Expression Levels Of Insulin-like Growth Factor 1 Receptor Research Articles

Breast tumor IGF1R regulates cell adhesion and metastasis: alignment of mouse single cell and human breast cancer transcriptomics.

The acquisition of a metastatic phenotype is the critical event that determines patient survival from breast cancer. Several receptor tyrosine kinases have functions both in promoting and inhibiting metastasis in breast tumors. Although the insulin-like growth factor 1 receptor (IGF1R) has been considered a target for inhibition in breast cancer, low levels of IGF1R expression are associated with worse overall patient survival. To determine how reduced IGF1R impacts tumor phenotype in human breast cancers, we used weighted gene co-expression network analysis (WGCNA) of Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) patient data to identify gene modules associated with low IGF1R expression. We then compared these modules to single cell gene expression analyses and phenotypes of mouse mammary tumors with reduced IGF1R signaling or expression in a tumor model of triple negative breast cancer. WGCNA from METABRIC data revealed gene modules specific to cell cycle, adhesion, and immune cell signaling that were inversely correlated with IGF1R expression in human breast cancers. Integration of human patient data with single cell sequencing data from mouse tumors revealed similar pathways necessary for promoting metastasis in basal-like mammary tumors with reduced signaling or expression of IGF1R. Functional analyses revealed the basis for the enhanced metastatic phenotype including alterations in E- and P-cadherins. Human breast and mouse mammary tumors with reduced IGF1R are associated with upregulation of several pathways necessary for promoting metastasis supporting the conclusion that IGF1R normally helps maintain a metastasis suppressive tumor microenvironment. We further found that reduced IGF1R signaling in tumor epithelial cells dysregulates cadherin expression resulting in reduced cell adhesion.

Insulin-like growth factor-1 is involved in the deteriorated performance of aged laying hens.

The underlying mechanism behind the deteriorated laying performance of aged laying hens remains unclear. In the present study, the laying performance and gene expression along the hypothalamus-pituitary-gonad axis were determined. A total of 300 healthy 90-wk-old ISA hens with similar body weights were classified into three groups according to their laying rate between 90 and 94 wk of age. The experimental groups were the low laying rate (<60%, LLR), high laying rate (>85%, HLR), and intermediate laying rate (60% < laying rate < 85%, MLR) hens. At the end of 94 wk of age, eight hens were randomly selected from each group for tissue collection. The gene expression of hormones and their receptors were determined in the hypothalamus, pituitary, and follicles. The results showed that the serum 17-β-estradiol had no significant difference among the three groups. However, the level of insulin-like growth factor 1 (IGF1) in LLR hens was significantly decreased in the serum, small white follicles (SWF), and dominant follicles (DF, P < 0.05). Within the hypothalamus and small yellow follicles (SYF), the mRNA expression level of estrogen receptor was higher in the MLR group (P < 0.05). Compared with HLR hens, the steroid hormone-synthesis key gene, CYP19A1 was significantly decreased in the SWF of MLR-hens and DF of MLR- and LLR-hens (P < 0.05). The mRNA expression level of IGF1 receptor was higher in the hypothalamus, pituitary, SWF, large white follicles (LWF), SYF, and DF of LLR hens, compared to the HLR hens (P < 0.05). These results suggest that decreased IGF1 in serum and follicles was associated with the decreased egg production of aged laying hens. The present study provides novel insights into the endocrine changes in aged hens having different egg production.

Defective IGF-1 prohormone N-glycosylation and reduced IGF-1 receptor signaling activation in congenital disorders of glycosylation

