Fibronectin Mechanobiology Regulates Tumorigenesis

Construction of an Exudative Age-Related Macular Degeneration Diagnostic and Therapeutic Molecular Network Using Multi-Layer Network Analysis, a Fuzzy Logic Model, and Deep Learning Techniques: Are Retinal and Brain Neurodegenerative Disorders Related?

Neovascular age-related macular degeneration (nAMD) is a leading cause of irreversible visual impairment in the elderly. The current management of nAMD is limited and involves regular intravitreal administration of anti-vascular endothelial growth factor (anti-VEGF). However, the effectiveness of these treatments is limited by overlapping and compensatory pathways leading to unresponsiveness to anti-VEGF treatments in a significant portion of nAMD patients. Therefore, a system view of pathways involved in pathophysiology of nAMD will have significant clinical value. The aim of this study was to identify proteins, miRNAs, long non-coding RNAs (lncRNAs), various metabolites, and single-nucleotide polymorphisms (SNPs) with a significant role in the pathogenesis of nAMD. To accomplish this goal, we conducted a multi-layer network analysis, which identified 30 key genes, six miRNAs, and four lncRNAs. We also found three key metabolites that are common with AMD, Alzheimer's disease (AD) and schizophrenia. Moreover, we identified nine key SNPs and their related genes that are common among AMD, AD, schizophrenia, multiple sclerosis (MS), and Parkinson's disease (PD). Thus, our findings suggest that there exists a connection between nAMD and the aforementioned neurodegenerative disorders. In addition, our study also demonstrates the effectiveness of using artificial intelligence, specifically the LSTM network, a fuzzy logic model, and genetic algorithms, to identify important metabolites in complex metabolic pathways to open new avenues for the design and/or repurposing of drugs for nAMD treatment.

Cerebrospinal fluid exosomal protein alterations via proteomic analysis of NSCLC with leptomeningeal carcinomatosis

PURPOSE

Leptomeningeal carcinomatosis (LC) is a rare complication of non-small cell lung cancer (NSCLC) with highly mortality. Cerebrospinal fluid (CSF) as a special kind of tumor microenvironment (TME) better represents alterations than plasma. However, the clinical value of protein profiles of exosome in CSF as liquid biopsy remains unclear.

METHODS

In this study, CSF samples of NSCLC patients with (LC group) or without (NSCLC group) LC were collected and compared to patients without tumors (normal group). CSF exosomes were isolated by ultracentrifugation and protein profiles were performed by label-free proteomics. Differentially expressed proteins (DEPs) were detected by bioinformatics tools and verified by parallel reaction monitoring (PRM).

RESULTS

A total of 814 proteins were detected. Bioinformatics analysis revealed their shared function in the complement activation, extracellular region, and complement and coagulation cascades. Between LC and NSCLC group, 72 DEPs were found among which FN1 demonstrated the highest betweenness centrality (BC) after protein-protein interaction network analysis.

CONCLUSION

We investigated the application of label free and PRM based proteomics to detect key proteins related to LC. FN1 may serve as potential indicator to classify LC and NSCLC. Extracellular matrix (ECM) and epithelial-mesenchymal transition (EMT) are important in the process of LC. These data is promising for early prediction and diagnosis of LC.

ADAMTS5 promotes neovascularization via autophagic degradation of PEDF in proliferative diabetic retinopathy

Proliferative diabetic retinopathy (PDR) adversely affects visual function. Extracellular matrix proteins (ECM) contribute significantly to the development of PDR. A Disintegrin and Metalloproteinase with Thrombospondin motifs 5 (ADAMTS5) is a member of ECM proteins. ADAMTS5 participates in angiogenesis and inflammation in diverse diseases. However, the role of ADAMTS5 in PDR remains elusive. Multiplex beam array technology was used to analyze vitreous humor of PDR patients and normal people. ELISA and Western blot were used to detect the expression of ADAMTS5, PEDF and autophagy related factors. Immunofluorescence assay was used to mark the expression and localization of ADAMTS5 and PEDF. The neovascularization was detected by tube formation test. Our results revealed that ADAMTS5 expression was increased in the vitreous humor of PDR patients and oxygen-induced retinopathy (OIR) mice retinas. Inhibiting ADAMTS5 alleviated pathological angiogenesis and upregulated PEDF expression in the OIR mice. In addition, ADAMTS5 inhibited PEDF secretion in ARPE-19 cells in vitro studies, thereby inhibiting the migration of HMEC-1. Mechanically, ADAMTS5 promoted the autophagic degradation of PEDF. Collectively, inhibition of ADAMTS5 during OIR suppresses pathological angiogenesis. Our study provides a new approach for resolving pathological angiogenesis in PDR.

Breast Cancers Secreting Sialyl-fibronectin Are Less Likely to Cause Epithelial-mesenchymal Transition and Have Good Prognoses

Background/Aim

Elevated blood fibronectin (FN) levels have been observed in various cancers; however, their significance is controversial. We measured sialyl-fibronectin (S-FN), a type of FN secreted by tumor cells in the blood, and investigated whether blood S-FN secretion is associated with cancer malignancy and recurrent metastases.

Materials and Methods

We constructed an enzyme-linked immunosorbent assay (ELISA) system that recognizes S-FN as an antigen and measured the amount of S-FN secreted into the blood of 89 patients with breast tumors. The relationship between S-FN secretion and prognostic predictors was analyzed. Immunostaining was performed to identify the site of S-FN secretion in the breast tissue.

