Fibulin-3 is uniquely upregulated in malignant gliomas and promotes tumor cell motility and invasion

Circulating exosomal protein EFEMP1 and SERPINC1 as diagnostic biomarkers for epithelial ovarian cancer

OBJECTIVES

Caner-derived exosomes, containing diverse nucleic acids and proteins, are being exploited in diagnostic biomarker development. This study aims to screen and identify the altered exosomal proteins between epithelial ovarian cancer (EOC) patient and healthy volunteers, and to evaluate their diagnostic accuracy for EOC.

METHODS

Exosomes were separate by ultracentrifugation, and then subjected to TEM, qNano, and western blot for identification. Exosomal EFEMP1 and SERPINC1 were selected by MS/MS analysis, validated by ELISA in a cohort with 163 healthy donors, 183 EOC patients and 30 patients with benign ovarian tumors.

RESULTS

MS/MS analyses identified a total of 207 differential exosomal proteins, including the 122 up-regulated and 85 down-regulated. Exosomal EFEMP1 and SERPINC1 were significantly upregulated in EOC patients compared with those in healthy donors as well as in the benign patients, possessing favorable diagnostic efficiency. The area under the curves (AUCs) were 0.8071, 0.8211, respectively. They also exerted rather high early diagnostic efficiency, as well as the potential to distinguish the malignant patients from the benign individuals. Besides, exosomal SERPINC1 was associated with coagulation index and LE-DVT (lower extremity deep venous thrombosis) in EOC patients.

CONCLUSIONS

Exosomal EFEMP1 and SERPINC1 are upregulated and serve as the promising diagnostic biomarkers for EOC.

GSK3 inhibition reduces ECM production and prevents age-related macular degeneration-like pathology

Malattia Leventinese/Doyne honeycomb retinal dystrophy (ML/DHRD) is an age-related macular degeneration-like (AMD-like) retinal dystrophy caused by an autosomal dominant R345W mutation in the secreted glycoprotein, fibulin-3 (F3). To identify new small molecules that reduce F3 production in retinal pigmented epithelium (RPE) cells, we knocked-in a luminescent peptide tag (HiBiT) into the endogenous F3 locus that enabled simple, sensitive, and high-throughput detection of the protein. The GSK3 inhibitor, CHIR99021 (CHIR), significantly reduced F3 burden (expression, secretion, and intracellular levels) in immortalized RPE and non-RPE cells. Low-level, long-term CHIR treatment promoted remodeling of the RPE extracellular matrix, reducing sub-RPE deposit-associated proteins (e.g., amelotin, complement component 3, collagen IV, and fibronectin), while increasing RPE differentiation factors (e.g., tyrosinase, and pigment epithelium-derived factor). In vivo, treatment of 8-month-old R345W+/+ knockin mice with CHIR (25 mg/kg i.p., 1 mo) was well tolerated and significantly reduced R345W F3-associated AMD-like basal laminar deposit number and size, thereby preventing the main pathological feature in these mice. This is an important demonstration of small molecule-based prevention of AMD-like pathology in ML/DHRD mice and may herald a rejuvenation of interest in GSK3 inhibition for the treatment of retinal degenerative diseases, including potentially AMD itself.

Multiomics Analysis Unravels Alteration in Molecule and Pathways Involved in Nondiabetic Chronic Wounds

The prevalence of chronic wounds (CW) continues to grow. A thorough knowledge of the mechanism of CW formation remains elusive due to a lack of relevant studies. Furthermore, most previous studies concentrated on diabetic ulcers with relatively few investigations on other types. We performed this multiomics study to investigate the proteomic and metabolomic changes in wound and surrounding tissue from a cohort containing 13 patients with nondiabetic CW. Differentially expressed proteins (DEPs) and metabolites (DEMs) were filtered out and analyzed through multiomic profiling. The DEPs were further confirmed with the use of parallel reaction monitoring. Compared with the surrounding tissue, there were 82 proteins and 214 metabolites altered significantly in wound tissue. The DEPs were mainly enriched in focal adhesion (FA), extracellular matrix-receptor interaction (ERI), and the PI3K-Akt (PA) signaling pathway. Moreover, the DEMs were significantly enriched in amino sugar and nucleotide sugar metabolism and biosynthesis of nucleotide sugar pathways. In correlation analysis, we discovered that the PA signaling pathway, as well as its upstream and downstream pathways, coenriched some DEPs and DEMs. Additionally, we found that FBLN1, FBLN5, and EFEMP1 (FBLN3) proteins dramatically elevated in wound tissue and connected with the above signaling pathways. This multiomics study found that changes in FA, ERI, and PA signaling pathways had an impact on the cellular activities and functions of wound tissue cells. Additionally, increased expression of those proteins in wound tissue may inhibit vascular and skin cell proliferation and degrade the extracellular matrix, which may be one of the causes of CW formation.

GSK3 inhibition reduces ECM production and prevents age-related macular degeneration-like pathology

Malattia Leventinese/Doyne Honeycomb Retinal Dystrophy (ML/DHRD) is an age-related macular degeneration (AMD)-like retinal dystrophy caused by an autosomal dominant R345W mutation in the secreted glycoprotein, fibulin-3 (F3). To identify new small molecules that reduce F3 production from retinal pigmented epithelium (RPE) cells, we knocked-in a luminescent peptide tag (HiBiT) into the endogenous F3 locus which enabled simple, sensitive, and high throughput detection of the protein. The GSK3 inhibitor, CHIR99021 (CHIR), significantly reduced F3 burden (expression, secretion, and intracellular levels) in immortalized RPE and non-RPE cells. Low-level, long-term CHIR treatment promoted remodeling of the RPE extracellular matrix (ECM), reducing sub-RPE deposit-associated proteins (e.g., amelotin, complement component 3, collagen IV, and fibronectin), while increasing RPE differentiation factors (e.g., tyrosinase, and pigment epithelium derived factor). In vivo, treatment of 8 mo R345W+/+ knockin mice with CHIR (25 mg/kg i.p., 1 mo) was well tolerated and significantly reduced R345W F3-associated AMD-like basal laminar deposit number and size, thereby preventing the main pathological feature in these mice. This is the first demonstration of small molecule-based prevention of AMD-like pathology in ML/DHRD mice and may herald a rejuvenation of interest in GSK3 inhibition for the treatment of neurodegenerative diseases, including, potentially AMD itself.

