Insulin-like Growth Factor-1 Receptor Protein Expression Research Articles

Inhibitory Effect of Iron Oxide Nanoparticle Liposome on the Growth of Non-Small Cell Lung Cancer In Vitro

In this study, we assessed the inhibitory potential of magnetic liposomes as gene vectors targeting human non-small cell lung cancer (NSCLC) growth In Vitro via hairpin RNA (shRNA) under the influence of an external magnetic field. Specifically, we engineered the plasmid pGFPshIGF-1R to co-express green fluorescent protein (GFP) and shRNA against insulin-like growth factor-1 receptor (IGF-1R), a gene associated with NSCLC progression. Utilizing superparamagnetic iron oxide nanoparticles (CombiMAG) and Lipofectamine2000,we constructed magnetic liposomes to deliver pGFPshIGF-1R into A549 NSCLC cells. Varying magnetic field strengths and exposure times were employed. The efficacy of transfection was gauged against liposome-only methods using Western blot analysis to measure IGF-1R protein reduction. In Vitro, the magnetic approach exhibited higher transfection efficiency (66.3%) compared to liposomes alone (22.1%), marking a threefold enhancement. In vivo, using a subcutaneous A549 tumor model in nude mice, shRNA-transfected A549 cells displayed substantial IGF-1R protein inhibition (interference rates: 56.1% and 85.1%). Importantly, magnetic transfection outperformed liposomal transfection in suppressing IGF-1R protein expression (P <0.05). Our findings suggest that magnetic liposome-mediated gene delivery, facilitated by an external magnetic field, holds promise as a targeted and safe therapeutic strategy for lung cancer.

+3179G/A Insulin-Like Growth Factor-1 Receptor Polymorphism: A Novel Susceptibility Contributor in Anti-Ro/SSA Positive Patients with Sjögren's Syndrome: Potential Clinical and Pathogenetic Implications.

Background: Alterations of the insulin-like growth factor (IGF) pathway along with genetic variations of the IGF1 receptor (IGF1R) gene have been linked to the development of systemic autoimmunity, possibly through apoptosis induction. This study aims to investigate whether genetic variations of the IGF1R contribute to Sjögren’s syndrome (SS) pathogenesis and explores potential functional implications. Methods: DNA extracted from whole peripheral blood derived from 277 primary SS patients, complicated or not by lymphoma, and 337 Healthy controls (HC) was genotyped for the rs2229765 IGF1R polymorphism using the RFLP-PCR assay. Gene expression of IGF1R and IGF1 isoforms, caspases 1, 4, and 5, and inflammasome components NLRP3, ASC, IL1β, IL18, IL33, IGFBP3, and IGFBP6 were quantitated by RT-PCR in total RNA extracted from minor salivary gland biopsies (MSGs) of 50 SS patients and 13 sicca controls (SCs). In addition, IGF1R immunohistochemical (IHC) expression was assessed in formalin-fixed, paraffin-embedded MSG tissue sections derived from 10 SS patients and 5 SCs. Results: The prevalence of the A/A genotype of the rs2229765 IGF1R polymorphism was significantly higher in the anti-Ro/SSA positive SS population compared to healthy controls (24.8% vs. 10.7%, p = 0.001). Moreover, IGF1Rs at both mRNA and protein levels were reduced in SS-derived MSGs compared to SCs and were negatively associated with caspase 1 transcripts. The latter were positively correlated with NLRP3, ASC, and IL1β at the salivary gland tissue level. IGF1R expression in peripheral blood was negatively correlated with ESR and IgG serum levels and positively correlated with urine-specific gravity values. Conclusions: The rs2229765 IGF1R variant confers increased susceptibility for seropositive primary SS. Dampened IGF1R mRNA and protein expression in salivary gland tissues could be related to increased apoptosis and subsequently to the activation of inflammasome pathways.

Interaction among estrogen, IGF-1, and H2S on smooth muscle cell proliferation.