Results

Among the 82 patients, 21 (25.6%, 21/82) and 61 (74.4%, 61/82) were blood S-FN-positive and S-FN-negative, respectively. Regarding prognostic predictors, blood S-FN-positive and S-FN-negative patients showed significant difference in locoregional recurrence (p=0.026), remote metastases (p=0.049), and histological margins (p=0.001). Locoregional recurrence was associated with positive histological margins in S-FN-positive patients. However, remote metastases were associated with N-factor and histological classification (HC) in S-FN-negative patients. Furthermore, S-FN particles were detected in the cytoplasm of breast cancer cells through immunostaining. After the onset of recurrent metastases, two S-FN-positive and six S-FN-negative patients received anticancer drug treatment; however, further progression was observed in five S-FN-negative patients.

Conclusion

S-FN-positive patients are less likely to develop distant metastases, have a better prognosis, and may be less resistant to therapeutic agents than S-FN-negative patients, which contain many epithelial-mesenchymal transition cells.

The extracellular matrix protein pattern in the canine neoplastic mammary gland

Extracellular matrix (ECM) proteins in the mammary gland provide structure and regulate its development and homeostasis. Alterations in its structure can regulate and support pathogenesis, like breast tumors. Aiming to identify the health and tumoral canine mammary ECM scaffold protein profile by immunohistochemistry, the decellularization process was carried out to remove the cellular content. Additionally, it was verified the influence of health and tumoral ECM on the attachment of health and tumoral cells. The types I, III, IV, and V structural collagens were scarce in the mammary tumor, and ECM fibers were disorganized. Vimentin and CD44 were more common in mammary tumor stroma, suggesting a role in cell migration that results in tumor progression. Elastin, fibronectin, laminin, vitronectin, and osteopontin were similarly detected under healthy and tumor conditions, providing the attachment of normal cells in healthy ECM, while tumoral cells were able to attach in tumoral ECM. The protein pattern demonstrates ECM alteration in canine mammary tumorigenesis, presenting new knowledge on mammary tumor ECM microenvironment.

Polymer Thin Film Promotes Tumor Spheroid Formation via JAK2-STAT3 Signaling Primed by Fibronectin-Integrin α5 and Sustained by LMO2-LDB1 Complex

Cancer stem-like cells (CSCs) are considered promising targets for anti-cancer therapy owing to their role in tumor progression. Extensive research is, therefore, being carried out on CSCs to identify potential targets for anti-cancer therapy. However, this requires the availability of patient-derived CSCs ex vivo, which remains restricted due to the low availability and diversity of CSCs. To address this limitation, a functional polymer thin-film (PTF) platform was invented to induce the transformation of cancer cells into tumorigenic spheroids. In this study, we demonstrated the functionality of a new PTF, polymer X, using a streamlined production process. Polymer X induced the formation of tumor spheroids with properties of CSCs, as revealed through the upregulated expression of CSC-related genes. Signal transducer and activator of transcription 3 (STAT3) phosphorylation in the cancer cells cultured on polymer X was upregulated by the fibronectin-integrin α5-Janus kinase 2 (JAK2) axis and maintained by the cytosolic LMO2/LBD1 complex. In addition, STAT3 signaling was critical in spheroid formation on polymer X. Our PTF platform allows the efficient generation of tumor spheroids from cancer cells, thereby overcoming the existing limitations of cancer research.

Targeted Contrast Agents for Magnetic Resonance Molecular Imaging of Cancer

Magnetic resonance imaging (MRI) is a clinical imaging modality that provides high-resolution images of soft tissues, including cancerous lesions. Stable gadolinium(III) chelates have been used as contrast agents (CA) in MRI to enhance the contrast between the tissues of interest and surrounding tissues for accurate diagnostic imaging. Magnetic resonance molecular imaging (MRMI) of cancer requires targeted CA to specifically elucidate cancer-associated molecular processes and can provide high-resolution delineation and characterization of cancer for precision medicine. The main challenge for MRMI is the lack of sufficient sensitivity to detect the low concentration of the cellular oncogenic markers. In addition, targeted CA must satisfy regulatory safety requirements prior to clinical development. Up to now, there is no FDA-approved targeted CA for MRMI of cancer.In this Account, we discuss the latest developments in the design and development of clinically translatable targeted CA for MRMI of cancer, with an emphasis on our own research. The primary limitation of MRMI can be overcome by designing small molecular targeted CA to target abundant cancer-specific targets found in the tumor microenvironment (TME). For example, aggressive tumors have a unique extracellular matrix (ECM) composed of oncoproteins, which can be used as targetable markers for MRMI. We have designed and prepared small peptide conjugates of clinical contrast agents, including Gd-DTPA and Gd-DOTA, to target fibrin-fibronectin clots in tumors. These small molecular CA have been effective in enhancing MRMI detection of solid tumors and have demonstrated the ability to detect submillimeter cancer micrometastases in mouse tumor models, exceeding the detection limit of current clinical imaging modalities. We have also identified extradomain B fibronectin (EDB-FN), an oncofetal subtype of fibronectin, as a promising TME target to leverage in the design and development of small peptide targeted CA for clinical translation. The expression level of EDB-FN is correlated with invasiveness of cancer cells and poor patient survival of multiple cancer types. ZD2 peptide with a sequence of seven amino acids (TVRTSAD) was identified to specifically bind to the EDB protein fragment. Several ZD2 conjugates of macrocyclic GBCA, including Gd-DOTA and Gd(HP-DO3A), have been synthesized and tested in mouse tumor models. ZD2-N3-Gd(HP-DO3A) (MT218) with a high r₁ relaxivity was selected as the lead agent for clinical translation. The physicochemical properties and preclinical assessments of MT218 are summarized in this Account. MRMI of EDB-FN with MT218 can effectively detect invasive tumors of multiple cancers with risk-stratification and monitor tumor response to anticancer therapies in mouse models. Currently, MT218 is in clinical trials for precision cancer MRMI. Herein, we will show that using targeted MRI contrast agents specific to abundant TME biomarkers is a pragmatic solution for effective precision cancer imaging in high spatial resolution. And thus, we illustrate a replicable approach for CA development that is vital for cancer MRMI.

