EFEMP1 expression promotes in vivo tumor growth in human pancreatic adenocarcinoma

A comprehensive meta-analysis of transcriptome data to identify signature genes associated with pancreatic ductal adenocarcinoma

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) has a five-year survival rate of less than 5%. Absence of symptoms at primary tumor stages, as well as high aggressiveness of the tumor can lead to high mortality in cancer patients. Most patients are recognized at the advanced or metastatic stage without surgical symptom, because of the lack of reliable early diagnostic biomarkers. The objective of this work was to identify potential cancer biomarkers by integrating transcriptome data.

METHODS

Several transcriptomic datasets comprising of 11 microarrays were retrieved from the GEO database. After pre-processing, a meta-analysis was applied to identify differentially expressed genes (DEGs) between tumor and nontumor samples for datasets. Next, co-expression analysis, functional enrichment and survival analyses were used to determine the functional properties of DEGs and identify potential prognostic biomarkers. In addition, some regulatory factors involved in PDAC including transcription factors (TFs), protein kinases (PKs), and miRNAs were identified.

RESULTS

After applying meta-analysis, 1074 DEGs including 539 down- and 535 up-regulated genes were identified. Pathway enrichment analyzes using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that DEGs were significantly enriched in the HIF-1 signaling pathway and focal adhesion. The results also showed that some of the DEGs were assigned to TFs that belonged to 23 conserved families. Sixty-four PKs were identified among the DEGs that showed the CAMK family was the most abundant group. Moreover, investigation of corresponding upstream regions of DEGs identified 11 conserved sequence motifs. Furthermore, weighted gene co-expression network analysis (WGCNA) identified 8 modules, more of them were significantly enriched in Ras signaling, p53 signaling, MAPK signaling pathways. In addition, several hubs in modules were identified, including EMP1, EVL, ELP5, DEF8, MTERF4, GLUP1, CAPN1, IGF1R, HSD17B14, TOM1L2 and RAB11FIP3. According to survival analysis, it was identified that the expression levels of two genes, EMP1 and RAB11FIP3 are related to prognosis.

CONCLUSION

We identified several genes critical for PDAC based on meta-analysis and system biology approach. These genes may serve as potential targets for the treatment and prognosis of PDAC.

The Diagnostic and Prognostic Significance of EFEMP1 in Breast Cancer: An Immunohistochemistry Study

EGF-containing fibulin-like extracellular matrix protein 1 (EFEMP1) has been associated to a variety of malignancies. Because EFEMP1 can act as both a tumor suppressor and an oncogene, this study aimed to evaluate the expression of EFEMP1 at mRNA and protein in breast cancer and to ascertain the diagnostic and prognostic value of EFEMP1 in relation to clinical features of breast cancer. Several bioinformatics websites such as GEPIA and Oncomine databases were used to analyze the mRNA level of EFEMP1. Immunohistochemistry assay was used to detect EFEMP1 immunoexpression using tissue microarray (TMA) and clinical breast cancer samples. EFEMP1 was shown to be overexpressed in breast cancer in some study cohorts while being low expressed in others. In TMA, 86 patients (39.1%) with a high H-score and 134 patients (60.9%) with a low H-score had EFEMP1 positive for breast cancer. While HER2 breast cancer and normal breast tissues had the lowest expression of EFEMP1, it was shown to be highly expressed in Luminal B, A, and TNBC. EFEMP1 H-score is associated with tumor stage and indicates poor overall survival in breast cancer. EFEMP1 H-score was high in the clinical tumor tissues compared with adjacent normal tissue (n = 20), therefore, it would to be a sensitive biomarker for breast cancer. EFEMP1 is a key indicator for assessing the clinical prognosis and diagnosis of patients with breast cancer, as evidenced by the higher expression of EFEMP1 in tumor tissue compared to normal tissue and its association with poor overall survival.

The extracellular matrix protein fibulin-3/EFEMP1 promotes pleural mesothelioma growth by activation of PI3K/Akt signaling

Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis and limited therapeutic options. The extracellular matrix protein fibulin-3/EFEMP1 accumulates in the pleural effusions of MPM patients and has been proposed as a prognostic biomarker of these tumors. However, it is entirely unknown whether fibulin-3 plays a functional role on MPM growth and progression. Here, we demonstrate that fibulin-3 is upregulated in MPM tissue, promotes the malignant behavior of MPM cells, and can be targeted to reduce tumor progression. Overexpression of fibulin-3 increased the viability, clonogenic capacity and invasion of mesothelial cells, whereas fibulin-3 knockdown decreased these phenotypic traits as well as chemoresistance in MPM cells. At the molecular level, fibulin-3 activated PI3K/Akt signaling and increased the expression of a PI3K-dependent gene signature associated with cell adhesion, motility, and invasion. These pro-tumoral effects of fibulin-3 on MPM cells were disrupted by PI3K inhibition as well as by a novel, function-blocking, anti-fibulin-3 chimeric antibody. Anti-fibulin-3 antibody therapy tested in two orthotopic models of MPM inhibited fibulin-3 signaling, resulting in decreased tumor cell proliferation, reduced tumor growth, and extended animal survival. Taken together, these results demonstrate for the first time that fibulin-3 is not only a prognostic factor of MPM but also a relevant molecular target in these tumors. Further development of anti-fibulin-3 approaches are proposed to increase early detection and therapeutic impact against MPM.

Regeneration of infarcted mouse hearts by cardiovascular tissue formed via the direct reprogramming of mouse fibroblasts

Fibroblasts can be directly reprogrammed into cardiomyocytes, endothelial cells or smooth muscle cells. Here we report the reprogramming of mouse tail-tip fibroblasts simultaneously into cells resembling these three cell types using the microRNA mimic miR-208b-3p, ascorbic acid and bone morphogenetic protein 4, as well as the formation of tissue-like structures formed by the directly reprogrammed cells. Implantation of the formed cardiovascular tissue into the infarcted hearts of mice led to the migration of reprogrammed cells to the injured tissue, reducing regional cardiac strain and improving cardiac function. The migrated endothelial cells and smooth muscle cells contributed to vessel formation, and the migrated cardiomyocytes, which initially displayed immature characteristics, became mature over time and formed gap junctions with host cardiomyocytes. Direct reprogramming of somatic cells to make cardiac tissue may aid the development of applications in cell therapy, disease modelling and drug discovery for cardiovascular diseases.

Role of Fibulins in Embryonic Stage Development and Their Involvement in Various Diseases

The extracellular matrix (ECM) plays an important role in the evolution of early metazoans, as it provides structural and biochemical support to the surrounding cells through the cell–cell and cell–matrix interactions. In multi-cellular organisms, ECM plays a pivotal role in the differentiation of tissues and in the development of organs. Fibulins are ECM glycoproteins, found in a variety of tissues associated with basement membranes, elastic fibers, proteoglycan aggregates, and fibronectin microfibrils. The expression profile of fibulins reveals their role in various developmental processes such as elastogenesis, development of organs during the embryonic stage, tissue remodeling, maintenance of the structural integrity of basement membrane, and elastic fibers, as well as other cellular processes. Apart from this, fibulins are also involved in the progression of human diseases such as cancer, cardiac diseases, congenital disorders, and chronic fibrotic disorders. Different isoforms of fibulins show a dual role of tumor-suppressive and tumor-promoting activities, depending on the cell type and cellular microenvironment in the body. Knockout animal models have provided deep insight into their role in development and diseases. The present review covers details of the structural and expression patterns, along with the role of fibulins in embryonic development and disease progression, with more emphasis on their involvement in the modulation of cancer diseases.

Bioinformatics analysis reveals the competing endogenous RNA (ceRNA) coexpression network in the tumor microenvironment and prognostic biomarkers in soft tissue sarcomas

Soft tissue sarcomas (STSs) are rare, heterogeneous mesenchymal neoplasias. Understanding the tumor microenvironment (TME) and identifying potential biomarkers for prognosis associated with the TME of STS might provide effective clues for immune therapy. We evaluated the immune scores and stromal scores of STS patients by using the RNA sequencing dataset from The Cancer Genome Atlas (TCGA) database and the ESTIMATE algorithm. Then, the differentially expressed mRNAs (DEGs), miRNAs (DEMs) and lncRNAs (DELs) were identified after comparing the high- and low-score groups. Next, we established a competing endogenous RNA (ceRNA) network and explored the prognostic values of biomarkers involved in the network with the help of bioinformatics analysis. High immune score was significantly associated with favorable overall survival in STS patients. A total of 328 DEGs, 18 DEMs and 67 DELs commonly regulated in the immune and stromal score groups were obtained. A ceRNA network and protein-protein interaction (PPI) network identified some hub nodes with considerable importance in the network. Kaplan-Meier survival analysis demonstrated that nine mRNAs, two miRNAs and three lncRNAs were closely associated with overall survival of STS patients. Gene set enrichment analysis (GSEA) suggested that these three lncRNAs were mainly involved in immune response-associated pathways in STS patients. Finally, the expression levels of five mRNAs (APOL1, EFEMP1, LYZ, RARRES1 and TNFAIP2) were verified, which were consistent with the results of the TCGA cohort. The results of our study confirmed the prognostic value of immune scores for STS patients. We also identified several TME-related biomarkers that might contribute to prognostic prediction and immune therapy.