The insulin-like growth factor-1 (IGF-1) signaling pathway is crucial for the regulation of growth and development. The correct processing of the IGF-1Ea prohormone (proIGF-1Ea) and the IGF-1 receptor (IGF-1R) peptide precursor requires proper N-glycosylation. Deficiencies of N-linked glycosylation lead to a clinically heterogeneous group of inherited diseases called Congenital Disorders of Glycosylation (CDG). The impact of N-glycosylation defects on IGF-1/IGF-1R signaling components is largely unknown. In this study, using dermal fibroblasts from patients with different CDG [PMM2-CDG (n = 7); ALG3-CDG (n = 2); ALG8-CDG (n = 1); GMPPB-CDG (n = 1)], we analyzed the glycosylation pattern of the proIGF-1Ea, IGF-1 secretion efficiency and IGF-1R signaling activity. ALG3-CDG, ALG8-CDG, GMPPB-CDG and some PMM2-CDG fibroblasts showed hypoglycosylation of the proIGF-1Ea and lower IGF-1 secretion when compared with control (CTR). Lower IGF-1 serum concentration was observed in ALG3-CDG, ALG8-CDG and in some patients with PMM2-CDG, supporting our in vitro data. Furthermore, reduced IGF-1R expression level was observed in ALG3-CDG, ALG8-CDG and in some PMM2-CDG fibroblasts. IGF-1-induced IGF-1R activation was lower in most PMM2-CDG fibroblasts and was associated with decreased ERK1/2 phosphorylation as compared to CTR. In general, CDG fibroblasts showed a slight upregulation of Endoplasmic Reticulum (ER) stress genes compared with CTR, uncovering mild ER stress in CDG cells. ER-stress-related gene expression negatively correlated with fibroblasts IGF-1 secretion. This study provides new evidence of a direct link between N-glycosylation defects found in CDG and the impairment of IGF-1/IGF-1R signaling components. Further studies are warranted to determine the clinical consequences of reduced systemic IGF-1 availability and local activity in patients with CDG.

CircRASSF2 promotes IGF1R and osteosarcoma metastasis via sponging miR-6838-5p.

BackgroundOsteosarcoma (OS) often occurs in children and adolescents and is highly malignant. Analyzing the pathogenesis of OS has great significance for prognosis and the discovery of new treatment strategies.MethodsThe effects and mechanism of circular RNA (circRNA) on OS were analyzed, as was the correlation between circRASSF2 and insulin-like growth factor 1 receptor (IGF1R) in data from The Cancer Genome Atlas (TCGA). The expression levels of microRNA (miR)-6838-5p and circRASSF2 in OS cells and osteoblasts were detected. The dual luciferase report was used to verify the targeting relationship. OS cells overexpressing circRASSF2, miR-6838-5p and/or IGF1R were constructed. The expression level of IGF1R and the biological behavior of the cells were detected. Eighty-two pairs of OS tissue and adjacent normal tissue samples were collected, and the levels of circRASSF2, miR-6838-5p, and IGF1R mRNA were detected by reverse transcription-quantitative PCR (RT-qPCR).ResultsCompared with osteoblasts, OS cells showed lower expression of miR-6838-5p and higher expression of circRASSF2. The dual luciferase report confirmed that miR-6838-5p targeted IGF1R. Overexpression of IGF1R significantly blocked the anticancer effects of miR-6838-5p. The dual luciferase report verified that circRASSF2 targeted miR-6838-5p, and promoted the expression of IGF1R. Overexpression of circRASSF2 not only promoted the malignant biological behavior of OS cells, but also blocked the anticancer effects of miR-6838-5p. In OS tissue, circRASSF2 and IGF1R were upregulated, and the two were positively correlated. MiR-6838-5p was downregulated, which negatively correlated with both circRASSF2 and IGF1R. High levels of circRASSF2 were associated with higher stage and metastasis of OS.ConclusionsIn conclusion, the promoting effects of IGF1R on OS are targeted by miR-6838-5p. CircRASSF2 restored the expression of IGF1R by sponging miR-6838-5p, thereby promoting the progression of OS.

Long non-coding RNA DUXAP8 promotes tumorigenesis by regulating IGF1R via miR-9-3p in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide with a low 5-year survival rate. Long non-coding RNA (lncRNA) double homeobox A pseudogene 8 (DUXAP8) is an oncogene and a potential biomarker in various tumors, such as ovarian, colorectal and non-small-cell lung cancer. However, the function and molecular mechanism underlying DUXAP8 in HCC progression is not completely understood. The expression of DUXAP8, microRNA (miR)-9-3p and insulin-like growth factor 1 receptor (IGF1R) in HCC tissues and cells was detected via reverse transcription-quantitative PCR. The expression levels of IGF1R and epithelial-mesenchymal transition-associated proteins (Snail, Slug, E-cadherin, N-cadherin and vimentin) were assessed via western blotting. The effects of DUXAP8, miR-9-3p and IGF1R on proliferation, migration and invasion were examined by conducting Cell Counting Kit-8 and Transwell assays, respectively. The interaction between miR-9-3p and DUXAP8 or IGF1R was predicted using StarBase or TargetScan, and further assessed using dual luciferase reporter and RNA immunoprecipitation assays. DUXAP8 and IGF1R were upregulated and miR-9-3p was downregulated in HCC tissues and cells compared with adjacent healthy tissues and a normal liver cell line, respectively. miR-9-3p overexpression decreased the protein expression level of IGF1R, and miR-9-3p knockdown enhanced the protein expression level of IGF1R in HCC cells compared with the corresponding control groups. Moreover, compared with the corresponding control groups, DUXAP8 knockdown and miR-9-3p overexpression increased E-cadherin protein expression levels, and decreased Snail, Slug, N-cadherin and vimentin protein expression levels. However, miR-9-3p inhibitor and IGF1R overexpression reversed DUXAP8 knockdown- and miR-9-3p overexpression-induced effects, respectively. In addition, compared with the corresponding control groups, DUXAP8 knockdown and miR-9-3p overexpression suppressed proliferation, migration and invasion, which was reversed by miR-9-3p inhibitor and IGF1R overexpression, respectively. Moreover, miR-9-3p as the target of DUXAP8 and IGF1R as the target of miR-9-3p were verified in HCC cells. lncRNA DUXAP8 contributed to HCC tumorigenesis via the miR-9-3p/IGF1R axis, providing a novel therapeutic approach for HCC diagnosis and treatment.