Dissecting Tumor Growth: The Role of Cancer Stem Cells in Drug Resistance and Recurrence

Simple Summary

Cancer is one of the most debated problems all over the world. Cancer stem cells are considered responsible of tumor initiation, metastasis, drug resistance, and recurrence. This subpopulation of cells has been found into the tumor bulk and showed the capacity to self-renew, differentiate, up to generate a new tumor. In the last decades, several studies have been set on the molecular mechanisms behind their specific characteristics as the Wnt/β-catenin signaling, Notch signaling, Hedgehog signaling, transcription factors, etc. The most powerful part of CSCs is represented by the niches as “promoter” of their self-renewal and “protector” from the common oncological treatment as chemotherapy and radiotherapy. In our review article we highlighted the primary mechanisms involved in CSC tumorigenesis for the setting of further targets to control the metastatic process.

Abstract

Emerging evidence suggests that a small subpopulation of cancer stem cells (CSCs) is responsible for initiation, progression, and metastasis cascade in tumors. CSCs share characteristics with normal stem cells, i.e., self-renewal and differentiation potential, suggesting that they can drive cancer progression. Consequently, targeting CSCs to prevent tumor growth or regrowth might offer a chance to lead the fight against cancer. CSCs create their niche, a specific area within tissue with a unique microenvironment that sustains their vital functions. Interactions between CSCs and their niches play a critical role in regulating CSCs’ self-renewal and tumorigenesis. Differences observed in the frequency of CSCs, due to the phenotypic plasticity of many cancer cells, remain a challenge in cancer therapeutics, since CSCs can modulate their transcriptional activities into a more stem-like state to protect themselves from destruction. This plasticity represents an essential step for future therapeutic approaches. Regarding self-renewal, CSCs are modulated by the same molecular pathways found in normal stem cells, such as Wnt/β-catenin signaling, Notch signaling, and Hedgehog signaling. Another key characteristic of CSCs is their resistance to standard chemotherapy and radiotherapy treatments, due to their capacity to rest in a quiescent state. This review will analyze the primary mechanisms involved in CSC tumorigenesis, with particular attention to the roles of CSCs in tumor progression in benign and malignant diseases; and will examine future perspectives on the identification of new markers to better control tumorigenesis, as well as dissecting the metastasis process.

Hexokinases 2 promoted cell motility and distant metastasis by elevating fibronectin through Akt1/p-Akt1 in cervical cancer cells

Background

Hexokinases 2 (HK2) is a member of the hexokinases, linking with malignant tumor growth and distant metastasis. However, evidence regarding the potential role of HK2 in regulating cell motility and tumor metastasis during the cervical cancer malignant progression remains limited.

Methods

In vitro migration and invasion assay, in vivo metastasis experiments were performed to detect the effective of HK2 on regulating cell motility and tumor metastasis in cervical cancer cells. RNA-Seq was performed to explore the potential molecules that participate in HK2-mediated cell motility and tumor metastasis in cervical cancer cells. The correlation between HK2 and Akt1, p-Akt1, FN1 expression in cervical cancer cells and human squamous cervical carcinoma (SCC) samples was verified in this study.

Results

In this study, cervical cancer cells with exogenous HK2 expression exhibited enhanced cell motility and distant metastasis. Transcriptome sequencing analysis revealed that fibronectin (FN1) was significantly increased in HK2-overexpressing HeLa cells, and the PI3K/Akt signaling pathway was identified by KEGG pathway enrichment analysis. Further studies demonstrated that this promotion of cell motility by HK2 was probably a result of it inducing FN1, MMP2 and MMP9 expression by activating Akt1 in cervical cancer cells. Additionally, HK2 expression was altered with the changing of Akt1/p-Akt1 expression, implying that HK2 expression is also modulated by Akt1/p-Akt1. Moreover, the positive correlation between HK2 and Akt1, p-Akt1, FN1 expression in human squamous cervical carcinoma (SCC) samples was verified by using Pearson correlation analysis.

Conclusions

This study demonstrated that HK2 could activate Akt1 in cervical cancer cells, subsequently enhancing cell motility and tumor metastasis by inducing FN1, MMP2 and MMP9 expression. There likely exists an interactive regulatory mechanism between HK2 and Akt1 during the malignant process of cervical cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02312-0.

Normalization in tumor ecosystem: Opportunities and challenges

Current research in cancer therapy aims to exploit efficient strategies to have long-lasting effects on tumors and to reduce or even revoke the chance of recurrence. Within the tumor stroma, O₂ and nutrients are abnormally distributed between various cells (preferentially for supplying cancer cells), the immune contexture is abnormally positioned (permissive essentially for cells exhibiting tumor-promoting capacity), the fibroblast and fibrotic content is abnormally distributed (presence of both extracellular matrix [ECM] stiffening and ECM-degrading factors both for tumor-promoting purposes), and the tumor vasculature is abnormally orchestrated (for hindering drug delivery and increasing the chance of tumor metastasis). Resistance is actually an adaptive response to an imbalance in the tumor ecosystem; thus, the key consideration for effective cancer therapy is to bring back the normal status in this ecosystem so as to reach the desired durable outcome. Vascular normalization, metabolic modulation (glucose delivery in particular), balancing cellular dispersion, and balancing the pH rate and O₂ delivery within the tumor microenvironment are suggested strategies to reverse abnormality within the tumor stroma.

