Plasma IGFBP-2 levels predict clinical outcomes of patients with high-grade gliomas

Cytokine profile of cerebrospinal fluid in pediatric patients with metastatic medulloblastoma

Background

Medulloblastoma (MB) is a malignant pediatric central nervous system tumor that is prone to leptomeningeal metastasis. Currently, apart from magnetic resonance imaging and cerebrospinal fluid (CSF) cytology, there are no reliable biomarkers for MB progression. Cytokines are key proteins in signaling pathways in the tumor microenvironment and are closely related to tumor recurrence and progression. This study aimed to investigate the CSF cytokine profile in pediatric patients with MB to identify biomarkers of tumor progression and metastasis.

Methods

In total, 10 patients were recruited for this study. Five patients had nonmetastatic MB and five had metastatic MB. A cytokine antibody array was used to detect the expression of 120 cytokines in the CSF, and differentially expressed cytokines were screened by integrated bioinformatics analysis.

Results

Twenty-seven cytokines were upregulated in patients with MB compared to control individuals. Of these, eight were upregulated by > 1.5-fold (CCL2, BMP-4, beta-NGF, FGF-7, IL-12p40, eotaxin-2, M-CSF, and NT-4). Twelve cytokines were differentially expressed between patients with metastatic MB and nonmetastatic (nine cytokines were upregulated and three were downregulated). Among them, NAP-2, MIP-1α, MIP-1β, IGFBP-1, IGFBP-2 and IGFBP-3 were upregulated by more than two-fold. Gene Ontology analysis revealed that the upregulated cytokines were enriched mainly in "epithelial cell proliferation" and "chemotaxis," and the Kyoto Encyclopedia of Genes and Genomes analysis indicated the enrichment of the "MAPK," "PI3K-Akt," and "Ras" signaling pathways.

Conclusions

The present study investigated cytokine profiles in the CSF of pediatric patients with MB. Our results suggest that these differentially expressed cytokines may serve as novel markers for detecting MB, especially for assessing the risk of progression and metastasis.

Potential of sonobiopsy as a novel diagnosis tool for brain cancer

Brain tumors have a poor prognosis. Early, accurate diagnosis and treatment are crucial. Although brain surgical biopsy can provide an accurate diagnosis, it is highly invasive and risky and is not suitable for follow-up examination. Blood-based liquid biopsies have a low detection rate of tumor biomarkers and limited evaluation ability due to the existence of the blood-brain barrier (BBB). The BBB is composed of brain capillary endothelial cells through tight junctions, which prevents the release of brain tumor markers to the human peripheral circulation, making it more difficult to diagnose, predict prognosis, and evaluate therapeutic response through brain tumor markers than other tumors. Focused ultrasound (FUS)-enabled liquid biopsy (sonobiopsy) is an emerging technique using FUS to promote the release of tumor markers into the circulatory system and cerebrospinal fluid, thus facilitating tumor detection. The feasibility and safety data from both animal models and clinical trials support sonobiopsy as a great potential in the diagnosis of brain diseases.

Association Study of IGF-1 rs35767 and rs6214 Gene Polymorphisms with Cancer Susceptibility and Circulating Levels of IGF-1, IGFBP-2, and IGFBP-3 in Colorectal Cancer Patients

Early detection of colorectal cancer (CRC) increases the 5-year survival rate by 90%; therefore, non-invasive biomarkers such as measurable circulating proteins for early detection and prognosis are crucial. Insulin-like growth factor-1 (IGF-1) is involved in the regulation of cell proliferation and apoptosis. IGF binding proteins (IGFBPs) bind and inhibit the activity of IGF-1. It was inconsistently reported that high IGF-1 and IGFBP-2 and low IGFBP-3 circulating levels are associated with high cancer risk, poor prognosis, and tumor metastasis in several cancers. A total of 175 patients with CRC and 429 controls were enrolled in this study. We genotyped for IGF-1 rs35767 and rs6214 gene polymorphisms and assessed their association with circulating levels of IGF-1 and/or the risk for CRC. We also determined plasma levels of IGF-1, IGFBP-2, and IGFBP-3. Neither rs35767 nor rs2614 were associated with cancer risk or IGF-1 levels in our study cohort. IGF-1 and IGFBP-3 levels were higher in controls than in patients, whereas IGFBP-2 was higher in patients than in controls. Only IGFBP-2 was associated with increased tumor grade but not stage. Therefore, IGF-1, IGFBP-2, and IGFBP-3 may be useful as early detection and prognostic biomarkers in CRC.

IGFBP2 promotes proliferation and cell migration through STAT3 signaling in Sonic hedgehog medulloblastoma

Medulloblastoma (MB) is the most common pediatric brain malignancy and is divided into four molecularly distinct subgroups: WNT, Sonic Hedgehog (SHHp53mut and SHHp53wt), Group 3, and Group 4. Previous reports suggest that SHH MB features a unique tumor microenvironment compared with other MB groups. To better understand how SHH MB tumor cells interact with and potentially modify their microenvironment, we performed cytokine array analysis of culture media from freshly isolated MB patient tumor cells, spontaneous SHH MB mouse tumor cells and mouse and human MB cell lines. We found that the SHH MB cells produced elevated levels of IGFBP2 compared to non-SHH MBs. We confirmed these results using ELISA, western blotting, and immunofluorescence staining. IGFBP2 is a pleiotropic member of the IGFBP super-family with secreted and intracellular functions that can modulate tumor cell proliferation, metastasis, and drug resistance, but has been understudied in medulloblastoma. We found that IGFBP2 is required for SHH MB cell proliferation, colony formation, and cell migration, through promoting STAT3 activation and upregulation of epithelial to mesenchymal transition markers; indeed, ectopic STAT3 expression fully compensated for IGFBP2 knockdown in wound healing assays. Taken together, our findings reveal novel roles for IGFBP2 in SHH medulloblastoma growth and metastasis, which is associated with very poor prognosis, and they indicate an IGFBP2-STAT3 axis that could represent a novel therapeutic target in medulloblastoma.

Identification of Prognostic Aging-Related Genes Associated with Immune Cell Infiltration in Glioblastoma

Background. Aging is recognized as a main tumor risk factor, and thus aging has become a field of interest in the tumor research field. Glioblastoma multiforme represents the most typical primary malignant intracranial tumor, particularly in the elderly. However, the association between aging-related genes (AGs) and GBM prognosis remains unknown. As a result, the primary goal of this study was to determine the association among AGs and the prognosis of GBM. Methods. A total of 307 human AGs were downloaded from the HAGR database, while the expression profiles of GSE4290 and GSE4412 were obtained from the GEO database. Furthermore, data on GBM expression profiles were obtained from the Chinese Glioma Genome Atlas (CGGA) database. The DEAGs that were differentially expressed among the AG and GBM gene expression profiles derived from GSE4290 were then identified, followed by functional analysis of the DEAGs. The survival-related AGs were then screened using univariate Cox regression analysis , which was used to build and validate a prognostic risk model. Furthermore, the ESTIMATE and CIBERSORT algorithms were utilized to explore the association between the survival-related AGs and the tumor immune microenvironment. Results. In entire, 29 DEAGs were identified in the GSE4290. This was monitored by the construction of the prognosis risk model using four DEAGs from the CGGA training set, including C1QA, CDK1, EFEMP1, and IGFBP2. Next, the risk model was confirmed in the CGGA experiment set and the GSE 4412 dataset. Results showed that C1QA, CDK1, EFEMP1, and IGFBP2 levels were remarkably higher in the high-risk score groups, and they had a good association with immune and stromal scores. Conclusion. A robust prognostic risk model was constructed and validated using four AGs, including C1QA, CDK1, EFEMP1, and IGFBP2, which had a close relationship with the immune microenvironment of GBM. This study offers a new reference to further explore the pathogenesis of GBM and recognize new and more effective GBM treatments.

Liquid biomarkers in glioma

An ideal biomarker must meet several parameters to enable its successful adoption; however, the nature of glioma makes it challenging to discover valuable biomarkers. While biomarkers require simplicity for clinical implementation, anatomical features and the complexity of the brain make it challenging to perform histological examination. Therefore, compared to biomarkers from general histological examination, liquid biomarkers for brain disease offer many more advantages in these minimally invasive methods. Ideal biomarkers should have high sensitivity and specificity, especially in malignant tumors. The heterogeneous nature of glioma makes it challenging to determine useful common biomarkers, and no liquid biomarker has yet been adopted clinically. The low incidence of brain tumors also hinders research progress. To overcome these problems, clinical applications of new types of specimens, such as extracellular vesicles and comprehensive omics analysis, have been developed, and some candidate liquid biomarkers have been identified. As against previous reviews, we focused on and reviewed the sensitivity and specificity of each liquid biomarker for its clinical application. Perusing an ideal glioma biomarker would help uncover the common underlying mechanism of glioma and develop new therapeutic targets. Further multicenter studies based on these findings will help establish new treatment strategies in the future.