EFEMP1 Overexpression Contributes to Neovascularization in Age-Related Macular Degeneration

Purpose: Age-related macular degeneration (AMD) is one of the leading causes of blindness, and choroidal neovascularization (CNV) in AMD can lead to serious visual impairment. Gene expression profiling of human ocular tissues have a great potential to reveal the pathophysiology of AMD. This study aimed to identify novel molecular biomarkers and gene expression signatures of AMD. Methods: We analyzed transcriptome profiles in retinal-choroid tissues derived from donor patients with AMD in comparison with those from healthy controls using a publicly available dataset (GSE29801). We focused on the EFEMP1 gene, which was found to be differentially upregulated in AMD, especially in wet AMD eyes. Serological validation analysis was carried out to verify the expression of EFEMP1 in 39 wet AMD patients and 39 age- and gender-matched cataract controls, using an enzyme-linked immunosorbent assay (ELISA). We then investigated the role of EFEMP1 in angiogenesis through in vitro experiments involving EFEMP1 overexpression (OE) and knockdown in human umbilical vein endothelial cells (HUVECs). Results: An increase in EFEMP1 expression was observed in the retinal-choroid tissues of eyes with AMD, which was more significant in wet AMD than in dry AMD. In addition, there was a significant increase in serum fibulin-3 (EFEMP1 encoded protein) concentration in patients with wet AMD compared with that in the controls. Tube formation and proliferation of EFEMP1-OE HUVECs increased significantly, whereas those of EFEMP1 knockdown HUVECs decreased significantly compared with those of the control. Additional extracellular fibulin-3 treatments did not increase tube formation and proliferation of wildtype and EFEMP1 knockdown HUVECs, indicating that the proangiogenic properties of EFEMP1 are of cell origin. We also found that vascular endothelial growth factor expression in HUVECs was upregulated by EFEMP1 overexpression and downregulated by EFEMP1 knockdown. Conclusion: Our findings demonstrate EFEMP1 as a novel biomarker for CNV in AMD, providing a new target for the development of wet AMD-directed pharmaceuticals and diagnostics.

Experimental conditions influence the formation and composition of the corona around gold nanoparticles

BACKGROUND

Ovarian cancer is one of the deadliest gynecological malignancies. While the overall survival of ovarian cancer patients has slightly improved in recent years in the developed world, it remains clinically challenging due to its frequent late diagnosis and the lack of reliable diagnostic and/or prognostic markers. The aim of this study was to identify potential new molecular target proteins (NMTPs) responsible for the poor outcomes. When nanoparticles (NP) are exposed to biological fluids, a protein coat, termed the protein corona (PC), forms around the NP, and the PC represents a tool to identify NMTPs. This study investigates the influence of pre-processing conditions, such as lysis conditions and serum/plasma treatment, on the PC composition and the resulting identification of NMTPs.

RESULTS

Using gel electrophoresis, pre-processing conditions, including cell-lysis techniques and enrichment of low-abundance proteins (LAPs) by immunocentrifugation of serum/plasma, were shown to alter the relative amounts and compositions of proteins. PCs formed when 20 nm gold-NPs (GNPs) were incubated with lysate proteins from either RIPA- or urea lysis. Proteomic analysis of these PCs showed 2-22-fold enrichment of NMTPs in PCs from urea lysates as compared to RIPA lysates. Enriched NMTPs were then classified as cellular components, biological and molecular functions-associated proteins. The impact of enriched LAPs (eLAPs) on both PC composition and NMTP identification was shown by comparative proteomic analysis of original plasma, eLAPs, and PCs derived from eLAPs; eLAPs-PCs enhanced the abundance of NMTPs approximately 13%. Several NMTPs, including gasdermin-B, dermcidin, and kallistatin, were identified by this method demonstrating the potential use of this PC approach for molecular target discovery.

CONCLUSION

The current study showed that the pre-processing conditions modulate PC composition and can be used to enhance identification of NMTPs.

Low level of plasma fibulin-1 in patients with thyroid lesions: a case-control study and literature review

Investigating novel biomarkers discriminating thyroid nodules is a matter of great importance for differential diagnosis. The current study was planned to investigate the diagnostic value of fibulin-1 in plasma specimens of patients with thyroid nodules. A literature review was also performed to gain an understanding of the existing research relevant to the main role of fibulin-1 in carcinogenesis. In this case-control study, the levels of plasma fibulin-1 were compared in 82 subjects including papillary thyroid cancer (PTC; n = 30), multinodular goiter (MNG; n = 30), and healthy subjects (n = 22) using enzyme-linked immunosorbent assay (ELISA). Fibulin-1 levels of patients with PTC and MNG were documented to be significantly lower than those of healthy subjects (PTC vs. Healthy; P = 0.000, MNG vs. Healthy; P = 0.000). No statistically significant differences were found between PTC and MNG groups when fibulin-1 levels were compared (P > 0.05). Low level of plasma fibulin-1 was associated with an increased risk of PTC tumorigenesis (odds ratio = 0.810; 95% CI: 0.704-0.933; P = 0.003). Further, fibulin-1 had an appropriate diagnostic value for detecting PTC patients with a sensitivity of 73.33%, and specificity of 100% at the cutoff value > 4.9 (ng/ml). According to the results of the present research which are tied well with previous studies, the abnormal downregulation of fibulin-1 may play a role in the PTC and MNG tumorigenesis. In addition, fibulin-1 probably promotes the development and progression of other human cancer; however, further studies are needed to improve current understandings.

The expression of Fibulin-3 in ovarian cancer and its relationship with prognosis

BACKGROUND

Despite the significant advancements made in the treatment of ovarian cancer (OC), poor prognosis remains a major concern because this disease is frequently diagnosed at an advanced stage. Tumor recurrence and metastasis have been implicated in the poor clinical outcomes of OC. Although Fibulin-3 has been shown to be closely related to the development of various tumors, its relationship with OC has not been widely examined. Hence, this study was conducted to investigate the expression of Fibulin-3 in epithelial ovarian cancer (EOC), determine its relationship with EOC prognosis, and correlate its expression with that of the epithelial-mesenchymal transition markers (Snail, E-cadherin, and N-cadherin).

METHODS

Immunohistochemistry analysis was performed to detect the expression of Fibulin-3 protein in 84 OC samples, 10 benign ovarian tumor samples, and eight borderline ovarian tumor samples.

RESULTS

The positive rates of Fibulin-3 protein expression in OC, benign ovarian tumors, and borderline ovarian tumors were 45.24%, 20%, and 0%, respectively, showing significant differences (P<0.05). Fibulin-3 expression was found to be correlated with the FIGO stage of EOC, with tumors in higher stages (FIGO III + IV) showing higher expression. Additionally, at the protein level, Fibulin-3 was negatively correlated with E-cadherin protein (r=-0.252, P<0.05), and positively correlated with Snail and N-cadherin protein (r=0.644, 0.451, P<0.01).Overexpression of Fibulin-3 and the FIGO stage (III + IV) were related to the poor prognosis of patients (P<0.05). High expression of Fibulin-3 was an independent prognostic factor of EOC (P<0.05) The survival curve analysis showed that patients overexpressing Fibulin-3 had significantly shorter survival than those with low expression (P<0.05).

CONCLUSIONS

Increased expression of Fibulin-3 was found to be related to the invasion, metastasis, and prognosis of ovarian tumors, suggesting that it is an important indicator for evaluating the clinical prognosis of patients with EOC.