Unveiling the role of osteosarcoma-derived secretome in premetastatic lung remodelling

BACKGROUND

Lung metastasis is the most adverse clinical factor and remains the leading cause of osteosarcoma-related death. Deciphering the mechanisms driving metastatic spread is crucial for finding open therapeutic windows for successful organ-specific interventions that may halt or prevent lung metastasis.

METHODS

We employed a mouse premetastatic lung-based multi-omics integrative approach combined with clinical features to uncover the specific changes that precede lung metastasis formation and identify novel molecular targets and biomarker of clinical utility that enable the design of novel therapeutic strategies.

RESULTS

We found that osteosarcoma-bearing mice or those preconditioned with the osteosarcoma cell secretome harbour profound lung structural alterations with airway damage, inflammation, neutrophil infiltration, and extracellular matrix remodelling with increased deposition of fibronectin and collagens by resident stromal activated fibroblasts, favouring the adhesion of disseminated tumour cells. Systemic-induced microenvironmental changes, supported by transcriptomic and histological data, promoted and accelerated lung metastasis formation. Comparative proteome profiling of the cell secretome and mouse plasma identified a large number of proteins involved in extracellular-matrix organization, cell-matrix adhesion, neutrophil degranulation, and cytokine-mediated signalling, consistent with the observed lung microenvironmental changes. Moreover, we identified EFEMP1, an extracellular matrix glycoprotein exclusively secreted by metastatic cells, in the plasma of mice bearing a primary tumour and in biopsy specimens from osteosarcoma patients with poorer overall survival. Depletion of EFEMP1 from the secretome prevents the formation of lung metastasis.

CONCLUSIONS

Integration of our data uncovers neutrophil infiltration and the functional contribution of stromal-activated fibroblasts in ECM remodelling for tumour cell attachment as early pro-metastatic events, which may hold therapeutic potential in preventing or slowing the metastatic spread. Moreover, we identified EFEMP1, a secreted glycoprotein, as a metastatic driver and a potential candidate prognostic biomarker for lung metastasis in osteosarcoma patients. Osteosarcoma-derived secreted factors systemically reprogrammed the lung microenvironment and fostered a growth-permissive niche for incoming disseminated cells to survive and outgrow into overt metastasis. Daily administration of osteosarcoma cell secretome mimics the systemic release of tumour-secreted factors of a growing tumour in mice during PMN formation; Transcriptomic and histological analysis of premetastatic lungs revealed inflammatory-induced stromal fibroblast activation, neutrophil infiltration, and ECM remodelling as early onset pro-metastatic events; Proteome profiling identified EFEMP1, an extracellular secreted glycoprotein, as a potential predictive biomarker for lung metastasis and poor prognosis in osteosarcoma patients. Osteosarcoma patients with EFEMP1 expressing biopsies have a poorer overall survival.

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 Barretos Cancer Hospital Animal Facility: Implementation and Results of a Dedicated Platform for Preclinical Oncology Models

The Barretos Cancer Hospital Animal Facility (BCHAF) is a unique facility in Brazil exclusively dedicated to working with animal models for cancer research. In this article, we briefly present our modern facility and the main experiments performed, focusing on mutant strains of mice (PTCH-knockout and ApcMin mice), xenograft models, and patient-derived xenografts (PDXs). Our results show the progress and challenges in establishing these models and the need for having an appropriate representation of our cancer population to better understand tumor biology and to identify cancer biomarkers, which could be putatively targeted, allowing for personalized therapy.

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.

The scaffolding protein DLG5 promotes glioblastoma growth by controlling Sonic Hedgehog signaling in tumor stem cells

BACKGROUND

Tumor invasion, a hallmark of malignant gliomas, involves reorganization of cell polarity and changes in the expression and distribution of scaffolding proteins associated with polarity complexes. The scaffolding proteins of the DLG family are usually downregulated in invasive tumors and regarded as tumor suppressors. Despite their important role in regulating neurodevelopmental signaling, the expression and functions of DLG proteins have remained almost entirely unexplored in malignant gliomas.

METHODS

Western blot, immunohistochemistry, and analysis of gene expression were used to quantify DLG members in glioma specimens and cancer datasets. Over-expression and knockdown of DLG5, the highest-expressed DLG member in glioblastoma, were used to investigate its effects on tumor stem cells and tumor growth. qRT-PCR, Western blotting, and co-precipitation assays were used to investigate DLG5 signaling mechanisms.

RESULTS

DLG5 was upregulated in malignant gliomas compared to other solid tumors, being the predominant DLG member in all glioblastoma molecular subtypes. DLG5 promoted glioblastoma stem cell invasion, viability, and self-renewal. Knockdown of this protein in vivo disrupted tumor formation and extended survival. At the molecular level, DLG5 regulated Sonic Hedgehog (Shh) signaling, making DLG5-deficient cells insensitive to Shh ligand. Loss of DLG5 increased the proteasomal degradation of Gli1, underlying the loss of Shh signaling and tumor stem cell sensitization.

