Function Of Insulin-like Growth Factor Research Articles

The Increased Apoptosis of Mesenchymal Stem Cells Mediated Osteopenia Due to Prenatal Nicotine Exposure in Female Offspring Rats via IGF1 Pathway.

Nicotine exposure is a common adverse environment during pregnancy and causes developmental toxicity of long bones in offspring. However, the effect of prenatal nicotine exposure (PNE) on bone mass accumulation in female offspring and its mechanism remained to be further investigated. In this study, we constructed a PNE rat model and collected the long bone and the bone marrow mesenchymal stem cells (BMSCs) from female offspring rats for the detection of bone mass, cell apoptosis, and the expressions of osteogenesis- and apoptosis-related genes. The results revealed that PNE induced low bone mass in female offspring rats and was associated with the suppression of osteogenic function. Moreover, the apoptosis of BMSCs derived from the PNE female offspring rats was raised, and the expression ratio of apoptosis marker genes BAX/BCL-2 was significantly increased. Further, PNE inhibited the expression and function of insulin-like growth factor l (IGF1) signaling pathway in BMSCs. However, the exogenous IGF1 treatment partially ameliorated the increased apoptosis of BMSCs derived from the PNE female offspring rats. In conclusion, PNE induced low bone mass in female offspring rats, which was attributed to the increased apoptosis of BMSCs due to functional inhibition of IGF1 signaling pathway.

Insulin-like growth factor 2 mRNA-binding protein 2 is a therapeutic target in ovarian cancer.

Ovarian cancer (OC) is a fatal gynecologic disease. The most common treatment for OC patients is surgery combined with chemotherapy but most patients at advanced stages eventually develop relapse due to chemoresistance. This study examined the role and function of insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) in OC. We observed that the expression of IGF2BP2 mRNA and protein was up-regulated in OC cells and tissues using quantitative real-time polymerase chain reaction (qRT-PCR) and western blot, respectively. An increase in IGF2BP2 expression at mRNA and protein levels was verified by the analyses of The Cancer Genome Atlas (TCGA) and Clinical Proteomic Tumor Analysis Consortium (CPTAC), respectively. Gene Expression Omnibus (GEO) and Cancer Cell Line Encyclopedia (CCLE) databases were applied to analyze the expression and clinical value of IGF2BP2. Gene set enrichment analysis (GSEA), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Ontology (GO) analyses explored biological functions and the involvement of IGF2BP2 in cell growth. Indeed, the knockdown of IGF2BP2 resulted in the inhibition of OC cell proliferation evaluated by the Cell Counting Kit-8 assay. Genomic amplification of IGF2BP2 partly accounted for its overexpression. High expression of IGF2BP2 was associated with signal transducer and activator of transcription 1 (STAT1) and drug sensitivity and was correlated with an unfavorable survival outcome in OC patients. Furthermore, the responsiveness of chemotherapy and immunotherapy were analyzed using the "pRRophetic" R package and The Cancer Immune Atlas (TCIA) database, respectively. The low expression of IGF2BP2 was associated with chemoresistance but with high tumor microenvironment scores and tumor-infiltrating immune cells, suggesting that immunotherapy may apply in chemoresistant patients. The alteration of IGF2BP2 expression may respond to chemotherapy and immunotherapy. Thus, IGF2BP2 shows potential as a therapeutic target and diagnostic biomarker for OC.

A novel tumour enhancer function of Insulin-like growth factor II mRNA-binding protein 3 in colorectal cancer