Prognostic value of IGFBP2 in various cancers: a systematic review and meta-analysis

BACKGROUND

The prognostic significance of insulin-like growth factor binding protein 2 (IGFBP2) expression has been explored in plenty of studies in human cancers. Because of the controversial results, the meta-analysis was carried out to evaluate the relevance of IGFBP2 expression with the prognosis in various tumors.

METHODS

The data searched from four databases (Pubmed, Embase, Cochrane library, and Web of science) was used to calculate pooled hazard ratios (HRs) in this meta-analysis. Subgroup analyses were stratified by ethnicity, cancer type, publication year, Newcastle-Ottawa Scale score, treatments, and populations.

RESULTS

Twenty-one studies containing 5560 patients finally met inclusion criteria. IGFBP2 expression was associated with lower overall survival (HR = 1.57, 95% CI = 1.31-1.88) and progression-free survival (HR = 1.18, 95% CI = 1.04-1.34) in cancer patients, but not with disease-free survival (HR = 1.50, 95% CI = 0.91-2.46) or recurrence-free survival (HR = 1.50, 95% CI = 0.93-2.40). The subgroup analyses indicated IGFBP2 overexpression was significantly correlated with overall survival in Asian patients (HR = 1.42, 95% CI = 1.18-1.72), Caucasian patients (HR = 2.20, 95% CI = 1.31-3.70), glioma (HR = 1.36, 95% CI = 1.03-1.79), and colorectal cancer (HR = 2.52, 95% CI = 1.43-4.44) and surgery subgroups (HR = 1.97, 95% CI = 1.50-2.58).

CONCLUSION

The meta-analysis showed that IGFBP2 expression was associated with worse prognosis in several tumors, and may serve as a potential prognostic biomarker in cancer patients.

A Novel Extracellular Matrix Gene-Based Prognostic Model to Predict Overall Survive in Patients With Glioblastoma

Background: Glioblastoma (GBM), one of the most prevalent brain tumor types, is correlated with an extremely poor prognosis. The extracellular matrix (ECM) genes could activate many crucial pathways that facilitate tumor development. This study aims to provide online models to predict GBM survival by ECM genes.

Methods: The associations of ECM genes with the prognosis of GBM were analyzed, and the significant prognosis-related genes were used to develop the ECM index in the CGGA dataset. Furthermore, the ECM index was then validated on three datasets, namely, GSE16011, TCGA-GBM, and GSE83300. The prognosis difference, differentially expressed genes, and potential drugs were obtained. Multiple machine learning methods were selected to construct the model to predict the survival status of GBM patients at 6, 12, 18, 24, 30, and 36 months after diagnosis.

Results: Five ECM gene signatures (AEBP1, F3, FLNC, IGFBP2, and LDHA) were recognized to be associated with the prognosis. GBM patients were divided into high– and low–ECM index groups with significantly different overall survival rates in four datasets. High–ECM index patients exhibited a worse prognosis than low–ECM index patients. Four small molecules (podophyllotoxin, lasalocid, MG-262, and nystatin) that might reduce GBM development were predicted by the Cmap dataset. In the independent dataset (GSE83300), the maximum values of prediction accuracy at 6, 12, 18, 24, 30, and 36 months were 0.878, 0.769, 0.748, 0.720, 0.705, and 0.868, respectively. These machine learning models were provided on a publicly accessible, open-source website (https://ospg.shinyapps.io/OSPG/).

Conclusion: In summary, our findings indicated that ECM genes were prognostic indicators for patient survival. This study provided an online server for the prediction of survival curves of GBM patients.

Serum insulin-like growth factor binding protein 2 levels as biomarker for pancreatic ductal adenocarcinoma-associated malnutrition and muscle wasting

BACKGROUND

Malnutrition and muscle wasting are common features frequently observed in pancreatic ductal adenocarcinoma (PDAC) patients with cancer cachexia. They are associated with reduced survival and quality of life. Nutrition therapy is an important part of multimodal cancer care in PDAC. However, due to the complexity of nutrition assessment, only 30-60% of patients with nutritional risks receive nutritional treatment at present. It is important to identify biomarkers that may be used to improve management of PDAC-associated malnutrition. Serum insulin-like growth factor binding protein 2 (IGFBP2) has emerged as a potential serum biomarker in a variety of tumours. However, its association with malnutrition and muscle wasting in PDAC is unclear.

METHODS

We evaluated the tumour IGFBP2 expression and serum IGFBP2 level in 98 PDAC patients using immunohistochemistry and enzyme-linked immunosorbent assay and analysed the correlation between them. Furthermore, we explored the relationship between IGFBP2 of both tumour and serum and nutritional status (Patient-Generated Subjective Global Assessment and skeletal muscle index). Pan02 IGFBP2 stable transfection cell lines, Pan02 PLV-IGFBP2 cells, and PLKO-IGFBP2 cells were injected subcutaneously into the flank of C57BL/6 mouse. Serum IGFBP2 levels, food intake, and body weight of these mice were measured. The degree of muscle atrophy is characterized by haematoxylin and eosin, Oil Red O, and Masson's trichrome staining. The mRNA and protein expression of several essential muscle-related signal proteins such as atrogin-1 and muscle RING finger 1 was measured.

RESULTS

Among 98 patients, we found that tumour IGFBP2 expression is related to plasma IGFBP2 levels (r_s  = 0.562, P < 0.001), and they significantly increased among patients with Patient-Generated Subjective Global Assessment ≥9 and correlated with overall survival. Moreover, serum IGFBP2 level is negatively correlated with skeletal muscle index (r_s  = -0.600, P < 0.001) and Hounsfield units (r_s  = -0.532, P < 0.001). In mice injected with Pan02 PLV-IGFBP2 cell, circulating IGFBP2 was elevated while body weight and food intake were decreased when compared with Pan02 PLV-Control group. These mice also exhibited significantly aggravated muscle fibre atrophy, lipid deposition, and increased collagen tissue, and the expression of mRNA and protein of atrogin-1 and muscle RING finger 1 in the gastrocnemius muscle is increased. Conversely, these symptoms were alleviated in the PLKO-IGFBP2 group.

CONCLUSIONS

In the current study, there is a significant correlation between serum IGFBP2 levels, malnutrition, and muscle atrophy in PDAC. Our results suggested that serum IGFBP2 level might be a promising biomarker and intervention targets for PDAC-associated severe malnutrition and muscle wasting.

Prognostic and Therapeutic Roles of the Insulin Growth Factor System in Glioblastoma

Glioblastoma multiforme (GBM) is the most common primary brain malignancy and is often resistant to conventional treatments due to its extensive cellular heterogeneity. Thus, the overall survival of GBM patients remains extremely poor. Insulin-like growth factor (IGF) signaling entails a complex system that is a key regulator of cell transformation, growth and cell-cycle progression. Hence, its deregulation is frequently involved in the development of several cancers, including brain malignancies. In GBM, differential expression of several IGF system components and alterations of this signaling axis are linked to significantly worse prognosis and reduced responsiveness to temozolomide, the most commonly used pharmacological agent for the treatment of the disease. In the present review we summarize the biological role of the IGF system in the pathogenesis of GBM and comprehensively discuss its clinical significance and contribution to the development of resistance to standard chemotherapy and experimental treatments.

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.