CONCLUSIONS

The high expression and pro-tumoral functions of DLG5 in glioblastoma, including its dominant regulation of Shh signaling in tumor stem cells, reveal a novel role for this protein that is strikingly different from its proposed tumor-suppressor role in other solid tumors.

Genetic Factors and Their Role in the Pathogenesis of Biliary Atresia

Biliary Atresia, a common basis for neonatal cholestasis and primary indication for Liver Transplantation, accounts for 60% of pediatric Liver Transplantations. While the pathogenesis of Biliary Atresia remains obscure, abnormalities within bile ducts and the liver, inflammation, fibrosis and cilia defects are thought to comprise the pathological basis for this condition. The findings of genetic variants in Biliary Atresia, such as Copy Number Variations and Single Nucleotide Polymorphism, are considered as essential factors in the development of this condition. In this review, we summarize and analyze these Biliary Atresia variants from a perspective of their pathological characteristics. In conclusion, such analyses may offer novel insights into the pathogenesis of Biliary Atresia and provide a foundation for future studies directed toward a better understanding and treatment of Biliary Atresia.

Plasma EFEMP1 Is Associated with Brain Aging and Dementia: The Framingham Heart Study

BACKGROUND

Epidermal growth factor containing fibulin extracellular matrix protein-1 (EFEMP1) has been associated with increased white matter hyperintensities (WMH) burden and disorders of premature aging and may have a shared pathophysiological role in the development of WMH and dementia.

OBJECTIVE

To determine the association between plasma EFEMP1 levels and MRI markers of vascular brain injury and incident all-cause and Alzheimer's disease (AD) dementia.

METHODS

We measured plasma EFEMP1 levels in 1597 [53% women, mean age 68.7 (SD 5.7) years] dementia-free Framingham Offspring cohort participants between 1998-2001 and subsequently followed them for incident dementia. Secondary outcomes included stroke, structural MRI brain measures and neurocognitive test performance.

RESULTS

During a median 11.8 [Q1, Q3 : 7.1, 13.3] year follow-up, 131 participants developed dementia. The highest quintile of plasma EFEMP1, compared to the bottom four quintiles, was associated with an increased risk of time to incident all-cause dementia (HR 1.77, 95% CI 1.18-2.64) and AD dementia (HR 1.76, 95% CI 1.11-2.81) but not with markers of vascular brain injury (WMH, covert brain infarcts or stroke). Higher circulating EFEMP1 concentrations were also cross-sectionally associated with lower total brain (β±SE, -0.28±0.11, p = 0.01) and hippocampal volumes (-0.006±0.003, p = 0.04) and impaired abstract reasoning (Similarities test, -0.18±0.08, p = 0.018 per standard deviation increment in EFEMP1).

CONCLUSION

Elevated circulating EFEMP1 is associated with an increased risk of all-cause and AD dementia, smaller hippocampal and total brain volumes, and poorer cognitive performance. EFEMP1 may play an important biological role in the development of AD dementia. Further studies to validate these findings are warranted.

METTL1-m7 G-EGFR/EFEMP1 axis promotes the bladder cancer development

BACKGROUND

The posttranscriptional modifications of transfer RNA (tRNA) are critical for all aspects of the tRNA function and have been implicated in the tumourigenesis and progression of many human cancers. By contrast, the biological functions of methyltransferase-like 1 (METTL1)-regulated m7 G tRNA modification in bladder cancer (BC) remain obscure.

RESULTS

In this research, we show that METTL1 was highly expressed in BC, and its level was correlated with poor patient prognosis. Silencing METTL1 suppresses the proliferation, migration and invasion of BC cells in vitro and in vivo. Multi-omics analysis reveals that METTL1-mediated m7 G tRNA modification altered expression of certain target genes, including EGFR/EFEMP1. Mechanistically, METTL1 regulates the translation of EGFR/EFEMP1 via modifying certain tRNAs. Furthermore, forced expression of EGFR/EFEMP1 partially rescues the effect of METTL1 deletion on BC cells.

CONCLUSIONS

Our findings demonstrate the oncogenic role of METTL1 and the pathological significance of the METTL1-m7 G-EGFR/EFEMP1 axis in the BC development, thus providing potential therapeutic targets for the BC treatment.

The Carbonic Anhydrase Inhibitor E7070 Sensitizes Glioblastoma Cells to Radio- and Chemotherapy and Reduces Tumor Growth

Glioblastomas (GBMs), the most common and lethal primary brain tumor, show inherent infiltrative nature and high molecular heterogeneity that make complete surgical resection unfeasible and unresponsive to conventional adjuvant therapy. Due to their fast growth rate even under hypoxic and acidic conditions, GBM cells can conserve the intracellular pH at physiological range by overexpressing membrane-bound carbonic anhydrases (CAs). The synthetic sulfonamide E7070 is a potent inhibitor of CAs that harbors putative anticancer properties; however, this drug has still not been tested in GBMs. The present study aimed to evaluate the effects of E7070 on CA9 and CA12 enzymes in GBM cells as well as in the tumor cell growth, migration, invasion, and resistance to radiotherapy and chemotherapy. We found that E7070 treatment significantly reduced tumor cell growth and increased radio- and chemotherapy efficacy against GBM cells under hypoxia. Our data suggests that E7070 has therapeutic potential as a radio-chemo-sensitizing in drug-resistant GBMs, representing an attractive strategy to improve the adjuvant therapy. We showed that CA9 and CA12 represent potentially valuable therapeutic targets that should be further investigated as useful diagnostic and prognostic biomarkers for GBM tailored therapy.

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.

