Insulin-like Growth Factor Receptor Research Articles

Lactate Administration Increases Skeletal Muscle Synthesis in Mice

PurposeLactate, secreted by skeletal muscle during exercise, had been known as fatigue substance. However, several physiological roles of lactate have been revealed in the last decades, and previous studies reported that lactate treatment increased protein synthesis factors in skeletal muscle. Nevertheless, underlying molecular mechanisms of exogenous lactate on protein synthesis and degradation remain unknown, and there was no study that confirm long‐term lactate administration with exercise training. Therefore, the purpose of study is to investigate the effect of long‐term exogenous lactate administration and lactate administration with exercise training on the skeletal muscle synthesis and degradation.Methods32 mice were randomly divided into four groups: sedentary + saline (Sed/Con), sedentary + lactate (Sed/Lac), exercise training + saline (Ex/Con), and Exercise training + lactate (Ex/Lac). Exercise training (VO2max 70%) and lactate administration (3 g/kg sodium lactate) performed 5 days a week. The timing of lactate administration was immediately after every exercise training, and saline administration groups were given same volume of saline as lactate. After 5 weeks, mice were sacrificed and immediately obtained skeletal muscle and blood. To confirm the effect of lactate on protein synthesis (IGF receptor, Akt and mTOR phosphate/total) and degradation (MuRF1, MAFbx1, FOXO1), mRNA and protein expression analyzed respectively plantaris and extensor digitorum longus. Blood parameters of lactate, insulin, IGF1, and glucose were measured.ResultsSkeletal muscle weight tended to higher Sed/Lac than Sed/Con, but Sed/Lac had significantly supplement effects compared to Sed/Con in only gastrocnemius weight (p = .000). Blood IGF1 showed that Sed/Lac was significantly lower than Sed/Con (p = .039) and Ex/Lac (p = .007). mRNA of IGF receptor had only exercise effects (p = .000). mRNA of Akt and mTOR showed that Sed/Lac was significantly higher than Sed/Con (respectively, p = .000 and p = .043). Protein expression of MuRF1, Sed/Lac was significantly lower than Sed/Con (p = .046), but exercise training effects was found saline groups (Sed/Con vs Ex/Con; p = .001).ConclusionThis study showed that long‐term lactate administration had positive effects on Akt / mTOR and MuRF1. Especially, it was confirmed that long‐term lactate administration increased skeletal muscle mass in mice. Hence, we suggest that long‐term lactate administration increases skeletal muscle synthesis and that lactate administration can be used as supplement for sarcopenia. Nevertheless, this study did not confirm synergistic effects of lactate administration with exercise training. It is suggested that post‐exercise lactate administration, unlike lactate administration at rest state, affects energy metabolism rather skeletal muscle synthesis. Therefore, future study would be necessary to investigate lactate administration timing with exercise training.

Type 1 Insulin-Like Growth Factor Receptor Nuclear Localization in High-Grade Glioma Cells Enhances Motility, Metabolism, and In Vivo Tumorigenesis.

Gliomas are the most frequent solid tumors in children. Among these, high-grade gliomas are less common in children than in adults, though they are similar in their aggressive clinical behavior. In adults, glioblastoma is the most lethal tumor of the central nervous system. Insulin-like growth factor 1 receptor (IGF1R) plays an important role in cancer biology, and its nuclear localization has been described as an adverse prognostic factor in different tumors. Previously, we have demonstrated that, in pediatric gliomas, IGF1R nuclear localization is significantly associated with high-grade tumors, worst clinical outcome, and increased risk of death. Herein we explore the role of IGF1R intracellular localization by comparing two glioblastoma cell lines that differ only in their IGF1R capacity to translocate to the nucleus. In vitro, IGF1R nuclear localization enhances glioblastoma cell motility and metabolism without affecting their proliferation. In vivo, IGF1R has the capacity to translocate to the nucleus and allows not only a higher proliferation rate and the earlier development of tumors but also renders the cells sensitive to OSI906 therapy. With this work, we provide evidence supporting the implications of the presence of IGF1R in the nucleus of glioma cells and a potential therapeutic opportunity for patients harboring gliomas with IGF1R nuclear localization.

Pathophysiological Link between Insulin Resistance and Adrenal Incidentalomas.