Both estrogen and hydrogen sulfide (H2S) inhibit the proliferation of vascular smooth muscle cells (SMCs) and development of atherosclerosis. In the absence of endogenous H2S as occurred in CSE-knockout (KO) mouse, however, estrogen stimulates the proliferation of vascular SMCs. The underlying mechanisms for this seemingly controversial vascular effect of estrogen are unclear. In the present study, we demonstrated that the stimulatory effect of estrogen on the proliferation of CSE-KO SMCs was suppressed by the inhibitor of insulin-like growth factor-1 receptor (IGF-1R) or knockdown of IGF-1R protein expression. Estrogen downregulated the expression of insulin-like growth factor-1 (IGF-1) and IGF-1R in aortic tissues or aortic SMCs isolated from WT and CSE-KO mice. Furthermore, endogenous H2S downregulated IGF-1R, but upregulated estrogen receptor (ER)-α, in aortic tissues or SMCs. ER-α and IGF-1R were co-located in SMCs and co-immunoprecipitated, which was decreased by H2S. Finally, both endogenous and exogenous H2S induced the S-sulfhydration of IGF-1R, but not ER-α, in WT-SMCs and CSE-KO SMCs, which underlies the decreased formation of IGF-1R/ER-α hybrid in the presence of H2S. Thus, the absence of H2S favors the interaction of estrogen with IGF-1R/ER-α hybrid to stimulate SMCs proliferation. The appreciation of a critical role of H2S in preventing estrogen-induced SMCs proliferation will help better understand the regulation of complex vascular effects of estrogen and sex-related cardiovascular diseases.

Insulin-Like Growth Factor-1 Receptor Expression and Disease Recurrence and Survival in Patients with Resected Pancreatic Ductal Adenocarcinoma.

Insulin-like growth factor-1 receptor (IGF1R) signaling is important in pancreatic ductal adenocarcinoma (PDAC) biology, but little is known regarding IGF1R expression and patient characteristics and outcomes. In 365 patients with resected PDAC, we evaluated IGF1R protein expression using IHC on whole-slide sections and IGF1R genomic status using next-generation sequencing. Associations of IGF1R expression, measured by H-scores incorporating staining intensity and proportion of positive tumor cells, with disease-free survival (DFS) and overall survival (OS) were evaluated in 317 and 321 patients, respectively, using Cox regression adjusting for known prognostic factors. Higher IGF1R expression in tumor cells was associated with worse DFS comparing highest versus lowest expression tertiles [median DFS, 10.8 vs. 16.1 months; adjusted hazard ratio (HR), 1.73; 95% confidence interval (CI), 1.24-2.44; P trend = 0.002] and worse OS (median OS, 17.4 vs. 25.8 months; HR, 1.39; 95% CI, 1.00-1.92; P trend = 0.046). The association between high IGF1R expression and reduced DFS was identified primarily among patients with a preoperative body mass index ≥25 kg/m2 (HR, 4.27; 95% CI, 2.03-8.96, comparing extreme tertiles; P interaction = 0.032). KRAS-mutant tumors had greater IGF1R expression, and IGF1R expression in tumor epithelium was inversely correlated with that in stromal cells. Mutations in IGF1R were infrequent, and no overt loss-of-function alterations were identified. Higher IGF1R expression was modestly associated with higher gene copy number (Pearson correlation coefficient = 0.26, P < 0.001). Higher IGF1R protein expression was associated with worse patient outcomes in resected PDAC. IGF1R expression in PDAC represents a potential biomarker to guide patient selection for more aggressive, multidrug regimens in the adjuvant setting.

MiR‑589‑3p sponged by the lncRNA TINCR inhibits theproliferation, migration and invasion and promotes the apoptosis of breast cancer cells by suppressing the Akt pathway via IGF1R.