Blood Biomarkers of Glioma in Response Assessment Including Pseudoprogression and Other Treatment Effects: A Systematic Review

Imaging-based monitoring of disease burden in glioma patients is frequently confounded by treatment effects. Circulating biomarkers could theoretically augment imaging-based response monitoring. This systematic review aimed to present and evaluate evidence for differential expression and diagnostic accuracy of circulating biomarkers with respect to outcomes of tumor response, progression, stable disease, and treatment effects (pseudoprogression, radionecrosis, pseudoresponse, and pseudolesions) in patients undergoing treatment for World Health Organization grades II-IV diffuse astrocytic and oligodendroglial tumors. MEDLINE, EMBASE, Web Of Science, and SCOPUS databases were searched until August 18, 2019, for observational or diagnostic studies on multiple circulating biomarker types: extracellular vesicles, circulating nucleic acids, circulating tumor cells, circulating proteins, and metabolites, angiogenesis related cells, immune cells, and other cell lines. Methodological quality of included studies was assessed using an adapted Quality Assessment of Diagnostic Accuracy Studies-2 tool, and level of evidence (IA-IVD) for individual biomarkers was evaluated using an adapted framework from the National Comprehensive Cancer Network guidelines on evaluating tumor marker utility. Of 13,202 unique records, 58 studies met the inclusion criteria. One hundred thirty-three distinct biomarkers were identified in a total of 1,853 patients across various treatment modalities. Fifteen markers for response, progression, or stable disease and five markers for pseudoprogression or radionecrosis reached level IB. No biomarkers reached level IA. Only five studies contained data for diagnostic accuracy measures. Overall methodological quality of included studies was low. While extensive data on biomarker dysregulation in varying response categories were reported, no biomarkers ready for clinical application were identified. Further assay refinement and evaluation in larger cohorts with diagnostic accuracy study designs are required. PROSPERO Registration: CRD42018110658.

Insulin-Like Growth Factor Binding Protein-2 Promotes Proliferation and Predicts Poor Prognosis in Hepatocellular Carcinoma

Background

Insulin-like growth factor binding protein-2 (IGFBP2) levels are significantly increased in the plasma of hepatocellular carcinoma (HCC) patients. However, the correlation between IGFBP2 levels and clinical parameters and the exact role of IGFBP2 in HCC are unclear. In this study, we identified the role and potential molecular mechanisms of IGFBP2 in HCC.

Materials and Methods

ELISA assays were used to detect plasma IGFBP2 levels in HCC patients and healthy controls, and the correlations with patients’ clinicopathological data were analyzed. The CCK8 assay was used to explore cell proliferation. Luciferase reporter, co-immunoprecipitation, and immunofluorescence assays were used to demonstrate the molecular mechanism of IGFBP2 in HCC.

Results

Plasma IGFBP2 levels were determined blindly in 37 HCC patients and 37 matched healthy controls. The mean plasma IGFBP2 concentrations in HCC patients were higher than in healthy controls, and IGFBP2 levels in HCC were positively correlated with the degree of differentiation, tumor size, metastasis, and portal venous invasion. Exogenous IGFBP2 activated integrin β1 and thus induced the combination and colocalization of activated integrin β1 and p-FAK, which promoted the phosphorylation of FAK, Erk, and Elk1, eventually inducing EGR1-mediated proliferation of the HCC cell lines HepG2 and HCCLM3. Meanwhile, neutralization of integrin β1 inhibited IGFBP2-induced FAK, Erk, Elk1, and EGR1 activation.

Conclusion

Taken together, these results indicated that exogenous IGFBP2 promoted the integrin β1/FAK/Erk/Elk1/EGR1 pathway, which stimulated the proliferation of HCC cells. Plasma IGFBP2 could be a novel prognostic biomarker for HCC patients.

IGFBP2: integrative hub of developmental and oncogenic signaling network

Insulin-like growth factor (IGF) binding protein 2 (IGFBP2) was discovered and identified as an IGF system regulator, controlling the distribution, function, and activity of IGFs in the pericellular space. IGFBP2 is a developmentally regulated gene that is highly expressed in embryonic and fetal tissues and markedly decreases after birth. Studies over the last decades have shown that in solid tumors, IGFBP2 is upregulated and promotes several key oncogenic processes, such as epithelial-to-mesenchymal transition, cellular migration, invasion, angiogenesis, stemness, transcriptional activation, and epigenetic programming via signaling that is often independent of IGFs. Growing evidence indicates that aberrant expression of IGFBP2 in cancer acts as a hub of an oncogenic network, integrating multiple cancer signaling pathways and serving as a potential therapeutic target for cancer treatment.

Blood-Based Biomarkers in High Grade Gliomas: a Systematic Review

High-grade gliomas (HGG) are the most common malignant primary brain tumor in adults. During the course of disease, several challenges occur, like measuring tumor burden, monitoring of treatment response, estimating the patient's prognosis, and distinguishing between true progression and pseudo-progression. So far, no blood-based biomarker has been established in the clinical routine to address these challenges. The aim of this systematic review was to analyze the present evidence on blood-based biomarkers for HGG. We systematically searched in PubMed, Web of Sciences, Scopus, and Cochrane Library databases for publications before 30th of March 2018 reporting on associations of blood-based biomarkers in HGG patients with different endpoints as overall survival, progression-free survival, and postoperative monitoring. Quality assessment of the studies according to QUIPS and STARD guidelines was performed. In accordance with the GRADE guidelines, level of evidence (I-IV) for each of the tested biomarkers was assessed. One thousand six hundred eighty unique records were identified. Of these, 170 original articles were included to this review. Four hundred fifteen different blood-based biomarkers analyzed in 15.041 patients with HGG as also their corresponding recurrent tumors. Ten predictive biomarkers reached level II of evidence. No biomarker achieved level I of evidence. In this review, 10 blood-based biomarkers were selected as most promising biomarkers for HGG: α2-Heremans-Schmid glycoprotein (AHSG), albumin, glucose, insulin-like growth factor- binding protein 2 (IGFBP-2), macrophage inflammatory protein 1δ (MIP-1 δ), macrophage inflammatory protein 3ß (MIP-3ß), neutrophil-lymphocyte ratio (NLR), red blood cell distribution width (RDW), soluble glycoprotein 130 (Sgp130), and chitinase-3-like protein 1 (YKL-40). To further assess the clinical significance of these biomarkers, the evaluation in a larger cohort of HGG and their corresponding subgroups would be necessary.

IGFBP2 promotes neural stem cell maintenance and proliferation differentially associated with glioblastoma subtypes

Neural stem cells (NSCs) give rise to the central nervous system (CNS) and persist in certain areas of adult brains for replenishing damaged differentiated cells. The loss of the balance between NSC self-renewal and differentiation could lead to tumor formation such as the occurrence of glioblastoma (GBM), the most common and deadly human brain tumor, which could be derived from neural stem or stem-like cells. Early studies showed that insulin-like growth factor binding protein 2 (IGFBP2) mRNA levels were maintained high during the fetal brain development but decreased in the adult brains. We previously reported that IGFBP2 was frequently overexpressed in GBMs, which was correlated with GBM recurrence and poor survival and promoted glioma progression. However, the role of IGFBP2 in the CNS was not investigated yet, whose understanding will help elucidate IGFBP2 functions in GBM. In the study, we identify IGFBP2 as a critical molecule for mouse NSC maintenance. IGFBP2 is highly expressed in NSCs, and its expression exhibits an apical-basal pattern in the neural tube with a higher apical level and decreased with NSC differentiation during the CNS development. IGFBP2 promotes NSC self-renewal and proliferation but inhibits its differentiation to neurons and astrocytes. The knockdown of IGFBP2 significantly affected the expression of cell cycle, Notch pathway, and neural stemness and differentiation genes in NSCs. Further, the expression of IGFBP2-regulated cell cycle genes is significantly correlated with IGFBP2 expression in non-Mesenchymal GBM subtypes including Classical, Proneural, and Neural subtypes and of its Notch pathway genes differentially associated in the four GBM subtypes, altogether suggesting its critical and similar functions in NSCs and GBM cells.

KDM6B Counteracts EZH2-Mediated Suppression of IGFBP5 to Confer Resistance to PI3K/AKT Inhibitor Treatment in Breast Cancer

Despite showing promise against PIK3CA-mutant breast cancers in preclinical studies, PI3K/AKT pathway inhibitors demonstrate limited clinical efficacy as monotherapy. Here, we found that histone H3K27me3 demethylase KDM6B-targeted IGFBP5 expression provides a protective mechanism for PI3K/AKT inhibitor-induced apoptosis in breast cancer cells. We found that overexpression of KDM6B and IGFBP5 in luminal breast cancer are positively associated with poorer disease outcomes. Mechanistically, KDM6B promotes IGFBP5 expression by antagonizing EZH2-mediated repression, and pharmacologic inhibition of KDM6B augments apoptotic response to PI3K/AKT inhibitor treatment. Moreover, the IGFBP5 expression is upregulated upon acquired resistance to the PI3K inhibitor GDC-0941, which is associated with an epigenetic switch from H3K27me3 to H3K27Ac at the IGFBP5 gene promoter. Intriguingly, GDC-0941-resistant breast cancer cells remained sensitive to KDM6B or IGFBP5 inhibition, indicating the dependency on the KDM6B-IGFBP5 axis to confer the survival advantage in GDC-0941-resistant cells. Our study reveals an epigenetic mechanism associated with resistance to targeted therapy and demonstrates that therapeutic targeting of KDM6B-mediated IGFBP5 expression may provide a useful approach to mitigate both intrinsic and acquired resistance to the PI3K inhibitor in breast cancer. Mol Cancer Ther; 17(9); 1973-83. ©2018 AACR.