Insulin-Like Growth Factor 1 Receptor Drives Hepatocellular Carcinoma Growth and Invasion by Activating Stat3-Midkine-Stat3 Loop.

Activation of the insulin-like growth factor 1 receptor (IGF-1R)-mediated Janus kinase (JAK)1/2-Stat3 pathway contributes to hepatocarcinogenesis. Specifically, a previous study showed that IGF-1R inhibition downregulated Midkine expression in hepatocellular carcinoma (HCC). The present study investigated the role of IGF-1R-JAK1/2-Stat3 and Midkine signaling in HCC, in addition to the molecular link between the IGF-1R-Stat3 pathway and Midkine. The expression levels of IGF-1R, Stat3, and Midkine were measured using reverse transcription-quantitative PCR, following which the association of IGF-1R with Stat3 and Midkine expression was evaluated in HCC. The molecular link between the IGF-1R-Stat3 pathway and Midkine was then investigated in vitro before the effect of IGF-1R-Stat3 and Midkine signaling on HCC growth and invasion was studied in vitroand in vivo. IGF-1R, Stat3, and Midkine mRNA overexpressions were all found in HCC, where the levels of Stat3 and Midkine mRNA correlated positively with those of IGF-1R. In addition, Midkine mRNA level also correlated positively with Stat3 mRNA expression in HCC tissues. IGF-1R promoted Stat3 activation, which in turn led to the upregulation of Midkine expression in Huh7 cells. Similarly, Midkine also promoted Stat3 activation through potentiating JAK1/2 phosphorylation. Persistent activation of this Stat3-Midkine-Stat3 positive feedback signal loop promoted HCC growth and invasion, the inhibition of which resulted in significant antitumor activities both in vitroand in vivo. Constitutive activation of the IGF-1R-mediated Stat3-Midkine-Stat3 positive feedback loop is present in HCC, the inhibition of which can serve as a potential therapeutic intervention strategy for HCC.

Inhibition of SNCG suppresses the proliferation of lung cancer cells induced by high glucose.

Lung cancer is the most common cancer type worldwide and the leading cause of cancer-related mortality. Diabetes is closely associated with the occurrence, development and prognosis of lung cancer. Therefore, the present study aimed to investigate whether SNCG could affect the proliferation of lung cancer cells induced by high glucose. Lung cancer cells induced by high glucose simulated the pathologies of patients with lung cancer with diabetes in vitro. The proliferation of HBE cells and lung cancer cells after transfection and treatment of glucose was detected using Cell Counting Kit-8 assay. The mRNA expression levels of synuclein γ (SNCG), insulin-like growth factor 1 (IGF-1) and IGF-1 receptor (IGF-1R) in HBE cells and lung cancer cells alone, or cells induced by high glucose were analyzed via reverse transcription-quantitative (RT-q)PCR analysis. Moreover RT-qPCR analysis was used to determine the transfection efficiencies. The clone formation ability, migration and inflammation of lung cancer cells after high glucose induction and transfection were detected using clone formation, wound healing and ELISA assays. The protein expression levels of SNCG, IGF-1, IGF-1R, ERK 1/2, phosphorylated (p)-ERK1/2 and JNK in lung cancer cells after high glucose induction and transfection were determined using western blot analysis. The results suggested that high glucose significantly promoted the proliferation of A549, NCI-H1975 and SK-MES-1 cells at 24 and 48 h, as well as upregulated the expression levels of SNCG, IGF-1 and IGF-1R. Knockdown of SNCG suppressed the proliferation, clone formation ability and migration, but alleviated inflammation in A549 cells induced by high glucose. Knockdown of SNCG suppressed the expression levels of SNCG, IGF-1, IGF-1R, ERK1/2 and p-ERK1/2, while it promoted JNK expression in A549 cells induced by high glucose. The effect of AXL1717 (an IGF-1R inhibitor) treatment on cells was consistent with that of SNCG knockdown. In conclusion, inhibition of SNCG suppresses proliferation of lung cancer cells induced by high glucose.