The long non-coding (lnc)RNA named tissue differentiation inducing non-protein coding RNA (TINCR) is a tumor marker that has not been studied in breast cancer. The present study aimed to investigate the TINCR-targeting micro (mi)RNAs and the regulatory mechanisms of TINCR in breast cancer. Following prediction by TargetScan and confirmation by dual-luciferase reporter assay, TINCR was demonstrated to be a target gene for miR-589-3p. The expression of TINCR and miR-589-3p in breast cancer and adjacent tissues was detected by reverse transcription-quantitative (RT-q)PCR, and the correlation between TINCR and miR-589-3p expression was determined by using Spearman correlation analysis. The 5-years survival was analyzed in patients with breast cancer according to TINCR expression (high or low). The effects of TINCR and miR-589-3p on the proliferation, apoptosis, migratory and invasive abilities of some breast cancer cell lines were detected by MTT assay, flow cytometry, wound healing assay and Transwell assay. The target gene of miR-589-3p was predicted and verified by TargetScan and dual-luciferase reporter assay, and the mechanism of miR-589-3p involvement in breast cancer cells was explored by overexpression or downregulation of miR-589-3p in breast cancer cells. RT-qPCR and western blotting were used to determine the expression of the insulin-like growth factor 1 receptor (IGF1R)/AKT pathway-related genes. The results demonstrated that TINCR expression level was negatively correlated with miR-589-3p expression level in breast cancer tissues and that patients with high expression of TINCR presented with lower survival rates. In addition, TINCR overexpression in cancer cells inhibited miR-589-3p expression, and cell transfection with miR-589-3p mimic partially reversed the effect of TINCR overexpression on the promotion of cancer cell proliferation, migration and invasion, and on the inhibition of cancer cell apoptosis. Furthermore, IGF1R, which is a target gene of miR-589-3p, increased cancer cell proliferation, migration and invasion and inhibited cancer cell apoptosis; however, these effects were partially reversed by miR-589-3p mimic. Furthermore, the results demonstrated that miR-589-3p mimic could downregulate the protein expression of IGF1R and p-AKT. In addition, TINCR overexpression downregulated miR-589-3p expression level. miR-589-3p partially reversed the effects of TINCR overexpression on cancer cell proliferation, migration and invasion, and inhibited cancer cell apoptosis by inhibiting the IGF1R-Akt pathway. The results from the present study demonstrated that TINCR may sponge miR-589-3p in order to inhibit IGF1R-Akt pathway activation in breast cancer cells, promoting therefore cancer cell proliferation, migration and invasion.

Receptor-mediated attenuation of insulin-like growth factor-1 activity by galactose-1-phosphate in neonate skin fibroblast cultures: Galactosemia pathogenesis.

The pathogenesis of classical galactosemia, a rare metabolic disorder associated with developmental complications in neonates and children due to inherited deficiency of galactose-1-phosphate (Gal-1-P) uridylyltransferase (GALT), is known to be mediated by elevated Gal-1-P levels and involves a cascade of cytokines, reactive oxygen species (ROS) and growth factors. To examine ex vivo the effect of Gal-1-P on the mitogenic activity of different growth factors, particularly insulin-like growth factor-1 (IGF-1), known to regulate growth and development from the fetal stage to adulthood. Fibroblasts derived from the foreskin of 3-8-day-old healthy neonates were cultured for 1-14 days with 0-20 mM galactose or 0-10 mM Gal-1-P and then stimulated with 5% fetal bovine serum (FBS) or 50 ng/mL of platelet-derived growth factor (PDGF) or fibroblast growth factor (FGF) or IGF-1 for 24 h. DNA synthesis was measured and protein expression of PDGFR, FGFR and IGF-1R was assessed with western blotting. Supra-physiological concentrations of galactose significantly decreased FBSand IGF-1-induced BrdU incorporation. The presence of Gal-1-P (5-10 mM) in culture medium for 7-14 days significantly (p < 0.01) decreased IGF-1-, PDGFand FBS-stimulated DNA synthesis. While treatment with Gal-1-P selectively and significantly (p < 0.01) reduced the protein expression of IGF-1 receptor, galactose treatment did not have any marked effect on examined growth factor receptors. This study demonstrates that Gal-1-P impairs IGF-1 activity through IGF-1-receptor impairment, thereby providing a new insight into the molecular mechanisms of galactosemia pathogenesis.