Adrenal incidentalomas are incidentally discovered adrenal masses greater than one centimeter in diameter. An association between insulin resistance and adrenal incidentalomas has been established. However, the pathophysiological link between these two conditions remains incompletely characterized. This review examines the literature on the interrelationship between insulin resistance and adrenal masses, their subtypes, and related pathophysiology. Some studies show that functional and non-functional adrenal masses elicit systemic insulin resistance, whereas others conclude the inverse. Insulin resistance, hyperinsulinemia, and the anabolic effects on adrenal gland tissue, which have insulin and insulin-like growth factor-1 receptors, offer possible pathophysiological links. Conversely, autonomous adrenal cortisol secretion generates visceral fat accumulation and insulin resistance. Further investigation into the mechanisms and timing of these two pathologies as they relate to one another is needed and could be valuable in the prevention, detection, and treatment of both conditions.

Effects of the Isolated and Combined Ablation of Growth Hormone and IGF-1 Receptors in Somatostatin Neurons.

Hypophysiotropic somatostatin (SST) neurons in the periventricular hypothalamic area express growth hormone (GH) receptor (GHR) and are frequently considered as the key neuronal population that mediates the negative feedback loop controlling the hypothalamic-GH axis. Additionally, insulin-like growth factor-1 (IGF-1) may also act at the hypothalamic level to control pituitary GH secretion via long-loop negative feedback. However, to the best of our knowledge, no study so far has tested whether GHR or IGF-1 receptor (IGF1R) signaling specifically in SST neurons is required for the homeostatic control of GH secretion. Here we show that GHR ablation in SST neurons did not impact the negative feedback mechanisms that control pulsatile GH secretion or body growth in male and female mice. The sex difference in hepatic gene expression profile was only mildly affected by GHR ablation in SST neurons. Similarly, IGF1R ablation in SST neurons did not affect pulsatile GH secretion, body growth, or hepatic gene expression. In contrast, simultaneous ablation of both GHR and IGF1R in SST-expressing cells increased mean GH levels and pulse amplitude in male and female mice, and partially disrupted the sex differences in hepatic gene expression. Despite the increased GH secretion in double knockout mice, no alterations in body growth and serum or liver IGF-1 levels were observed. In summary, GHR and IGF1R signaling in SST neurons play a redundant role in the control of GH secretion. Furthermore, our results reveal the importance of GH/IGF-1 negative feedback mechanisms on SST neurons for the establishment of sex differences in hepatic gene expression profile.

Insulin like growth factor-1 works synergistically with dopamine to attenuate diabetic retinopathy by downregulating vascular endothelial growth factor

AimLevels of Insulin-like growth factor-1 (IGF-1), a proangiogenic growth factor is elevated and dopamine downregulated in proliferative diabetic retinopathy (PDR). This study aims to investigate whether IGF-1 with dopamine can together modulate vascular endothelial growth factor (VEGF) to prevent proliferative diabetic retinopathy while also attenuating angiogenic effects of IGF-1. MethodsEffect of combination of levodopa L-Dopa with IGF-1 was tested on normal retinal pigment epithelium cells (ARPE-19) and human umbilical vein endothelial cells (HUVEC), followed by tube formation. Invivo analysis of anti-angiogenic potential assessed by chick chorioallantoic membrane (CAM) assay. Diabetes induction in wistar rats at two time points, 12 and 16 weeks, treated with L-Dopa+IGF-1 and analysed for morphological variations, serum and tissue dopamine levels, gene expression by real-time PCR and western blot assay. ResultsL-Dopa+IGF-1 on ARPE-19 cells caused no toxicity and worked synergistically. Reduced number of vessels observed. Significant improvement in inner retina thickness (*p < 0.05) was observed when L-Dopa was given alone and/or with IGF-1. Dopamine levels improved significantly in both serum and tissue (*p < 0.05). Levels of VEGF and IGF-1 receptors reduced significantly in 12 weeks. Western studies suggest that L-Dopa+IGF-1 modulates its effects via Akt/ERK dependent pathway. ConclusionFirst ever report on synergistic effect of L-Dopa+IGF-1 in a rat model of diabetic retinopathy. Even though the effect of L-Dopa in combination with IGF-1 is comparable to levels of L-Dopa alone, this study presents an interesting finding of neuroprotective function of IGF-1, which has been studied in disease models of Parkinson’s but not diabetes.