The role of physical cues in the development of stem cell-derived organoids

Organoids are a novel three-dimensional stem cells’ culture system that allows the in vitro recapitulation of organs/tissues structure complexity. Pluripotent and adult stem cells are included in a peculiar microenvironment consisting of a supporting structure (an extracellular matrix (ECM)-like component) and a cocktail of soluble bioactive molecules that, together, mimic the stem cell niche organization. It is noteworthy that the balance of all microenvironmental components is the most critical step for obtaining the successful development of an accurate organoid instead of an organoid with heterogeneous morphology, size, and cellular composition. Within this system, mechanical forces exerted on stem cells are collected by cellular proteins and transduced via mechanosensing—mechanotransduction mechanisms in biochemical signaling that dictate the stem cell specification process toward the formation of organoids. This review discusses the role of the environment in organoids formation and focuses on the effect of physical components on the developmental system. The work starts with a biological description of organoids and continues with the relevance of physical forces in the organoid environment formation. In this context, the methods used to generate organoids and some relevant published reports are discussed as examples showing the key role of mechanosensing–mechanotransduction mechanisms in stem cell-derived organoids.

Hold on or Cut? Integrin- and MMP-Mediated Cell-Matrix Interactions in the Tumor Microenvironment

The tumor microenvironment (TME) has become the focus of interest in cancer research and treatment. It includes the extracellular matrix (ECM) and ECM-modifying enzymes that are secreted by cancer and neighboring cells. The ECM serves both to anchor the tumor cells embedded in it and as a means of communication between the various cellular and non-cellular components of the TME. The cells of the TME modify their surrounding cancer-characteristic ECM. This in turn provides feedback to them via cellular receptors, thereby regulating, together with cytokines and exosomes, differentiation processes as well as tumor progression and spread. Matrix remodeling is accomplished by altering the repertoire of ECM components and by biophysical changes in stiffness and tension caused by ECM-crosslinking and ECM-degrading enzymes, in particular matrix metalloproteinases (MMPs). These can degrade ECM barriers or, by partial proteolysis, release soluble ECM fragments called matrikines, which influence cells inside and outside the TME. This review examines the changes in the ECM of the TME and the interaction between cells and the ECM, with a particular focus on MMPs.

Circulating Tumor Cell Migration Requires Fibronectin Acting through Integrin B1 or SLUG

Fibronectin (FN1) is an extracellular matrix protein gaining increasing attention for its multifaceted roles in cancer progression. Using our recently established circulating tumor cell (CTC) lines, we had demonstrated increased FN1 expression and enhanced migration in CTC lines, in comparison to primary tumor cell lines. Whether increased FN1 expression is directly required for CTC migration, and the specific role of FN1’s regulation of integrin B1 (ITGB1) and SLUG (SNAI2) in CTC migration remains unclear. Here, for the first time, we report that the knockdown of FN1, ITGB1, or SLUG expression in CTCs leads to a significant decrease in CTC migration. Knocking down two or all three of these proteins simultaneously did not further inhibit migration. We observed a corresponding increase in CTC migration when recombinant FN1 was added to CTCs. This effect was significantly impeded by prior knockdown of ITGB1 or SLUG. Using knock down experiments and western blotting analysis, we confirmed FN1’s regulation of ITGB1 and SLUG to occur via two separate, independent pathways. Consequently, we can conclude that FN1-dependent enhanced migration of CTCs requires downstream signaling through either ITGB1 or SLUG and that FN1 regulation of ITGB1 and SLUG may have important implications for cancer progression and metastasis.

Index of Cancer-Associated Fibroblasts Is Superior to the Epithelial-Mesenchymal Transition Score in Prognosis Prediction

In many solid tumors, tissue of the mesenchymal subtype is frequently associated with epithelial–mesenchymal transition (EMT), strong stromal infiltration, and poor prognosis. Emerging evidence from tumor ecosystem studies has revealed that the two main components of tumor stroma, namely, infiltrated immune cells and cancer-associated fibroblasts (CAFs), also express certain typical EMT genes and are not distinguishable from intrinsic tumor EMT, where bulk tissue is concerned. Transcriptomic analysis of xenograft tissues provides a unique advantage in dissecting genes of tumor (human) or stroma (murine) origins. By transcriptomic analysis of xenograft tissues, we found that oral squamous cell carcinoma (OSCC) tumor cells with a high EMT score, the computed mesenchymal likelihood based on the expression signature of canonical EMT markers, are associated with elevated stromal contents featured with fibronectin 1 (Fn1) and transforming growth factor-β (Tgfβ) axis gene expression. In conjugation with meta-analysis of these genes in clinical OSCC datasets, we further extracted a four-gene index, comprising FN1, TGFB2, TGFBR2, and TGFBI, as an indicator of CAF abundance. The CAF index is more powerful than the EMT score in predicting survival outcomes, not only for oral cancer but also for the cancer genome atlas (TCGA) pan-cancer cohort comprising 9356 patients from 32 cancer subtypes. Collectively, our results suggest that a further distinction and integration of the EMT score with the CAF index will enhance prognosis prediction, thus paving the way for curative medicine in clinical oncology.

The critical effects of matrices on cultured carcinoma cells: Human tumor-derived matrix promotes cell invasive properties

The interaction between squamous cell carcinoma (SCC) cells and the tumor microenvironment (TME) plays a major role in cancer progression. Therefore, understanding the TME is essential for the development of cancer therapies. We used four (primary and metastatic) head and neck (HN) SCC cell lines and cultured them on top of or within 5 matrices (mouse sarcoma-derived Matrigel®, rat collagen, human leiomyoma-derived Myogel, human fibronectin and human fibrin). We performed several assays to study the effects of these matrices on the HNSCC behavior, such as proliferation, migration, and invasion, as well as cell morphology, and molecular gene profile. Carcinoma cells exhibited different growth patterns depending on the matrix. While fibrin enhanced the proliferation of all the cell lines, collagen did not. The effects of the matrices on cancer cell migration were cell line dependent. Carcinoma cells in Myogel-collagen invaded faster in scratch wound invasion assay. On the other hand, in the spheroid invasion assay, three out of four cell lines invaded faster in Myogel-fibrin. These matrices significantly affected hundreds of genes and a number of pathways, but the effects were cell line dependent. The matrix type played a major role in HNSCC cell phenotype. The effects of the ECMs were either constant, or cell line dependent. Based on these results, we suggest to select the most suitable matrix, which provides the closest condition to the in vivo TME, in order to get reliable results in in vitro experiments.