Cytoplasmic m1A reader YTHDF3 inhibits trophoblast invasion by downregulation of m1A-methylated IGF1R

N1-methyladenosine (m1A) is one of the important post-transcriptional modifications in RNA and plays an important role in promoting translation or decay of m1A-methylated messenger RNA (mRNA), but the “reader” protein and the exact biological role of m1A remain to be determined. Here, we identified that nine potential m1A “reader” proteins including YTH domain family and heterogeneous nuclear ribonucleoprotein by mass spectrometry, and among them, YTH domain-containing protein 3 (YTHDF3), could bind directly to m1A-carrying RNA. YTHDF3 was then identified to negatively regulate invasion and migration of trophoblast. Mechanistically, we found that the m1A “reader” YTHDF3 bound to certain m1A-methylated transcripts, such as insulin-like growth factor 1 receptor (IGF1R), with the combination of iCLIP-seq (individual-nucleotide resolution ultraviolet crosslinking and immunoprecipitation high-throughput sequencing) and m1A-seq. Furthermore, YTHDF3 could promote IGF1R mRNA degradation and thus inhibit IGF1R protein expression along with its downstream matrix metallopeptidase 9 signaling pathway, consequently decreasing migration and invasion of trophoblast. Thus, we demonstrated that YTHDF3 as an m1A reader decreased invasion and migration of trophoblast by inhibiting IGF1R expression. Our study outlines a new m1A epigenetic way to regulate the trophoblast activity, which suggests a novel therapeutic target for trophoblast-associated pregnancy disorders.

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.

Pathogenetic implications of early growth response 1 in Ewing sarcoma

Ewing sarcoma (ES) is the second most common primary malignant bone tumour, mainly occurs in children and adolescents, and has an overwhelming mortality. Despite extensive studies, few effective oncogenic signals have been described. Therefore, it is crucial to exploit novel pathognomonic factors and targetable biomarkers for ES patients. Based on previous studies, we speculate that insulin-like growth factor 1 receptor (IGF1R), which is upregulated by early growth response 1 (EGR1), may play a pivotal role in strengthening the downward transmission of IGF1 cascades. Therefore, in this study, we concentrated on determining the pathogenetic contribution of EGR1 in diverse ES cells. This report is the first to study the pathogenic role of EGR1 in ES. ES cells were cultured and transfected with Stealth RNAi human EGR1 small interfering RNA (siRNA) or negative control. Cell proliferation and invasion potential were measured. mRNA and protein expression of EGR1, IGF1R, and EWS-FLI1 also were assessed. In all EGR1 siRNA-transfected cells (SK-ES-1, RD-ES, and HS863.T), cell proliferation and invasive potential decreased significantly in EGR1 siRNA-transfected ES cells. mRNA and protein expression for EGR1, IGF1R, and EWS-FLI1 were also significantly reduced. In conclusion, EGR1 upregulated IGF1R expression and enhanced the expression of the oncogenic fusion protein EWS-FLI1. The EWS-FLI1/EGR1/IGF1R cascade combined with the previously confirmed pathways can form a speculative circuit, implicating positive feedback for tumourigenesis in ES. Therefore, EGR1 inhibitors are expected to be useful for the treatment of ES by preventing oncogenic IGF1/IGF1R expression.

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.

Expression of IGF/insulin receptor in prostate cancer tissue and progression to lethal disease.