Refining triple negative breast cancer targeted therapy: special focus on tyrosine kinase receptors

Triple negative breast cancer (TNBC) has a poor prognosis. TNBC does not respond to targeted therapy, unlike HER2+ and hormone receptor-positive Breast Cancer, and chemotherapy remains the major treatment option. As a result, there is an unmet demand for effective TNBC therapy. RTKs (Receptor Tyrosine Kinases) are a type of receptor that plays a key role in cancer growth. The RTK family includes the insulin-like growth factor receptor (IGFR). The insulin-like growth factor 1 (IGF-I) axis regulates MAPK, PI3K/AKt, and JAK/STAT signalling pathways, all of which are important in the progression of Breast Cancer. The function of such pathways in the regulation of metastasis, angiogenesis, and tumour stem cells is well known. The main goal of this chapter was to discuss the specific role of tyrosine kinase receptors and their involvement in TNBC-promoting signalling pathways.

Reconstruction and Exploratory Analysis of mTORC1 Signaling Pathway and Its Applications to Various Diseases Using Network-Based Approach.

Mammalian target of rapamycin (mTOR) is a serine-threonine kinase member of the cellular phosphatidylinositol 3-kinase (PI3K) pathway, which is involved in multiple biological functions by transcriptional and translational control. mTOR is a downstream mediator in the PI3K/Akt signaling pathway and plays a critical role in cell survival. In cancer, this pathway can be activated by membrane receptors, including the HER (or ErbB) family of growth factor receptors, the insulin-like growth factor receptor, and the estrogen receptor. In the present work, we congregated an electronic network of mTORC1 built on an assembly of data using natural language processing, consisting of 470 edges (activations/interactions and/or inhibitions) and 206 nodes representing genes/proteins, using the Cytoscape 3.6.0 editor and its plugins for analysis. The experimental design included the extraction of gene expression data related to five distinct types of cancers, namely, pancreatic ductal adenocarcinoma, hepatic cirrhosis, cervical cancer, glioblastoma, and anaplastic thyroid cancer from Gene Expression Omnibus (NCBI GEO) followed by pre-processing and normalization of the data using R & Bioconductor. ExprEssence plugin was used for network condensation to identify differentially expressed genes across the gene expression samples. Gene Ontology (GO) analysis was performed to find out the over-represented GO terms in the network. In addition, pathway enrichment and functional module analysis of the protein-protein interaction (PPI) network were also conducted. Our results indicated NOTCH1, NOTCH3, FLCN, SOD1, SOD2, NF1, and TLR4 as upregulated proteins in different cancer types highlighting their role in cancer progression. The MCODE analysis identified gene clusters for each cancer type with MYC, PCNA, PARP1, IDH1, FGF10, PTEN, and CCND1 as hub genes with high connectivity. MYC for cervical cancer, IDH1 for hepatic cirrhosis, MGMT for glioblastoma and CCND1 for anaplastic thyroid cancer were identified as genes with prognostic importance using survival analysis.

Determinants of IGF-II influencing stability, receptor binding and activation

Insulin like growth factor II (IGF-II) is involved in metabolic and mitogenic signalling in mammalian cells and plays important roles in normal fetal development and postnatal growth. It is structurally similar to insulin and binds not only with high affinity to the type 1 insulin-like growth factor receptor (IGF-1R) but also to the insulin receptor isoform A (IR-A). As IGF-II expression is commonly upregulated in cancer and its signalling promotes cancer cell survival, an antagonist that blocks IGF-II action without perturbing insulin signalling would be invaluable. The high degree of structural homology between the IR and IGF-1R makes selectively targeting either receptor in the treatment of IGF-II-dependent cancers very challenging. However, there are sequence differences between insulin and IGF-II that convey receptor selectivity and influence binding affinity and signalling outcome. Insulin residue YB16 is a key residue involved in maintaining insulin stability, dimer formation and IR binding. Mutation of this residue to glutamine (as found in IGF-II) results in reduced binding affinity. In this study we sought to determine if the equivalent residue Q18 in IGF-II plays a similar role. We show through site-directed mutagenesis of Q18 that this residue contributes to IGF-II structural integrity, selectivity of IGF-1R/IR binding, but surprisingly does not influence IR-A signalling activation. These findings provide insights into a unique IGF-II residue that can influence receptor binding specificity whilst having little influence on signalling outcome.