CRC cells evolve a variety of strategies to limit or circumvent apoptosis cell death. RNA binding proteins (RBPs) regulate many of the molecular mechanisms that underlie the development of cancer. The insulin-like growth factor II mRNA-binding proteins (IMP) family are oncofoetal RBPs, consisting of IMP1, IMP2 and IMP3, which have an important role in RNA metabolism. IMP3 is highly expressed in colorectal cancer (CRC) tissue, where its expression often correlates with poor prognosis. However, the role of IMP3 in CRC is not fully understood. IMP3 expression was analysed using a public database and by Western blotting and immunohistochemistry in human colon samples derived from patients with sporadic CRC and healthy subjects. To address whether IMP3 controls cancer cell survival, we analysed cell death pathways in in vitro and in vivo experiments after IMP3 downregulation by siRNA or an antisense oligonucleotide. IMP3 was highly expressed in CRC samples compared to normal control tissues. The knockdown of IMP3 enhanced a caspase-independent cell death in CRC cell lines. Furthermore, the treatment of CRC cells with IMP3 siRNA did not alter the expression of GSDMD, GPX-4 and the activated form of RIP3, three key molecules that govern pyroptosis, ferroptosis and necroptosis, respectively. Abrogation of IMP3 in CRC significantly reduced Bcl-2 and Bcl-xL mRNA and was associated with an altered mitochondrial membrane potential that allowed the nuclear migration of the apoptosis-inducing factor (AIF). Moreover, specific immunoprecipitation experiments on CRC human cell lines indicated that IMP3 binds Bcl-2 and Bcl-xL mRNA, suggesting that IMP3 acts as a regulator of the intrinsic apoptotic pathway through the surveillance of anti-apoptotic Bcl mRNA metabolism. Finally, we showed that IMP3 block inhibited the growth of CRC cell lines in vivo after transplantation into immunodeficient mice. Altogether, these data support a novel role for IMP3 in controlling the intrinsic caspase-independent apoptotic pathway in CRC.

Insulin-like growth factor 1 ameliorates pre-eclampsia by inhibiting zinc finger E-box binding homeobox 1 by up-regulation of microRNA-183.

As a common hypertensive complication of pregnancy, preeclampsia (PE) remains one of the leading causes of maternal and fetal with high morbidity and mortality worldwide. Much research has identified the vital functions of insulin-like growth factor 1 (IGF-1) in PE treatment. However, the combined roles and molecular mechanism of IGF-1 and microRNAs (miRNAs) underlying PE remain unclear. Therefore, we first measured the expression of IGF-1, zinc finger E-box binding homeobox 1 (ZEB1) and microRNA-183 (miR-183) expression in the placenta tissues of patients with PE by Western blot analysis and RT-qPCR. Interactions among IGF-1, ZEB1 and miR-183 were assessed by Western blot analysis, ChIP-PCR and dual-luciferase reporter gene assay. The effect of IGF-1 on the biological characteristics of trophoblast cells was investigated by CCK-8, colony formation assay and in vitro angiogenesis experiments after cells were transfected with si-IGF-1. Finally, a mouse eclampsia model induced by knockdown of IGF-1 was established to confirm the in vitro effect of IGF-1 on PE. We found that IGF-1, ZEB1 and miR-183 were highly expressed in the placental tissues of patients with PE. The knockdown of IGF-1 resulted in reduced proliferation and invasion of trophoblast cells and was accompanied by inhibited angiogenesis. ZEB1 was positively regulated by IGF-1 via ERK/MAPK pathway, which in turn inhibited miR-153 expression by binding to the miR-183 promoter. The in vitro experiments further confirmed that IGF-1 knockdown could induce PE. To sum up, IGF-1 knockdown elevated expression of miR-183 by downregulating ZEB1, thereby promoting deterioration of PE.

Insulin-Like Growth Factor Binding Proteins in Kidney Disease.

The seven members of the insulin-like growth factor (IGF) binding protein family (IGFBPs) were initially considered to be the regulatory proteins of IGFs in the blood circulation, mainly as the subsequent reserve for bidirectional regulation of IGF function during environmental changes. However, in recent years, IGFBPs has been found to have many functions independent of IGFs. The role of IGFBPs in regulating transcription, inducing cell migration and apoptosis is closely related to the occurrence and development of kidney disease. IGFBP-1, IGFBP-3, IGFBP-4 are closely associated with diabetes and diabetic nephropathy. IGFBP-3, IGFBP-4, IGFBP-5, IGFBP-6 are involved in different kidney disease such as diabetes, FSGS and CKD physiological process as apoptosis proteins, IGFBP-7 has been used in clinical practice as a biomarker for early diagnosis and prognosis of AKI. This review focuses on the differential expression and pathogenesis of IGFBPs in kidney disease.

Towards Understanding the Direct and Indirect Actions of Growth Hormone in Controlling Hepatocyte Carbohydrate and Lipid Metabolism

Growth hormone (GH) is critical for achieving normal structural growth. In addition, GH plays an important role in regulating metabolic function. GH acts through its GH receptor (GHR) to modulate the production and function of insulin-like growth factor 1 (IGF1) and insulin. GH, IGF1, and insulin act on multiple tissues to coordinate metabolic control in a context-specific manner. This review will specifically focus on our current understanding of the direct and indirect actions of GH to control liver (hepatocyte) carbohydrate and lipid metabolism in the context of normal fasting (sleep) and feeding (wake) cycles and in response to prolonged nutrient deprivation and excess. Caveats and challenges related to the model systems used and areas that require further investigation towards a clearer understanding of the role GH plays in metabolic health and disease are discussed.