Depletion of insulin-like growth factor 1 receptor increases radiosensitivity in colorectal cancer.

Although radiation therapy for advanced colorectal cancer (CRC) is very effective in some patients, treatment resistance limits its efficacy. Insulin-like growth factor 1 receptor (IGF1R) can affect tumor responsiveness and sensitivity to radiation in several cancer types. Herein, we studied the underlying function of IGF1R in the resistance of advanced CRC to radiation therapy and the possible use of drugs targeting IGF1R to overcome this resistance in patients with CRC. Differences in the expression levels of the IGF1R were assessed in CRC samples from patients who were radiosensitive or radioresistant. Two radio-resistant colorectal cancer cell lines, SW480 and HT29, were selected for in vitro studies, and the involvement of the IGF1R in their radiation resistance was elucidated by suppressing its expression through a targeted siRNA and through the use of a specific IGF1R inhibitor, BMS-754807. We assessed radiosensitivity in these human CRC cells lines by examining their proliferation and colony formation, as well as cell cycle analysis. Activation of the Akt pathway was assessed using western blotting. Compared with tissues from radiosensitive patients, higher IGF1R expression levels were found in patients with radiation-resistant colorectal cancer, while BMS-754807 had improved radiosensitivity and reversed radiation tolerance in both colorectal cancer cell lines. Pre-treatment with BMS-754807 prior to irradiation inhibited Akt phosphorylation, induced cell cycle arrest, and increased DNA damage. Therefore, the IGF1R contributes to radiation resistance of CRC cells in vitro. This study supports the notion that the radiosensitivity of radiation-resistant colorectal cancer cells can be enhanced by directly targeting IGF1R expression or activity. Ultimately, the combination of radiotherapy with IGF1R targeted inhibitors could potentially increase its effectiveness in the treatment of advanced colorectal cancer.

The role of insulin-like growth factor in Acrochordon Etiopathology

BackgroundThere are reports that acrochordon (skin tag), the most common fibroepithelial tumor of the skin, may be associated with metabolic syndrome components, particularly insulin metabolism disorders. However, to the best of our knowledge, there is no study examining its association with insulin resistance and tissue levels of insulin-like growth factor 1 receptor (IGF-1R) and insulin-like growth factor 2 receptor (IGF-2R).MethodsThirty patients with at least one acrochordon in their body who had no known history of diabetes mellitus and a control group comprised 30 individuals who had no acrochordon or no known history of diabetes mellitus were included. The tissue expression of IGF-1R and IGF-2R were investigated via immunohistochemical assessment in both groups.ResultsIn the group with acrochordon, IGF-1R and IGF-2R expression was found to be significantly higher compared to the control group (p < 0,01). Using logistic regression analysis, an increase in serum insulin, serum IGF-1 and HOMA-IR levels was found to be associated with the expression levels of IGF-1R and IGF-2R.ConclusionThese findings support the view that insulin metabolism disorders should be evaluated in patients with acrochordon. Our study indicates that IGF receptors may have an effect on acrochordon pathogenesis and that acrochordon etiology and related conditions can be clarified by detection of parameters that influence receptor levels.

Differential expression of receptors mediating receptor-mediated transcytosis (RMT) in brain microvessels, brain parenchyma and peripheral tissues of the mouse and the human