Fibronectin in Cancer: Friend or Foe

The role of fibronectin (FN) in tumorigenesis and malignant progression has been highly controversial. Cancerous FN plays a tumor-suppressive role, whereas it is pro-metastatic and associated with poor prognosis. Interestingly, FN matrix deposited in the tumor microenvironments (TMEs) promotes tumor progression but is paradoxically related to a better prognosis. Here, we justify how FN impacts tumor transformation and subsequently metastatic progression. Next, we try to reconcile and rationalize the seemingly conflicting roles of FN in cancer and TMEs. Finally, we propose future perspectives for potential FN-based therapeutic strategies.

Replication Study: Biomechanical remodeling of the microenvironment by stromal caveolin-1 favors tumor invasion and metastasis

As part of the Reproducibility Project: Cancer Biology we published a Registered Report (Fiering et al., 2015) that described how we intended to replicate selected experiments from the paper 'Biomechanical remodeling of the microenvironment by stromal caveolin-1 favors tumor invasion and metastasis' (Goetz et al., 2011). Here we report the results. Primary mouse embryonic fibroblasts (pMEFs) expressing caveolin 1 (Cav1WT) demonstrated increased extracellular matrix remodeling in vitro compared to Cav1 deficient (Cav1KO) pMEFs, similar to the original study (Goetz et al., 2011). In vivo, we found higher levels of intratumoral stroma remodeling, determined by fibronectin fiber orientation, in tumors from cancer cells co-injected with Cav1WT pMEFs compared to cancer cells only or cancer cells plus Cav1KO pMEFs, which were in the same direction as the original study (Supplemental Figure S7C; Goetz et al., 2011), but not statistically significant. Primary tumor growth was similar between conditions, like the original study (Supplemental Figure S7Ca; Goetz et al., 2011). We found metastatic burden was similar between Cav1WT and Cav1KO pMEFs, while the original study found increased metastases with Cav1WT (Figure 7C; Goetz et al., 2011); however, the duration of our in vivo experiments (45 days) were much shorter than in the study by Goetz et al. (2011) (75 days). This makes it difficult to interpret the difference between the studies as it is possible that the cells required more time to manifest the difference between treatments observed by Goetz et al. We also found a statistically significant negative correlation of intratumoral remodeling with metastatic burden, while the original study found a statistically significant positive correlation (Figure 7Cd; Goetz et al., 2011), but again there were differences between the studies in terms of the duration of the metastasis studies and the imaging approaches that could have impacted the outcomes. Finally, we report meta-analyses for each result.

Tumour Initiation: a Discussion on Evidence for a "Load-Trigger" Mechanism

Appropriate mechanical forces on cells are vital for normal cell behaviour and this review discusses the possibility that tumour initiation depends partly on the disruption of the normal physical architecture of the extracellular matrix (ECM) around a cell. The alterations that occur thence promote oncogene expression. Some questions, that are not answered with certainty by current consensus mechanisms of tumourigenesis, are elegantly explained by the triggering of tumours being a property of the physical characteristics of the ECM, which is operative following loading of the tumour initiation process with a relevant gene variant. Clinical observations are consistent with this alternative hypothesis which is derived from studies that have, together, accumulated an extensive variety of data incorporating biochemical, genetic and clinical findings. Thus, this review provides support for the view that the ECM may have an executive function in induction of a tumour. Overall, reported observations suggest that either restoring an ECM associated with homeostasis or targeting the related signal transduction mechanisms may possibly be utilised to modify or control the early progression of cancers. The review provides a coherent template for discussing the notion, in the context of contemporary knowledge, that tumourigenesis is an alliance of biochemistry, genetics and biophysics, in which the physical architecture of the ECM may be a fundamental component. For more definitive clarification of the concept there needs to be a phalanx of experiments conceived around direct questions that are raised by this paper.

Engineered Fibrillar Fibronectin Networks as Three-Dimensional Tissue Scaffolds

Extracellular matrix (ECM) proteins, and most prominently, fibronectin (Fn), are routinely used in the form of adsorbed pre-coatings in an attempt to create a cell-supporting environment in both two- and three-dimensional cell culture systems. However, these protein coatings are typically deposited in a form which is structurally and functionally distinct from the ECM-constituting fibrillar protein networks naturally deposited by cells. Here, the cell-free and scalable synthesis of freely suspended and mechanically robust three-dimensional (3D) networks of fibrillar fibronectin (fFn) supported by tessellated polymer scaffolds is reported. Hydrodynamically induced Fn fibrillogenesis at the three-phase contact line between air, an Fn solution, and a tessellated scaffold microstructure yields extended protein networks. Importantly, engineered fFn networks promote cell invasion and proliferation, enable in vitro expansion of primary cancer cells, and induce an epithelial-to-mesenchymal transition in cancer cells. Engineered fFn networks support the formation of multicellular cancer structures cells from plural effusions of cancer patients. With further work, engineered fFn networks can have a transformative impact on fundamental cell studies, precision medicine, pharmaceutical testing, and pre-clinical diagnostics.