Insulin-like Growth Factor 2 mRNA-Binding Protein 2-a Potential Link Between Type 2 Diabetes Mellitus and Cancer.

ContextType 2 diabetes mellitus (T2DM) and cancer share a variety of risk factors and pathophysiological features. It is becoming increasingly accepted that the 2 diseases are related, and that T2DM increases the risk of certain malignancies.ObjectiveThis review summarizes recent advancements in the elucidation of functions of insulin-like growth factor 2 (IGF-2) messenger RNA (mRNA)-binding protein 2 (IGF2BP2) in T2DM and cancer.MethodsA PubMed review of the literature was conducted, and search terms included IGF2BP2, IMP2, or p62 in combination with cancer or T2DM. Additional sources were identified through manual searches of reference lists. The increased risk of multiple malignancies and cancer-associated mortality in patients with T2DM is believed to be driven by insulin resistance, hyperinsulinemia, hyperglycemia, chronic inflammation, and dysregulation of adipokines and sex hormones. Furthermore, IGF-2 is oncogenic, and its loss-of-function splice variant is protective against T2DM, which highlights the pivotal role of this growth factor in the pathogenesis of these 2 diseases. IGF-2 mRNA-binding proteins, particularly IGF2BP2, are also involved in T2DM and cancer, and single-nucleotide variations (formerly single-nucleotide polymorphisms) of IGF2BP2 are associated with both diseases. Deletion of the IGF2BP2 gene in mice improves their glucose tolerance and insulin sensitivity, and mice with transgenic p62, a splice variant of IGF2BP2, are prone to diet-induced fatty liver disease and hepatocellular carcinoma, suggesting the biological significance of IGF2BP2 in T2DM and cancer.ConclusionAccumulating evidence has revealed that IGF2BP2 mediates the pathogenesis of T2DM and cancer by regulating glucose metabolism, insulin sensitivity, and tumorigenesis. This review provides insight into the potential involvement of this RNA binding protein in the link between T2DM and cancer.

Factor de crecimiento ligado a la insulina en la reproducción animal

The development of female gametes production (gametogenesis) occurs in an interesting way, as its process depends of many combined factors. This review will approach these morphofunction mechanisms of the ovary and the folliculogenesis, correlating the function of Insulin-Like Growth Factors (IGFs), which will influence in the production of steroids hormones, in the maintenance follicular maturation, and still elucidate how the diet assists better in this phases. Besides that, with the new researches in animal reproduction, it is important emphasize the role and assists of Insulin-Like Growth Factors during these physiologic process, showing all its potential for a more efficient follicular dynamics in any species.

The Roles of Insulin-Like Growth Factor Binding Protein Family in Development and Diseases.

The insulin-like growth factor (IGF) system comprises ligands of IGF-I/II, IGF receptors (IGFR), IGF binding proteins (IGFBPs), and IGFBP hydrolases. The IGF system plays multiple roles during various disease development as IGFs are widely involved in cell proliferation and differentiation through regulating DNA transcription. Meanwhile, IGFBPs, which are mainly synthesized in the liver, can bind to IGFs and perform two different functions: either inhibition of IGFs by forming inactive compounds with IGF or enhancement of the function of IGFs by strengthening the IGF-IGFR interaction. Interestingly, IGFBPs may have wider functions through IGF-independent mechanisms. Studies have shown that IGFBPs play important roles in cardiovascular disease, tumor progression, fetal growth, and neuro-nutrition. In this review, we emphasize that different IGFBP family members have common or unique functions in numerous diseases; moreover, IGFBPs may serve as biomarkers for disease diagnosis and prediction.

The IGF/Insulin-IGFBP Axis in Corneal Development, Wound Healing, and Disease.