Identification of genes associated with gastric cancer survival and construction of a nomogram to improve risk stratification for patients with gastric cancer

The present study aimed to identify genes associated with gastric cancer survival and improve risk stratification for patients with gastric cancer. Transcriptomic and clinicopathological data from 443 gastric cancer samples were retrieved from The Cancer Genome Atlas database. The DESeq R package was applied to screen for differentially expressed genes between Tumor-Node-Metastasis (TNM) stage (I vs. IV) and histological grade (G3 vs. G1 and G2). A total of seven genes were common to both comparisons; spondin 1 (SPON1); thrombospondin 4 (THBS4); Sushi, Von Willebrand factor type A, EGF and pentraxin domain containing 1 (SVEP1); prickle planar cell polarity protein 1 (PRICKLE1); ATP binding cassette subfamily A member 8 (ABCA8); Slit guidance ligand 2 (SLIT2); and EGF containing fibulin extracellular matrix protein 1 (EFEMP1), were selected as candidate survival-associated genes for further analysis. The prognostic value of these genes was assessed according to a literature review and Kaplan-Meier survival analysis. In addition, a multivariate Cox regression analysis revealed PRICKLE1 expression to be an independent prognostic factor for patients with gastric cancer. Furthermore, a predictive nomogram was generated using PRICKLE1 expression, patient age and TNM stage to assess overall survival (OS) rate at 1, 3 and 5 years, with an internal concordance index of 0.65. External validation was conducted in an independent cohort of 59 patients with gastric cancer, and high consistency between the predicted and observed results for OS was exhibited. Overall, the current findings suggest that PRICKLE1 expression may serve as an independent prognostic factor that can be integrated with age and TNM stage in a nomogram able to predict OS rate in patients with gastric cancer.

Dual antivascular function of human fibulin-3 variant, a potential new drug discovery strategy for glioblastoma

The ECM protein EFEMP1 (fibulin-3) is associated with all types of solid tumor through its cell context-dependent dual function. A variant of fibulin-3 was engineered by truncation and mutation to alleviate its oncogenic function, specifically the proinvasive role in glioblastoma multiforme (GBM) cells at stem-like state. ZR30 is an in vitro synthesized 39-kDa protein of human fibulin-3 variant. It has a therapeutic effect in intracranial xenograft models of human GBM, through suppression of epidermal growth factor receptor/AKT and NOTCH1/AKT signaling in GBM cells and extracellular MMP2 activation. Glioblastoma multiforme is highly vascular, with leaky blood vessels formed by tumor cells expressing endothelial cell markers, including CD31. Here we studied GBM intracranial xenografts, 2 weeks after intratumoral injection of ZR30 or PBS, by CD31 immunohistochemistry. We found a 70% reduction of blood vessel density in ZR30-treated xenografts compared with that of PBS-treated ones. Matrigel plug assays showed the effect of ZR30 on suppressing angiogenesis. We further studied the effect of ZR30 on genes involved in endothelial transdifferentiation (ETD), in 7 primary cultures derived from 3 GBMs under different culture conditions. Two GBM cultures formed mesh structures with upregulation of ETD genes shortly after culture in Matrigel Matrix, and ZR30 suppressed both. ZR30 also downregulated ETD genes in two GBM cultures with high expression of these genes. In conclusion, multifaceted tumor suppression effects of human fibulin-3 variant include both suppression of angiogenesis and vasculogenic mimicry in GBM.

EFEMP1 as a Potential Biomarker for Diagnosis and Prognosis of Osteosarcoma

Osteosarcoma (OS) is the most common primary bone malignancy. Our previous study revealed an association between the level of epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) and the invasion, metastasis, and poor prognosis of OS. However, the exact correlation between the serum EFEMP1 level and OS diagnosis and progression was unclear. This study is aimed at determining the value of the serum EFEMP1 level in the diagnosis and prognosis of OS. Fifty-one consecutive OS patients were prospectively registered in this study. The serum EFEMP1 levels were measured using ELISA at diagnosis, after neoadjuvant chemotherapy, and before and after surgical treatment. Sixty-nine healthy subjects in the control group, nine patients with chondrosarcoma, and 12 patients with giant cell tumor of the bone were also enrolled in this study. Surgical orthotopic implantation was used to generate a mouse OS model, and the correlation between the circulating EFEMP1 levels and tumor progression was examined. Then, OS patients had significantly higher mean serum EFEMP1 levels (7.61 ng/ml) than the control subjects (1.47 ng/ml). The serum EFEMP1 levels were correlated with the Enneking staging system (r = 0.32, P = 0.021) and lung metastasis (r = 0.50, P < 0.001). There was also a correlation between the serum EFEMP1 level and EFEMP1 expression in the respective OS samples (r = 0.49, P < 0.001). Additionally, patients with either chondrosarcoma or giant cell tumor of the bone had significantly higher serum EFEMP1 levels than OS patients. Surgical and chemotherapeutic treatment led to an increase in the serum EFEMP1 levels. Then, the destruction of bone tissues might be one of the factors about the EFEMP1 levels. In the mouse OS model, the serum EFEMP1 level was correlated with tumor progression. Our results suggested that serum EFEMP1 levels might be used to distinguish OS patients from healthy controls and as an indicator for OS lung metastasis. Serum EFEMP1 levels could serve as a new and assisted biomarker for the auxiliary diagnosis and prognosis of OS.

EFEMP2 Inhibits Breast Cancer Invasion And Metastasis In Vitro And In Vivo

Background

EGF-containing fibulin-like extracellular matrix protein 2 (EFEMP2) is an extracellular matrix (ECM) glycoprotein, which is regarded as potential prognostic biomarkers in some carcinoma. Little is known about the association of EFEMP2 and breast cancer.

Methods

EFEMP2 expressions in normal breast tissue, benign fibroadenoma, breast cancer, the normal mammary epithelial cell line, and 4 different invasive breast cancer cell lines were evaluated by immunohistochemistry (IHC) or immunocytochemistry (ICC) and real time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR). Expression and prognostic value of EFEMP2 in breast cancer were verified by the Public databases (Oncomine and Kaplan-Meier plotter database). Lentiviral vector with EFEMP2 cDNA was constructed and used to infect breast cancer cell lines to investigate the effects of EFEMP2 on the biological behavior of breast cancer cells by functional in vitro and in vivo assays.

Results

Down-regulated EFEMP2 expression was found in breast cancer tissues and cells, and low expression of EFEMP2 was associated with poor prognosis in patients with breast cancer. Analysis by the Public database leaded to the same conclusion. Up-regulated EFEMP2 expression significantly hampered the invasion and metastasis abilities of breast cancer cells and the process of epithelial interstitial transformation (EMT) via the Wnt/β-catenin pathway.

Conclusion

EFEMP2 expression was lower in breast cancer and closely related to the prognosis of patients, its anti-oncogenic roles indicated the underlying therapeutic target for the future treatment of breast cancer.

Novel Associations Within the Tumor Microenvironment: Fibulins Meet ADAMTSs

The maintenance of tissue homeostasis in any organism is a very complex and delicate process in which numerous factors intervene. Cellular homeostasis not only depends on intrinsic factors but also relies on external factors that compose the microenvironment or cellular niche. Thus, extracellular matrix (ECM) components play a very important role in maintaining cell survival and behavior, and alterations in the ECM composition can lead to different pathologies. Fibulins and ADAMTS metalloproteases play crucial roles in the upkeep and function of the ECM in different tissues. In fact, members of both of these families of secreted multidomain proteins can interact with numerous other ECM components and thus shape or regulate the molecular environment. Individual members of both families have been implicated in tumor-related processes by exhibiting either pro- or antitumor properties. Recent studies have shown both an important relation among members of both families and their participation in several pathologies, including cardiogenesis or cancer. In this review, we summarize the associations among fibulins and ADAMTSs and the effects elicited by those interactions on cellular behavior.

Predictive proteomic signatures for response of pancreatic cancer patients receiving chemotherapy

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer that is characterized by its poor prognosis, rapid progression and development of drug resistance. Chemotherapy is a vital treatment option for most of PDAC patients. Stratification of PDAC patients, who would have a higher likelihood of responding to chemotherapy, could facilitate treatment selection and patient management.

METHODS

A quantitative proteomic study was performed to characterize the protein profiles in the plasma of PDAC patients undergoing chemotherapy to determine if specific biomarkers could be used to predict likelihood of therapeutic response.