Serum soluble mesothelin-related protein (SMRP) and fibulin-3 levels correlate with baseline malignant pleural mesothelioma (MPM) tumor volumes but are not useful as biomarkers of response in an immunotherapy trial

OBJECTIVES

Soluble mesothelin-related protein (SMRP) and fibulin-3 serum levels may serve as diagnostic and prognostic biomarkers of malignant pleural mesothelioma (MPM). Here, we evaluate these markers for correlation to tumor volume, prognosis and response assessment in a clinical trial of immunogene therapy in combination with chemotherapy.

MATERIALS AND METHODS

Serial serum levels of SMRP and fibulin-3 were measured in adult patients with biopsy-proven MPM enrolled in two prospective clinical trials. Pre-therapy computed tomography (CT) measurements of tumor burden were calculated and correlated with pre-therapy serum SMRP and fibulin-3 levels in these two trials. Serological data were also correlated with radiological assessment of response using Modified RECIST criteria over the first 6 months of intrapleural delivery of adenovirus-IFN alpha (Ad.IFN-α) combined with chemotherapy.

RESULTS

A cohort of 58 patients who enrolled in either a photodynamic therapy trial or immunotherapy clinical trial had available imaging and SMRP serological data for analysis of whom 45 patients had serological fibulin-3 data. The cohort mean total tumor volume was 387 cm³ (STD 561 cm³). Serum SMRP was detectable in 57 of 58 patients (mean 3.8 nM, STD 6.0). Serum fibulin-3 was detected in 44 of 45 patients (mean 23 ng/mL, STD 14). At pre-therapy baseline in these two trials, there was a strong correlation between tumor volume and serum SMRP levels (r = 0.61, p < 0.001), and a moderate correlation between tumor volume and serum fibulin-3 levels (r = 0.36, p = 0.014). Twenty-eight patients in the immunotherapy trial had longitudinal serologic and radiographic data. Fold-changes in SMRP and fibulin-3 did not show significant correlations with modified RECIST measurements.

CONCLUSIONS

Although our data show correlations of SMRP and fibulin-3 with initial tumor volumes as measured by CT scanning, the use of SMRP and fibulin-3 as serological biomarkers in the immunotherapy trial were not useful in following tumor response longitudinally.

Quantitative endophenotypes as an alternative approach to understanding genetic risk in neurodegenerative diseases

Endophenotypes, as measurable intermediate features of human diseases, reflect underlying molecular mechanisms. The use of quantitative endophenotypes in genetic studies has improved our understanding of pathophysiological changes associated with diseases. The main advantage of the quantitative endophenotypes approach to study human diseases over a classic case-control study design is the inferred biological context that can enable the development of effective disease-modifying treatments. Here, we summarize recent progress on biomarkers for neurodegenerative diseases, including cerebrospinal fluid and blood-based, neuroimaging, neuropathological, and clinical studies. This review focuses on how endophenotypic studies have successfully linked genetic modifiers to disease risk, disease onset, or progression rate and provided biological context to genes identified in genome-wide association studies. Finally, we review critical methodological considerations for implementing this approach and future directions.

AEG-1 deletion promotes cartilage repair and modulates bone remodeling-related cytokines via TLR4/MyD88/NF-κB inhibition in ovariectomized rats with osteoporosis

Background

Osteoporosis is a systemic skeletal disorder that can impact a variety of bones throughout the body. Astrocyte-elevated gene-1 (AEG-1) is involved in multiple pro-tumorigenic functions and participates in various inflammatory reactions. However, whether it has an impact on osteoporosis-related cartilage repair and bone remodeling remains unknown.

Methods

We utilized an ovariectomy mouse model with AEG-1 deletion to investigate the role of AEG-1 in osteoporosis. The mRNA level of AEG-1 was detected by RT-PCR, bone markers, bone volume/total volume (BV/TV), trabecular bone surface/bone volume (BSA/BV) and trabecular bone thickness (Tb. Th) were detected by micro computed tomography (µCT), bone injury was observed by HE and alcian blue staining. The contents of IL-6, IL-17, iNOS and IL-10 in peripheral blood of the three groups were detected by ELISA. The expression of OSX, coi1a1, OC, TLR4, MyD88 and NF-κB were detected by Western Blot.

Results

µCT revealed increased bone volume in the AEG-1 knockout (KO) ovariectomy (OVX) group compared to the wildtype (WT) OVX group 4 weeks after surgery, indicating restored bone formation after AEG-1 deletion. Flow sorting revealed that AEG-1 deletion inhibited the production of inflammatory factors. Western blot demonstrated activation of the TLR4/MyD88/NF-κB pathway after LPS exposure, which was reduced by AEG-1 deletion. AEG-1 deletion also improved lipopolysaccharide (LPS) induced adverse reactions.

Conclusions

Taken together, these findings indicate that AEG-1 deletion improves cartilage repair and bone remodeling during osteoporosis, which may partly occur through the inhibition of the TLR4/MyD88/NF-κB signaling pathway.

The Pathophysiological Significance of Fibulin-3

Fibulin-3 (also known as EGF-containing fibulin extracellular matrix protein 1 (EFEMP1)) is a secreted extracellular matrix glycoprotein, encoded by the EFEMP1 gene that belongs to the eight-membered fibulin protein family. It has emerged as a functionally unique member of this family, with a diverse array of pathophysiological associations predominantly centered on its role as a modulator of extracellular matrix (ECM) biology. Fibulin-3 is widely expressed in the human body, especially in elastic-fibre-rich tissues and ocular structures, and interacts with enzymatic ECM regulators, including tissue inhibitor of metalloproteinase-3 (TIMP-3). A point mutation in EFEMP1 causes an inherited early-onset form of macular degeneration called Malattia Leventinese/Doyne honeycomb retinal dystrophy (ML/DHRD). EFEMP1 genetic variants have also been associated in genome-wide association studies with numerous complex inherited phenotypes, both physiological (namely, developmental anthropometric traits) and pathological (many of which involve abnormalities of connective tissue function). Furthermore, EFEMP1 expression changes are implicated in the progression of numerous types of cancer, an area in which fibulin-3 has putative significance as a therapeutic target. Here we discuss the potential mechanistic roles of fibulin-3 in these pathologies and highlight how it may contribute to the development, structural integrity, and emergent functionality of the ECM and connective tissues across a range of anatomical locations. Its myriad of aetiological roles positions fibulin-3 as a molecule of interest across numerous research fields and may inform our future understanding and therapeutic approach to many human diseases in clinical settings.