Fibronectin in malignancy: Cancer-specific alterations, protumoral effects, and therapeutic implications

Initial studies on cancer primarily focused on malignant cells themselves. The overarching narrative of cancer revolved around unchecked and rapidly proliferating cells. Special attention was given to the molecular, genetic, and metabolic profiles of isolated cancer cells in hopes of elucidating a critical factor in malignancy. However, the scope of cancer research has broadened over the past few decades to include the local environment around cancer. It has become increasingly apparent that the immune cells, vascular networks, and the extracellular matrix all have a part in cancer progression. The impact of the extracellular matrix is particularly fascinating and key stromal changes have been identified in various cancers. Pioneering work studying laminin and hyaluronate has shown that these molecules have vital roles in cancer progression. More recently, fibronectin has been included as an extracellular driver of malignancy. Fibronectin is thought to play a considerable, albeit poorly understood, role in cancer pathogenesis. In this review, we present fundamental studies that have investigated the impact of fibronectin in cancer. As an abundant component of the extracellular matrix, understanding the effect of this molecule has the potential to elucidate cancer biology.

The Bone Extracellular Matrix as an Ideal Milieu for Cancer Cell Metastases

Bone is a preferential site for cancer metastases, including multiple myeloma, prostate, and breast cancers.The composition of bone, especially the extracellular matrix (ECM), make it an attractive site for cancer cell colonization and survival. The bone ECM is composed of living cells embedded within a matrix composed of both organic and inorganic components. Among the organic components, type I collagen provides the tensile strength of bone. Inorganic components, including hydroxyapatite crystals, are an integral component of bone and provide bone with its rigidity. Under normal circumstances, two of the main cell types in bone, the osteoblasts and osteoclasts, help to maintain bone homeostasis and remodeling through cellular communication and response to biophysical signals from the ECM. However, under pathological conditions, including osteoporosis and cancer, bone remodeling is dysregulated. Once in the bone matrix, disseminated tumor cells utilize normal products of bone remodeling, such as collagen type I, to fuel cancer cell proliferation and lesion outgrowth. Models to study the complex interactions between the bone matrix and metastatic cancer cells are limited. Advances in understanding the interactions between the bone ECM and bone metastatic cancer cells are necessary in order to both regulate and prevent metastatic cancer cell growth in bone.

The extracellular matrix in tumor progression and metastasis

The extracellular matrix (ECM) constitutes the scaffold of tissues and organs. It is a complex network of extracellular proteins, proteoglycans and glycoproteins, which form supramolecular aggregates, such as fibrils and sheet-like networks. In addition to its biochemical composition, including the covalent intermolecular cross-linkages, the ECM is also characterized by its biophysical parameters, such as topography, molecular density, stiffness/rigidity and tension. Taking these biochemical and biophysical parameters into consideration, the ECM is very versatile and undergoes constant remodeling. This review focusses on this remodeling of the ECM under the influence of a primary solid tumor mass. Within this tumor stroma, not only the cancer cells but also the resident fibroblasts, which differentiate into cancer-associated fibroblasts (CAFs), modify the ECM. Growth factors and chemokines, which are tethered to and released from the ECM, as well as metabolic changes of the cells within the tumor bulk, add to the tumor-supporting tumor microenvironment. Metastasizing cancer cells from a primary tumor mass infiltrate into the ECM, which variably may facilitate cancer cell migration or act as barrier, which has to be proteolytically breached by the infiltrating tumor cell. The biochemical and biophysical properties therefore determine the rates and routes of metastatic dissemination. Moreover, primed by soluble factors of the primary tumor, the ECM of distant organs may be remodeled in a way to facilitate the engraftment of metastasizing cancer cells. Such premetastatic niches are responsible for the organotropic preference of certain cancer entities to colonize at certain sites in distant organs and to establish a metastasis. Translational application of our knowledge about the cancer-primed ECM is sparse with respect to therapeutic approaches, whereas tumor-induced ECM alterations such as increased tissue stiffness and desmoplasia, as well as breaching the basement membrane are hallmark of malignancy and diagnostically and histologically harnessed.

Uptake and distribution of carboxylated quantum dots in human mesenchymal stem cells: cell growing density matters

BACKGROUND

Human mesenchymal stem cells (MSCs) have drawn much attention in the field of regenerative medicine for their immunomodulatory and anti-inflammatory effects. MSCs possess specific tumor-oriented migration and incorporation highlighting the potential for MSCs to be used as an ideal carrier for anticancer agents. Bone marrow is the main source of MSCs for clinical applications. MSCs tracking in vivo is a critical component of the safety and efficacy evaluation of therapeutic cell products; therefore, cells must be labeled with contrast agents to enable visualization of the MSCs migration in vivo. Due to their unique properties, quantum dots (QDs) are emerging as optimal tools in long-term MSC optical imaging applications. The aim of this study was to investigate the uptake dynamics, cytotoxity, subcellular and extracellular distribution of non-targeted carboxylated quantum dots in human bone marrow MSCs at different cell growing densities.

RESULTS

QDs had no negative impact on MSC viability throughout the experiment and accumulated in all observed cells efficiently; however, in some MSCs QDs induced formation of lipid droplets. At low cell growing densities QDs distribute within MSCs cytoplasm already after 1 h of incubation reaching saturation after 6 h. After 24 h QDs localize mainly in the perinuclear region of the cells in endosomes. Interestingly, in more confluent culture QDs localize mostly outside MSCs. QDs abundantly mark MSC long filopodia-like structures attaching neighboring cells. At high cell density cultivation, we for the first time demonstrated that carboxylated QDs localize in human bone marrow MSC extracellular matrix. Moreover, we observed that average photoluminescence lifetime of QDs distributed in extracellular matrix are longer than lifetimes of QDs entrapped in endocytic vesicles; thus, for the first time showing the possibility to identify and distinguish localization of QDs in various extracellular and intracellular structures using fluorescence-lifetime imaging microscopy without additional staining assays.