RESULTS

By comparing the plasma proteome of the PDAC patients with positive therapeutic response and longer overall survival (Good-responders) to those who did not respond as well with shorter survival time (Limited-responders), we identified differential proteins and protein variants that could effectively segregate Good-responders from Limited-responders. Functional clustering and pathway analysis further suggested that many of these differential proteins were involved in pancreatic tumorigenesis. Four proteins, including vitamin-K dependent protein Z (PZ), sex hormone-binding globulin (SHBG), von Willebrand factor (VWF) and zinc-alpha-2-glycoprotein (AZGP1), were further evaluated as single or composite predictive biomarker with/without inclusion of CA 19-9. A composite biomarker panel that consists of PZ, SHBG, VWF and CA 19-9 demonstrated the best performance in distinguishing Good-responders from Limited-responders.

CONCLUSION

Based on the cohort investigated, our data suggested that systemic proteome alterations involved in pathways associated with inflammation, immunoresponse, coagulation and complement cascades may be reporters of chemo-treatment outcome in PDAC patients. For the majority of the patients involved, the panel consisting of PZ, SHBG, VWF and CA 19-9 was able to segregate Good-responders from Limited-responders effectively. Our data also showed that dramatic fluctuations of biomarker concentration in the circulating system of a PDAC patient, which might result from biological heterogeneity or confounding complications, could diminish the performance of a biomarker. Categorization of PDAC patients in terms of their tumor stages and histological types could potentially facilitate patient stratification for treatment.

Pathological and therapeutic aspects of matrix metalloproteinases: Implications in osteosarcoma

Osteosarcoma (OS) is one of the most common malignant bone tumors in children and adolescents, and the eighth leading form of childhood cancer. Matrix metalloproteinases (MMPs) are proteolytic enzymes implicated in certain cancers including OS. In this review, we discuss the mechanism of actions of MMPs in progression of OS, and the therapeutic use of MMPs inhibitors in the treatment of OS with subsequent clinical studies and future management. The expression of MMPs is upregulated in cancer cells by a variety of cytokines and growth factors, and upregulation of MMPs induces degradation of the extracellular matrix that contributes to cell proliferation by releasing growth factors. MMPs promote the detachment and migration of endothelial cells, cross the basement membrane as well as invade the surrounding lymphatic vessels and causes cancer metastasis. The use of selective MMP inhibitors with limited side effects might be promising therapeutic strategy in the treatment of OS. More clinical trials are necessary to evaluate the role of selective MMPs inhibitors in the prevention and treatment of OS along with their assessment of toxicity.

Extracellular Interactions between Fibulins and Transforming Growth Factor (TGF)-β in Physiological and Pathological Conditions

Transforming growth factor (TGF)-β is a multifunctional peptide growth factor that has a vital role in the regulation of cell growth, differentiation, inflammation, and repair in a variety of tissues, and its dysregulation mediates a number of pathological conditions including fibrotic disorders, chronic inflammation, cardiovascular diseases, and cancer progression. Regulation of TGF-β signaling is multifold, but one critical site of regulation is via interaction with certain extracellular matrix (ECM) microenvironments, as TGF-β is primarily secreted as a biologically inactive form sequestrated into ECM. Several ECM proteins are known to modulate TGF-β signaling via cell–matrix interactions, including thrombospondins, SPARC (Secreted Protein Acidic and Rich in Cystein), tenascins, osteopontin, periostin, and fibulins. Fibulin family members consist of eight ECM glycoproteins characterized by a tandem array of calcium-binding epidermal growth factor-like modules and a common C-terminal domain. Fibulins not only participate in structural integrity of basement membrane and elastic fibers, but also serve as mediators for cellular processes and tissue remodeling as they are highly upregulated during embryonic development and certain disease processes, especially at the sites of epithelial–mesenchymal transition (EMT). Emerging studies have indicated a close relationship between fibulins and TGF-β signaling, but each fibulin plays a different role in a context-dependent manner. In this review, regulatory interactions between fibulins and TGF-β signaling are discussed. Understanding biological roles of fibulins in TGF-β regulation may introduce new insights into the pathogenesis of some human diseases.

Fibulin-3 knockdown inhibits cervical cancer cell growth and metastasis in vitro and in vivo

To explore the function of fibulin-3 in cervical carcinoma malignant cell growth and metastasis, fibulin-3 expression in normal cervical tissue, cervical intraepithelial neoplasia (CIN), and cervical carcinoma were evaluated by immunohistochemistry. Quantitative real-time-polymerase chain reaction, western blotting, and immunocytochemistry were performed to assess the expression of fibulin-3 at mRNA and protein levels in different invasive clone sublines. Fibulin-3 shRNA and fibulin-3 cDNA were used to transfect the strongly and weakly invasive clone sublines. Using in vitro and in vivo functional assays, we investigated the effects of down-regulating and up-regulating fibulin-3 expression on the proliferation and invasion of different clone sublines. Epithelial mesenchymal transition (EMT) and its signaling pathways PI3K/AKT and ERK were studied carefully in lentiviral transfection systems. Fibulin-3 was upregulated in cervical carcinoma, and its overexpression was significantly related with malignant phenotype and poor prognosis of cervical carcinoma. Fibulin-3 promoted cervical cancer cell invasive capabilities by eliciting EMT and activating the PI3K-Akt-mTOR signal transduction pathway. Fibulin-3 could facilitate the process of cervical cancer development. The results presented here will help develop novel prognostic factors and possible therapeutic options for patients with cervical cancer.

The matrix protein Fibulin-3 promotes KISS1R induced triple negative breast cancer cell invasion

Breast cancer is a leading cause of cancer mortality. In particular, triple negative breast cancer (TNBC) comprise a heterogeneous group of basal-like tumors lacking estrogen receptor (ERα), progesterone receptor (PR) and HER2 (ErbB2). TNBC represents 15-20% of all breast cancers and occurs frequently in women under 50 years of age. Unfortunately, these patients lack targeted therapy, are typically high grade and metastatic at time of diagnosis. The mechanisms regulating metastasis remain poorly understood. We have previously shown that the kisspeptin receptor, KISS1R stimulates invasiveness of TNBC cells. In this report, we demonstrate that KISS1R signals via the secreted extracellular matrix protein, fibulin-3, to regulate TNBC invasion. We found that the fibulin-3 gene is amplified in TNBC primary tumors and that plasma fibulin-3 levels are elevated in TNBC patients compared to healthy subjects. In this study, we show that KISS1R activation increases fibulin-3 expression and secretion. We show that fibulin-3 regulates TNBC metastasis in a mouse experimental metastasis xenograft model and signals downstream of KISS1R to stimulate TNBC invasion, by activating matrix metalloproteinase 9 (MMP-9) and the MAPK pathway. These results identify fibulin-3 as a new downstream mediator of KISS1R signaling and as a potential biomarker for TNBC progression and metastasis, thus revealing KISS1R and fibulin-3 as novel drug targets in TNBC.

EFEMP1 promotes ovarian cancer cell growth, invasion and metastasis via activated the AKT pathway

EFEMP1, a kind of extracellular matrix (ECM) protein, has been suggested to correlate with the development of different types of carcinoma. However, its functions in ovarian cancer remain unclear. In our study, we performed cDNA microarray analysis and identified EFEMP1 dramatically elevated in the highly invasive subclone, compared with the low invasive subclone. Lentivirus transfection experiments were constructed afterwards. The results demonstrated that knockdown of EFEMP1 significantly inhibited ovarian cancer cell proliferation and induced cell cycle arrest at the G1/G0 phase. We also found that decreased the activity of phospho-AKT could suppress cell invasion and metastasis. Meanwhile, the increased phospho-AKT activity induced by the overexpression of EFEMP1 had significantly enhanced the abilities of ovarian cancer cells to invade and migrate. In addition, the vivo nude mice model confirmed that EFEMP1 was tightly correlated with the development of tumor. The results of RT² Profiler EMT PCR array further indicated that decreased EFEMP1 suppressed epithelial-to-mesenchymal transition (EMT). Collectively, by activating AKT signaling pathway, EFEMP1 contributed to ovarian cancer invasion and metastasis as a positive regulator. Overall, EFEMP1 had showed the potential use in the development of new therapeutic strategies for ovarian cancer.