Cryo-EM Structure Reveals Polymorphic Ligand-bound States of IGF1R

Type 1 insulin-like growth factor receptor (IGF1R) plays an important role in regulating cellular metabolism and cell growth and has been identified as an anticancer drug target. Although previous studies have revealed some structures of IGF1R with different ligands, the continuous dynamic conformation change remains unclear. Here, we report 10 distinct structures (7.9–3.6 Å) of IGF1R bound to IGF1 or insulin to reveal the polymorphic conformations of ligand-bound IGF1R. These results showed that the α-CT2, disulfide bond (C670-C670′), and FnIII-2 domains had the most flexible orientations for the conformational change that occurs when ligands bind to the receptor. In addition, we found one special conformation (tentatively named the diverter-switch state) in both complexes, which may be one of the apo-IGF1R forms under ligand-treatment conditions. Hence, these results illustrated the mechanism of how different ligands could bind to human IGF1R and provided a rational template for drug design.

Liver and muscle-specific effects of phoenixin-20 on the insulin-like growth factor system mRNAs in zebrafish

ObjectivePhoenixin-20 (Pnx-20) is a bioactive peptide with endocrine-like actions in vertebrates. Recent studies suggest Pnx-20 promotes growth hormone/insulin-like growth factors (Gh/Igf) axis, an important endocrine regulator of growth in mammals and fish. DesignIn this research, we determined whether Pnx-20 affects the different members of the Igf family, its binding proteins and receptors (Igf-system) in zebrafish liver and muscle. ResultsIn vivo administration of Pnx-20 downregulated igfs, igf receptors (igfrs) and igf binding protein (igfbp) 5 mRNA expression in the liver of male and female zebrafish at both 1 and 6 h post-intraperitoneal (IP) injection. Interestingly, this effect occurred at a relatively earlier timepoint in female zebrafish suggesting sex-specific differences in Pnx-20 action. Besides, either 6 or 24 h in vitro incubations with Pnx-20 downregulated the expression of all igfs, igfrs and igfbp5 mRNAs (except igf2a) analyzed in a zebrafish liver cell (ZFL) line. Moreover, siRNA-mediated knockdown of Pnx-20 upregulated all Igf-system mRNAs analyzed in ZFL cells. Together, these results (both in vivo and in vitro) revealed a general suppressive action for both endogenous and exogenous Pnx-20 on the hepatic Igf-system of zebrafish. In contrast, a general sex-specific upregulation of the Igf-system mRNAs analyzed was found in the muscle of Pnx-20 injected fish. Future research should explore the sex- and time-differences observed in the present study. ConclusionsCollectively, this research shows that Pnx-20 is a tissue-specific regulator of the liver (suppressor) and muscle (stimulant) Igf signaling in both male and female zebrafish.

Identification of a tachykinin receptor and its implication in carbohydrate and lipid homeostasis in Rhodnius prolixus, a chagas disease vector

Neuropeptides and their receptors are fundamentally important in regulating many physiological and behavioural processes in insects. In this work, we have identified, cloned, and sequenced the tachykinin receptor (Rhopr-TKR) from Rhodnius prolixus, a vector of Chagas disease. The receptor is a G protein-coupled receptor belonging to the Rhodopsin Family A. The total length of the open reading frame of the Rhopr-TKR transcript is 1110 bp, which translates into a receptor of 338 amino acids. Fluorescent in-situ RNA-hybridization (FISH) for the Rhopr-TKR transcript shows a signal in a group of six bilaterally paired neurons in the protocerebrum of the brain, localized in a similar region as the insulin producing cells. To examine the role of tachykinin signaling in lipid and carbohydrate homeostasis we used RNA interference. Downregulation of the Rhopr-TKR transcript led to a decrease in the size of blood meal consumed and a significant increase in circulating carbohydrate and lipid levels. Further investigation revealed a close relationship between tachykinin and insulin signaling since the downregulation of the Rhopr-TKR transcript negatively affected the transcript expression for insulin-like peptide 1 (Rhopr-ILP1), insulin-like growth factor (Rhopr-IGF) and insulin receptor 1 (Rhopr-InR1) in both the central nervous system and fat body. Taken together, these findings suggest that tachykinin signaling regulates lipid and carbohydrate homeostasis via the insulin signaling pathway.

Biglycan Interacts with Type I Insulin-like Receptor (IGF-IR) Signaling Pathway to Regulate Osteosarcoma Cell Growth and Response to Chemotherapy.