CONCLUSION

Carboxylated QDs can be used as nonspecific and effective dye for staining of human bone marrow MSCs and their specific extracellular structures. These results are promising in fundamental stem cell biology as well as in cellular therapy, anticancer drug delivery and tissue engineering.

Mitogen Inducible Gene-6 Is a Prognostic Marker for Patients with Colorectal Liver Metastases

PURPOSE

Prognostic schemes that rely on clinical variables to predict outcome after resection of colorectal metastases remain imperfect. We hypothesized that molecular markers can improve the accuracy of prognostic schemes.

METHODS

We screened the transcriptome of matched colorectal liver metastases (CRCLM) and primary tumors from 42 patients with unresected CRCLM to identify differentially expressed genes. Among the differentially expressed genes identified, we looked for associations between expression and time to disease progression or overall survival. To validate such associations, mRNA levels of the candidate genes were assayed by qRT-PCR from CRCLM in 56 additional patients who underwent hepatectomy.

RESULTS

Seven candidate genes were selected for validation based on their differential expression between metastases and primary tumors and a correlation between expression and surgical outcome: lumican; tissue inhibitor metalloproteinase 1; basic helix-loop-helix domain containing class B2; fibronectin; transmembrane 4 superfamily member 1; mitogen inducible gene 6 (MIG-6); and serpine 2. In the hepatectomy group, only MIG-6 expression was predictive of poor survival after hepatectomy. Quantitative PCR of MIG-6 mRNA was performed on 25 additional hepatectomy patients to determine if MIG-6 expression could substratify patients beyond the clinical risk score. Patients within defined clinical risk score categories were effectively substratified into distinct groups by relative MIG-6 expression.

CONCLUSIONS

MIG-6 expression is inversely associated with survival after hepatectomy and may be used to improve traditional prognostic schemes that rely on clinicopathologic data such as the Clinical Risk Score.

Anti-cancer effect of dung beetle glycosaminoglycans on melanoma

BACKGROUND

Dung beetle glycosaminoglycan is known to possess anti-aging activities. However, its anti-cancer mechanisms are not fully elucidated yet. The objective of this study was to evaluate the anti-cancer effect of insect-derived polymer dung beetle glycosaminoglycan (GAG) after intraperitoneally injecting it to melanoma mice induced by B16F10 cells.

METHODS

To determine molecular mechanism involved in the anti-cancer effect of dung beetle GAG, its origin N-glycan under 3KD Dalton was assayed for melanoma cell cytotoxicity. Quantitative comparisons of adhesive molecule on extracellular matrix and activities of tissue inhibitor of metalloprotease 2 (TIMP-2) were also investigated. In vivo anti-cancer effect of dung beetle GAG on solid tumor size, survival time and gene-expression profiles was also assayed using B10F10 melanoma mice model. Mice with induced melanoma were then treated with Catharsius molossus (dung beetle) GAG (CaG) at 5 mg/kg for 8 weeks to investigate its anti-cancer effects compared to bumblebee (Bombus ignitus) queen glycosaminoglycan (IQG) and Huechys sanguinea glycosaminoglycan (HEG).

RESULTS

These N-glycans derived from these GAG were composed of many linear heparinoid polysaccharides, polymers with hexose and N-acetylhexose. Adminstration with these GAGs increased survival time and decreased melanoma sizes in mice, in accordance with their inhibitory effects on cell growth ratio of melanoma B16F10. In addition, treatment with N-glycans derived from theses glycosaminoglycan increased activities of TIMP-2 in HMVEC cells pretreated with TNF-alpha and in melanoma cells, suggesting that they had anti-inflammatory and anticancer activities. In DNA microarray results, compared to control, CaG treated mouse group showed upregulation of 192 genes including collagen,typeI,alpha1 (Col1a1), consistent with the highly increased in vitro extracellular matrix (ECM) adhesion on collagen 1 and up-regulation of heparanase (Hpse). After treatment with CaG, a total of 152 genes were down-regulated, including nuclear RNA export factor (Nxf3) and hyaluronan proteoglycan link protein1 (Hapln1).

CONCLUSIONS

Glycosaminoglycan, CaG can strengthen ECM by increasing activity of TIMP-2 and adhesion activity on collagen known to inhibit changes of ECM, leading to tumor cell invasion and progression.

Recruitment of integrin ανβ3 to integrin α5β1-induced clusters enables focal adhesion maturation and cell spreading

The major fibronectin (FN) binding integrins α5β1 and αvβ3 exhibit cooperativity during cell adhesion, migration and mechanosensing, through mechanisms that are not yet fully resolved. Exploiting mechanically-tunable, nano-patterned substrates, and peptidomimetic ligands designed to selectively bind corresponding integrins, we report that focal adhesions (FAs) of endothelial cells assembled on integrin α5β1-selective substrates, rapidly recruit αvβ3 integrins, but not vice versa. Blocking of integrin αvβ3 hindered FA maturation and cell spreading on α5β1-selective substrates, indicating a mechanism dependent on extracellular ligand binding and highlighting the requirement of αvβ3 engagement for efficient adhesion. Recruitment of αvβ3 integrins additionally occurred on hydrogel substrates of varying mechanical properties, above a threshold stiffness supporting FA formation. Mechanistic studies revealed the need for soluble factors present in serum to allow recruitment, and excluded exogenous, or endogenous, FN as the responsible ligand for integrin αvβ3 accumulation to adhesion clusters. Our findings highlight a novel mechanism of integrin co-operation and the critical role for αvβ3 integrins in promoting cell adhesion on α5β1-selective substrates.