EFEMP1 is repressed by estrogen and inhibits the epithelial-mesenchymal transition via Wnt/β-catenin signaling in endometrial carcinoma

Epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) acted as a tumor suppressor in endometrial carcinoma (EC). However, the correlation between EFEMP1 and estrogen is unknown. Here, we reported that the expression of EFEMP1 was conversely associated with ERα in endometrial carcinoma tissues. In endometrial carcinoma cells, estrogen/ERα signaling significantly suppressed the expression of EFEMP1. Moreover, chromatin immunoprecipitation (CHIP) and dual-luciferase reporter assays demonstrate that estrogen/ERα bound to the estrogen response element (ERE) located in EFEMP1 promoter and repressed its expression. Besides, in vitro and in vivo, EFEMP1 could remarkably suppress the expression of epithelial-mesenchymal transition (EMT) markers such as Vimentin, Snail and the Wnt/β-catenin target genes like Cyclin-D1 and c-Myc, which could be restored when EFEMP1 was silenced. In addition, XAV93920 (the inhibitor of the Wnt/β-catenin pathway) blocked and LiCl (the activator of the Wnt/β-catenin pathway) enhanced the effect of EFEMP1 on EMT. In conclusion, we demonstrated that estrogen/ERα signal suppresses EFEMP1. Besides, EFEMP1 inhibits EMT via interfering the Wnt/β-catenin signaling.

Fibulin-4 is associated with prognosis of endometrial cancer patients and inhibits cancer cell invasion and metastasis via Wnt/β-catenin signaling pathway

Fibulin-4, an extracellular glycoprotein, which plays significant roles in elastic fiber assembly, is correlated to the progression of some cancers. However, the role of fibulin-4 in endometrial cancer cell invasion and metastasis remains unexplored. In our study, fibulin-4 expression was assessed by immunohistochemistry (IHC) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in normal endometrial tissues and endometrial carcinoma tissues. Using single cell cloning, strongly, and weakly, invasive subclones were derived from KLE and Ishikawa endometrial carcinoma cell lines. RT-qPCR, western blotting, and immunocytochemistry (ICC) were used to assess mRNA and protein expressions of fibulin-4 in primary cultured endometrial cells, 4 types of endometrial cancer cell lines, and the different invasive subclones. Using lentivirus transfection, fibulin-4 shRNA and pLVX-fibulin-4 were constructed and used to infect the strongly and weakly invasive subclones. The effects of fibulin-4 on the biological characteristics of endometrial carcinoma cells were detected by cell functional assays in vitro and in vivo. Using Wnt signaling pathway inhibitor XAV-939 and activator LiCl, we detected the role of fibulin-4 in the Wnt/β-catenin pathway and the relationship with epithelial to mesenchymal transition (EMT). Fibulin-4 was decreased in endometrial carcinoma tissues, and loss of fibulin-4 expression was significantly related with poor differentiation, lymph node metastasis, and poor prognosis of endometrial carcinoma. Fibulin-4 significantly inhibited endometrial carcinoma cell proliferation, invasion, metastasis, and EMT through the Wnt/β-catenin pathway. Fibulin-4 has the ability to suppress endometrial cancer progression. These results can contribute to the development of a new potential therapeutic target for patients with endometrial carcinoma.

Fibulin-3 promotes osteosarcoma invasion and metastasis by inducing epithelial to mesenchymal transition and activating the Wnt/β-catenin signaling pathway

This study explored the role of fibulin-3 in osteosarcoma progression and the possible signaling pathway involved. Fibulin-3 mRNA and protein expression in normal tissue, benign fibrous dysplasia, osteosarcoma, osteosarcoma cell lines (HOS and U-2OS), the normal osteoblastic cell line hFOB, and different invasive subclones was evaluated by immunohistochemistry (IHC) or immunocytochemistry (ICC) and real time reverse transcriptase-polymerase chain reaction (real time qRT-PCR). To assess the role of fibulin-3 in the invasion and metastasis of osteosarcoma cells, lentiviral vectors with fibulin-3 small hairpin RNA (shRNA) and pLVX-fibulin-3 were constructed and used to infect the highly invasive and low invasive subclones. The effects of fibulin-3 knockdown and upregulation on the biological behavior of osteosarcoma cells were investigated by functional in vitro and in vivo assays. The results revealed that fibulin-3 expression was upregulated in osteosarcoma, and was positively correlated with low differentiation, lymph node metastasis, and poor prognosis. Fibulin-3 could promote osteosarcoma cell invasion and metastasis by inducing EMT and activating the Wnt/β-catenin signaling pathway. Collectively, our findings demonstrate that fibulin-3 is a promoter of osteosarcoma development and progression, and suggest a novel therapeutic target for future studies.

Analysis of fibulin-3 after exposure to asbestos-like fibers

A significantly increased incidence of malignant mesothelioma in Biancavilla (Sicily, Italy) has been ascribed to exposure to fluoro-edenite, a fibrous amphibole extracted from a local stone quarry. Fibulin-3 is a highly conserved glycoprotein proposed as a biomarker for malignant mesothelioma that belongs to the family of extracellular matrix proteins. Previous studies demonstrated high Fibulin-3 plasma levels in workers with pleural plaques exposed to fluoro-edenite. Therefore, in order to gain insight into the biomolecular mechanisms of fluoro-edenite toxicity, we performed the analysis of Fibulin-3 expression by immunohistochemistry in the lung samples derived from sheep belonging to the area of Biancavilla. Furthermore, an in vitro model of exposed fluoro-edenite fibroblasts was used to perform functional experiments to better understand the modulation of Fibulin-3 expression. The percentage of immunostained area by Fibulin-3 was very much higher in exposed lungs compared with non-exposed ones. The Fibulin-3 protein level was significantly expressed in primary human lung fibroblasts exposed to 50 and 100µg/ml of fluoro-edenite fibers for 72h, compared to the unexposed controls. The results from the present study further demonstrate the implication of Fibulin-3 during fluoro-edenite exposure. This would endorse our previous results regarding the use of Fibulin-3 as a possible screening biomarker for fluoro-edenite exposed individuals, thereby contributing to the monitoring of the population at risk. The present study also suggested that the Fibulin-3 overexpression may reflect a defensive response of the tissues after exogenous stimuli and may be implicated in cancer development, especially in the context of fluoro-edenite contamination. However, further studies are necessary in order to make Fibulin-3 a customized screening tool.

Tumor-derived fibulin-3 activates pro-invasive NF-κB signaling in glioblastoma cells and their microenvironment

Molecular profiling of glioblastomas has revealed the presence of key signaling hubs that contribute to tumor progression and acquisition of resistance. One of these main signaling mechanisms is the NF-κB pathway, which integrates multiple extracellular signals into transcriptional programs for tumor growth, invasion, and maintenance of the tumor-initiating population. We show here that an extracellular protein released by glioblastoma cells, fibulin-3, drives oncogenic NF-κB in the tumor and increases NF-κB activation in peritumoral astrocytes. Fibulin-3 expression correlates with a NF-κB-regulated “invasive signature” linked to poorer survival, being a possible tissue marker for regions of active tumor progression. Accordingly, fibulin-3 promotes glioblastoma invasion in a manner that requires NF-κB activation both in the tumor cells and their microenvironment. Mechanistically, we found that fibulin-3 activates the metalloprotease ADAM17 by competing with its endogenous inhibitor, TIMP3. This results in sustained release of soluble TNFα by ADAM17, which in turn activates TNF receptors and canonical NF-κB signaling. Taken together, our results underscore fibulin-3 as a novel extracellular signal with strong activating effect on NF-κB in malignant gliomas. Because fibulin-3 is produced de novo in these tumors and is absent from normal brain we propose that targeting the fibulin-3/NF-κB axis may provide a novel avenue to disrupt oncogenic NF-κB signaling in combination therapies for malignant brain tumors.

Fibulin-4 promotes osteosarcoma invasion and metastasis by inducing epithelial to mesenchymal transition via the PI3K/Akt/mTOR pathway

This study explored the role of fibulin-4 in osteosarcoma progression and the possible signaling pathway involved. Fibulin-4 mRNA and protein expression in normal tissue, benign fibrous dysplasia, osteosarcoma, osteosarcoma cell lines, the normal osteoblastic cell line hFOB, and different invasive subclones were evaluated by immunohistochemistry (IHC) or immunocytochemistry (ICC) and real-time reverse transcriptase-polymerase chain reaction (real-time qRT-PCR). Using in vitro functional assays, we analyzed the invasive and proliferative abilities of different osteosarcoma cell lines and subclones with differing invasive potential. To assess the role of fibulin-4 in the invasion and metastasis of osteosarcoma cells, lentiviral vectors with fibulin-4 small hairpin RNA (shRNA) and pLVX-fibulin-4 were constructed and used to infect the highly invasive and low invasive subclones and osteosarcoma cell lines. The effects of fibulin-4 knockdown and upregulation on the biological behavior of osteosarcoma cells were investigated by functional in vitro and in vivo assays. The results revealed that fibulin-4 expression was upregulated in osteosarcoma, and was positively correlated with low differentiation, lymph node metastasis, and poor prognosis. Fibulin-4 was also found to be over-expressed in highly invasive cell lines and in the highly invasive subclones. Fibulin-4 could promote osteosarcoma cell invasion and metastasis by inducing EMT via the PI3K/AKT/mTOR pathway. Collectively, our findings demonstrate that fibulin-4 is a promoter of osteosarcoma development and progression, and suggest a novel therapeutic target for future studies.