Simple SummaryOsteosarcoma (OS) is an aggressive, primary bone cancer. OS cells produce altered osteoid whose components participate in signaling correlated to the development of this cancer. Biglycan (BGN), a proteoglycan, is correlated to aggressive OS type and resistance to chemotherapy. A constitutive signaling of insulin-like growth factor receptor I (IGF-IR) signaling in sarcoma progression was established. We showed that biglycan binds IGF-IR resulting in prolonged IGF-IR activation, nuclear translocation, and growth response of the poorly-differentiated MG63 cells correlated to increased aggressiveness markers expression and enhanced chemoresistance. This mechanism is not valid in moderately and well-differentiated, biglycan non-expressing U-2OS and Saos-2 OS cells.Osteosarcoma (OS) is a mesenchymally derived, aggressive bone cancer. OS cells produce an aberrant nonmineralized or partly mineralized extracellular matrix (ECM) whose components participate in signaling pathways connected to specific pathogenic phenotypes of this bone cancer. The expression of biglycan (BGN), a secreted small leucine-rich proteoglycan (SLRP), is correlated to aggressive OS phenotype and resistance to chemotherapy. A constitutive signaling of IGF-IR signaling input in sarcoma progression has been established. Here, we show that biglycan activates the IGF-IR signaling pathway to promote MG63 biglycan-secreting OS cell growth by forming a complex with the receptor. Computational models of IGF-IR and biglycan docking suggest that biglycan binds IGF-IR dimer via its concave surface. Our binding free energy calculations indicate the formation of a stable complex. Biglycan binding results in prolonged IGF-IR activation leading to protracted IGF-IR-dependent cell growth response of the poorly-differentiated MG63 cells. Moreover, biglycan facilitates the internalization (p ≤ 0.01, p ≤ 0.001) and sumoylation-enhanced nuclear translocation of IGF-IR (p ≤ 0.05) and its DNA binding in MG63 cells (p ≤ 0.001). The tyrosine kinase activity of the receptor mediates this mechanism. Furthermore, biglycan downregulates the expression of the tumor-suppressor gene, PTEN (p ≤ 0.01), and increases the expression of endothelial–mesenchymal transition (EMT) and aggressiveness markers vimentin (p ≤ 0.01) and fibronectin (p ≤ 0.01) in MG63 cells. Interestingly, this mechanism is not valid in moderately and well-differentiated, biglycan non-expressing U-2OS and Saos-2 OS cells. Furthermore, biglycan exhibits protective effects against the chemotherapeutic drug, doxorubicin, in MG63 OS cells (p ≤ 0.01). In conclusion, these data indicate a potential direct and adjunct therapeutical role of biglycan in osteosarcoma.

Abstract P2-03-02: Detection of insulin receptor isoforms by mass spectrometry in breast cancer

Abstract Breast cancer cells express Type 1 Insulin-like Growth Factor Receptor (IGF1R) and Insulin Receptor (IR). These receptors have a role in breast cancer biology and mediate metabolism, proliferation, survival, and motility. IR gene undergoes differential splicing that generates two IR isoforms, IRA (exclusion of exon 11) and IRB. High levels of IRA expression in prenatal growth and development are observed, whereas IRB expression is more highly expressed in adult insulin responsive tissues. IRA overexpression is the predominant receptor isoform expressed in breast cancer specimens obtained from patients with endocrine resistant disease. To measure levels of IRA and IRB mRNA expression, we utilized IR isoform specific primers in quantitative reverse transcription PCR (qRT-PCR). The validation of IRA and IRB primers was determined via using IRA and IRB overexpressing clones of MCF7 cells. IRA and IRB mRNA expression was also studied in human adipose and liver tissues that majorly express the adult IRB isoform. Over 40 breast cancer cell lines and 20 ER+ patient tumor samples were studied to determine IRA and IRB mRNA expression. Total IR, IGF1R, IRS1, and IRS2 were also analyzed in cell lines and patient samples. Across the ATCC breast cancer cell lines and ER+ patient tumors, heterogeneity was found among all targeted genes. Using MCF-7 cells as control, we found one of the breast cancer cell lines, Du4475, has very high IRA mRNA expression level (200-fold of that in MCF-7). Using mass spectrometry technology, we quantified levels of IR isoform expression in Du4475 cells. Briefly, IR immunoprecipitates were subjected to SDS-PAGE gels and the IRA protein gel band was submitted for mass spectrometry. Since IRA does not contain exon 11, the identified unique peptide consistent with its expression is TFEDYLHNVVFVPRPS. After this IRA specific peptide was determined, the heavy-labeled (C13- and N15-containing) IRA peptide was used as an internal injection control to quantify the IRA level. Quantitative results of IRA peptode sequence were proportional to the mRNA levels previously detected in Du4475 cell lysate. Using MCF-7 IRB overexpression cell line MCF7L-IRB-C5, we identified two IRB peptides, KTSSGTGAEDPRPSR and TSSGTGAEDPRPSR at exon 11 region by mass spectrometry. Cell membrane and total cell lysates could also be used to detect IR protein isoforms by mass spectrometry analysis. Further measurement of IRA and IRB level on other breast cancer cell lines is ongoing. In summary, we are the first to use mass spectrometry to validate protein expression of IR isoforms at levels that correlate with mRNA expression. IRA mRNA and protein expression levels in breast cancer cell lines may serve as biomarkers to screen patients for targeted therapy. Citation Format: Xihong Zhang, LeeAnn Higgins, Todd Markowski, Tzu-Yi Yang, Jacob Wragge, Kevin Murray, Bruce Witthuhn, Albert Barrios, Douglas Yee. Detection of insulin receptor isoforms by mass spectrometry in breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-03-02.