The insulin-like growth factor (IGF) family plays key roles in growth and development. In the cornea, IGF family members have been implicated in proliferation, differentiation, and migration, critical events that maintain a smooth refracting surface that is essential for vision. The IGF family is composed of multiple ligands, receptors, and ligand binding proteins. Expression of IGF type 1 receptor (IGF-1R), IGF type 2 receptor (IGF-2R), and insulin receptor (INSR) in the cornea has been well characterized, including the presence of the IGF-1R and INSR hybrid (Hybrid-R) in the corneal epithelium. Recent data also indicates that each of these receptors display unique intracellular localization. Thus, in addition to canonical ligand binding at the plasma membrane and the initiation of downstream signaling cascades, IGF-1R, INSR, and Hybrid-R also function to regulate mitochondrial stability and nuclear gene expression. IGF-1 and IGF-2, two of three principal ligands, are polypeptide growth factors that function in all cellular layers of the cornea. Unlike IGF-1 and IGF-2, the hormone insulin plays a unique role in the cornea, different from many other tissues in the body. In the corneal epithelium, insulin is not required for glucose uptake, due to constitutive activation of the glucose transporter, GLUT1. However, insulin is needed for the regulation of metabolism, circadian rhythm, autophagy, proliferation, and migration after wounding. There is conflicting evidence regarding expression of the six IGF-binding proteins (IGFBPs), which function primarily to sequester IGF ligands. Within the cornea, IGFBP-2 and IGFBP-3 have identified roles in tissue homeostasis. While IGFBP-3 regulates growth control and intracellular receptor localization in the corneal epithelium, both IGFBP-2 and IGFBP-3 function in corneal fibroblast differentiation and myofibroblast proliferation, key events in stromal wound healing. IGFBP-2 has also been linked to cellular overgrowth in pterygium. There is a clear role for IGF family members in regulating tissue homeostasis in the cornea. This review summarizes what is known regarding the function of IGF and related proteins in corneal development, during wound healing, and in the pathophysiology of disease. Finally, we highlight key areas of research that are in need of future study.

Igfbp3 in grass carp (Ctenopharyngodon idellus): Molecular identification and mRNA expression under glucose, insulin and glucagon.

IGFBPs play a pivotal role in regulating the physiological function of IGFs (insulin-like growth factors). As an important member of IGFBPs, IGFBP3 is involved in the regulation of physiological functions of IGFs. To investigate the functional role of Igfbp3 in a herbivorous fish species, grass carp igfbp3 (GenBank accession no. MN251843) was isolated from the liver by molecular cloning. The ORF of grass carp igfbp3 was 882bp, which encoded 293 amino acids, and the first 22 amino acids comprised the signal peptide. The predicted molecular weight of grass carp Igfbp3 is 31.95kDa, and the theoretical isoelectric point is 8.32. Grass carp Igfbp3 displayed a high identity with its counterparts of common carp and zebrafish. And phylogenetic tree analysis showed that the grass carp Igfbp3 was clustered into the Igfbp3 subgroups of common carp and zebrafish. Tissue distribution study showed that igfbp3 was ubiquitously expressed in all tissues examined in the present study. High expression level of igfbp3 was detected in the heart, brain and fat of grass carp. The OGTT demonstrated that igfbp3 mRNA expression was significantly elevated in the liver of grass carp in response to glucose treatment. In vitro study showed that insulin could markedly stimulated igfbp3 mRNA expression in primary grass carp hepatocytes. Moreover, igfbp3 mRNA levels were also regulated by glucagon in grass carp primary hepatocytes. These results may provide the theoretical foundation for investigating the role of Igfbp3 in fish metabolism.

IGF2BP2 regulates DANCR by serving as an N6-methyladenosine reader

The major function of Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) is to regulate cell metabolism. However, emerging evidence indicates that IGF2BP2 plays a role in cancer, but the underlying mechanism is largely unknown. Here we showed that upregulation of IGF2BP2 is associated with poor outcomes of pancreatic cancer patients and suppression of IGF2BP2 inhibits cell proliferation. We further showed that IGF2BP2 regulates lncRNA DANCR. Ectopic expression IGF2BP2 enhances, whereas knockdown (KD) or knockout (KO) of IGF2BP2 suppresses DANCR expression. Moreover, in vivo RNA precipitation and reciprocal RNA immunoprecipitation revealed that IGF2BP2 interacts with DANCR. DANCR promotes cell proliferation and stemness-like properties. Experiments with xenograft models revealed that while ectopic expression of DANCR promotes, DANCR KO suppresses tumor growth. Mechanistically, DANCR is modified at N6-methyladenosine (m6A) and mutagenesis assay identified that adenosine at 664 of DANCR is critical to the interaction between IGF2BP2 and DANCR where IGF2BP2 serves a reader for m6A modified DANCR and stabilizes DANCR RNA. Together, these results suggest that DANCR is a novel target for IGF2BP2 through m6A modification, and IGF2BP2 and DANCR work together to promote cancer stemness-like properties and pancreatic cancer pathogenesis.