Epidermal Growth Factor-Containing Fibulin-Like Extracellular Matrix Protein 1 (EFEMP1) Acts as a Potential Diagnostic Biomarker for Prostate Cancer

Background

The aim of this study was to detect the expression of epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) and estimate its diagnostic value in prostate cancer (PCa).

Material/Methods

EFEMP1 expression in serum and urine of patients with PCa, benign controls and healthy controls at mRNA and protein level were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) analysis, respectively. The chi-square test was used to analyze the relationship between EFEMP1 expression and clinical factors of patients with PCa. A receiver operating characteristic (ROC) curve was established to evaluate the potential values of EFEMP1 for the diagnosis of PCa.

Results

The relative expression of EFEMP1 was significantly decreased in patients with PCa compared with that in the benign controls and healthy individuals, both at mRNA and protein levels (P<0.05). In the postoperative serum, the EFEMP1 expression was significantly higher than that in preoperative serum at 2 levels. Urine EFEMP1 expression was also down-regulated in patients with PCa compared to that in the other 2 control groups. The low expression of EFEMP1 was obviously affected by Gleason’s score, serum PSA, pathological stage, and lymph node metastasis. Moreover, there was a significant inverse correlation between EFEMP1 expression and PSA levels. The ROC curve revealed that EFEMP1 distinguished PCa patients from healthy controls, with a high AUC of 0.908, corresponding with high sensitivity and specificity, which was significantly higher than the PSA value.

Conclusions

Serum EFEMP1 is down-regulated and involved in the progression of PCa. It may serve as a useful diagnostic biomarker, with better diagnostic accuracy than PSA in PCa.

A nuclear-directed human pancreatic ribonuclease (PE5) targets the metabolic phenotype of cancer cells

Ribonucleases represent a new class of antitumor RNA-damaging drugs. However, many wild-type members of the vertebrate secreted ribonuclease family are not cytotoxic because they are not able to evade the cytosolic ribonuclease inhibitor. We previously engineered the human pancreatic ribonuclease to direct it to the cell nucleus where the inhibitor is not present. The best characterized variant is PE5 that kills cancer cells through apoptosis mediated by the p21^WAF1/CIP1 induction and the inactivation of JNK. Here, we have used microarray-derived transcriptional profiling to identify PE5 regulated genes on the NCI/ADR-RES ovarian cancer cell line. RT-qPCR analyses have confirmed the expression microarray findings. The results show that PE5 cause pleiotropic effects. Among them, it is remarkable the down-regulation of multiple genes that code for enzymes involved in deregulated metabolic pathways in cancer cells.

Overexpression of IFN-induced protein with tetratricopeptide repeats 3 (IFIT3) in pancreatic cancer: cellular "pseudoinflammation" contributing to an aggressive phenotype

Inflammation contributes to important traits that cancer cells acquire during malignant progression. Gene array data recently identified upregulation of interferon-induced protein with tetratricopeptide repeats 3 (IFIT3) in aggressive pancreatic cancer cells. IFIT3 belongs to the group of interferon stimulated genes (ISG), can be induced by several cellular stress stimuli and by its tetratricopeptide repeats interacts with a multitude of cellular proteins.

Upregulation of IFIT3 was confirmed in the aggressive pancreatic cancer cell line L3.6pl compared with its less aggressive cell line of origin, COLO357FG. Transgenic induction of IFIT3 expression in COLO357FG resulted in greater mass of orthotopic tumors and higher prevalence of metastases. Several important traits that mediate malignancy were altered by IFIT3: increased VEGF and IL-6 secretion, chemoresistance and decreased starvation-induced apoptosis. IFIT3 showed binding to JNK and STAT1, the latter being an important inducer of IFIT3 expression. Despite still being alterable by “classical” IFN or NFκB signaling, our findings indicate constitutive - possibly auto-regulated - upregulation of IFIT3 in L3.6pl without presence of an adequate inflammatory stimulus. The transcription factor SOX9, which is linked to regulation of hypoxia-related genes, was identified as a key mediator of upregulation of the oncogene IFIT3 and thereby sustaining a “pseudoinflammatory” cellular condition.

Epidermal growth factor-containing fibulin-like extracellular matrix protein 1 expression and regulation in uterine leiomyoma

OBJECTIVE

To determine the presence, differential expression, and regulation of epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) in uterine leiomyomas.

DESIGN

Laboratory in vivo and in vitro study with the use of human leiomyoma and myometrial tissue and primary cells.

SETTING

Academic medical center.

SAMPLE(S)

Leiomyoma and myometrial tissue samples and cultured cells.

INTERVENTION(S)

5-Aza-2'-deoxycytidine (5-aza-dC) treatment.

MAIN OUTCOME MEASURE(S)

Fold-change difference between EFEMP1 and fibulin-3 expression in leiomyoma tissue and cells compared with matched myometrial samples, and fold-change difference in EFEMP1 expression with 5-Aza-dC treatment.

RESULT(S)

In vivo, EFEMP1 expression was 3.19-fold higher in myometrial tissue than in leiomyoma tissue. EFEMP1 expression in vitro was 5.03-fold higher in myometrial cells than in leiomyoma cells. Western blot and immunohistochemistry staining of tissue and cells confirmed similar findings in protein expression. Treatment of leiomyoma cells with 5-Aza-dC resulted in increased expression of EFEMP1 in vitro.

CONCLUSION(S)

The EFEMP1 gene and its protein product, fibulin-3, are both significantly down-regulated in leiomyoma compared with myometrium when studied both in vivo and in vitro. The increase in EFEMP1 expression in leiomyoma cells with 5-Aza-dC treatment suggest that differential methylation is responsible, in part, for the differences seen in gene expression.

Fibulin-3 as a biomarker of response to treatment in malignant mesothelioma

Background

Fibulin-3 is a new potential biomarker for malignant mesothelioma (MM). This study evaluated the potential applicability of fibulin-3 plasma levels as a biomarker of response to treatment and its prognostic value for progressive disease within 18 months. The potential applicability of fibulin-3 in comparison with or in addition to soluble mesothelin-related peptides (SMRP) was also assessed.

Patients and methods.

The study included 78 MM patients treated at the Institute of Oncology Ljubljana between 2007 and 2011. Fibulin-3 levels in plasma samples obtained before treatment and in various responses to treatment were measured with the enzyme-linked immunosorbent assay.

Results

In patients evaluated before the treatment, fibulin-3 levels were not influenced by histopathological sub-types, tumour stages or the presence of metastatic disease. Significantly higher fibulin-3 levels were found in progressive disease as compared to the levels before treatment (Mann-Whitney [U] test = 472.50, p = 0.003), in complete response to treatment (U = 42.00, p = 0.010), and in stable disease (U = 542.00, p = 0.001). Patients with fibulin-3 levels exceeding 34.25 ng/ml before treatment had more than four times higher probability for developing progressive disease within 18 months (odds ratio [OR] = 4.35, 95% confidence interval [CI] 1.56–12.13). Additionally, patients with fibulin-3 levels above 34.25 ng/ml after treatment with complete response or stable disease had increased odds for progressive disease within 18 months (OR = 6.94, 95% CI 0.99–48.55 and OR = 4.39, 95% CI 1.63–11.81, respectively).

Conclusions

Our findings suggest that in addition to SMRP fibulin-3 could also be helpful in detecting the progression of MM.

Fibulin-3 levels in malignant pleural mesothelioma are associated with prognosis but not diagnosis

Background:

Fibulin-3 (FBLN3) was recently presented as a promising novel biomarker for malignant pleural mesothelioma (MPM), warranting independent validation studies.

Methods:

ELISA was used to measure cellular and secreted FBLN3 in cell lines, in plasma of xenograft tumour-bearing mice, in plasma from two independent series of MPM and non-MPM patients and in pleural fluid from a third series. Diagnostic and prognostic potential of FBLN3 was assessed by receiver operating characteristics curve analysis and Kaplan–Meier method, respectively.