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.

Cell Derived Matrix Fibulin-1 Associates With Epidermal Growth Factor Receptor to Inhibit Its Activation, Localization and Function in Lung Cancer Calu-1 Cells

Epidermal Growth Factor Receptor (EGFR) is a known promoter of tumor progression and is overexpressed in lung cancers. Growth factor receptors (including EGFR) are known to interact with extracellular matrix (ECM) proteins, which regulate their activation and function. Fibulin-1 (FBLN1) is a major component of the ECM in lung tissue, and its levels are known to be downregulated in non-small cell lung cancers (NSCLC). To test the possible role FBLN1 isoforms could have in regulating EGFR signaling and function in lung cancer, we performed siRNA mediated knockdown of FBLN1C and FBLN1D in NSCLC Calu-1 cells. Their loss significantly increased basal (with serum) and EGF (Epidermal Growth Factor) mediated EGFR activation without affecting net EGFR levels. Overexpression of FBLN1C and FBLN1D also inhibits EGFR activation confirming their regulatory crosstalk. Loss of FBLN1C and FBLN1D promotes EGFR-dependent cell migration, inhibited upon Erlotinib treatment. Mechanistically, both FBLN1 isoforms interact with EGFR, their association not dependent on its activation. Notably, cell-derived matrix (CDM) enriched FBLN1 binds EGFR. Calu-1 cells plated on CDM derived from FBLN1C and FBLN1D knockdown cells show a significant increase in EGF mediated EGFR activation. This promotes cell adhesion and spreading with active EGFR enriched at membrane ruffles. Both adhesion and spreading on CDMs is significantly reduced by Erlotinib treatment. Together, these findings show FBLN1C/1D, as part of the ECM, can bind and regulate EGFR activation and function in NSCLC Calu-1 cells. They further highlight the role tumor ECM composition could have in influencing EGFR dependent lung cancers.

EFEMP2 Suppresses the Invasion of Lung Cancer Cells by Inhibiting Epithelial-Mesenchymal Transition (EMT) and Down-Regulating MMPs

Background

Epidermal growth factor-containing fibulin-like extracellular matrix protein 2 (EFEMP2), also known as fibulin-4, MBP1 and UPH1, is an extracellular matrix protein associated with a variety of tumors. The purpose of this study was to investigate the prognostic value and the function of EFEMP2 in lung cancer.

Methods

The mRNA and protein expression of EFEMP2 in lung normal and cancer tissues, lung cancer cell lines (A549, H460, H1299 and H1650) and normal epithelial cell line BEAS-2B were evaluated by immunohistochemistry, RT-qPCR and Western blotting. The Public databases (Oncomine and Kaplan-Meier plotter) were used to investigate the prognostic value of EFEMP2 in lung cancer. RNA interference (RNAi) and overexpression transfection were performed to detect the effects of EFEMP2 up- or down-regulation on lung normal and cancer cell proliferation, invasion and metastasis in vitro and in vivo.

Results

EFEMP2 was lowly expressed in lung cancer tissues and cells, and its low expression was associated with malignant phenotype and poor prognosis of lung cancer. The same conclusion had been drawn from the Public databases. EFEMP2 overexpression significantly inhibited the invasion of lung cancer cells, hampered the process of EMT, and decreased the expression and activity of MMP2 and MMP9, while EFEMP2 knockdown remarkably enhanced the invasion of lung cancer cells, promoted EMT, and increased the expression and activity of MMP2 and MMP9.

Conclusion

The low expression of EFEMP2 was detected in lung cancer and was positively correlated with the poor prognosis of patients. EFEMP2 was a tumor suppressor gene that inhibited the progress of lung cancer, which suggested a new research objective for the future studies.

The spectraplakin Dystonin antagonizes YAP activity and suppresses tumourigenesis

Aberrant expression of the Spectraplakin Dystonin (DST) has been observed in various cancers, including those of the breast. However, little is known about its role in carcinogenesis. In this report, we demonstrate that Dystonin is a candidate tumour suppressor in breast cancer and provide an underlying molecular mechanism. We show that in MCF10A cells, Dystonin is necessary to restrain cell growth, anchorage-independent growth, self-renewal properties and resistance to doxorubicin. Strikingly, while Dystonin maintains focal adhesion integrity, promotes cell spreading and cell-substratum adhesion, it prevents Zyxin accumulation, stabilizes LATS and restricts YAP activation. Moreover, treating DST-depleted MCF10A cells with the YAP inhibitor Verteporfin prevents their growth. In vivo, the Drosophila Dystonin Short stop also restricts tissue growth by limiting Yorkie activity. As the two Dystonin isoforms BPAG1eA and BPAG1e are necessary to inhibit the acquisition of transformed features and are both downregulated in breast tumour samples and in MCF10A cells with conditional induction of the Src proto-oncogene, they could function as the predominant Dystonin tumour suppressor variants in breast epithelial cells. Thus, their loss could deem as promising prognostic biomarkers for breast cancer.