Circulating insulin-like growth factor-1 (IGF-1) is consistently associated with prostate cancer risk. IGF-1 binds to IGF-1 receptor (IGF1R) and insulin receptor (IR), activating cancer hallmark pathways. Experimental evidence suggests that TMPRSS2:ERG may interact with IGF/insulin signaling to influence progression. We investigated IGF1R and IR expression and its association with lethal prostate cancer among 769 men. Protein expression of IGF1R, IR and ERG (i.e. a surrogate of ERG fusion genes) were assayed by immunohistochemistry. Cox models estimated hazard ratios (HR) and 95% confidence intervals (CI) adjusted for clinical characteristics. Among patients, 29% had strong tumor IGF1R expression and 10% had strong IR expression. During a mean follow-up of 13.2 years through 2012, 80 men (11%) developed lethal disease. Tumors with strong IGF1R or IR expression showed increased cell proliferation, decreased apoptosis and a higher prevalence of ERG. In multivariable models, strong IGF1R was associated with a borderline increased risk of lethal prostate cancer (HR 1.7; 95% CI 0.9-3.1). The association appeared greater in ERG-positive tumors (HR 2.8; 95% CI 0.9-8.4) than in ERG-negative tumors (HR 1.3; 95% CI 0.6-3.0, p-heterogeneity 0.08). There was no association between IR and lethal prostate cancer (HR 0.8; 95% CI 0.4-1.9). These results suggest that tumor IGF1R expression may play a role in prostate cancer progression to a lethal phenotype and that ERG-positive tumors may be more sensitive to IGF signaling. These data may improve our understanding of IGF signaling in prostate cancer and suggest therapeutic options for disease subtypes.

Identifying Involvement of H19-miR-675-3p-IGF1R and H19-miR-200a-PDCD4 in Treating Pulmonary Hypertension with Melatonin

Non-coding RNAs play an important role in the pathogenesis of pulmonary arterial hypertension (PAH). The aim of this study was to characterize the therapeutic role of melatonin as well as the underlying molecular mechanism (its effects on the expression of H19 and its downstream signaling pathways) in the treatment of PAH. Real-time PCR and western blot analysis were performed to evaluate the expression of H19, miR-200a, miR-675, insulin-like growth factor-1 receptor (IGF1R), and programmed cell death 4 (PDCD4). The value of systolic pulmonary artery pressure (SPAP) and the ratio of medial thickening in the monocrotaline (MCT) group were increased, whereas the melatonin treatment could decrease these values to some extent. The weights of RV (right ventricle), LV (left ventricle) + IVS (interventricular septal), and RV/(LV + IVS) in the MCT group were much higher than those in the MCT + melatonin and control groups. In addition, the expression of H19, miR-675, IGF1R mRNA, and IGF1R protein in the MCT group was the highest, whereas their expression in the control group was the lowest. The expression of miR-200, PDCD4 mRNA, and PDCD4 protein in the MCT group was the lowest, whereas their expression in the control group was the highest. Furthermore, H19 directly suppressed the expression of miR-200a, whereas miR-675-3p and miR-200a directly inhibited the expression of IGF1R and PDCD4, respectively. Finally, melatonin treatment inhibited cell proliferation; upregulated the expression of H19, miR-675-3p, and PDCD4; and downregulated the expression of miR-200a and IGF1R. This study demonstrated the role of H19-miR-675-3p-IGF1R- and H19-miR-200a-PDCD4-signaling pathways in the melatonin treatment of PAH.

Up-regulation of microRNA-503 by high glucose reduces the migration and proliferation but promotes the apoptosis of human umbilical vein endothelial cells by inhibiting the expression of insulin-like growth factor-1 receptor.

The present study is aimed to investigate the regulatory effect of microRNA (miRNA or miR)-503 on endothelial functions, as well as the mechanism by which high glucose leads to injury of endothelial cells. When reaching 80% confluency, human umbilical vein endothelial cells (HUVECs) were subjected to non-serum synchronization for 12 h, and medium of cells in high-glucose (HG) group was replaced by normal medium supplemented with 25 mmol/L D-glucose. HUVECs cultured in normal glucose (NG) medium were used as control. To overexpress miR-503, HUVECs were transfected with miR-503 mimics. To silence insulin-like growth factor-1 receptor (IGF-1R) mRNA, HUVECs were transfected with small interfering RNA (siRNA). To predict whether miR-503 targets IGF-1R, bioinformatics was performed. Quantitative Real-time polymerase chain reaction was used to determine miR-503 and IGF-1R mRNA expression, and Western blotting was employed to measure IGF-1R protein expression. Cell-Counting Kit 8 assay was used to determine HUVECs proliferation, while wound-healing assay was used to evaluate HUVECs migration. HUVECs apoptosis was investigated by measuring caspase 3 activity. Expression of IGF-1R in HUVECs in high glucose was decreased compared to that in normal glucose. miR-503 was predicted to target IGF-1R mRNA, and miR-503 expression in HUVECs in high glucose was higher than that in normal glucose. Overexpression of miR-503 inhibited the transcription and the translation of IGF-1R gene reducing migration, suppressed proliferation and promoted apoptosis. Transfection with IGF-1R siRNA decreased IGF-1R protein expression in HUVECs. Down-regulated IGF-1R expression reduced migration and proliferation, but promoted apoptosis of HUVECs. The present study demonstrates that miR-503 expression in HUVECs is elevated in high glucose condition. Also, miR-503 reduces migration and proliferation, but promotes apoptosis of HUVECs by inhibiting IGF-1R expression.