Results:

FBLN3 was expressed in all MPM and benign mesothelial cell lines tested, and a correlation was observed between cellular protein expression and secreted levels. Human FBLN3 was detectable in plasma of tumour-bearing mice, suggesting that MPM cells contribute to levels of circulating FBLN3. Plasma FBLN3 was significantly elevated in MPM patients from the Sydney cohort, but not the Vienna cohort, but the diagnostic accuracy was low (63%, (95% CI: 50.1–76.4) and 56% (95% CI: 41.5–71.0), respectively). Although FBLN3 levels in pleural effusions were not significantly different between cases and controls, FBLN3 levels in pleural effusion fluid were found to be independently associated with prognosis (hazard ratio of 9.92 (95% CI: 2.14–45.93)).

Conclusions:

These data confirm the potential prognostic value of pleural effusion FBLN3, but question the diagnostic value of this protein in MPM patients.

EFEMP1 promotes the migration and invasion of osteosarcoma via MMP-2 with induction by AEG-1 via NF-κB signaling pathway

The role of epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) in osteosarcoma remains unknown. Then applying EFEMP1 siRNA, plasmids transfection and adding purified EFEMP1 protein in human osteosarcoma cell lines, and using immunohistochemistry on 113 osteosarcoma tissues, demonstrated that EFEMP1 was a poor prognostic indicator of osteosarcoma; EFEMP1 was specifically upregulated in osteosarcoma and associated with invasion and metastasis in vitro and in vivo. At the same time, we found a direct regulatory effect of EFEMP1 on MMP-2. Moreover, we firstly found the marked induction of EFEMP1 by oncogenic AEG-1. And EFEMP1 expression was inhibited by the selective inhibitor of NF-κB (PDTC) in osteosarcoma cells. Then we thought that NF-κB pathways might be one of the effective ways which EFEMP1 was induced by AEG-1. Thus, we suggested that EFEMP1 played a part as the mediator between AEG-1 and MMP-2. And NF-κB signaling pathway played an important role in this process. In summary, EFEMP1 was associated with invasion, metastasis and poor prognosis of osteosarcoma patients. EFEMP1 might indirectly enhance the expression of MMP-2, providing a potential explanation for the role of AEG-1 in metastasis. NF-κB pathways might be one of the effective ways which EFEMP1 was induced by AEG-1.

Fibulin-4 is associated with tumor progression and a poor prognosis in ovarian carcinomas

Background

Fibulin-4, a member of the fibulin family of extracellular glycoproteins, is implicated in the progressions of some cancers. However, no information has been available to date regarding the function of fibulin-4 in ovarian carcinoma progression.

Methods

In this study, fibulin-4 mRNA and protein expression in normal ovarian tissue, ovarian tumor, high invasive subclones and low invasive subclones were evaluated by immunohistochemistry and real time reverse transcriptase-polymerase chain reaction (RT-PCR). The serum levels of fibulin-4, cancer antigen 125 (CA-125) and cerbohydrate antigen 199 (CA19-9) in patients with ovarian tumor were measured by enzyme-linked immunosorbent assay and electrochemiluminescent immunoassay. To assess the angiogenic properties of fibulin-4, vascular endothelial growth factor (VEGF) expression and tumor microvessel density were analyzed in ovarian carcinoma by immunohistochemistry.

Results

Fibulin-4 expression was upregulated in ovarian carcinoma, and positively correlated with MVD and VEGF expression. Fibulin-4 overexpression was significantly associated with advanced stage, low differentiation, lymph node metastasis and poor prognosis in patients with ovarian cancer. The serum levels of fibulin-4, CA-125 and CA19-9 in patients with ovarian carcinoma were much higher than those with benign ovarian tumors and normal controls. Compared to CA-125 and CA19-9, fibulin-4 had better diagnostic sensitivity and specificity.

Conclusions

Fibulin-4 is a novel gene that is found overexpressed in ovarian cancer and associated with poor prognostic clinicopathologic features. This study shows that fibulin-4 may serve as a new prognostic factor and as a potential therapeutic target for patients with ovarian cancer in the future.

[EFEMP1 suppresses growth and invasion of lung cancer cells by downregulating matrix metalloproteinase-7 expression]

背景与目的

EFEMP1属于fibulin家族成员，是一种与细胞代谢密切相关的重要的细胞外基质蛋白，其在肿瘤的发生发展中的作用尚不清楚。本研究旨在探讨EFEMP1影响肺癌细胞生长和侵袭转移的生物学作用及其机制。

方法

Western blot方法检测肺癌细胞中EFEMP1表达，甲基化特异性PCR（methylation-specific PCR, MSP）方法检测EFEMP1在肺癌细胞中启动子区甲基化状态。肺癌细胞中转染EFEMP1后，检测细胞克隆形成及侵袭能力变化，并用Western blot及实时定量PCR检测MMP-7表达，Luciferase实验检测EFEMP1对基质金属蛋白酶7（matrix metalloproteinase-7, MMP-7）报告质粒的影响。

结果

Western blot结果显示肺癌细胞中EFEMP1表达下降，MSP分析结果说明A549和H1299中EFEMP1启动子区存在甲基化位点，5-aza-2’-deoxycytidine处理后，EFEMP1表达升高。A549和H1299转染EFEMP1后细胞克隆形成能力以及侵袭活性明显下降，MMP-7蛋白表达下调。Luciferase实验结果显示EFEMP1可以抑制MMP-7报告质粒的表达活性。

结论

EFEMP1是一种肺癌生长和侵袭的抑制因子，由于表观遗传学的改变，其在肺癌细胞中表达下降，通过上调MMP-7的表达促进肺癌细胞的侵袭转移。

EFEMP1 induces γ-secretase/Notch-mediated temozolomide resistance in glioblastoma

Glioblastoma is the most common malignant primary brain tumor. Temozolomide (TMZ) is the standard chemotherapeutic agent for this disease. However, intrinsic and acquired TMZ-resistance represents a major obstacle for this therapy. In order to identify factors involved in TMZ-resistance, we engineered different TMZ-resistant glioblastoma cell lines. Gene expression analysis demonstrated that EFEMP1, an extracellular matrix protein, is associated with TMZ-resistant phenotype. Silencing of EFEMP1 in glioblastoma cells resulted in decreased cell survival following TMZ treatment, whereas overexpression caused TMZ-resistance. EFEMP1 acts via multiple signaling pathways, including γ-secretase-mediated activation of the Notch pathway. We show that inhibition of γ-secretase by RO4929097 causes at least partial sensitization of glioblastoma cells to temozolomide in vitro and in vivo. In addition, we show that EFEMP1 expression levels correlate with survival in TMZ-treated glioblastoma patients. Altogether our results suggest EFEMP1 as a potential therapeutic target to overcome TMZ-resistance in glioblastoma.

Association of EFEMP1 gene polymorphisms with the risk of glioma: A hospital-based case-control study in a Chinese Han population

BACKGROUND

EGF-containing fibulin-like extracellular matrix protein1 (EFEMP1) gene was relative with the formation and development of tumors and had an anti-angiogenic function. Recently, many studies investigating the function of EFEMP1 gene, including its roles in prostate cancer and glioma, have been reported. EFEMP1 suppressed glioma growth by modulating EGFR and AKT signaling pathway or promoted growth through the regulation of Notch pathway were identified. However, the susceptibility of EFEMP1and glioma has not been well studied to date. Here, the authors were aimed to investigate whether the single nucleotide polymorphisms (SNPs) of EFEMP1 were associated with glioma susceptibility.

METHODS

The authors genotyped 14 common tagging SNPs of EFEMP1 gene via the Sequenom Mass ARRYiPLEX platform and assessed their association with glioma risk in a hospital-based case-control study in a Chinese Han population (979 cases and 1007 controls).

RESULTS

Four SNPs were significant associated with glioma risk (rs1346787, P=0.004, adjusted OR=1.49; rs3791679, P=0.014, adjusted OR=1.27; rs1346786, P=0.002, adjusted OR=1.41; rs3791675, P=0.011, adjusted OR=1.27). In further stratified analysis, all the significant SNPs except rs1346787 were associated with both low-grade gliomas and glioblastoma (GBM). In haplotype analysis, 4 haplotype blocks were identified and 2 of them were revealed significant associated with glioma, the haplotype "AA" (adjusted OR=1.44, P=0.005) in block 1 and haplotype "GG" (adjusted OR=1.65, P=0.0004) in block 2 had a 44% and 65% increased glioma risk respectively, compared with corresponding non-carriers. The results of haplotype analysis were significantly consistent with the single-locus analysis.