Receptor-mediated transcytosis (RMT) is a principal pathway for transport of macromolecules essential for brain function across the blood–brain barrier (BBB). Antibodies or peptide ligands which bind RMT receptors are often co-opted for brain delivery of biotherapeutics. Constitutively recycling transferrin receptor (TfR) is a prototype receptor utilized to shuttle therapeutic cargos across the BBB. Several other BBB-expressed receptors have been shown to mediate transcytosis of antibodies or protein ligands including insulin receptor (INSR) and insulin-like growth factor-1 receptor (IGF1R), lipid transporters LRP1, LDLR, LRP8 and TMEM30A, solute carrier family transporter SLC3A2/CD98hc and leptin receptor (LEPR). In this study, we analyzed expression patterns of genes encoding RMT receptors in isolated brain microvessels, brain parenchyma and peripheral organs of the mouse and the human using RNA-seq approach. IGF1R, INSR and LRP8 were highly enriched in mouse brain microvessels compared to peripheral tissues. In human brain microvessels only INSR was enriched compared to either the brain or the lung. The expression levels of SLC2A1, LRP1, IGF1R, LRP8 and TFRC were significantly higher in the mouse compared to human brain microvessels. The protein expression of these receptors analyzed by Western blot and immunofluorescent staining of the brain microvessels correlated with their transcript abundance. This study provides a molecular transcriptomics map of key RMT receptors in mouse and human brain microvessels and peripheral tissues, important to translational studies of biodistribution, efficacy and safety of antibodies developed against these receptors.

Porcine IGF-1R synonymous mutations in the intracellular domain affect cell proliferation and alter kinase activity

Miniature pigs are regarded as ideal organ donors for xenotransplantation into humans. Elucidating the formation mechanism of miniature pigs is important. The insulin-like growth factor 1 receptor (IGF-1R) is crucial in the regulation of cell proliferation and organismal growth. According to our previous research, the IGF-1R expression levels between large and miniature pigs showed different profiles in liver and muscle tissues. Here, five synonymous mutations of IGF-1R in the coding sequence (CDS) of intracellular domain (ICD) between large and miniature pigs were analysed by constructing expression vectors of two haplotypes and named pcDNA3.1-LP (with the CDS of IGF-1R ICD of Large White pigs, LP group) and pcDNA3.1-BM (with the CDS of IGF-1R ICD of Bama Xiang pigs, BM group). The IGF-1R of the BM group was expressed lower than that of the LP group in transcription, translation and autophosphorylation levels. The IGF-1R of the BM group also down-regulated the protein levels of p-AKT/p-ERK than that of the LP group. PK-15 and C2C12 cell proliferation were detected to further understand the function of the haplotype. Results showed that the proliferation viability of PK-15 and C2C12 cells weakened in the BM group. Moreover, the mRNA and protein stabilities of the BM group were higher than those of the LP group. Our data indicated that two haplotypes of IGF-1R CDS in ICD between large and miniature pigs altered IGF-1R expression and down-regulated AKT and ERK signalling pathways at translation levels, resulting in an inhibitory effect on PK-15 and C2C12 cell proliferation.

Short-term starvation reduces IGF-1 levels to sensitize lung tumors to PD-1 immune checkpoint blockade.

Harnessing the immune system by blocking the programmed cell death protein 1 (PD-1) pathway has been a major breakthrough in non-small-cell lung cancer treatment. Nonetheless, many patients fail to respond to PD-1 inhibition. Using three syngeneic models, we demonstrate that short-term starvation synergizes with PD-1 blockade to inhibit lung cancer progression and metastasis. This antitumor activity was linked to a reduction in circulating insulin-like growth factor 1 (IGF-1) and a downregulation of IGF-1 receptor (IGF-1R) signaling in tumor cells. A combined inhibition of IGF-1R and PD-1 synergistically reduced tumor growth in mice. This effect required CD8 cells, boosted the intratumoral CD8/Treg ratio and led to the development of tumor-specific immunity. In patients with non-small-cell lung cancer, high plasma levels of IGF-1 or high IGF-1R expression in tumors was associated with resistance to anti-PD-1-programmed death-ligand 1 immunotherapy. In conclusion, our data strongly support the clinical evaluation of IGF-1 modulators in combination with PD-1 blockade.

High IGF1R protein expression correlates with disease-free survival of patients with stage III colon cancer

The aim of this study was to investigate the association between expression of insulin-like growth factor-1 receptor (IGF1R) and its ligand, IGF-II, and disease-free survival (DFS) in patients with stage III colon cancer (CC). In this retrospective study we included consecutive patients who underwent curative surgery for stage III CC. IGF1R and IGF-II/IGF2 status were evaluated in tumour samples by immunohistochemistry and quantitative real-time PCR (qRT-PCR). Associations of markers with DFS were analysed using Cox proportional hazards models. Hundred and fifty-one CC patients were included (median age, 66.6years; female, 54.3%). Low levels of IGF1R and IGF-II protein expression were observed in 16.1% and 10.7% of the cases, respectively. No significant differences in clinicopathological characteristics between patients with tumours expressing low IGF1R or IGF-II protein levels and those with high levels were observed. A low IGF1R protein expression was found to be significantly associated with a shorter DFS (HR 3.32; 95% CI, 1.7-6.31; p= 0.0003), while no association was observed between IGF-II protein expression and DFS (HR 0.91; 95% CI, 0.28-2.96; p= 0.87). In a multivariate analysis, IGF1R protein status remained an independent prognostic factor for DFS (HR 2.73; 95% CI, 1.40-5.31; p= 0.003). Furthermore, we found that neither IGF1R nor IGF2 mRNA expression levels as measured by qRT-PCR correlated with the respective protein expression levels as assessed by immunohistochemistry. Neither of the mRNA expression levels was significantly associated with DFS. From our data we conclude that low IGF1R protein expression represents a poor prognostic biomarker in stage III colon cancer.