RETRACTED: Long noncoding RNA PVT1 enhances the viability and invasion of papillary thyroid carcinoma cells by functioning as ceRNA of microRNA-30a through mediating expression of insulin like growth factor 1 receptor

Invasion and metastasis of papillary thyroid carcinoma (PTC) significantly affects prognosis and quality of life of patients. Herein, we explored the binding relationship of long noncoding RNA PVT1 as ceRNA to microRNA-30a (miR-30a), and their effect on the development of PTC through regulating insulin like growth factor 1 receptor (IGF1R). PTC and adjacent normal tissues were collected, where the qRT-PCR and western blot assay were employed to evaluate the expression levels of PVT1, miR-30a and IGF1R. The correlation between PVT1 expression and clinicopathological characteristics of PTC patients was observed. PTC cell lines with the most/least significant difference from normal thyroid cells were selected and treated with siRNA PVT1 or overexpression PVT1 plasmids, miR-30a mimics or miR-30a inhibitors. Nucleus and cytoplasm segmentation was used to identify subcellular fractionation of PVT1. The binding relationship of PVT1 to miR-30a and the targeting relationship of miR-30a to IGF1R were confirmed by using bioinformatic prediction program, dual-luciferase reporter gene assay and RNA-pull down. Cell viability, cell cycle and apoptosis, invasion and migration capacities were assessed by MTT, flow cytometry, Transwell assay and scratch test, respectively. Western blot assay was employed to examine protein expression of IGF1R, apoptosis-related factors (caspase-3, cleaved capase-3) and epithelial-mesenchymal transition (EMT)-related factors (E-cadherin, Vimentin). In the PTC tissues and cells, PVT1 and IGF1R were highly expressed and miR-30a was poorly expressed. PVT1 exerted its effects on PTC mainly in the cytoplasm. The PVT1 expression was correlated with TNM staging, LNM and tumor infiltration of PTC. The competitive binding of PVT1 to miR-30a enhanced expression of IGF1R. In the in vitro experiments, BCPAP and TPC-1 cells were selected. When subjected to siRNA PVT1 or miR-30a mimics, BCPAP and TPC-1 cells exhibited inhibited proliferation, cell cycle progression, invasion, migration, EMT (increased E-cadherin and reduced Vimentin) and promoted apoptosis (reduced caspase-3 and increased cleaved capase-3), and moreover, the expression of IGF1R was reduced. This study provides evidence that long noncoding RNA PVT1 enhances the expression of IGF1R through competitive binding to miR-30a, whereby PVT1 facilitates the development of PTC.

MicroRNA-30a Inhibits Colorectal Cancer Metastasis Through Down-Regulation of Type I Insulin-Like Growth Factor Receptor

miR-30a expression is down-regulated and regulates tumor suppressors in various cancers. We investigated the mechanisms underlying the biological role of miR-30a in CRC. MicroRNA, mRNA, and protein expression were analyzed by quantitative real-time PCR and Western blot. The migration and invasion abilities of CRC were determined by wound healing assay, and trans-well migration and invasion. A luciferase reporter assay was used to confirm the targets of miR-30a. miR-30a expression was significantly down-regulated in CRC tissues and in CRC tissue with lymph node metastasis compared to CRC tissue without metastasis. Overexpression of miR-30a suppressed migration and invasion through insulin-like growth factor 1 receptor (IGF1R) in CRC cells. miR-30a suppresses IGF1R protein expression and inhibits β-catenin or p-AKT and increases E-cadherin expression. The IGF1R expression level is also up-regulated in CRC tumors and inversely correlated with miR-30a in CRC specimens. miR-30a functions as a tumor-suppressive miRNA, which may provide a therapeutic strategy for metastasis of CRC.