Radioimmunotherapy (RIT) in Brain Tumors

Annually, the incidence of brain tumors has slightly increased and also the patient prognosis is still disappointing, especially for high-grade neoplasms. So, researchers seek methods to improve therapeutic index as a critical aim of treatment. One of these new challenging methods is radioimmunotherapy (RIT) that involves recruiting a coupling of radionuclide component with monoclonal antibody (mAb) which are targeted against cell surface tumor-related antigens or antigens of cells within the tumor microenvironment. In the context of cancer care, precision medicine is exemplified by RIT; precision medicine can offer a tailored treatment to meet the needs for treatment of brain tumors. This review aims to discuss the molecular targets used in radioimmunotherapy of brain tumors, available and future radioimmunopharmaceutics, clinical trials of radioimmunotherapy in brain neoplasms, and eventually, conclusion and future perspective of application of radioimmunotherapy in neurooncology cancer care.

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.

Why are olfactory ensheathing cell tumors so rare?

The glial cells of the primary olfactory nervous system, olfactory ensheathing cells (OECs), are unusual in that they rarely form tumors. Only 11 cases, all of which were benign, have been reported to date. In fact, the existence of OEC tumors has been debated as the tumors closely resemble schwannomas (Schwann cell tumors), and there is no definite method for distinguishing the two tumor types. OEC transplantation is a promising therapeutic approach for nervous system injuries, and the fact that OECs are not prone to tumorigenesis is therefore vital. However, why OECs are so resistant to neoplastic transformation remains unknown. The primary olfactory nervous system is a highly dynamic region which continuously undergoes regeneration and neurogenesis throughout life. OECs have key roles in this process, providing structural and neurotrophic support as well as phagocytosing the axonal debris resulting from turnover of neurons. The olfactory mucosa and underlying tissue is also frequently exposed to infectious agents, and OECs have key innate immune roles preventing microbes from invading the central nervous system. It is possible that the unique biological functions of OECs, as well as the dynamic nature of the primary olfactory nervous system, relate to the low incidence of OEC tumors. Here, we summarize the known case reports of OEC tumors, discuss the difficulties of correctly diagnosing them, and examine the possible reasons for their rare incidence. Understanding why OECs rarely form tumors may open avenues for new strategies to combat tumorigenesis in other regions of the nervous system.

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.

Bioinformatics analysis of microarray data to identify the candidate biomarkers of lung adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is the major subtype of lung cancer and the most lethal malignant disease worldwide. However, the molecular mechanisms underlying LUAD are not fully understood.

Methods

Four datasets (GSE118370, GSE85841, GSE43458 and GSE32863) were obtained from the gene expression omnibus (GEO). Identification of differentially expressed genes (DEGs) and functional enrichment analysis were performed using the limma and clusterProfiler packages, respectively. A protein–protein interaction (PPI) network was constructed via Search Tool for the Retrieval of Interacting Genes (STRING) database, and the module analysis was performed by Cytoscape. Then, overall survival analysis was performed using the Kaplan–Meier curve, and prognostic candidate biomarkers were further analyzed using the Oncomine database.

Results

Totally, 349 DEGs were identified, including 275 downregulated and 74 upregulated genes which were significantly enriched in the biological process of extracellular structure organization, leukocyte migration and response to peptide. The mainly enriched pathways were complement and coagulation cascades, malaria and prion diseases. By extracting key modules from the PPI network, 11 hub genes were screened out. Survival analysis showed that except VSIG4, other hub genes may be involved in the development of LUAD, in which MYH10, METTL7A, FCER1G and TMOD1 have not been reported previously to correlated with LUAD. Briefly, novel hub genes identified in this study will help to deepen our understanding of the molecular mechanisms of LUAD carcinogenesis and progression, and to discover candidate targets for early detection and treatment of LUAD.

Fibulin-7 is overexpressed in glioblastomas and modulates glioblastoma neovascularization through interaction with angiopoietin-1

Glioblastoma (GBM) is pathologically characterized by highly malignant neoplastic cells, focal necrosis and aberrant blood vessels composed of disorganized endothelial cells and pericytes. The recent cancer microarray database revealed upregulation of fibulin-7 (Fbln7), a member of the fibulin family, but provided no information on the tissue localization or biological function. In the present study, we demonstrated that Fbln7 is markedly overexpressed by the GBM tissue among astrocytic tumors, and immunolocalized mainly to endothelial cells and pericytes of the glomeruloid and hypertrophied microvessels. The production of Fbln7 by endothelial cells and pericytes was confirmed in cultured human umbilical vein endothelial cells (HUVEC) and human brain vascular pericytes (HBVP) and vascular endothelial growth factor (VEGF) stimulated the Fbln7 expression in HUVEC. Fbln7 bound to angiopoietin-1, but not angiopoietin-2 or Tie2 receptor, through interaction between the N-terminal portions of Fbln7 and angiopoietin-1, and it blocked phosphorylation of Tie2 receptor in HUVEC. In a coculture assay using HUVEC and HBVP, multilayered and irregular-shaped tube-like structures of HUVEC were induced by treatment with a high concentration of VEGF. This was accompanied by Fbln7 overproduction by HUVEC and angiopoietin-1 expression by HBVP. The production of aberrant VEGF-induced tube-like structures was attenuated by treatment with antibody or synthetic peptides specific to the Fbln7 N-terminal domain or knockdown of Fbln7. These data demonstrate that Fbln7 is overexpressed by endothelial cells and pericytes of the abnormal microvessels in GBM, and suggest that Fbln7 may contribute to the aberrant vessel formation by modulation of the angiopoietin-1/angiopoietin-2-Tie2 axis.

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.

The associations between common SNPs of EFEMP1 gene and glioma risk in Chinese population

Background

Although the associations between common single nucleotide polymorphisms (SNPs) of EFEMP1 gene and glioma risk have been investigated in Chinese population-based case–control studies, investigation results for several SNPs are inconsistent. In addition, the single-center study has a poor statistical power due to finite sample size. Therefore, a meta-analysis was conducted to comprehensively determine the associations.