Identification of blood biomarkers in glioblastoma by SWATH mass spectrometry and quantitative targeted absolute proteomics

Molecular biomarkers in blood are needed to aid the early diagnosis and clinical assessment of glioblastoma (GBM). Here, in order to identify biomarker candidates in plasma of GBM patients, we performed quantitative comparisons of the plasma proteomes of GBM patients (n = 14) and healthy controls (n = 15) using SWATH mass spectrometry analysis. The results were validated by means of quantitative targeted absolute proteomics analysis. As a result, we identified eight biomarker candidates for GBM (leucine-rich alpha-2-glycoprotein (LRG1), complement component C9 (C9), C-reactive protein (CRP), alpha-1-antichymotrypsin (SERPINA3), apolipoprotein B-100 (APOB), gelsolin (GSN), Ig alpha-1 chain C region (IGHA1), and apolipoprotein A-IV (APOA4)). Among them, LRG1, C9, CRP, GSN, IGHA1, and APOA4 gave values of the area under the receiver operating characteristics curve of greater than 0.80. To investigate the relationships between the biomarker candidates and GBM biology, we examined correlations between plasma concentrations of biomarker candidates and clinical presentation (tumor size, progression-free survival time, or overall survival time) in GBM patients. The plasma concentrations of LRG1, CRP, and C9 showed significant positive correlations with tumor size (R² = 0.534, 0.495, and 0.452, respectively).

The influence of simulated microgravity on proliferation and apoptosis in U251 glioma cells

Several studies have indicated that microgravity can influence cellular progression, proliferation, and apoptosis in tumor cell lines. In this study, we observed that simulated microgravity inhibited proliferation and induced apoptosis in U251 malignant glioma (U251MG) cells. Furthermore, expression of the apoptosis-associated proteins, p21 and insulin-like growth factor binding protein-2 (IGFBP-2), was upregulated and downregulated, respectively, following exposure to simulated microgravity. These findings indicate that simulated microgravity inhibits proliferation while inducing apoptosis of U251MG cells. The associated effects appear to be mediated by inhibition of IGFBP-2 expression and stimulation of p21 expression. This suggests that simulated microgravity might represent a promising method to discover new targets for glioma therapeutic strategy.

Preoperative serum levels of insulin-like growth factor-binding protein 2 predict prognosis of gastric cancer patients

It has been reported that serum insulin-like growth factor-binding protein 2 (IGFBP2) levels are elevated in various types of cancers. However, the clinicopathologic and prognostic implications of circulating IGFBP2 have never been investigated in gastric cancer. We tested IGFBP2 levels in the sera of 118 gastric cancer patients and 34 healthy controls using enzyme-linked immunosorbent assay (ELISA). The mean serum IGFBP2 level was significantly elevated in the gastric cancer patients compared to controls (805.23 ± 590.56 ng/ml vs. 459.61 ± 277.01 ng/ml; P < 0.001). Serum IGFBP2 levels were significantly higher in larger (> 6 cm) tumors (956.8 ± 734.0 ng/ml vs. 548.6 ± 364.0 ng/ml; P = 0.007) and in higher (T3/4) T stages (854.8 ± 621.4 ng/ml vs. 546.5 ± 315.1 ng/ml; P = 0.037). Multivariate Cox analysis showed that higher serum IGFBP2 level (> 400.01 ng/ml) was an independent prognostic factor predicting worse overall survival in patients with gastric cancer (hazard ratio (HR): 3.749, P = 0.034). When we divided patients into four groups based on blood IGFBP2 levels, survival was stratified. The HRs for death in the 3rd and 4th quartiles of serum IGFBP2 levels in comparison to that in the 1st quartile were 2.527 (P = 0.043) and 3.092 (P = 0.012). In conclusion, circulating IGFBP2 has potential as a biomarker predicting prognosis for gastric cancer patients.

FBLN4 as candidate gene associated with long-term and short-term survival with primary glioblastoma

Background

Glioblastoma multiforme (GBM) is the most common malignant and lethal type of primary central nervous system tumor in humans. In spite of its high lethality, a small percentage of patients have a relatively good prognosis, with median survival times of 36 months or longer. The identification of clinical subsets of GBM associated with distinct molecular genetic profiles has made it possible to design therapies tailored to treat individual patients.

Methods

We compared microarray data sets from long-term survivors (LTSs) and short-term survivors (STSs) to screen for prognostic biomarkers in GBM patients using the WebArrayDB platform. We focused on FBLN4, IGFBP-2, and CHI3L1, all members of a group of 10 of the most promising, differentially regulated gene candidates. Using formalin-fixed paraffin-embedded GBM samples, we corroborated the relationship between these genes and patient outcomes using methylation-specific polymerase chain reaction (PCR) for MGMT methylation status and quantitative reverse transcription PCR for expression of these genes.

Results

Expression levels of the mRNAs of these 3 genes were higher in the GBM samples than in normal brain samples and these 3 genes were significantly upregulated in STSs compared to the levels in LTS samples (P<0.01). Furthermore, Kaplan–Meier analysis showed that the expression patterns of FBLN4 and IGFBP-2 serve as independent prognostic indicators for overall survival (P<0.01 and P<0.05, respectively).

Conclusion

To our knowledge, this is the first report describing FBLN4 as a prognostic factor for GBM patient survival, demonstrating that increased GBM survival time correlates with decreased FBLN4 expression. Understanding FBLN4 expression patterns could aid in the creation of powerful tools to predict clinical prognoses of GBM patients.

IGFBP2 Activates the NF-κB Pathway to Drive Epithelial-Mesenchymal Transition and Invasive Character in Pancreatic Ductal Adenocarcinoma

The molecular basis underlying the particularly aggressive nature of pancreatic ductal adenocarcinoma (PDAC) still remains unclear. Here we report evidence that the insulin-like growth factor-binding protein IGFBP2 acts as a potent oncogene to drive its extremely malignant character. We found that elevated IGFBP2 expression in primary tumors was associated with lymph node metastasis and shorter survival in patients with PDAC. Enforced expression of IGFBP2 promoted invasion and metastasis of PDAC cells in vitro and in vivo by inducing NF-κB-dependent epithelial-mesenchymal transition (EMT). Mechanistic investigations revealed that IGFBP2 induced the nuclear translocation and phosphorylation of the p65 NF-κB subunit through the PI3K/Akt/IKKβ pathway. Conversely, enforced expression of PTEN blunted this signaling pathway and restored an epithelial phenotype to PDAC cells in the presence of overexpressed IGFBP2. Overall, our results identify IGFBP2 as a pivotal regulator of an EMT axis in PDAC, the activation of which is sufficient to confer the characteristically aggressive clinical features of this disease. Cancer Res; 76(22); 6543-54. ©2016 AACR.

The miR-204-3p-targeted IGFBP2 pathway is involved in xanthohumol-induced glioma cell apoptotic death

Xanthohumol (XN), a prenylated chalcone extracted from hop plant Humulus lupulus L. (Cannabaceae), has potential for cancer therapy, including gliomas. Micro (mi)RNAs are small noncoding RNAs that control gene expression. Several miRNAs have been identified to participate in regulating glioma development. However, no studies have demonstrated whether miRNA is involved in XN cytotoxicity resulting in glioma cell death. This study investigated the effects of XN-mediated miRNA expression in activating apoptotic pathways in glioblastoma U87 MG cells. First, we found that XN significantly reduced cell viability and induced apoptosis via pro-caspase-3/8 cleavage and poly(ADP ribose) polymerase (PARP) degradation. We also identified that pro-caspase-9 cleavage, Bcl2 family expression changes, mitochondrial dysfunction, and intracellular ROS generation also participated in XN-induced glioma cell death. With a microarray analysis, miR-204-3p was identified as the most upregulated miRNA induced by XN cytotoxicity. The extracellular signal-regulated kinase (ERK)/c-Fos pathway was validated to participate in XN-upregulated miR-204-3p expression. With a promoter assay and ChIP analysis, we found that c-Fos dose-dependently bound to the miR-204-3p gene promoter region. Furthermore, miR-204-3p levels decreased in several glioma cell lines compared to astrocytes. Overexpression of miR-204-3p enhanced glioma cell apoptosis. IGFBP2, an upregulated regulator of glioma proliferation, was validated by a TCGA analysis as a direct target gene of miR-204-3p. XN's inhibition of the IGFBP2/AKT/Bcl2 pathway via miR-204-3p targeting played a critical role in mediating glioma cell death. These results emphasized that the XN-mediated miR-204-3p network may provide novel therapeutic strategies for future glioblastoma therapy and drug development.