Insulin-like growth factor binding proteins inhibit oocyte maturation of zebrafish

The function of insulin-like growth factor (Igf) system in ovary has attracted much attention, but the role of Igf binding proteins (Igfbps) in ovary is still largely unknown. In this study, the role of Igfbps in oocyte maturation was investigated in zebrafish. The expression of all eight identified Igfbps except Igfbp6b could be detected in the adult ovary and exhibited differential expression profiles during folliculogenesis. The expression of several Igfbps is dynamically changed during oocyte maturation induced by human chorionic gonadotropin (hCG). By treatment of an Igfbps inhibitor NBI-31772 in vitro, the oocyte maturation could be stimulated in a clear dose-, time- and stage-dependent manner. Such effects were also observed by administration of NBI-31772 in vivo. Igfbps are differentially expressed in both follicular cells and oocytes, but the effect of NBI-31772 could only be found in intact follicles and not in the denuded oocytes. Previous studies have demonstrated that Igf3 is the major Igf member in regulating oocyte maturation of zebrafish. Interestingly, NBI-31772 could increase the effect of Igf3 on oocyte maturation. Furthermore, we found the effect of NBI-31772 on oocyte maturation could be blocked by an Igf type 1 receptor inhibitor BMS-536924 in vitro, suggesting the Igfbps can inhibit the oocyte maturation via Igf/Igf1r pathway. Together, we provided the first evidence in fish that Igfbps inhibit oocyte maturation of zebrafish.

Abstract P5-04-20: Targeting CDK4/6 and IGF1R or insulin receptor synergistically inhibits growth of endocrine sensitive and endocrine resistant breast cancers

Abstract Estrogen receptor positive (ER+) breast cancers are treated with hormonal therapies such as tamoxifen or aromatase inhibitors. More than 30% of patients with early-stage ER+ breast cancer treated with endocrine therapy will relapse and all patients with metastatic breast cancer expressing ER eventually acquire resistance to hormonal therapy. Endocrine therapy resistant patients therefore require novel therapeutic options. Insulin-like growth factors (IGFs) and insulin signaling via the type I IGF receptor (IGF1R) and insulin receptor (IR) respectively regulate breast cancer biology. Unfortunately, IGF1R targeted therapies failed to show a benefit in prolonging either disease-free or overall survival in clinical trials. In pre-clinical models acquired resistance to tamoxifen results in loss of IGF1R and enhanced sensitivity to IR signaling. Inhibition of mTOR alone relieves the negative feedback loop regulating levels of the adaptor protein IRS-1, which mediates proliferative effects of IGFs and insulin and enhanced phosphorylation of Akt. The ribosomal protein S6 kinase (S6K) phosphorylates IRS-1 on serine residues targeting it for proteasomal degradation, and this negative feedback regulation is important in attenuating IGF and insulin signaling. Cyclin dependent kinases (CDKs) 4 and 6 are required for cell cycle progression. CDK4/6 inhibitors have recently been approved for treatment of ER+, Her2- advanced breast cancers and these such as palbociclib and abemaciclib block phosphorylation of retinoblastoma. IGFs and insulin stimulate cell cycle progression and increase cyclin D1 levels in breast cancers. Therefore, we hypothesized that CDK4/6 inhibition combined with IGF1R or IR targeting, to block mitogenic functions of IGF or insulin signaling, could be a viable therapeutic option in endocrine sensitive and endocrine resistant breast cancer, respectively. Parental MCF-7 and T47D were more sensitive to palbociclib compared to matched cells with acquired resistance to tamoxifen, MCF-7/TamR and T47D/TamR. Palbociclib also blocked IGF-I and insulin stimulated entry into cell cycle leading to G0/G1 arrest in ER+ breast cancer cells. Unlike mTOR inhibitors that upregulated IRS-1 levels leading to increased phosphorylation of Akt through IGF1R/IR, palbociclib did not affect IRS-1 levels and did not enhance phosphorylation of Akt in ER+ breast cancer cells. Combination of palbociclib with an IGF1R inhibitory antibody (huEM164), but not IR antibody (83-7), was better at inhibiting growth of endocrine sensitive MCF-7 and T-47D cells than either drug alone. Further, in a formal synergy study using the method of Chou-Talalay, the combination index of palbociclib and the IGF1R antibody was <1 for MCF-7 parent cells, indicating the two drugs synergistically inhibit growth. Combination of palbociclib with an IR antibody synergistically inhibited the growth of endocrine resistant MCF-7/TamR cells. Our data show that cotrageting CDK4/6 and IGF1R is more effective in endocrine sensitive but cotargeting CDK4/6 and IR is more effective in tamoxifen resistant breast cancer cells. These data indicate that targeting CDK4/6 and IR could be a therapeutic option for patients with endocrine resistant disease. Citation Format: Hoff K, Sachdev D. Targeting CDK4/6 and IGF1R or insulin receptor synergistically inhibits growth of endocrine sensitive and endocrine resistant breast cancers [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-04-20.

