Expression data from human carcinoma (MCF7) derived cells that have been exposed to insulin analogues
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ABSTRACT: Insulin analogues are designed to improve the pharmacokinetic parameters compared to regular human insulin. This provides a sustained control of blood glucose levels in diabetic patients. All novel insulin analogues are tested for their mitogenic side effects, however these assays do not take into account the molecular mode-of-action of different insulin analogues. Insulin analogues can bind the insulin receptor (INSR) and the insulin-like growth factor-1 receptor (IGF1R) with different affinities and consequently will activate different downstream signaling pathways. Here we used a panel of MCF7 human breast cancer cell lines that selectively express either one of the isoforms of the INSR (IRA or IRB) or the IGF1R. We sought to study the role of the different receptors (IRA, IRB and IGF1R) in the mitogenic signaling of insulin-like molecules (including insulin, glargine, X10 (or AspB10) and IGF1).
Project description:Insulin analogues are designed to improve the pharmacokinetic parameters compared to regular human insulin. This provides a sustained control of blood glucose levels in diabetic patients. All novel insulin analogues are tested for their mitogenic side effects, however these assays do not take into account the molecular mode-of-action of different insulin analogues. Insulin analogues can bind the insulin receptor (INSR) and the insulin-like growth factor-1 receptor (IGF1R) with different affinities and consequently will activate different downstream signaling pathways. Here we used a panel of MCF7 human breast cancer cell lines that selectively express either one of the isoforms of the INSR (IRA or IRB) or the IGF1R. We sought to study the role of the different receptors (IRA, IRB and IGF1R) in the mitogenic signaling of insulin-like molecules (including insulin, glargine, X10 (or AspB10) and IGF1). MCF7 IRA, MCF7 IRB or MCF7 IGF1R cells (as described in Arch Toxicol. 2014 Apr;88(4):953-66. doi: 10.1007/s00204-014-1201-2. Epub 2014 Jan 25.) were cultured in RPMI supplemented with 5% (v/v) CDFBS (Hyclone) and used for experiments. Cells have been exposed for 1 or 6 hours to 10 nM of the indicated insulin-like molecule. As a control sample a vehicle stimulation was performed that contained everything except the active compound.
Project description:Commonalities and dissimilarities between the IGF1R and INSR pathways Insulin and insulin-like growth factor-1 (IGF1), acting respectively via the insulin (INSR) and IGF1 (IGF1R) receptors, play key developmental and metabolic roles throughout life. In addition, both signaling pathways fulfill important roles in cancer initiation and progression. The inherent complexity of the INSR/IGF1R pathways, along with the well documented cross-talk between insulin-like ligands and receptors, translated into a disappointingly slow pace in the development of INSR/IGF1R-directed therapies in oncology. The present study was aimed at identifying mechanistic differences between INSR and IGF1R using a recently developed bioinformatics tool, the Biological Network Simulator (BioNSi). This application allows to import and merge multiple pathways and interaction information from the KEGG database into a single network representation. The BioNsi network simulation tool allowed us to exploit the availability of gene expression data derived from breast cancer cell lines with specific disruptions of the INSR or IGF1R genes in order to investigate potential differences in protein expression that might be linked to biological attributes of the specific receptor networks. Modeling-generated information was corroborated by experimental and biological assays. Our simulation analysis identified a number of commonalities and, most importantly, dissimilarities between the IGF1R and INSR pathways that were experimentally validated and that might help explain the basis for the biological differences between these networks.
Project description:Resistance to insulin and insulin-like growth factor 1 (IGF1) in pancreatic β-cells causes overt diabetes in mice; thus, therapies that sensitize β-cells to insulin may protect patients with diabetes against β-cell failure. Here we identify an inhibitor of insulin receptor (INSR) and IGF1 receptor (IGF1R) signalling in mouse β-cells, which we name the insulin inhibitory receptor (inceptor; encoded by the gene Iir). Inceptor contains an extracellular cysteine-rich domain with similarities to INSR and IGF1R4, and a mannose 6-phosphate domain that is also found in the IGF2 receptor (IGF2R)5. Knockout mice that lack inceptor (Iir-/-) exhibit signs of hyperinsulinaemia and hypoglycaemia, and die within a few hours of birth. Molecular and cellular analyses of embryonic and postnatal pancreases from Iir-/- mice showed an increase in the activation of INSR–IGF1R in Iir-/- pancreatic tissue, resulting in an increase in the proliferation and mass of β-cells. Similarly, inducible β-cell-specific Iir-/- knockout in adult mice and in ex vivo islets led to an increase in the activation of INSR–IGF1R and increased proliferation of β-cells, resulting in improved glucose tolerance in vivo. Mechanistically, inceptor interacts with INSR–IGF1R to facilitate clathrin-mediated endocytosis for receptor desensitization. Blocking this physical interaction using monoclonal antibodies against the extracellular domain of inceptor resulted in the retention of inceptor and INSR at the plasma membrane to sustain the activation of INSR–IGF1R in β-cells. Together, our findings show that inceptor shields insulinproducing β-cells from constitutive pathway activation, and identify inceptor as a potential molecular target for INSR–IGF1R sensitization and diabetes therapy.