Integration of Breast Cancer Secretomes with Clinical Data Elucidates Potential Serum Markers for Disease Detection, Diagnosis, and Prognosis

Cancer cells secrete factors that influence adjacent cell behavior and can lead to enhanced proliferation and metastasis. To better understand the role of these factors in oncogenesis and disease progression, estrogen and progesterone receptor positive MCF-7 cells, triple negative breast cancer MDA-MB-231, DT22, and DT28 cells, and MCF-10A non-transformed mammary epithelial cells were grown in 3D cultures. A special emphasis was placed on triple negative breast cancer since these tumors are highly aggressive and no targeted treatments are currently available. The breast cancer cells secreted factors of variable potency that stimulated proliferation of the relatively quiescent MCF-10A cells. The conditioned medium from each cell line was subjected to mass spectrometry analysis and a variety of secreted proteins were identified including glycolytic enzymes, proteases, protease inhibitors, extracellular matrix proteins, and insulin-like growth factor binding proteins. An investigation of the secretome from each cell line yielded clues about strategies used for breast cancer proliferation and metastasis. Some of the proteins we identified may be useful in the development of a serum-based test for breast cancer detection, diagnosis, prognosis, and monitoring.

Glioma progression is mediated by an addiction to aberrant IGFBP2 expression and can be blocked using anti-IGFBP2 strategies

Insulin-like growth factor binding protein 2 (IGFBP2) overexpression is common in high-grade glioma and is both a strong biomarker of aggressive behaviour and a well-documented prognostic factor. IGFBP2 is a member of the secreted IGFBP family that functions by interacting with circulating IGFs to modulate IGF-mediated signalling. This traditional view of IGFBP2 activities has been challenged by the recognition of the diverse functions and cellular locations of members of the IGFBP family. IGFBP2 has been previously established as a driver of glioma progression to a higher grade. In this study, we sought to determine whether IGFBP2-overexpressing tumours are dependent on continued oncogene expression and whether IGFBP2 is a viable therapeutic target in glioma. We took advantage of the well-characterized RCAS/Ntv-a mouse model to create a doxycycline-inducible IGFBP2 model of glioma and demonstrated that the temporal expression of IGFBP2 has dramatic impacts on tumour progression and survival. Further, we demonstrated that IGFBP2-driven tumours are dependent on the continued expression of IGFBP2, as withdrawal of this oncogenic signal led to a significant decrease in tumour progression and prolonged survival. Inhibition of IGFBP2 also impaired tumour cell spread. To assess a therapeutically relevant inhibition strategy, we evaluated a neutralizing antibody against IGFBP2 and demonstrated that it impaired downstream IGFBP2-mediated oncogenic signalling pathways. The studies presented here indicate that IGFBP2 not only is a driver of glioma progression and a prognostic factor but is also required for tumour maintenance and thus represents a viable therapeutic target in the treatment of glioma. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Investigation of serum levels and tissue expression of two genes IGFBP-2 and IGFBP-3 act as potential biomarker for predicting the progression and survival in patients with glioblastoma multiforme

BACKGROUND

Identification of genetic copy number changes in glial tumors is of importance in the context of improved/refined diagnostic, prognostic procedures and therapeutic decision-making. Blood-derived biomarkers, therefore, would be useful as minimally invasive markers that could support diagnosis and enable monitoring of tumour growth and response to treatment.

OBJECTIVE

The aim of this study was to evaluate the clinical significance of IGFBP-2/3 in glioblastoma multiforme (GBM) and their value as predictors of survival.

METHODS

We examined the plasma levels of IGFBP-2 and IGFBP-3 using ELISA in patient suffering from GBM and controls groups. Furthermore, immunohistochemistry method was used to evaluate the expression levels of these markers.

RESULTS

Preoperative plasma levels of IGFBP-2 and IGFBP-3 were markedly higher in glioblastoma patients (mean±SD: 521.5±164.2ng/ml; 402.4±126ng/ml) when compared with healthy controls (301.28±73.12; 244±89.5ng/ml; p<0.001). Immunohistochemical results indicated that the median H score for glioblastoma tissues was higher when compared with normal tissues. The mean scores for IGFBP-2 expression in glioblastoma was higher than normal tissues (p<0.001). Our result showed that the median H score for glioblastoma tissues was higher when compared with normal tissue for IGFBP-3 expression. The mean scores for glioblastoma tissues was higher than normal tissues (p<0.001). We also evaluated whether plasma IGFBP-2 and IGFBP-3 levels were related to clinical features. The plasma IGFBP-2 level was strongly linked to the patient's age (R=0.769, P=0.001) that were strongly increased in patients with older age (>65), (mean±SD: 594.36±33.3ng/ml). On the other hand, plasma IGFBP-3 level was not correlated with age (P=0.462), sex (P=0.532), and tumor size (P=0.245). Our findings indicated that the tissue IGFBP-2 level was also markedly correlated with the patient's age (R=0.612, P=0.015). On the other hand, tissue IGFBP-3 expression level was not correlated with age (P=0.472), sex (P=0.512), and tumor size (P=0.241). Kaplan-Meier survival and log-rank analysis suggested that patients with high plasma level of IGFBP-2 and tissue expression of IGFBP-2 had shorter overall survival than those with low levels (log-rank test P=0.027; P<0.001). Kaplan-Meier survival and log-rank analysis suggested that patients with high plasma level of IGFBP-3 and tissue expression of IGFBP-3 had shorter overall survival than those with low levels groups (log-rank test P=0.018; P<0.001).

CONCLUSION

These data suggest that plasma levels and tissue levels of IGFBP-2 and IGFBP-3 may be as potential biomarkers for predicting the progression and survival in patients with GBM.

Insulin-like growth factor binding protein-2 regulates β-catenin signaling pathway in glioma cells and contributes to poor patient prognosis

BACKGROUND

Upregulation of insulin-like growth factor binding protein 2 (IGFBP-2) is often associated with aggressiveness of glioblastoma (GBM) and contributes to poor prognosis for GBM patients. In view of the regulation of β-catenin by IGFBP-2 in breast cancer and the crucial role of β-catenin pathway in glioma invasion, proliferation and maintenance of glioma stem cells, the mechanism of regulation of β-catenin by IGFBP-2, and its role in GBM prognosis was studied.

METHODS

Regulation of the β-catenin pathway was studied by immunocytochemistry, Western blot analysis, luciferase assays, and real-time RT-PCR. The role of IGFBP-2 was studied by subcutaneous tumor xenografts in immunocompromised mice using glioma cells engineered to express IGFBP-2 and its domains. GBM patient tumor tissues (n = 112) were analyzed for expression of IGFBP-2 and β-catenin by immunohistochemistry. Survival analysis was performed employing Cox regression and Kaplan-Meier survival analyses.

RESULTS

IGFBP-2 knockdown in U251, T98G, and U373 or overexpression in LN229 and U87 cells revealed a role for IGFBP-2 in stabilization of β-catenin and regulation of its nuclear functions involving integrin-mediated inactivation of GSK3β. Similar results were obtained upon overexpression of the C-terminal domain of IGFBP-2 but not the N-terminal domain. Subcutaneous xenograft tumors overexpressing either full-length or the C-terminal domain of IGFBP-2 showed larger volume as compared with controls. Coexpression of high levels of IGFBP-2 and β-catenin was associated with worse prognosis (P = .001) in GBM patients.

CONCLUSION

IGFBP-2 potentiates GBM tumor growth by the activation of the β-catenin pathway through its C-terminal domain, and their coexpression possibly contributes to worse patient prognosis.

Integrated analysis of genome-wide DNA methylation, gene expression and protein expression profiles in molecular subtypes of WHO II-IV gliomas

Background

Glioma is the most common malignant primary brain tumor among adults, among which glioblastoma (GBM) exhibits the highest malignancy. Despite current standard chemoradiation, glioma is still invariably fatal. A further insight into the molecular background of glioma is required to improve patient outcomes.

Method

Previous studies evaluated molecular genetic differences through comparing different grades of glioma. Here, we integrated DNA methylation, RNA sequencing and protein expression data sets of WHO grade II to IV gliomas, to screen for dysregulated genes in subtypes during malignant progression of glioma.