Increased expression of insulin-like growth factor-1 receptor predicts poor prognosis in patients with hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a lethal disease worldwide. In this study, we sought to explore the expression of insulin-like growth factor-1 receptor (IGF-1R) and its prognostic value in HCC.The expressions of IGF-1R mRNA and protein were estimated using quantitative real-time polymerase chain reaction and immunohistochemistry assays, respectively. The association between IGF-1R expression and clinicopathologic characteristic of patients with HCC was analyzed through Chi-squared test. Kaplan–Meier analysis and multivariate Cox analysis were performed to analyze prognostic value of IGF-1R in HCC.The IGF-1R was significantly upregulated in HCC tissues at both mRNA and protein levels compared with adjacent normal ones (P < .01). Its expression was associated with tumor node metastasis stage (P = .037) and lymph node metastasis (P = .027) of patients with HCC. Patients with HCC with high expression of IGF-1R had worse overall survival than those with low expression. IGF-1R might be a potential prognostic biomarker for HCC (hazard ratio [HR] = 1.912, 95% confidence interval [CI]: 1.023–3.572, P = .042).The IGF-1R expression level is upregulated in HCC tissues and may act as a prognostic biomarker for the disease.

Receptor tyrosine kinase expression in high-grade gliomas before and after chemoradiotherapy.

Glioma is the most common type of malignant brain tumor, and is characterized by invasive growth and chemoradiotherapy resistance. The following Cancer Genome Atlas mutation subtypes were identified in initial high-grade gliomas and recurrent gliomas treated by chemoradiotherapy: Isocitrate dehydrogenase 1/2 (IDH1/2) mutation, epidermal growth factor receptor variant III (EGFRvIII) mutation, tumor protein P53 mutation, PTEN mutation, O6-methylguanine-DNA methyltransferase promoter methylation and telomerase reverse transcriptase (TERT) mutation. The expression profile of 58 receptor tyrosine kinases (RTKs) were also examined. It was revealed that the proneural tumor subtype and IDH1/2 mutation are more frequent in recurrent tumors compared with initial tumors. Lower frequencies of the classical subtype, EGFRvIII mutation and TERT mutation were identified in recurrent tumors. A set of six RTK genes in which the level of expression was influenced by chemoradiotherapy was identified. Survival analysis revealed that the expression of several RTKs, including apoptosis-associated tyrosine kinase, fibroblast growth factor receptor 1 and insulin-like growth factor 1 receptor (IGF1R), was associated with patient survival. The stimulation of glioma cells by IGF1 in vitro was found to decreased the viability of the cells following treatment with temozolomide (TMZ). In addition, the expression level of IGF1R was increased in glioma cells treated with TMZ. These data suggest that altered RTK expression levels may influence the sensitivity of glioma to chemoradiotherapy.

MiR-126 inhibits the proliferation and invasion of gastric cancer by downregulation of IGF-1R