Abstract P4-02-01: Targeting insulin receptor in estrogen receptor positive breast cancer

Abstract Obesity and metabolic dysfunction are on the rise in the United States. Hyperinsulinemia, frequently seen in these conditions, correlates with an increased risk of development and mortality from estrogen receptor (ER) positive breast cancer. Expression of components of the insulin and insulin-like growth factor (IGF) family of proteins promote cancer cell growth in vitro, link to shorter progression-free survival, and is associates with an increased risk of metastatic disease and death in breast cancer patients. Previously our lab found that development of resistance to the commonly used ER-targeting drug tamoxifen (Tam) in vitro is associated with a loss of the type I IGF receptor expression with an increased dependence on the homologous insulin receptor (IR). These data argue for targeting IR in breast cancer, but concern has been raised due to the potential of disrupting glucose homeostasis in patients with or without existing metabolic disease. To address this concern, a novel insulin-Fc fusion protein (AKS-130) was developed to lower blood glucose levels without causing clinical hypoglycemia with a potential to target tumor IR. AKS-130 was found to downregulate IR expression in models of colorectal cancer (HCT-116) and malignant melanoma (WM266.4). Further, AKS-130 suppressed xenograft growth in fed and fasted states. We examined if AKS-130 had similar effects on ER positive breast cancer cells. To test the hypothesis that resistance to endocrine therapy increases the reliance of ER positive breast cancer cells on IR signaling, we utilized the ER positive breast cancer cell lines (MCF-7L, T47D) and their Tam resistant derivatives (MCF-7L TamR, T47D TamR). Similar to in HCT-116 and WM266.4 cells, we found that AKS-130 is a modest agonist of IR in ER+ breast cancer cells. Exposure to AKS-130 led to a marked reduction in IR expression in both parental and TamR cell lines, and was associated with partially suppressed downstream signaling to Akt. Interestingly, AKS130 induced IR downregulation was inhibited by pretreatment of BMS 536924, a dual IGF1R/IR kinase inhibitor. In vivo, AKS-130 treatment by itself scaled down MCF7L parental xenograft growth as compared to vehicle group, and AKS-130 in combination with Tam trended toward extending time to a tumor size of 500mm3. In MCF7L TamR xenografts, addition of AKS-130 to Tam treatment also trended toward delaying xenograft growth, though it was not statistically significant. Importantly, prolonged treatment with AKS-130 did not lead to significant changes in weight or blood glucose. Taken together these data show that novel agents, such as AKS-130, may serve as way to disrupt IR signaling in cancer cells without affecting host glucose metabolism. Addition of AKS-130 to Tam treatment trended toward delaying xenograft growth though further studies are needed, especially animal model systems of insulin resistance. These data indicate that IR signaling may represent a target to overcome or delay endocrine therapy resistance in breast cancer. Citation Format: Jingran Cao, Lynsey M. Fettig, Kelly LaPara, Xihong Zhang, Sylaja Murikipudi, Andrea R. Delpero, Thomas M. Lancaster, Todd C. Zion, Douglas Yee. Targeting insulin receptor in estrogen receptor positive breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-02-01.