Results

We propose a list of universal genes (UG) as novel glioma biomarkers: 977 up-regulated genes and 114 down-regulated genes, who involved in cell cycle, Wnt receptor signaling pathway and fatty acid metabolic process. Poorer survival was associated significantly with the high expression of 977 up-regulated genes and low expression of 114 down-regulated in UG (P <0.001).

Conclusion

To our knowledge, this was the first study that focused on subtypes to detect dysregulated genes that could contribute to malignant progression. Furthermore, the differentially expressed genes profile may lead to the identification of new therapeutic targets for glioma patients.

An Eighteen Serum Cytokine Signature for Discriminating Glioma from Normal Healthy Individuals

Glioblastomas (GBM) are largely incurable as they diffusely infiltrate adjacent brain tissues and are difficult to diagnose at early stages. Biomarkers derived from serum, which can be obtained by minimally invasive procedures, may help in early diagnosis, prognosis and treatment monitoring. To develop a serum cytokine signature, we profiled 48 cytokines in sera derived from normal healthy individuals (n = 26) and different grades of glioma patients (n = 194). We divided the normal and grade IV glioma/GBM serum samples randomly into equal sized training and test sets. In the training set, the Prediction Analysis for Microarrays (PAM) identified a panel of 18 cytokines that could discriminate GBM sera from normal sera with maximum accuracy (95.40%) and minimum error (4.60%). The 18-cytokine signature obtained in the training set discriminated GBM sera from normal sera in the test set as well (accuracy 96.55%; error 3.45%). Interestingly, the 18-cytokine signature also differentiated grade II/Diffuse Astrocytoma (DA) and grade III/Anaplastic Astrocytoma (AA) sera from normal sera very efficiently (DA vs. normal–accuracy 96.00%, error 4.00%; AA vs. normal–accuracy 95.83%, error 4.17%). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis using 18 cytokines resulted in the enrichment of two pathways, cytokine-cytokine receptor interaction and JAK-STAT pathways with high significance. Thus our study identified an 18-cytokine signature for distinguishing glioma sera from normal healthy individual sera and also demonstrated the importance of their differential abundance in glioma biology.

Pre-treatment neutrophil-to-lymphocyte ratio is associated with neutrophil and T-cell infiltration and predicts clinical outcome in patients with glioblastoma

BACKGROUND

Markers of systemic inflammation are correlated with patient survival in various cancers. The prognostic value of neutrophil-to-lymphocyte ratio (NLR) was compared with that of platelet-to-lymphocyte ratio (PLR) in patients with glioblastoma. The association of NLR with neutrophil and T- cell infiltration was also explored.

METHODS

A total of 152 patients with glioblastoma were retrospectively analyzed. Clinical information was obtained from electronic medical records. Kaplan-Meier analysis and the Cox proportional hazards models were used to examine the survival function of pre-treatment NLR and PLR in these glioblastoma patients. Neutrophil and CD3(+) T-cell infiltration was assessed by immunohistochemical staining of tissue microarray cores from glioblastomas.

RESULTS

Pre-treatment NLR levels were significantly correlated with overall survival (OS) in glioblastoma patients (multivariate hazard ratio =1.050; 95% confidence interval, 1.003-1.100; P = 0.037). Despite the correlation between NLR and PLR (R = 0.509, P < 0.001), NLR was superior to PLR as a prognostic factor. High pre-treatment NLR (≥4 versus < 4) was significantly associated with high neutrophil infiltration and low CD3(+) T-cell infiltration into tumors, and predicted poor OS (mean, 10.6 vs. 17.9 months, P < 0.001).

CONCLUSIONS

Pre-treatment NLR is of prognostic significance independent of MGMT status and is superior to PLR as a prognostic factor. Our results demonstrate a correlation between elevated peripheral blood NLR levels and increased tumor neutrophil infiltration/decreased CD3(+) T-cell infiltration.

Understanding the Key to Targeting the IGF Axis in Cancer: A Biomarker Assessment

Type 1 insulin like growth factor receptor (IGF-1R) targeted therapies showed compelling pre-clinical evidence; however, to date, this has failed to translate into patient benefit in Phase 2/3 trials in unselected patients. This was further complicated by the toxicity, including hyperglycemia, which largely results from the overlap between IGF and insulin signaling systems and associated feedback mechanisms. This has halted the clinical development of inhibitors targeting IGF signaling, which has limited the availability of biopsy samples for correlative studies to understand biomarkers of response. Indeed, a major factor contributing to lack of clinical benefit of IGF targeting agents has been difficulty in identifying patients with tumors driven by IGF signaling due to the lack of predictive biomarkers. In this review, we will describe the IGF system, rationale for targeting IGF signaling, the potential liabilities of targeting strategies, and potential biomarkers that may improve success.

TRIB3 enhances cell viability during glucose deprivation in HEK293-derived cells by upregulating IGFBP2, a novel nutrient deficiency survival factor

Glucose deprivation occurs in several human diseases, including infarctions and solid tumors, and leads to cell death. In this article, we investigate the role of the pseudokinase Tribbles homolog 3 (TRIB3) in the cellular stress response to glucose starvation using cell lines derived from HEK293, which is highly glycolytic under standard conditions. Our results show that TRIB3 mRNA and protein levels are strongly upregulated in glucose-deprived cells via the induction of activating transcription factor 4 (ATF4) by the endoplasmic reticulum (ER) stress sensor kinase PERK. Cell survival in glucose-deficient conditions is enhanced by TRIB3 overexpression and reduced by TRIB3 knockdown. Genome-wide gene expression profiling uncovered approximately 40 glucose deprivation-responsive genes that are affected by TRIB3, including several genes involved in signaling processes and metabolism. Based on transcription factor motif analysis, the majority of TRIB3-downregulated genes are target genes of ATF4, which TRIB3 is known to inhibit. The gene most substantially upregulated by TRIB3 is insulin-like growth factor binding protein 2 (IGFBP2). IGFBP2 mRNA and protein levels are downregulated in cells subjected to glucose deprivation, and reduced IGFBP2 expression aggravates cell death during glucose deficiency, while overexpression of IGFBP2 prolongs cell survival. Moreover, IGFBP2 silencing abrogates the pro-survival effect of TRIB3. Since TRIB3 augments IGFBP2 expression in glucose-starved cells, the data indicate that IGFBP2 contributes to the attenuation of cell death by TRIB3. These results implicate TRIB3 and IGFBP2, both of which are known to be overexpressed in several types of cancers, as pro-survival modulators of cell viability in nutrient-deficient microenvironments.

Liquid biopsies in patients with diffuse glioma

Diffuse gliomas are the most common malignant primary tumors of the central nervous system. Like other neoplasms, these gliomas release molecular information into the circulation. Tumor-derived biomarkers include proteins, nucleic acids, and tumor-derived extracellular vesicles that accumulate in plasma, serum, blood platelets, urine and/or cerebrospinal fluid. Recently, also circulating tumor cells have been identified in the blood of glioma patients. Circulating molecules, vesicles, platelets, and cells may be useful as easily accessible diagnostic, prognostic and/or predictive biomarkers to guide patient management. Thereby, this approach may help to circumvent problems related to tumor heterogeneity and sampling error at the time of diagnosis. Also, liquid biopsies may allow for serial monitoring of treatment responses and of changes in the molecular characteristics of gliomas over time. In this review, we summarize the literature on blood-based biomarkers and their potential value for improving the management of patients with a diffuse glioma. Incorporation of the study of circulating molecular biomarkers in clinical trials is essential for further assessment of the potential of liquid biopsies in this context.

Noncoding RNAs that associate with YB-1 alter proliferation in prostate cancer cells

The highly conserved, multifunctional YB-1 is a powerful breast cancer prognostic indicator. We report on a pervasive role for YB-1 in which it associates with thousands of nonpolyadenylated short RNAs (shyRNAs) that are further processed into small RNAs (smyRNAs). Many of these RNAs have previously been identified as functional noncoding RNAs (http://www.johnlab.org/YB1). We identified a novel, abundant, 3'-modified short RNA antisense to Dicer1 (Shad1) that colocalizes with YB-1 to P-bodies and stress granules. The expression of Shad1 was shown to correlate with that of YB-1 and whose inhibition leads to an increase in cell proliferation. Additionally, Shad1 influences the expression of additional prognostic markers of cancer progression such as DLX2 and IGFBP2. We propose that the examination of these noncoding RNAs could lead to better understanding of prostate cancer progression.