Chromosome 15 structural abnormalities: effect on IGF1R gene expression and function.

Insulin-like growth factor 1 receptor (IGF1R), mapping on the 15q26.3 chromosome, is required for normal embryonic and postnatal growth. The aim of the present study was to evaluate the IGF1R gene expression and function in three unrelated patients with chromosome 15 structural abnormalities. We report two male patients with the smallest 15q26.3 chromosome duplication described so far, and a female patient with ring chromosome 15 syndrome. Patient one, with a 568 kb pure duplication, had overgrowth, developmental delay, mental and psychomotor retardation, obesity, cryptorchidism, borderline low testis volume, severe oligoasthenoteratozoospermia and gynecomastia. We found a 1.8-fold increase in the IGF1R mRNA and a 1.3-fold increase in the IGF1R protein expression (P < 0.05). Patient two, with a 650 kb impure duplication, showed overgrowth, developmental delay, mild mental retardation, precocious puberty, low testicular volume and severe oligoasthenoteratozoospermia. The IGF1R mRNA and protein expression was similar to that of the control. Patient three, with a 46,XX r(15) (p10q26.2) karyotype, displayed intrauterine growth retardation, developmental delay, mental and psychomotor retardation. We found a <0.5-fold decrease in the IGF1R mRNA expression and an undetectable IGF1R activity. After reviewing the previously 96 published cases of chromosome 15q duplication, we found that neurological disorders, congenital cardiac defects, typical facial traits and gonadal abnormalities are the prominent features in patients with chromosome 15q duplication. Interestingly, patients with 15q deletion syndrome display similar features. We speculate that both the increased and decreased IGF1R gene expression may play a role in the etiology of neurological and gonadal disorders.

The significate of IGF-1 and IGF-1R in reducing PTSD cognitive function symptoms

ObjectiveTo study the expressions of insulin-like growth factor 1 (IGF-1) and IGF-1 receptor in the hippocampal CA1 region of posttraumatic stress disorder (PTSD) rats. MethodsForty healthy adult male Wistar rats were adopted. The internationally established single prolonged stress (SPS) method was used to set up the PTSD rat model and the immunohistochemical (IHC) method was applied to detect the expressions of IGF-1 and its receptor in the hippocampal CA1 region of PTSD rats. ResultsAfter SPS stimulus, the expression of IGF-1 protein in the rat hippocampal CA1 region increased with the development of PTSD and reached the maximum on the 14th day, which is statistically different from that of the control group (P<0.05); While the expression of IGF-1 receptor protein showed no significant difference on the 1st day and 7th day before and after stress (P>0.05), but slightly decreased on the 14th day and 28th day than before (P<0.05). ConclusionAfter stress, the expression of IGF-1 receptor didn’t grow in pace with that of IGF-1 accordingly, but slightly lowered instead. This indicates that IGF-1 receptor may affect the positive role of IGF-1 to some degree and meanwhile involve the pathophysiological process of cognitive changes of PTSD.

MicroRNA-30a-5p inhibits the proliferation and invasion of gastric cancer cells by targeting insulin-like growth factor 1 receptor.