Objective: To investigate the expression levels and the mechanism of miR-126 and insulin like growth factor 1 receptor (IGF1R) in gastric cancer tissues and cells. Methods: The expression levels of miR-126 and IGF1R in 60 gastric cancer tissues and matched normal gastric tissues were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot, respectively. The association of miR-126 expression with clinicopathology and prognosis of gastric cancer patients was further analyzed. CCK-8, soft agar assay, transwell assay were used to analyze the proliferation and invasion capacity of gastric cancer cells, respectively, while the dual luciferase reporter assay was used to determine the direct target of miR-126. Results: The expression of miR-126 was obviously correlated with lymphatic metastasis, distant metastasis and TNM stage of gastric cancer (all P<0.05). Cox multivariate analysis revealed that lymphatic metastasis, TNM stage, miR-126 and IGF-1R expression were independent risk factors for prognosis of gastric cancer patients (all P<0.05). The expression level of miR-126 in gastric cancer tissues was 2.01±0.23 significantly lower than 10.12±2.15 of normal gastric tissues (P<0.05). CCK-8 result showed that the absorbance values of MKN28 and BGC823 cells at 72 hours after transfected with miR-126 mimics were 1.06±0.05 and 1.01±0.09, respectively, significantly lower than 1.55±0.12 and 1.36±0.12 of the control group (all P<0.05). The clone numbers of MKN28 and BGC823 cells transfected with miR-126 mimics formed in the soft agar were 33±9 and 29±8, respectively, significantly lower than 76±13 and 71±11 of the control group (all P<0.05). Transwell assay showed that the invasived number of MKN28 and BGC823 cells transfected by miR-126 mimics was 98±12 and 89±8, respectively, significantly lower than 154±18 and 161±17 of the control group (all P<0.05). Double luciferase assay further clarified that miR-126 the 3'-untranslated region (3'-UTR) of IGF-1R, and inhibited its protein expression. CCK-8 results showed that overexpression of IGF-1R partially reversed the miR-126 induced proliferation inhibition in MKN28 (1.65±0.14 v. s. 0.98±0.11, P=0.003) and BGC823 cells (1.44 ±0.15 v. s. 0.89±0.10; P=0.006). Likewise, overexpression of IGF-1R partially reversed the miR-126-inhibited invasion of MKN28 (176±19 v. s. 101±14, P=0.005) and BGC823 cells (186±21 v. s. 92±9, P=0.002). Moreover, the inhibitory effects of miR-126 on proliferation were aggravated by silencing of IGF-1R in MKN28 (0.67±0.09 v. s. 0.99±0.12, P=0.021) and BGC823 cells (0.57±0.07 v. s. 0.92±0.12, P=0.012). Conclusion: miR-126 suppresses the proliferation and invasion of gastric cancer cells through targeting the 3'-UTR of IGF-1R and inhibiting its expression.

Seasonal expressions of growth hormone receptor, insulin-like growth factor 1 and insulin-like growth factor 1 receptor in the scented glands of the muskrats (Ondatra zibethicus)

The growth hormone (GH)/insulin-like growth factor-1 (IGF-1) system plays an important role in regulating the cellular growth and organ development. The present study investigated the seasonal expressions of growth hormone receptor (GHR), IGF-1 and insulin-like growth factor 1 receptor (IGF-1R) in the scented glands of the muskrats. Morphological changes in the scented glands of the muskrats were observed significantly between the breeding and non-breeding seasons. Immunohistochemically, the expressions of GH, GHR, IGF-1 and IGF-1R were found in glandular cells and epithelial cells of the scented glands in both seasons. The protein and mRNA expression levels of GHR, IGF-1 and IGF-1R in the scented glands during the breeding season were noticeably higher than those of the non-breeding season. In parallel, the levels of GH and IGF-1 in the sera and scented glands were remarkably higher during the breeding season. In addition, small RNA sequencing showed that the predicted targets of the significantly changed hsa-miR-5100 and mmu-miR-6937-5p might regulate the expressions of Ghr, Igf-1 or Igf-1r. These results suggested that the morphological changes in the scented glands of the muskrats during the different seasons might be related to the expression levels of GHR, IGF-1 and IGF-1R. Meanwhile, GHR/IGF-1 system might regulate the scented glandular functions via endocrine or autocrine/paracrine manners.

Role of miR-16-5p in the proliferation and metastasis of hepatocellular carcinoma.

The aim of this study was to investigate the role of miR-16-5p in hepatocellular carcinoma (HCC), and to explore the possible underlying mechanism. 100 pairs of cancerous and para-cancerous tissues surgically removed in our hospital were collected. Real Time quantitative-Polymerase Chain Reaction (qRT-PCR) was used to detect the expression level of miR-16-5p in tissues. Bioinformatics and Dual-Luciferase reporter gene assay were used to screen and verify the potential target genes of miR-16-5p, respectively. Human HCC SMMC-7721 cells were used for functional experiments. Cell proliferation was detected by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. Cell invasion and migration were evaluated by transwell and scratch wound-healing assay, respectively. The protein expression levels of epithelial-mesenchymal transition (EMT) associated markers were measured by Western blot (WB) assay. QRT-PCR showed that miR-16-5p expression in HCC tissues was significantly lower than that of adjacent normal liver tissues. At the cellular level, miR-16-5p was lowly expressed in HCC cells (SMMC-7721). Bioinformatics websites (including Targetscan, PicTar, miRanda) predicted that insulin-like growth factor 1 receptor (IGF1R) was a potential target gene of miR-16-5p. Meanwhile, IGF1R was selected for further investigation due to its metastatic function. The results showed that no significant difference was found in the mRNA expression level of IGF1R in HCC tissues. However, the protein level of IGF1R was significantly up-regulated, which was negatively correlated with miR-16-5p. Combined with Dual-Luciferase reporter gene assay, it was confirmed that miR-16-5p could regulate the expression of IGF1R in a targeted manner. Furthermore, down-regulation of IGF1R significantly reduced the inhibitory effect of miR-16-5p on the proliferation and metastasis of SMMC-7721 cells. We showed that miR-16-5p suppressed invasion and migration of HCC cells, mechanically by directly targeting and inhibiting IGF1R protein expression. The newly identified miR-16-5p/IGF1R axis might provide new insights into the pathogenesis of HCC and novel potential therapeutic targets for the treatment of HCC.