IGF2BP1 over-expression in skin squamous cell carcinoma cells is essential for cell growth

The present study examined expression and potential functions of insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) in human skin squamous cell carcinoma (SCC). We show that IGF2BP1 mRNA and protein expression levels were upregulated in established (A431 line) and primary human skin SCC cells. Its expression was also increased in human skin SCC tissues, as compared to the normal skin tissues. In skin SCC cells, IGF2BP1 silencing or CRISPR/Cas9 knockout decreased levels of IGF2BP1-stablized mRNAs, including IGF2, CD44, Gli1 and Myc. Furthermore, skin SCC cell survival and proliferation were inhibited by IGF2BP1 silencing/knockout. Conversely, forced over-expression of IGF2BP1 further promoted A431 cell survival and proliferation. Furthermore, siRNA-mediated knockdown of IGF2BP1-bound long non-coding RNA THOR (“Lnc-THOR”) similarly depleted IGF2BP1-dependent mRNAs, causing inhibition on A431 cell survival and proliferation. In vivo, IGF2BP1 silencing or knockout inhibited A431 tumor xenograft growth in mice. Together, we conclude that IGF2BP1 over-expression in skin SCC cells is essential for cell growth.

IMP3 promotes TNBC stem cell property through miRNA-34a regulation.

To explore the expression and function of insulin-like growth factor II (IGFII) mRNA binding protein (IMP3) in the Triple Negative Breast Cancer (TNBC). According to previously reported gene expression array, we found that IMP3 had significantly higher expression in the CD44+CD24-ESA+ cell cluster, tumor initiating cell or cancer stem cell (CSCs), compared to other tumor cells. Based on the GEO database (GEO accession No. GSE6883), we detected the mRNA levels of IMP 1,2 and 3 by quantitative polymerase chain reaction (q-PCR) in CD44+CD24-ESA+ cell cluster and other breast tumor cell clusters. Besides, we measured IMP3 expression in microsphere of breast cancer, which exerted more significant tumor stem cell properties. The effects of IMP3 on breast cancer cell stem cell properties were studied by RNA interference and overexpression approaches in vitro. Furthermore, we predicted and identified microRNA, which could target and regulate IMP3 from bioinformatics analysis, and verified the interaction by luciferase assays and rescue experiments. Previously reported data showed that IMP3 expression was significantly upregulated in CD44+CD24-ESA+ cell cluster from breast cancer tissues. Besides, we found IMP3 had higher expression in mesenchymal cells rather than epithelial cells, which was also significantly elevated in SUM159 and T49D cell lines cultured as microsphere rather than adherent cells or differentiated cells. CD44+CD24-ESA+ cell cluster proportion was significantly decreased after silencing IMP3 in SUM1315, and its ability to develop into microsphere was significantly inhibited. By re-expressing IMP3 in SUM315, we restored the self-renewal capacity and tumorigenesis potential of SUM315. Through relative predicting website, we found several miRNAs which could regulate IMP3. miR-34a with highest score was chosen for further analysis. Mimicking miR-34a significantly downregulated IMP3 expression and inhibited its ability to develop into microsphere, while overexpressing IMP3 could rescue this process. IMP3 plays a vital role in maintaining stem cell properties of breast cancer cells, which could be regulated by mir-34a.

Expression profile, clinical significance, and biological function of insulin-like growth factor 2 messenger RNA-binding proteins in non-small cell lung cancer.