Novel anti IGFBP2 single chain variable fragment inhibits glioma cell migration and invasion

Insulin like growth factor binding protein 2 (IGFBP2) is highly up regulated in glioblastoma (GBM) tissues and has been one of the prognostic indicators. There are compelling evidences suggesting important roles for IGFBP2 in glioma cell proliferation, migration and invasion. Extracellular IGFBP2 through its carboxy terminal arginine glycine aspartate (RGD) motif can bind to cell surface α5β1 integrins and activate pathways downstream to integrin signaling. This IGFBP2 activated integrin signaling is known to play a crucial role in IGFBP2 mediated invasion of glioma cells. Hence a molecular inhibitor of carboxy terminal domain of IGFBP2 which can inhibit IGFBP2-cell surface interaction is of great therapeutic importance. In an attempt to develop molecular inhibitors of IGFBP2, we screened single chain variable fragment (scFv) phage display libraries, Tomlinson I (Library size 1.47 × 10(8)) and Tomlinson J (Library size 1.37 × 10(8)) using human recombinant IGFBP2. After screening we obtained three IGFBP2 specific binders out of which one scFv B7J showed better binding to IGFBP2 at its carboxy terminal domain, blocked IGFBP2-cell surface association, reduced activity of matrix metalloprotease 2 in the conditioned medium of glioma cells and inhibited IGFBP2 induced migration and invasion of glioma cells. We demonstrate for the first time that in vitro inhibition of extracellular IGFBP2 activity by using human scFv results in significant reduction of glioma cell migration and invasion. Therefore, the inhibition of IGFBP2 can serve as a potential therapeutic strategy in the management of GBM.

Relevance of IGFBP2 proteolysis in glioma and contribution of the extracellular protease ADAMTS1

Expression of IGFBP2 (Insulin-like Growth Factor Binding Protein 2) has been positively correlated with glioma progression. Although the proteolysis of IGFBP2 has been widely recognized, with consequences as a major modulator of IGFII signaling, the relevance of this post-translational modification has not been well studied in tumors. Using an in vivo proteomic approach by Isotope-Coded Protein Label (ICPL), we identified IGFBP2 as a target of the extracellular protease ADAMTS1 (A Disintegrin And Metalloproteinase with ThromboSpondin motifs 1). Notably, the proteolytic pattern of IGFBP2 was also detected in human glioma culture cells and, more importantly, in all glioma samples evaluated. In addition, high expression of ADAMTS1 correlates with higher levels of cleaved IGFBP2 in glioblastoma multiforme cases. Using gene expression public databases, we confirmed that IGFBP2 is a poor prognosis marker for gliomas, and we also observed an important contribution of ADAMTS1.Finally, we showed the impact of ADAMTS1 on IGFII-mediated IGF1R phosphorylation and cellular migration. Our results support a functional interaction between IGFBP2 and ADAMTS1 and suggest the need to evaluate post-translational modifications of IGFBP2 in glioma, in order to approach new therapies.

Simulation predicts IGFBP2-HIF1α interaction drives glioblastoma growth

Tremendous strides have been made in improving patients’ survival from cancer with one glaring exception: brain cancer. Glioblastoma is the most common, aggressive and highly malignant type of primary brain tumor. The average overall survival remains less than 1 year. Notably, cancer patients with obesity and diabetes have worse outcomes and accelerated progression of glioblastoma. The root cause of this accelerated progression has been hypothesized to involve the insulin signaling pathway. However, while the process of invasive glioblastoma progression has been extensively studied macroscopically, it has not yet been well characterized with regards to intracellular insulin signaling. In this study we connect for the first time microscale insulin signaling activity with macroscale glioblastoma growth through the use of computational modeling. Results of the model suggest a novel observation: feedback from IGFBP2 to HIF1α is integral to the sustained growth of glioblastoma. Our study suggests that downstream signaling from IGFI to HIF1α, which has been the target of many insulin signaling drugs in clinical trials, plays a smaller role in overall tumor growth. These predictions strongly suggest redirecting the focus of glioma drug candidates on controlling the feedback between IGFBP2 and HIF1α.

Current treatment for glioblastoma patients is limited to nonspecific methods: surgery followed by a combination of radio- and chemotherapy. With these methods, glioma patient survival is less than one year post-diagnosis. Targeting specific protein signaling pathways offers potentially more potent therapies. One promising potential target is the insulin signaling pathway, which is known to contribute to glioblastoma progression. However, drugs targeting this pathway have shown mixed results in clinical trials, and the detailed mechanisms of how the insulin signaling pathway promotes glioblastoma growth remain to be elucidated. Here, we developed a computational model of insulin signaling in glioblastoma in order to study this pathway’s role in tumor progression. Using the model, we systematically test contributions of different insulin signaling protein interactions on glioblastoma growth. Our model highlights a key driver for the growth of glioblastoma: IGFBP2-HIF1α feedback. This interaction provides a target that could open the door for new therapies in glioma and other solid tumors.

IGF-Binding Protein 2 - Oncogene or Tumor Suppressor?

The role of insulin-like growth factor binding protein 2 (IGFBP2) in cancer is unclear. In general, IGFBP2 is considered to be oncogenic and its expression is often observed to be elevated in cancer. However, there are a number of conflicting reports in vitro and in vivo where IGFBP2 acts in a tumor suppressor manner. In this mini-review, we discuss the factors influencing the variation in IGFBP2 expression in cancer and our interpretation of these findings.

Lung Cancer Biomarkers

Lung cancer is the most frequently occurring cancer in the world and continually leads in mortality among cancers. The overall 5-year survival rate for lung cancer has risen only 4% (from 12% to 16%) over the past 4 decades, and late diagnosis is a major obstacle in improving lung cancer prognosis. Survival of patients undergoing lung resection is greater than 80%, suggesting that early detection and diagnosis of cancers before they become inoperable and lethal will greatly improve mortality. Lung cancer biomarkers can be used for screening, detection, diagnosis, prognosis, prediction, stratification, therapy response monitoring, and so on. This review focuses on noninvasive diagnostic and prognostic biomarkers. For that purpose, our discussion in this review will focus on biological fluid-based biomarkers. The body fluids include blood (serum or plasma), sputum, saliva, BAL, pleural effusion, and VOC. Since it is rich in different cellular and molecular elements and is one of the most convenient and routine clinical procedures, serum or plasma is the main source for the development and validation of many noninvasive biomarkers. In terms of molecular aspects, the most widely validated ones are proteins, some of which are used in the clinical sector, though in limited accessory purposes. We will also discuss the lung cancer (protein) biomarkers in clinical trials and currently in the validation phase with hundreds of samples. After proteins, we will discuss microRNAs, methylated DNA, and circulating tumor cells, which are being vigorously developed and validated as potential lung cancer biomarkers. The main aim of this review is to provide researchers and clinicians with an understanding of the potential noninvasive lung cancer biomarkers in biological fluids that have recently been discovered.

Circulating glioma biomarkers

Validated biomarkers for patients suffering from gliomas are urgently needed for standardizing measurements of the effects of treatment in daily clinical practice and trials. Circulating body fluids offer easily accessible sources for such markers. This review highlights various categories of tumor-associated circulating biomarkers identified in blood and cerebrospinal fluid of glioma patients, including circulating tumor cells, exosomes, nucleic acids, proteins, and oncometabolites. The validation and potential clinical utility of these biomarkers is briefly discussed. Although many candidate circulating protein biomarkers were reported, none of these have reached the required validation to be introduced for clinical practice. Recent developments in tracing circulating tumor cells and their derivatives as exosomes and circulating nuclear acids may become more successful in providing useful biomarkers. It is to be expected that current technical developments will contribute to the finding and validation of circulating biomarkers.

Towards developing biomarkers for glioblastoma multiforme: a proteomics view

Glioblastoma multiforme (GBM) is one of the most aggressive and lethal forms of the primary brain tumors. With predominance of tumor heterogeneity and emergence of new subtypes, new approaches are needed to develop tissue-based markers for tumor typing or circulatory markers to serve as blood-based assays. Multi-omics data integration for GBM tissues would offer new insights on the molecular view of GBM pathogenesis useful to identify biomarker panels. On the other hand, mapping differentially expressed tissue proteins for their secretory potential through bioinformatics analysis or analysis of the tumor cell secretome or tumor exosomes would enhance our understanding of the tumor microenvironment and prospects for targeting circulatory biomarkers. In this review, the authors first present potential biomarker candidates for GBM that have been reported and then focus on plausible pipelines for multi-omic data integration to identify additional, high-confidence molecular panels for clinical applications in GBM.