CONCLUSIONS

The authors' results suggested that common genetic variants in EFEMP1 gene were associated with glioma and contributed to glioma susceptibility, which might help to reveal the mechanism of gliomas and provide new insight for the diagnosis and treatment.

p38 MAPK down-regulates fibulin 3 expression through methylation of gene regulatory sequences: role in migration and invasion

p38 MAPKs regulate migration and invasion. However, the mechanisms involved are only partially known. We had previously identified fibulin 3, which plays a role in migration, invasion, and tumorigenesis, as a gene regulated by p38α. We have characterized in detail how p38 MAPK regulates fibulin 3 expression and its role. We describe here for the first time that p38α, p38γ, and p38δ down-regulate fibulin 3 expression. p38α has a stronger effect, and it does so through hypermethylation of CpG sites in the regulatory sequences of the gene. This would be mediated by the DNA methylase, DNMT3A, which is down-regulated in cells lacking p38α, but once re-introduced represses Fibulin 3 expression. p38α through HuR stabilizes dnmt3a mRNA leading to an increase in DNMT3A protein levels. Moreover, by knocking-down fibulin 3, we have found that Fibulin 3 inhibits migration and invasion in MEFs by mechanisms involving p38α/β inhibition. Hence, p38α pro-migratory/invasive effect might be, at least in part, mediated by fibulin 3 down-regulation in MEFs. In contrast, in HCT116 cells, Fibulin 3 promotes migration and invasion through a mechanism dependent on p38α and/or p38β activation. Furthermore, Fibulin 3 promotes in vitro and in vivo tumor growth of HCT116 cells through a mechanism dependent on p38α, which surprisingly acts as a potent inducer of tumor growth. At the same time, p38α limits fibulin 3 expression, which might represent a negative feed-back loop.

Fibulin-3 negatively regulates ALDH1 via c-MET suppression and increases γ-radiation-induced sensitivity in some pancreatic cancer cell lines

Fibulin-3 (FBLN-3) has been postulated to be either a tumor suppressor or promoter depending on the cell type, and hypermethylation of the FBLN-3 promoter is often associated with human disease, especially cancer. We report that the promoter region of the FBLN-3 was significantly methylated (>95%) in some pancreatic cancer cell lines and thus FBLN-3 was poorly expressed in pancreatic cancer cell lines such as AsPC-1 and MiaPaCa-2. FBLN-3 overexpression significantly down-regulated the cellular level of c-MET and inhibited hepatocyte growth factor-induced c-MET activation, which were closely associated with γ-radiation resistance of cancer cells. Moreover, we also showed that c-MET suppression or inactivation decreased the cellular level of ALDH1 isozymes (ALDH1A1 or ALDH1A3), which serve as cancer stem cell markers, and subsequently induced inhibition of cell growth in pancreatic cancer cells. Therefore, forced overexpression of FBLN-3 sensitized cells to cytotoxic agents such as γ-radiation and strongly inhibited the stemness and epithelial to mesenchymal transition (EMT) property of pancreatic cancer cells. On the other hand, if FBLN3 was suppressed in FBLN-3-expressing BxPC3 cells, the results were opposite. This study provides the first demonstration that the FBLN-3/c-MET/ALDH1 axis in pancreatic cancer cells partially modulates stemness and EMT as well as sensitization of cells to the detrimental effects of γ-radiation.

Novel paracrine modulation of Notch-DLL4 signaling by fibulin-3 promotes angiogenesis in high-grade gliomas

High-grade gliomas are characterized by exuberant vascularization, diffuse invasion, and significant chemoresistance, resulting in a recurrent phenotype that makes them impossible to eradicate in the long term. Targeting protumoral signals in the glioma microenvironment could have significant impact against tumor cells and the supporting niche that facilitates their growth. Fibulin-3 is a protein secreted by glioma cells, but absent in normal brain, that promotes tumor invasion and survival. We show here that fibulin-3 is a paracrine activator of Notch signaling in endothelial cells and promotes glioma angiogenesis. Fibulin-3 overexpression increased tumor VEGF levels, microvascular density, and vessel permeability, whereas fibulin-3 knockdown reduced vessel density in xenograft models of glioma. Fibulin-3 localization in human glioblastomas showed dense fiber-like condensations around tumor blood vessels, which were absent in normal brain, suggesting a remarkable association of this protein with tumor endothelium. At the cellular level, fibulin-3 enhanced endothelial cell motility and association to glioma cells, reduced endothelial cell sprouting, and increased formation of endothelial tubules in a VEGF-independent and Notch-dependent manner. Fibulin-3 increased ADAM10/17 activity in endothelial cells by inhibiting the metalloprotease inhibitor TIMP3; this resulted in increased Notch cleavage and increased expression of DLL4 independently of VEGF signaling. Inhibition of ADAM10/17 or knockdown of DLL4 reduced the proangiogenic effects of fibulin-3 in culture. Taken together, these results reveal a novel, proangiogenic role of fibulin-3 in gliomas, highlighting the relevance of this protein as an important molecular target in the tumor microenvironment.

Human retinal transmitochondrial cybrids with J or H mtDNA haplogroups respond differently to ultraviolet radiation: implications for retinal diseases

Background

It has been recognized that cells do not respond equally to ultraviolet (UV) radiation but it is not clear whether this is due to genetic, biochemical or structural differences of the cells. We have a novel cybrid (cytoplasmic hybrids) model that allows us to analyze the contribution of mitochondrial DNA (mtDNA) to cellular response after exposure to sub-lethal dose of UV. mtDNA can be classified into haplogroups as defined by accumulations of specific single nucleotide polymorphisms (SNPs). Recent studies have shown that J haplogroup is high risk for age-related macular degeneration while the H haplogroup is protective. This study investigates gene expression responses in J cybrids versus H cybrids after exposure to sub-lethal doses of UV-radiation.

Methodology/Principal Findings

Cybrids were created by fusing platelets isolated from subjects with either H (n = 3) or J (n = 3) haplogroups with mitochondria-free (Rho⁰) ARPE-19 cells. The H and J cybrids were cultured for 24 hours, treated with 10 mJ of UV-radiation and cultured for an additional 120 hours. Untreated and treated cybrids were analyzed for growth rates and gene expression profiles. The UV-treated and untreated J cybrids had higher growth rates compared to H cybrids. Before treatment, J cybrids showed lower expression levels for CFH, CD55, IL-33, TGF-A, EFEMP-1, RARA, BCL2L13 and BBC3. At 120 hours after UV-treatment, the J cybrids had decreased CFH, RARA and BBC3 levels but increased CD55, IL-33 and EFEMP-1 compared to UV-treated H cybrids.

Conclusion/Significance

In cells with identical nuclei, the cellular response to sub-lethal UV-radiation is mediated in part by the mtDNA haplogroup. This supports the hypothesis that differences in growth rates and expression levels of complement, inflammation and apoptosis genes may result from population-specific, hereditary SNP variations in mtDNA. Therefore, when analyzing UV-induced damage in tissues, the mtDNA haplogroup background may be important to consider.

Overexpression of fibulin-4 is associated with tumor progression and poor prognosis in patients with cervical carcinoma

Fibulin-4, a member of the fibulin family of extracellular glycoproteins, is implicated in the progression of a number of types of cancer. However, the function of fibulin-4 in cervical cancer progression remains unexplored. Fibulin-4 mRNA and protein expression levels in normal cervical tissue, cervical intraepithelial neoplasia (CIN), cervical carcinoma, highly invasive subclones and low-invasive subclones were evaluated by real-time reverse transcriptase-polymerase chain reaction and immunohistochemistry. Serum fibulin-4 levels in patients with CIN and cervical carcinoma were measured by enzyme-linked immunosorbent assay. To assess the angiogenic properties of fibulin-4, vascular endothelial growth factor (VEGF) expression and tumor microvessel density (MVD) were analyzed in the cervical carcinoma cases by immunohistochemistry. Fibulin-4 expression was upregulated in the cervical carcinoma cases, and was positively correlated with MVD and VEGF expression. Fibulin-4 overexpression and high serum levels were significantly associated with advanced stage, low differentiation, lymph node metastasis, and poor prognosis in patients with cervical cancer. Fibulin-4 expression was also found to be overexpressed in highly invasive subclones when compared with the low-invasive subclones. Fibulin-4 is a newly identified glycoprotein that is overexpressed in cervical carcinoma. Fibulin-4 promotes angiogenesis and is associated with poor prognostic clinicopathologic features. This study demonstrated that fibulin-4 may serve as a new prognostic factor and as a potential therapeutic target for patients with cervical carcinoma.