IGF1R:4551) is a promising candidate for visualization of IGF-1R expression in malignant tumours.

Insulin-like growth factor type 1 receptor (IGF-1R) exclusive nuclear staining: A predictive biomarker for IGF-1R monoclonal antibody (Ab) therapy in sarcomas

AimsA minority of patients with advanced sarcoma achieve prolonged progression free survival (PFS) with insulin growth factor type 1 receptor (IGF-1R) monoclonal antibody (Ab) therapy. A biomarker identifying those patients beforehand would be useful to select patients for the development of these agents. MethodsThis single centre series includes patients with unresectable or metastatic soft tissue sarcomas (STS), Ewing sarcoma (ES) and osteosarcoma treated with IGF-1R Ab (R1507, IMC-A12, SCH 717454 and CP-751.871) in the Centre Léon Bérard. Tumour samples were analysed by immunohistochemistry for expression of IGF-1R, insulin-like growth factor binding protein type 3 (IGFBP-3), Ki67, epidermal growth factor receptor (HER1) and human epidermal growth factor receptor 2 (HER2). Predictive factors for PFS and overall survival (OS) were investigated. ResultsAll tumour samples had a positive IGF-1R immunostaining on 60% to 100% of tumour cells. IGFBP-3 immunostaining was observed in 12 (75%) samples with 5% to 100% of positive cells. IGF-1R immunostaining was nuclear (n=9, 56%), cytoplasmic (n=4, 25%), or nuclear +cytoplasmic (n=3, 19%). Neither IGFBP-3 expression, nor Ki67 was correlated to PFS. HER2 and HER1 staining were positive in 0 and 2 samples respectively (both primary resistant to IGF-1R Ab therapy). Exclusive intra-nuclear immunoreactivity for IGF-1R was significantly associated with a better PFS (p=0.01) and OS (p=0.007). ConclusionExclusive nuclear localisation of IGF-1R is an easily testable biomarker associated with a better PFS and OS for patients treated with IGF-1R Ab therapy. Nuclear localisation of IGF-1R in tumour cells might be a hallmark of pathway activation.

Imaging of Insulinlike Growth Factor Type 1 Receptor in Prostate Cancer Xenografts Using the Affibody Molecule111In-DOTA-ZIGF1R:4551

One of the pathways leading to androgen independence in prostate cancer involves upregulation of insulinlike growth factor type 1 receptor (IGF-1R). Radionuclide imaging of IGF-1R in tumors might be used for selection of patients who would most likely benefit from IGF-1R-targeted therapy. The goal of this study was to evaluate the feasibility of in vivo radionuclide imaging of IGF-1R expression in prostate cancer xenografts using a small nonimmunoglobulin-derived binding protein called an Affibody molecule. The IGF-1R-binding Z(IGF1R:4551) Affibody molecule was site-specifically conjugated with a maleimido derivative of DOTA and labeled with (111)In. The binding of radiolabeled Z(IGF1R:4551) to IGF-1R-expressing cells was evaluated in vitro and in vivo. DOTA-Z(IGF1R:4551) can be stably labeled with (111)In with preserved specific binding to IGF-1R-expressing cells in vitro. In mice, (111)In-DOTA-Z(IGF1R:4551) accumulated in IGF-1R-expressing organs (pancreas, stomach, lung, and salivary gland). Receptor saturation experiments demonstrated that targeting of DU-145 prostate cancer xenografts in NMRI nu/nu mice was IGF-1R-specific. The tumor uptake was 1.1 ± 0.3 percentage injected dose per gram, and the tumor-to-blood ratio was 3.2 ± 0.2 at 8 h after injection. This study demonstrates the feasibility of in vivo targeting of IGF-1R-expressing prostate cancer xenografts using an Affibody molecule. Further development of radiolabeled Affibody molecules might provide a useful clinical tool for stratification of patients with prostate cancer for IGF-1R-targeting therapy.

Targeting of Insulin-Like Growth Factor Type 1 Receptor in Ewing Sarcoma: Unfulfilled Promise or a Promising Beginning?

Targeting of Insulin-Like Growth Factor Type 1 Receptor in Ewing Sarcoma: Unfulfilled Promise or a Promising Beginning?

Divergent effects of insulin-like growth factor-1 receptor expression on prognosis of estrogen receptor positive versus triple negative invasive ductal breast carcinoma

The insulin-like growth factor type 1 receptor (IGF1R) is involved in progression of breast cancer and resistance to systemic treatment. Targeting IGF1R signaling may, therefore, be beneficial in systemic treatment. We report the effect of IGF1R expression on prognosis in invasive ductal breast carcinoma (IDC), the most common type of breast cancer. Immunohistochemistry was performed on tumor tissue of a consecutive cohort of 429 female patients treated for operable primary IDC. Associations between IGF1R expression with clinicopathological parameters, disease free survival (DFS) and breast cancer specific survival (BCSS) were evaluated by multivariate analyses focusing on ER-positive and triple negative IDC (TN-IDC). To enlarge the TN-IDCs cohort, we analyzed a combined dataset of 51 TN-IDC tumors from our series with 64 TN-IDCs with similar clinicopathological parameters. Patients with tumors expressing cytoplasmic IGF1R have a longer DFS and BCSS (DFS: HR 0.46, 95% CI 0.27-0.49, P = 0.005, BCSS: HR 0.38, 95% CI 0.19-0.74, P = 0.005). This effect was most prominent in ER-positive tumors. However, in a combined series of 105 TN-IDCs cytoplasmic IGF1R expression was associated with a shorter DFS (HR = 2.29, 95% CI 1.08-4.84, P = 0.03), also when combined in a multivariate model, including well-known prognostic factors (HR 2.06; 95% CI 0.95-4.47; P = 0.07). IGF1R expression in ER-positive IDC is strongly related to a favorable DFS and BCSS, but to a shorter DFS in TN-IDC tumors. This divergent effect of IGF1R expression in subgroups of IDC may affect selection of patients for IGF1R targeted therapy.