Tyrphostin AG1024 downregulates aryl hydrocarbon receptor (AhR) expression in an IGF1R and IR-independent manner

The aryl hydrocarbon receptor (AhR) is a receptor-type transcription factor that is crucial for endocrine disruption and carcinogenesis caused by environment chemicals. Previous studies have indicated that certain intracellular signals are involved in AhR activation by their agonists, but the detailed mechanism remains unclear. In this study, we screened for important molecules for AhR activation using SCAD inhibitor kits. Among 164 kinase inhibitors listed in these kits, tyrphostin AG1024, commonly used as an inhibitor of insulin-like growth factor receptor (IGF1R) and insulin receptor (IR), was identified as a potent inhibitor of 3-methylcholanthrene (MC)-mediated AhR activation. We further investigated the mechanism by which AG1024 suppresses MC-mediated AhR activation. AG1024 decreased AhR-dependent luciferase activity, CYP1A1 gene expression, and its protein expression. However, when IGF1R siRNA and IR siRNA were used, AhR activation was slightly increased, in contrast to AG1024 treatment. In addition, AG1024 treatment downregulated the expression of AhR protein but not AhR gene, and decreased both nucleic and cytosolic AhR proteins. Therefore, AG1024 suppressed AhR activation by downregulating AhR protein expression. The molecular target of AG1024 remains unclear, and should be an important target for the regulation of AhR-dependent toxicity.

SY-707, an ALK/FAK/IGF1R inhibitor, suppresses growth and metastasis of breast cancer cells.

Focal adhesion kinase (FAK), a multi-functional cytoplasmic tyrosine kinase, plays a critical role in cancer migration, proliferation and metastasis via regulating multiple signaling pathways. SY-707 is an anaplastic lymphoma kinase (ALK)/FAK/type 1 insulin-like growth factor receptor (IGF1R) multi-kinase inhibitor which is now being evaluated in phase II clinical trials for ALK positive non-small cell lung cancer (NSCLC). However, the effect of SY-707 on breast cancer is unknown. In this study, we assessed preclinical the anti-growth and anti-metastasis potency of SY-707 in breast cancer cells. ATP content, PE-Annexin V, and would healing assays were used to examine cell proliferation, cell cycle and migration. Then, SD rat and beagle dog models were used to evaluate the pharmacokinetics profile of SY-707, and mouse xenograft model was used to evaluate the anti-cancer activities of SY-707 . We found that breast cancer cells apoptosis were induced by SY-707. Moreover, SY-707 exerted inhibition on cell migration and adhesion in a dose-dependent manner. In T47D xenograft mice, SY-707 had significant anti-tumor activities alone or synergistically with Paclitaxel. Meanwhile, SY-707 also displayed significant suppression on spontaneous metastasis of tumor to the lung in 4T1 murine breast cancer xenograft model. In conclusion, SY-707 has potent anti-proliferation and anti-migration potential in breast cancer and , implying its therapeutic application for the treatment of breast cancer in future clinical trials.

Effect of conditioned medium of umbilical cord-derived mesenchymal stem cells as a culture medium for human granulosa cells: An experimental study.

Background The umbilical cord-derived mesenchymal stem cells conditioned medium (UC-MSCs-CM) produces secretomes with anti-apoptotic properties, and has the potential to prevent apoptosis of granulosa cells (GC) during controlled ovarian hyperstimulation.ObjectiveTo observe the effect of UC-MSCs-CM on the interaction between pro- and anti-apoptotic proteins and the influence of growth differentiation factor 9 (GDF9) production in GC.Materials and MethodsUC-MSCs-CM was collected from umbilical cord stem cell culture on passage 4. GC from 23 women who underwent in vitro fertilization were cultured and exposed to UC-MSCs-CM for 24 hr. Then RNA of the GC was extracted and the mRNA expression of BCL-2 associated X (BAX), survivin and GDF9 were analysed using quantitative real-time PCR. The spent culture media of the GC were collected for measurement of insulin growth factor 1 using ELISA.ResultsThe expression of BAX was significantly different after UC-MSCs-CM exposure (4.09E-7 vs. 3.74E-7, p = 0.02). No significant changes occurred in survivin, BAX/survivin ratio, and GDF9 expression after UC-MSCs-CM exposure (p 0.05). The IGF-1 level of the CM was significantly higher after the CM was used as a culture medium for GC (2.28 vs. 3.07 1.72, p 0.001). A significant positive correlation was found between survivin and GDF9 (r = 0.966, p 0.001).Conclusion IGF-1 produced by UC-MSCs-CM can work in paracrine fashion through the IGF receptor, which can inhibit BAX and maintain GDF9 production. Moreover, under the influence of UC-MSCs-CM, GC are also capable of producing IGF-1, which can impact GC through autocrine processes.