Methods

All eligible case–control studies were obtained by searching PubMed, EMBASE, Web of Science, and Chinese National Knowledge Infrastructure. Pooled odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of the associations in fixed- or random-effects model.

Results

EFEMP1 rs1346787 polymorphism was significantly associated with glioma risk in Chinese population under all genetic models (GG vs AA, OR =2.22, 95% CI =1.46–3.36; AG vs AA, OR =1.54, 95% CI =1.27–1.87; (GG+AG) vs AA, OR =1.60, 95% CI =1.34–1.93; GG vs (AG+AA), OR =1.86, 95% CI =1.24–2.78; G vs A, OR =1.54, 95% CI =1.32–1.79). However, the significant association of EFEMP1 rs1346786 with glioma risk in Chinese population was observed only under heterozygous model of AG vs AA (OR =1.34, 95% CI =1.10–1.62), dominant model of (GG+AG) vs AA (OR =1.36, 95% CI =1.13–1.63), and allelic model of G vs A (OR =1.28, 95% CI =1.10–1.50).

Conclusion

Our study demonstrated that EFEMP1 polymorphisms, especially rs1346787 and rs1346786, might predict glioma risk in Chinese population. However, high-quality case–control studies with larger sample sizes are warranted to confirm the above-mentioned findings.

Development of a Function-Blocking Antibody Against Fibulin-3 as a Targeted Reagent for Glioblastoma

Purpose: We sought a novel approach against glioblastomas (GBM) focused on targeting signaling molecules localized in the tumor extracellular matrix (ECM). We investigated fibulin-3, a glycoprotein that forms the ECM scaffold of GBMs and promotes tumor progression by driving Notch and NFκB signaling.Experimental Design: We used deletion constructs to identify a key signaling motif of fibulin-3. An mAb (mAb428.2) was generated against this epitope and extensively validated for specific detection of human fibulin-3. mAb428.2 was tested in cultures to measure its inhibitory effect on fibulin-3 signaling. Nude mice carrying subcutaneous and intracranial GBM xenografts were treated with the maximum achievable dose of mAb428.2 to measure target engagement and antitumor efficacy.Results: We identified a critical 23-amino acid sequence of fibulin-3 that activates its signaling mechanisms. mAb428.2 binds to that epitope with nanomolar affinity and blocks the ability of fibulin-3 to activate ADAM17, Notch, and NFκB signaling in GBM cells. mAb428.2 treatment of subcutaneous GBM xenografts inhibited fibulin-3, increased tumor cell apoptosis, and enhanced the infiltration of inflammatory macrophages. The antibody reduced tumor growth and extended survival of mice carrying GBMs as well as other fibulin-3-expressing tumors. Locally infused mAb428.2 showed efficacy against intracranial GBMs, increasing tumor apoptosis and reducing tumor invasion and vascularization, which are enhanced by fibulin-3.Conclusions: To our knowledge, this is the first rationally developed, function-blocking antibody against an ECM target in GBM. Our results offer a proof of principle for using "anti-ECM" strategies toward more efficient targeted therapies for malignant glioma. Clin Cancer Res; 24(4); 821-33. ©2017 AACR.

Biomarkers in mesothelioma

Mesothelioma is an aggressive cancer of pleural and peritoneal cells that is difficult to diagnose and monitor. Numerous studies have attempted to identify a blood- or pleural fluid-based biomarker that could be used in the diagnostic pathway. More recently, there has been interest in the ability of serum/plasma biomarkers to monitor mesothelioma, given the development of newer treatments and limitations of radiological assessment. The majority of research has focused on soluble mesothelin, a soluble glycoprotein expressed by mesothelial cells. Although soluble mesothelin lacks the sensitivity to be used as a standalone diagnostic marker, serial measurements may be informative, with rising concentrations indicating disease progression and poor survival. High concentrations of other soluble glycoproteins, such as osteopontin, fibulin-3 and vascular endothelial growth factor are independently associated with poor prognosis at baseline, although further research is required to ascertain any role outside of clinical trials. More recent literature has focused on the development of novel biomarkers from discovery cohorts. Although many DNA and mRNA biomarkers show promise in the diagnosis or screening of mesothelioma, none have been prospectively evaluated for use in clinical practice. In this review article, we highlight the potential utility of biomarkers and evaluate the existing literature.

Impact of mesenchymal stem cells' secretome on glioblastoma pathophysiology

Background

Glioblastoma (GBM) is a highly aggressive primary brain cancer, for which curative therapies are not available. An emerging therapeutic approach suggested to have potential to target malignant gliomas has been based on the use of multipotent mesenchymal stem cells (MSCs), either unmodified or engineered to deliver anticancer therapeutic agents, as these cells present an intrinsic capacity to migrate towards malignant tumors. Nevertheless, it is still controversial whether this innate tropism of MSCs towards the tumor area is associated with cancer promotion or suppression. Considering that one of the major mechanisms by which MSCs interact with and modulate tumor cells is via secreted factors, we studied how the secretome of MSCs modulates critical hallmark features of GBM cells.

Methods

The effect of conditioned media (CM) from human umbilical cord perivascular cells (HUCPVCs, a MSC population present in the Wharton’s jelly of the umbilical cord) on GBM cell viability, migration, proliferation and sensitivity to temozolomide treatment of U251 and SNB-19 GBM cells was evaluated. The in vivo chicken chorioallantoic membrane (CAM) assay was used to evaluate the effect of HUCPVCs CM on tumor growth and angiogenesis. The secretome of HUCPVCs was characterized by proteomic analyses.