Microtia patients: Auricular chondrocyte ECM is promoted by CGF through IGF-1 activation of the IGF-1R/PI3K/AKT pathway.

To explore the effectiveness of the insulin-like growth factor 1receptor (IGF-1R)/PI3K/AKT pathway in promoting the synthesis of the auricular chondrocyte extracellular matrix (ECM) using concentrated growth factor (CGF). Chondrocytes isolated from the remnant auricular cartilage of microtia patients were randomly divided into different experimental and control groups, then stimulated with a reagent.IGF-1 released by CGF was quantified by enzyme-linked immunosorbent assay. Glycosaminoglycan (GAG), proteoglycan, and type II collagen (COLAII) were examined by histological and immunohistological analysis. Expression levels of IGF-1R, pIGF-1R, PI3K, pPI3K, AKT, pAKT, COLAII, and Aggrecan were detected by western blot analysis technique andgene expression was tested by real-time polymerase chain reaction. CGF significantly stimulated the synthesis of COLAII and Aggrecan and increased the phosphorylation levels of IGF-1R, PI3K, and AKT. Small interfering RNA IGF-1 blocked ECM synthesis, COLAII and Aggrecan gene expression, and IGF-1R/PI3K/AKT activation. Inhibitor AG1024 and LY294002 significantly inhibited ECM synthesis and the phosphorylation of IGF-1R, PI3K, and AKT. CGF-released IGF-1 stimulates the synthesis of the auricular chondrocyte ECM via the IGF-1R/PI3K/AKT signaling pathway.

IR-A/IGF-1R-mediated signals promote epithelial-mesenchymal transition of endometrial carcinoma cells by activating PI3K/AKT and ERK pathways

ABSTRACT Background Obesity is a risk factor for endometrial cancer (EC). However, it is not known how insulin receptor isoform A (IR-A) and insulin-like growth factor 1 receptor (IGF-1R), cognate receptors for insulin and IGFs, respectively, regulate malignant behaviors of EC. In this study, we examined the biological effects of IR-A/IGF-1R, explored the downstream signaling cascades, and assessed the therapeutic potential of targeting IR-A/IGF-1R in vivo. Methods The expression levels of IR-A and IGF-1R were examined by qRT-PCR and Western blotting. Upon down-regulating IR-A and/or IGF-1R by sh-IR-A and/or sh-IGF-1R, respectively, cell migration, invasion, apoptosis, and epithelial-mesenchymal transition (EMT) were examined by wound healing, transwell invasion, flow cytometry, and Western blotting, respectively. Furthermore, the effect of sh-IR-A and/or sh-IGF-1R on phosphatidylinositide 3-kinases (PI3K)/AKT and ERK pathways was measured by Western blotting. Lastly, we monitored xenograft growth and EMT in vivo. Results Both IR-A and IGF-1R were significantly up-regulated in EC cells. Knockdown of IR-A or IGF-1R alone was sufficient to reduce migration and invasion, enhance apoptosis, and inhibit EMT of EC cells, and the most significant alterations were observed in cells co-transfected with sh-IR-A+ sh-IGF-1R. These phenotypes were associated with inactivating PI3K/AKT and ERK signaling by sh-IR-A and/or sh-IGF-1R. Consistent with in vitro findings, sh-IR-A or sh-IGF-1R significantly inhibited xenograft growth and EMT in vivo. Conclusion IR-A and IGF-1R-mediated signals, by activating PI3K/AKT and ERK pathways, can induce multiple malignant phenotypes of EC cells. Therefore, targeting IR-A or IGF-1R may provide therapeutic benefits for EC.