Plasma microRNA-320a as a Potential Biomarker of Physiological Changes during Training in Professional Volleyball Players.

A deeper insight into the mechanisms responsible for athlete performance that may serve as specific and detailed training indicators is still desired, because conventionally used biomarkers provide limited information about the adaptive processes that occur during exercise. The objective of our study was to assess insulin-like growth factor 1 receptors (IGF1R) gene expression and evaluate plasma concentration of selected microRNAs (miRNAs) during a 10-week training period (sampling times: week 1, 4, 7, and 10) in a group of 12 professional female volleyball players. Circulating miRNAs (miR-223, miR-320a, and miR-486) with established concentration in plasma and documented association with the IGF1 signaling pathway, which is involved in muscle development and recovery, were tested. The levels of analyzed miRNAs, tested by one-way ANOVA, were significantly different between four training periods during a 10-week training cycle (miR-223 p < 0.0001, miR-320a p = 0.00021, miR-486 p = 0.0037, respectively). The levels of IGF1R also appeared to be different (p = 0.00092), and their expression showed a trend to increase between the first and third periods. In the fourth period, the expression decreased, although it was higher compared with the baseline. Correlations between concentration levels of miR-223 and miR-320a (rs = 0.54, p < 0.001), as well as between miR-320a and miR-486 (rs = 0.73, p < 0.001) were also found. In the fourth period, a negative correlation between miR-223 plasma level and leucocyte IGF1R expression was found (rs = −0.63, p = 0.028). Multiple linear regression analysis showed that miR-320a (p = 0.024) and creatine kinase (p = 0.028) had the greatest impact on the expression levels of the IGF1R gene. Future studies are required to define whether these miRNAs, especially miR-320a, as well as IGF1R expression could be useful biomarkers of physiological changes during exercise and to discover their detailed biological roles in mode-specific exercise training adaptations of professional athletes.

An altered expression of components of the IGF system could contribute to follicular persistence in Holstein cows

In dairy cows, reproductive diseases such as cystic ovarian disease (COD) represent a major problem that impacts on dairy production. It has been postulated that the insulin-like growth factor (IGF) system may contribute to follicular persistence and development of COD. Thus, the aim of the present study was to analyze relevant members of the IGF system in a critical period immediately after the expected time of ovulation, to obtain information about their role in follicular persistence in dairy cows. Proteins of the IGF system were evaluated at 0 (expected day of ovulation), 5, 10 and 15 days of follicular persistence to determine whether the changes previously detected in cows with COD occur early in COD pathogenesis. The serum concentration of IGF1 was higher in cows with 10 and 15 days of follicular persistence than in control cows. IGF1 expression in granulosa cells was similar in the follicles analyzed. In contrast, in theca cells, persistent follicles of days 5 and 10 showed the lowest IGF1 expression. IGF binding protein (IGFBP) 2 and 3 expression was lower in persistent follicles than in dominant follicles of the control group. Although IGF receptor (IGFR) 1 expression was similar in the groups analyzed, p-IGFR1 expression was significantly higher in dominant follicles of the control group than in persistent follicles. These data suggest alterations in the IGF system at the early stages of follicular persistence. The evidences obtained allow supporting that the IGF system could plays a key role in dairy cattle reproduction.

Various phenotypes of short stature with heterozygous IGF-1 receptor (IGF1R) mutations.

.Type 1 insulin-like growth factor receptor (IGF1R) plays an important role in normal fetal and postnatal growth. Over 30 pathogenic variants of IGF1R have been identified in patients with short stature. Yet, 20 years after the first report, a variety of phenotypes remain poorly defined. We analyzed the genetic and clinical data and responses to GH therapy in 11 patients using results from questionnaires. Eight of the 11 patients have already been reported in previous articles, and all of the identified mutations were heterozygous. The patients exhibited various phenotypes. At least two patients did not meet the criteria for GH treatment for small for gestational age (SGA) short stature, and two more patients showed lower serum IGF1 levels. Nine of the 11 patients had thin upper lips. Five patients with heterozygous IGF1R treated with GH exhibited similar height gains to those reported in previous Japanese studies on SGA short stature, which also led to extremely high serum IGF1 levels. Patients with short stature due to IGF1R mutations exhibit various phenotypes. Their presentation at diagnosis may be indistinguishable from common short stature. More specific clinical scoring that considers elevated IGF1 levels after GH treatment is needed to better detect IGF1R mutations.