Exogenous IGFBP-2 promotes proliferation, invasion, and chemoresistance to temozolomide in glioma cells via the integrin β1-ERK pathway

BACKGROUND

Insulin-like growth factor binding protein-2 (IGFBP-2) is significantly increased in the serum of patients with malignant gliomas. High plasma IGFBP-2 levels are correlated with poor prognosis in glioma patients. However, the exact role of exogenous IGFBP-2 in gliomas is unclear.

METHODS AND RESULTS

Using the MTT cell viability assay, cell cycle analysis, and the transwell migration assay, it was demonstrated that IGFBP-2 treatment stimulated proliferation and invasion in U87 and U251 cell lines and primary SU3 glioma cells. Western blot analysis and immunofluorescence staining revealed that IGFBP-2 promoted ERK phosphorylation and nuclear translocation. Moreover, blocking ERK activation using the inhibitor PD98059 markedly reduced the effects of IGFBP-2 in glioma cells. As IGFBP-2 has an integrin-binding domain, the contribution of integrin β1 to these IGFBP-2-mediated processes was examined. Neutralisation or knockdown of the expression of integrin β1 inhibited IGFBP-2-induced ERK activation, cell proliferation, and cell invasion. Significantly, IGFBP-2 induced temozolomide resistance in glioma cells in an integrin β1/ERK-dependent manner.

CONCLUSIONS

Exogenous IGFBP-2 induces proliferation, invasion, and chemoresistance in glioma cells via integrin β1/ERK signaling, suggesting that targeting this pathway could represent a potential therapeutic strategy for the treatment of gliomas. The identification of this pathway in glioma progression provides insight into the mechanism by which serum IGFBP-2 levels can predict the prognosis of glioma patients.

An integrated mRNA and microRNA expression signature for glioblastoma multiforme prognosis

Although patients with Glioblastoma multiforme (GBM) have grave prognosis, significant variability in patient outcome is observed. The objective of this study is to identify a molecular signature for GBM prognosis. We subjected 355 mRNA and microRNA expression profiles to elastic net-regulated Cox regression for identification of an integrated RNA signature for GBM prognosis. A prognostic index (PI) was generated for patient stratification. Survival comparison was conducted by Kaplan-Meier method and a general multivariate Cox regression procedure was applied to evaluate the independence of the PI. The abilities and efficiencies of signatures to predict GBM patient outcome was assessed and compared by the area under the curve (AUC) of the receiver-operator characteristic (ROC). An integrated RNA prognostic signature consisted by 4 protective mRNAs, 12 risky mRNAs, and 1 risky microRNA was identified. Decreased survival was associated with being in the high-risk group (hazard ratio = 2.864, P<0.0001). The prognostic value of the integrated signature was validated in five independent GBM expression datasets (n = 201, hazard ratio = 2.453, P<0.0001). The PI outperformed the known clinical factors, mRNA-only, and miRNA-only prognostic signatures for GBM prognosis (area under the ROC curve for the integrated RNA, mRNA-only, and miRNA-only signatures were 0.828, 0.742, and 0.757 at 3 years of overall survival, respectively, P<0.0001 by permutation test). We describe the first, to our knowledge, robust transcriptome-based integrated RNA signature that improves the current GBM prognosis based on clinical variables, mRNA-only, and miRNA-only signatures.

Plasma IGFBP-2 levels after postoperative combined radiotherapy and chemotherapy predict prognosis in elderly glioblastoma patients

It has been found that preoperative plasma IGFBP-2 levels correlate with prognosis in glioma patients. The prognostic value of plasma IGFBP-2 after postoperative combined radiotherapy and chemotherapy in glioma patients is unknown. Plasma IGFBP-2 levels in 83 glioblastoma patients after postoperative radiotherapy plus chemotherapy were analyzed using an IGFBP-2 ELISA kit. We found that after standard therapy plasma IGFBP-2 levels significantly correlated with the patient's age (R = 0.738, P<0.001) and Karnofsky performance status (KPS, R = −0.633, P<0.05). Cox proportional hazards models were used to calculate hazard ratios (HRs) of death according to plasma IGFBP-2 levels adjusted for patient clinical characteristics. Plasma IGFBP-2 levels significantly correlated with overall survival in glioblastoma patients (multivariate HR = 1.035; 95% CI, 1.024–1.047; P<0.001). The effect of plasma IGFBP-2 levels on survival seemed to differ according to patients' age. Among patients older than 60, high plasma IGFBP-2 levels were associated with a significant increase in overall mortality (HR = 1.097; 95% CI, 1.055–1.140; P<0.001). In contrast, plasma IGFBP-2 levels conferred no significant effect on mortality among patients younger than 60. Elevated plasma IGFBP-2 levels after combined postoperative radiotherapy and chemotherapy in elderly glioblastoma patients correlate with poor KPS score and predicts poor prognosis.

Systematic review of protein biomarkers of invasive behavior in glioblastoma

Glioblastoma (GBM) is an aggressive and incurable brain tumor with a grave prognosis. Recurrence is inevitable even with maximal surgical resection, in large part because GBM is a highly invasive tumor. Invasiveness also contributes to the failure of multiple cornerstones of GBM therapy, including radiotherapy, temozolomide chemotherapy, and vascular endothelial growth factor blockade. In recent years there has been significant progress in the identification of protein biomarkers of invasive phenotype in GBM. In this article, we comprehensively review the literature and survey a broad spectrum of biomarkers, including proteolytic enzymes, extracellular matrix proteins, cell adhesion molecules, neurodevelopmental factors, cell signaling and transcription factors, angiogenic effectors, metabolic proteins, membrane channels, and cytokines and chemokines. In light of the marked variation seen in outcomes in GBM patients, the systematic use of these biomarkers could be used to form a framework for better prediction, prognostication, and treatment selection, as well as the identification of molecular targets for further laboratory investigation and development of nascent, directed therapies.

Insulin-like growth factor binding protein-2 level is increased in blood of lung cancer patients and associated with poor survival

Background

We recently showed that IGFBP2 is overexpressed in primary lung cancer tissues. This study aims to determine whether IGFBP2 is elevated in blood samples of lung cancer patients and whether its level is associated with clinical outcomes.

Methodology/Principal Findings

Plasma IGFBP2 levels were determined blindly by enzyme-linked immunosorbent assay in 80 lung cancer patients and 80 case-matched healthy controls for comparison. We analyzed blood samples for IGFBP2 levels from an additional 84 patients with lung cancer and then tested for associations between blood IGFBP2 levels and clinical parameters in all 164 lung cancer patients. All statistical tests were two-sided and differences with p<0.05 were considered significant. The mean plasma concentration of IGFBP2 in lung cancer patients was significantly higher than that in healthy controls (388.12±261.00 ng/ml vs 219.30±172.84 ng/ml, p<0.001). IGFBP2 was increased in all types of lung cancer, including adenocarcinoma, squamous cell cancer, and small-cell cancer, regardless of patients’ age, sex, or smoking status. IGFBP2 levels were mildly but significantly associated with tumor size and were significantly higher in stage IV than stage I or III disease. A multivariate analysis showed that lung cancer patients whose blood IGFBP2 was higher than 160.9 ng/ml had a poor survival outcome, with a hazard ratio of 8.76 (95% CI 1.12-68.34, p=0.038 after adjustment for tumor size, pathology, and stage). The median survival time for patients with blood IGFBP2 >160.9 ng/ml is 15.1 months; whereas median survival time was 128.2 months for the patients whose blood IGFBP2 was ≤160.9 ng/ml (p =0.0002).

Conclusions/Significance

Blood IGFBP2 is significantly increased in lung cancer patients. A high circulating level of IGFBP2 is significantly associated with poor survival, suggesting that blood IGFBP2 levels could be a prognostic biomarker for lung cancer.

Interaction of insulin-like growth factor-binding protein 2 with α2-macroglobulin in the circulation

Insulin-like growth factors (IGFs) play active role in mitogenic and metabolic processes. In the peripheral circulation, they are mostly bound to specific IGF-binding proteins (IGFBPs). Proteolysis of IGFBPs releases free, active IGFs. IGFBP-2 is the second most abundant of the six binding proteins and its concentration increases in catabolic states. The possible interaction between IGFBP-2 and other proteins in the circulation was investigated in this study. Our results showed that IGFBP-2 associates with α2-macroglobulin (α2M), a protease inhibitor. Formation of IGFBP-2/α2M complexes most likely contributes to the regulation of IGFBP-2 proteolysis and, thus, the activity of IGFs.