Project description:The insulin inhibitory receptor (inceptor) was recently identified as a key terminator of insulin and insulin-like growth factor 1 receptor (INSR/IGF1R) signaling in pancreatic ?-cells12. Yet, the relevance of ?-cell inceptor for glucose regulation through the INS1R/IGF1R axis has only been demonstrated for normoglycemic and insulin sensitive lean mice, questioning whether inceptor regulation of INS1R/IGF1R action also plays a role in glucose metabolism under conditions of diet-induced obesity and insulin resistance. Here we demonstrate that whole-body germline loss of inceptor improves glucose metabolism in diet-induced obese mice with only minimal effects on weight and body composition. To assess the effect in different tissues we performed proteomics in the global, neuronal and beta cell specific mouse knock-outs.
Project description:we performed the analysis of SF1-GFP+ cells purified from mouse embryonic gonads at embryonic day E11.5 and analyzed the effect of the deletion of the Insulin receptor (InsR) and Igf1 receptor (Igf1R) by comparing double mutant and control, in male and female.
Project description:we performed the analysis of SOX9-GFP+ cells purified from mouse embryonic testis at embryonic day E17.5 and Postnatal day 5 and analyzed the effect of the deletion of the Insulin receptor (InsR) and Igf1 receptor (Igf1R) by comparing double mutant and control SOX9+ Sertoli cells
Project description:Despite a high degree of homology, insulin and IGF-1 receptors (IR/IGF1R) mediate distinct cellular and physiological functions. Here, using chimeric and site-mutated receptors, we demonstrate how domain differences between IR and IGF1R contribute the distinct functions of these receptors. Receptors with the intracellular domain of IGF1R show increased activation of Shc and Gab-1 and more potent regulation of genes involved in proliferation, corresponding to its higher mitogenic activity. Conversely, receptors with the intracellular domain of IR display higher IRS-1 phosphorylation, stronger regulation of genes in metabolic pathways and more dramatic glycolytic responses to hormonal stimulation. We generated mouse brown preadipocytes in which both insulin and IGF-1 receptors (IR and IGF1R) had been genetically inactivated using Cre-lox recombination. These IR and IGF1R DKO cells were then reconstituted with wild-type mouse IR, IGF1R, or one of two chimeric receptors: IR/IGF1R with the IR extracellular domain (ECD) fused to the IGF1R transmembrane and intracellular domains (ICD) and IGF1R/IR with the ECD of IGF1R fused to the ICD domains of IR. Three independent clones for each line were used for the study. For expression analysis, we serum-starved the preadipocytes clones overnight and stimulated cells with 100 nM insulin, IGF-1 or vehicle for 6 h, and subjected the cellular RNA to analysis using Affymetrix Mouse Gene 2.0 ST arrays.
Project description:Insulin and IGF-1 receptors (IR/IGF1R) are highly homologous and share similar signaling systems, but each has a unique physiological role, with IR primarily regulating metabolic homeostasis and IGF1R regulating mitogenic control and growth. Here, we show that replacement of a single amino acid at position 973, just distal to the NPEY motif in the intracellular juxtamembrane region, from leucine, which is highly-conserved in IRs, to phenylalanine, the highly-conserved homologous residue in IGF1Rs, results in decreased IRS-1-PI3K-Akt-mTORC1 signaling and increased of Shc-Gab1-MAPK-cell cycle signaling. As a result, cells expressing L973F-IR exhibit decreased insulin-induced glucose uptake, increased cell growth and impaired receptor internalization. Mice with knockin of the L973F-IR show similar alterations in signaling in vivo, and this leads to decreased insulin sensitivity, a modest increase in growth and decreased weight gain when challenged with high-fat diet. Thus, leucine973 in the juxtamembrane region of the IR acts is a crucial residue differentiating IR signaling from IGF1R signaling.
Project description:Identification of filamin-A as a target for insulin and IGF1 action. Insulin analogues have been developed to achieve further improvement in the therapy of diabetes. However, modifications introduced into the insulin molecule might enhance their affinity to the insulin-like growth factor-1 receptor (IGF1R). Most tumors, including endometrial cancers, express high levels of IGF1R. The present study was aimed at identifying the entire set of genes that are differentially activated by insulin glargine or detemir, in comparison to regular insulin and IGF1, in Type 1 and Type 2 endometrial cancer cell lines (ECC-1 and USPC-1, respectively). Global gene expression analyses demonstrated a ligand-dependent up-regulated expression of filamin-A (FLNA), a gene that encodes an actin filament cross-linking protein, in both endometrial cancer cell types. Silencing experiments linked to migration assays confirmed the role of FLNA in cell growth and motility. Our data suggest that the activation of distinct sets of genes by glargine may lead to stimulation of specific pathways or, alternatively, may provide additive effects, different from those classically induced by insulin. Given that metastasis is one of the major factors contributing to the aggressiveness of tumors, the identification of FLNA as a downstream target for insulin-like hormones may be of translational relevance in cancer research. Clinical studies in endometrial cancer may add further relevant information regarding the possible differential actions of insulin analogues with respect to native insulin.
Project description:Despite a high degree of homology, insulin and IGF-1 receptors (IR/IGF1R) mediate distinct cellular and physiological functions. Here, using chimeric and site-mutated receptors, we demonstrate how domain differences between IR and IGF1R contribute the distinct functions of these receptors. Receptors with the intracellular domain of IGF1R show increased activation of Shc and Gab-1 and more potent regulation of genes involved in proliferation, corresponding to its higher mitogenic activity. Conversely, receptors with the intracellular domain of IR display higher IRS-1 phosphorylation, stronger regulation of genes in metabolic pathways and more dramatic glycolytic responses to hormonal stimulation.