Abstract B125: Antiproliferative and anti-invasive effect of the novel anti-IGF-1R monoclonal antibody R1507 in endocrine-responsive and -resistant breast cancer cell lines

Abstract R1507 is a novel insulin-like growth factor type 1 receptor (IGF-1R)-specific, human monoclonal antibody that binds the extracellular domain of the receptor to inhibit ligand binding and promote receptor internalization. IGF-1R signalling has been implicated in both endocrine-responsive and -resistant breast cancer and the IGF-1R identified as a potential therapeutic target to treat these disease states. In the present study we have examined the effect of R1507 in tamoxifen-resistant (Tam-R) and wild-type MCF-7 cells to determine the therapeutic potential of this agent in breast cancer. Both cell lines were exposed to R1507 (3–300 nM) for periods ranging from 1 to 7 days and effects on signalling, growth and invasive capacity were assessed. R1507 treatment of both MCF-7 and Tam-R cells for 24 hours reduced both expression and activity of IGF-1R and this effect was maintained through to 7 days treatment with this antibody. This effect of R1507 was observed both in the absence and presence of ligand (IGF-I and II) stimulation in the two cell lines. In MCF-7 cells the reduction in basal and ligand-stimulated IGF-1R activity was associated with reduced IRS-1 phosphorylation and inhibition of AKT and ERK1/2 activity at day 1 with the reduction in AKT phosphorylation being maintained through to day 7. However, basal and ligand-stimulated ERK1/2 phosphorylation demonstrated some evidence of recovery in the presence of R1507 although a small inhibitory effect was still apparent at day 7. This potent blockade of IGF-1R signalling by R1507 was associated with a significant inhibition of basal and ligand-stimulated cell growth. A similar effect of R1507 on signalling activity was also observed in Tam-R cells with reductions in basal and ligand-stimulated IRS-1 phosphorylation and AKT activity apparent at day 1 through to day 7. However, although prolonged exposure to R1507 also reduced basal and ligand-stimulated levels of phosphorylated EGFR and erbB2 in this cell line, there was no effect of this antibody on ERK1/2 activity at this time point. Indeed, there was evidence of an increase in basal and ligand-stimulated ERK1/2 activity at the higher concentrations of antibody used in this study. Although R1507 abolished ligand-stimulated Tam-R cell growth there was little effect of this antibody on basal growth of these cells. Interestingly, however, R1507 potently reduced the basal and ligand-stimulated invasive capacity of this cell line. In conclusion these studies would suggest that R1507 can potently inhibit IGF-1R signalling in both an endocrine-responsive and -resistant breast cancer cell line. In endocrine-responsive MCF-7 cells this action of R1507 is anti-proliferative, whereas, in Tam-R cells R1507 appears to have potent anti-invasive properties and only modest growth inhibitory activity. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B125.

55LBA Randomized phase II trial: Effect of all-trans retinoic acid with chemotherapy based in paclitaxel and cisplatin as first line treatment of patients with advanced non-small cell lung cancer

Signaling via the Insulin-like Growth Factor type 1 Receptor (IGF1R) plays a crucial role in cancer development. In breast cancer (BC), IGF1R and estrogen receptor expression are correlated. In this current study we explored the hypothesis that postmenopausal hormone receptor positive (HR+ve) BC patients with high IGF1R tumor expression still have estrogen driven IGF1R stimulated tumor growth when treated with tamoxifen, resulting in detrimental clinical outcome compared to patients treated with exemestane. Additionally, we assessed the added value of metformin as this drug may lower IGF1R stimulation.Of 2,446 Dutch TEAM patients, randomized to either exemestane for 5 years or sequential treatment (tamoxifen for 2–3 years followed by exemestane for another 3–2 years) tumor tissue microarray sections were immunohistochemically stained for IGF1R. Overall Survival (OS), Breast Cancer specific Survival (BCSS) and Relapse-Free Survival (RFS) were assessed in patient subgroups with low and high IGF1R expression, and in patients with or without metformin use.High IGF1R tumor expression was significantly associated with exemestane therapy for RFS (Hazard Ratio (HR) 0.74, 95% Confidence Interval (CI) 0.58–0.95, p = 0.02). In addition, the combination of metformin with exemestane resulted in improved efficacy, yielding a 5-yrs RFS of 95% (HR 0.32, 95% CI 0.10–1.00, p = 0.02, compared to sequential treatment). No relation was observed in tumors with low IGF-1R expression.This study suggests IGF1R as a potential biomarker of improved clinical outcome in HR+ve BC patients treated with exemestane. Adding metformin to exemestane treatment may add to this effect.