MicroRNAs (miRs) are a class of small non-coding RNAs of 18–25 nucleotides in length that serve as key regulators in the development and progression of human cancers. Recently, miR-30b-5p, as a member of the miR-30 family, has been reported to act as a tumor suppressor in gastric cancer. However, the expression and function of miR-30a-5p in gastric cancer, as well as the corresponding underlying mechanism, remain unknown. In the present study, it was demonstrated that the expression of miR-30a-5p was significantly reduced in gastric cancer tissues (n=43) compared with normal gastric tissues (n=10; P<0.01). Similarly, miR-30a-5p was significantly downregulated in the gastric cancer cell lines AGS, HGC27, BGC823 and SGC7901, when compared with the normal gastric mucosa epithelial cell line GES-1 (P<0.01). In addition, overexpression of miR-30a-5p significantly inhibited the proliferation and invasion of AGS cells (P<0.01). Insulin-like growth factor 1 receptor (IGF-1R) was identified as a novel target of miR-30a-5p, and the protein expression of IGF-1R was negatively regulated by miR-30a-5p in AGS cells (P<0.01). Furthermore, overexpression of IGF-1R significantly reversed the inhibitory effect of miR-30a-5p on the proliferation and invasion of AGS cells (P<0.01), indicating that IGF-1R was involved in miR-30a-5p-mediated proliferation and invasion of AGS cells. It was also observed that the expression of IGF-1R mRNA was upregulated in gastric cancer tissues compared with normal gastric tissues (P<0.01), and its levels of expression were reversely correlated with that of miR-30a-5p in gastric cancer tissues (R2=0.3892; P<0.01). Collectively, these data suggest that miR-30a-5p inhibits the growth and metastasis of gastric cancer by directly targeting IGF-1R. Therefore, the miR-30a-5p/IGF-1R axis may be a potential therapeutic target in the treatment of gastric cancer.

MicroRNA-223 promotes mast cell apoptosis by targeting the insulin-like growth factor 1 receptor.

The present study aimed to examine the functional role of miR-223 in the regulation of mast cell apoptosis. Overexpressed miR-223 in mast cells transfected by Lipofectamine 2000 was used as a model, and miR-223 was found to promote mast cell apoptosis. To investigate the underlying mechanisms involved, the potential and putative target molecules of miR-223 were detected by bioinformatical analysis using predictive software, and western blotting. Insulin-like growth factor-1 receptor (IGF-1R) was found to be the functional target of miR-223 in the promotion of cell apoptosis. The downstream PI3K/protein kinase B (Akt) signaling pathway was also inhibited, and signaling was mediated by IGF-1R. Furthermore, the relative luciferase activity of the reporter containing the 3′-untranslated region (3′-UTR) of IGF-1R was significantly suppressed, while suppression of miR-223-inhibited IGF-1R protein expression was also observed. In conclusion, the results suggest that IGF-1R is the functional target for miR-223 promotion of cell apoptosis, and its downstream PI3K/Akt signaling pathway was suppressed by miR-223 through targeting of IGF-1R.

Metformin inhibits the proliferation of human prostate cancer PC-3 cells via the downregulation of insulin-like growth factor 1 receptor

Metformin is a biguanide drug that is widely used for the treatment of type 2 diabetes. Recent studies have shown that metformin inhibits cancer cell proliferation and tumor growth both in vitro and in vivo. The anti-tumor mechanisms of metformin include activation of the AMP-activated protein kinase/mTOR pathway and direct inhibition of insulin/insulin-like growth factor (IGF)-mediated cellular proliferation. However, the anti-tumor mechanism in prostate cancer remains unclear. Because activation of the IGF-1 receptor (IGF-1R) is required for prostate cell proliferation, IGF-1R inhibitors may be of therapeutic value. Accordingly, we examined the effects of metformin on IGF-1R signaling in prostate cancer cells. Metformin significantly inhibited PC-3 cell proliferation, migration, and invasion. IGF-1R mRNA expression decreased significantly after 48 h of treatment, and IGF-1R protein expression decreased in a similar manner. IGF-1R knockdown by siRNA transfection led to inhibited proliferation, migration and invasion of PC-3 cells. IGF-1 activated both ERK1/2 and Akt, but these effects were attenuated by metformin treatment. In addition, intraperitoneal treatment with metformin significantly reduced tumor growth and IGF-1R mRNA expression in PC-3 xenografts. Our results suggest that metformin is a potent inhibitor of the IGF-1/IGF-1R system and may be beneficial in prostate cancer treatment.