Insulin-like growth factor 2 messenger RNA-binding proteins have been described to associate with malignant process in many cancers. However, the role of insulin-like growth factor 2 messenger RNA-binding protein family has not been thoroughly elucidated in non-small cell lung cancer. This study was to investigate the expression profile, clinical significance, and biological function of insulin-like growth factor 2 messenger RNA-binding proteins family in non-small cell lung cancer. The expression levels of IGF2BP1-IGF2BP3 in tumor and adjacent normal tissues were determined, and association with clinicopathological features and overall survival was investigated by analyzing The Cancer Genome Atlas lung cancer database. Proliferation, migration, invasion assays, and flow-cytometry analysis were used to investigate the biological function in vitro. Insulin-like growth factor 2 messenger RNA-binding protein expression levels were significantly increased in non-small cell lung cancer compared to adjacent normal lung tissues. Chi-square test indicated that IGF2BP1 and IGF2BP3 expressions correlated with some meaningful clinical characteristics in non-small cell lung cancer. Kaplan-Meier analysis showed that high-level expression of IGF2BP1 or IGF2BP3 predicted poor overall survival in lung adenocarcinoma patients. Multivariate regression analysis showed that high level of IGF2BP3 was an independent risk factor for poor prognosis in lung adenocarcinoma patients (hazard ratio = 1.616, p = 0.017). In vitro, knockdown of IGF2BP3 inhibited lung adenocarcinoma cell proliferation by inducing cell cycle arrest and apoptosis, and undermined abilities of migration and invasion, and overexpression of IGF2BP3 could promote malignant phenotypes in lung adenocarcinoma cells. Our study revealed that expression of insulin-like growth factor 2 messenger RNA-binding proteins was widely upregulated and correlated with some certain clinicopathological features in non-small cell lung cancer. Especially, in insulin-like growth factor 2 messenger RNA-binding protein family, IGF2BP3 might play the most important role in tumor aggressiveness and prognosis in lung adenocarcinoma, and IGF2BP3 might serve as a potential therapeutic target and a novel prognostic biomarker in lung adenocarcinoma patients.

Insulin-like Growth Factor Binding Protein6 Associated withNeuronal Apoptosis Following Intracerebral Hemorrhage in Rats.

The insulin-like growth factor (IGF) system is linked to CNS pathological states. The functions of IGFs are modulated by a family of binding proteins termed insulin-like growth factor binding proteins (IGFBPs). Here, we demonstrate that IGFBP-6 may be associated with neuronal apoptosis in the processes of intracerebral hemorrhage (ICH). We obtained a significant upregulation of IGFBP-6 in neurons adjacent to the hematoma following ICH with the results of Western blot, immunohistochemistry, and immunofluorescence. Increasing IGFBP-6 level was found to be accompanied by the upregulation of Bax, Bcl-2, and active caspase-3. Besides, IGFBP-6 co-localized well with active caspase-3 in neurons, indicating its potential role in neuronal apoptosis. Knocking down IGFBP-6 by RNA-interference in PC12 cells reduced active caspase-3 expression. Thus, IGFBP-6 may play a role in promoting the brain secondary damage following ICH.

Subcellular localization and function of insulin-like growth factor 2 (IGF2) in uterine carcinosarcoma

Subcellular localization and function of insulin-like growth factor 2 (IGF2) in uterine carcinosarcoma

Insulin-like growth factors in embryonic and fetal growth and skeletal development (Review).

The insulin-like growth factors (IGF)-I and -II have a predominant role in fetal growth and development. IGFs are involved in the proliferation, differentiation and apoptosis of fetal cells in vitro and the IGF serum concentration has been shown to be closely correlated with fetal growth and length. IGF transcripts and peptides have been detected in almost every fetal tissue from as early in development as pre-implantation to the final maturation stage. Furthermore, IGFs have been demonstrated to be involved in limb morphogenesis. However, although ablation of Igf genes in mice resulted in growth retardation and delay in skeletal maturation, no impact on outgrowth and patterning of embryonic limbs was observed. Additionally, various molecular defects in the Igf1 and Igf1r genes in humans have been associated with severe intrauterine growth retardation and impaired skeletal maturation, but not with truncated limbs or severe skeletal dysplasia. The conflicting data between in vitro and in vivo observations with regard to bone morphogenesis suggests that IGFs may not be the sole trophic factors involved in fetal skeletal growth and that redundant mechanisms may exist in chondro- and osteogenesis. Further investigation is required in order to elucidate the functions of IGFs in skeletal development.