Results

We found that both tested GBM cell lines exposed to HUCPVCs CM presented significantly higher cellular viability, proliferation and migration. In contrast, resistance of GBM cells to temozolomide chemotherapy was not significantly affected by HUCPVCs CM. In the in vivo CAM assay, CM from HUCPVCs promoted U251 and SNB-19 tumor cells growth. Proteomic analysis to characterize the secretome of HUCPVCs identified several proteins involved in promotion of cell survival, proliferation and migration, revealing novel putative molecular mediators for the effects observed in GBM cells exposed to HUCPVCs CM.

Conclusions

These findings provide novel insights to better understand the interplay between GBM cells and MSCs, raising awareness to potential safety issues regarding the use of MSCs as stem-cell based therapies for GBM.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1303-8) contains supplementary material, which is available to authorized users.

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.

Drusen in patient-derived hiPSC-RPE models of macular dystrophies

Age-related macular degeneration (AMD) and related macular dystrophies (MDs) are a major cause of vision loss. However, the mechanisms underlying their progression remain ill-defined. This is partly due to the lack of disease models recapitulating the human pathology. Furthermore, in vivo studies have yielded limited understanding of the role of specific cell types in the eye vs. systemic influences (e.g., serum) on the disease pathology. Here, we use human induced pluripotent stem cell-retinal pigment epithelium (hiPSC-RPE) derived from patients with three dominant MDs, Sorsby's fundus dystrophy (SFD), Doyne honeycomb retinal dystrophy/malattia Leventinese (DHRD), and autosomal dominant radial drusen (ADRD), and demonstrate that dysfunction of RPE cells alone is sufficient for the initiation of sub-RPE lipoproteinaceous deposit (drusen) formation and extracellular matrix (ECM) alteration in these diseases. Consistent with clinical studies, sub-RPE basal deposits were present beneath both control (unaffected) and patient hiPSC-RPE cells. Importantly basal deposits in patient hiPSC-RPE cultures were more abundant and displayed a lipid- and protein-rich "drusen-like" composition. Furthermore, increased accumulation of COL4 was observed in ECM isolated from control vs. patient hiPSC-RPE cultures. Interestingly, RPE-specific up-regulation in the expression of several complement genes was also seen in patient hiPSC-RPE cultures of all three MDs (SFD, DHRD, and ADRD). Finally, although serum exposure was not necessary for drusen formation, COL4 accumulation in ECM, and complement pathway gene alteration, it impacted the composition of drusen-like deposits in patient hiPSC-RPE cultures. Together, the drusen model(s) of MDs described here provide fundamental insights into the unique biology of maculopathies affecting the RPE-ECM interface.

Transcriptome analysis of PDGFRα+ cells identifies T-type Ca2+ channel CACNA1G as a new pathological marker for PDGFRα+ cell hyperplasia

Platelet-derived growth factor receptor alpha (PDGFRα)+ cells are distributed into distinct morphological groups within the serosal, muscular, and submucosal layers as well as the myenteric and deep muscular plexi. PDGFRα+ cells directly interact with interstitial cells of Cajal (ICC) and smooth muscle cells (SMC) in gastrointestinal smooth muscle tissue. These three cell types, SMC, ICC, and PDGFRα+ cells (SIP cells), form an electrical syncytium, which dynamically regulates gastrointestinal motility. We have previously reported the transcriptomes of SMC and ICC. To complete the SIP cell transcriptome project, we obtained transcriptome data from jejunal and colonic PDGFRα+ cells. The PDGFRα+ cell transcriptome data were added to the Smooth Muscle Genome Browser that we previously built for the genome-scale gene expression data of ICC and SMC. This browser provides a comprehensive reference for all transcripts expressed in SIP cells. By analyzing the transcriptomes, we have identified a unique set of PDGFRα+ cell signature genes, growth factors, transcription factors, epigenetic enzymes/regulators, receptors, protein kinases/phosphatases, and ion channels/transporters. We demonstrated that the low voltage-dependent T-type Ca2+ channel Cacna1g gene was particularly expressed in PDGFRα+ cells in the intestinal serosal layer in mice. Expression of this gene was significantly induced in the hyperplasic PDGFRα+ cells of obstructed small intestine in mice. This gene was also over-expressed in colorectal cancer, Crohn's disease, and diverticulitis in human patients. Taken together, our data suggest that Cacna1g exclusively expressed in serosal PDGFRα+ cells is a new pathological marker for gastrointestinal diseases.

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.

TWEAK promotes migration and invasion in MEFs through a mechanism dependent on ERKs activation and Fibulin 3 down-regulation

TWEAK regulates multiple physio-pathological processes in fibroblasts such as fibrosis. It also induces migration and invasion in tumors and it can activate p38 MAPK in various cell types. Moreover, p38α MAPK promotes migration and invasion in several cancer cells types and in mouse embryonic fibroblasts (MEFs). However, it remains unknown if TWEAK could promote migration in fibroblasts and whether p38α MAPK might play a role. Our results reveal that TWEAK activates ERKs, Akt, and p38α/β MAPKs and reduces secreted Fibulin 3 in MEFs. TWEAK also increases migration and invasion in wt and p38α deficient MEFs, which indicates that p38α MAPK is not required to mediate these effects. In contrast, ERKs inhibition significantly decreases TWEAK-induced migration and Fibulin 3 knock-down mimics TWEAK effect. These results indicate that both ERKs activation and Fibulin 3 down-regulation would contribute to mediate TWEAK pro-migratory effect. In fact, the additional regulation of ERKs and/or p38β as a consequence of Fibulin 3 decrease might be also involved in the pro-migratory effect of TWEAK in MEFs. In conclusion, our studies uncover novel mechanisms by which TWEAK would favor tissue repair by promoting fibroblasts migration.

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.