TGF-β signaling promotes tumor vasculature by enhancing the pericyte-endothelium association

Background

The breast cancer microenvironment promotes tumor vascularization through the complex interactions involving tumor-associated fibroblasts (TAFs). Emerging data indicate that TAFs increase production and signaling by TGF-β cytokines, while the role of TGF-β signaling in the regulation of tumor blood vessels is not fully understood. The current study presents evidence that TAFs enhance the organization of tumor blood capillaries, and TGF-β signaling plays an important role in this response.

Methods

Tumor vascularization was studied in xenograft models of breast carcinoma cells, alone and in combination with fibroblasts. TGF-β signaling in breast cancer cells was modulated by expression of kinase-inactive TGFBR1-K232R (dnTGFBR1) or constitutive-active TGFBR1-T204D (caTGFBR1) receptor mutants. The architecture of tumor blood capillaries was assessed by immune-histochemical analysis of endothelium and pericytes. The role of TGF-β-Smad signaling in fibronectin expression was examined using adenoviral transduction of signaling components.

Results

Our studies revealed that TAFs significantly increase the lumen size of blood microvessels. Inactivation of TGF-β signaling in tumor cells by dnTGFBR1 reduced the microvessel density and lumen sizes, decreasing tumor growth. In contrast, caTGFBR1-tumors exhibited greater vessel density and lumen sizes. Tumors with inactive dnTGFBR1 showed lower amounts of TAFs, while caTGFBR1 increased amounts of TAFs compared to the control. Inspection of pericytes and endothelial cells in tumor vasculature revealed that TAFs enhanced vessel coverage by pericytes, vascular cells supporting capillaries. This effect was impaired in dnTGFBR1-tumors, whereas active caTGFBR1 enhanced the association of pericytes with endothelium. Accordingly, dnTGFBR1-tumors exhibited the presence of hemorrhages, a sign of fragile blood vessels. Biochemical analysis showed that TGFBR1-SMAD signaling up-regulates fibronectin, a prominent regulator of endothelium-pericyte interactions.

Conclusions

The current study indicates that tumor-fibroblast crosstalk enhances tumor vascularization by increasing the pericyte-endothelium association via a mechanism involving the TGFβ-fibronectin axis. The tumor-fibroblast model represents a useful system for dissecting the complex interactions governing tumor angiogenesis and developing new approaches to therapeutic targeting tumor vasculature.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4587-z) contains supplementary material, which is available to authorized users.

Mechanisms and context underlying the role of autophagy in cancer metastasis

Macroautophagy/autophagy is a fundamental cellular degradation mechanism that maintains cell homeostasis, regulates cell signaling, and promotes cell survival. Its role in promoting tumor cell survival in stress conditions is well characterized, and makes autophagy an attractive target for cancer therapy. Emerging research indicates that autophagy also influences cancer metastasis, which is the primary cause of cancer-associated mortality. However, data demonstrate that the regulatory role of autophagy in metastasis is multifaceted, and includes both metastasis-suppressing and -promoting functions. The metastasis-suppressing functions of autophagy, in particular, have important implications for autophagy-based treatments, as inhibition of autophagy may increase the risk of metastasis. In this review, we discuss the mechanisms and context underlying the role of autophagy in metastasis, which include autophagy-mediated regulation of focal adhesion dynamics, integrin signaling and trafficking, Rho GTPase-mediated cytoskeleton remodeling, anoikis resistance, extracellular matrix remodeling, epithelial-to-mesenchymal transition signaling, and tumor-stromal cell interactions. Through this, we aim to clarify the context-dependent nature of autophagy-mediated metastasis and provide direction for further research investigating the role of autophagy in cancer metastasis.

Characterization of increasing stages of invasiveness identifies stromal/cancer cell crosstalk in rat models of mesothelioma

Sarcomatoid mesothelioma (SM) is a devastating cancer associated with one of the poorest outcome. Therefore, representative preclinical models reproducing different tumor microenvironments (TME) observed in patients would open up new prospects for the identification of markers and evaluation of innovative therapies. Histological analyses of four original models of rat SM revealed their increasing infiltrative and metastatic potential were associated with differences in Ki67 index, blood-vessel density, and T-lymphocyte and macrophage infiltration. In comparison with the noninvasive tumor M5-T2, proteomic analysis demonstrated the three invasive tumors F4-T2, F5-T1 and M5-T1 shared in common a very significant increase in the abundance of the multifunctional proteins galectin-3, prohibitin and annexin A5, and a decrease in proteins involved in cell adhesion, tumor suppression, or epithelial differentiation. The increased metastatic potential of the F5-T1 tumor, relative to F4-T2, was associated with an increased macrophage vs T-cell infiltrate, changes in the levels of expression of a panel of cytokine genes, an increased content of proteins involved in chromatin organization, ribosome structure, splicing, or presenting anti-adhesive properties, and a decreased content of proteins involved in protection against oxidative stress, normoxia and intracellular trafficking. The most invasive tumor, M5-T1, was characterized by a pattern of specific phenotypic and molecular features affecting the presentation of MHC class I-mediated antigens and immune cell infiltration, or involved in the reorganization of the cytoskeleton and composition of the extracellular matrix. These four preclinical models and data represent a new resource available to the cancer research community to catalyze further investigations on invasiveness.

MicroRNA regulation of extracellular matrix components in the process of atherosclerotic plaque destabilization

The process of atherosclerotic plaque destabilization, leading to myocardial infarction, is still not fully understood. The pathway - composed of structural and regulatory proteins of the extracellular matrix (ECM) such as collagen, elastin, small leucine-rich proteoglycans, metalloproteinases, cathepsins and serine proteases - is one potential way of atherosclerotic plaque destabilization. The expression of these proteins is controlled by different microRNA molecules. The goal of this paper is to summarize the current investigations and knowledge about ECM in the process of atherosclerotic plaque destabilization, giving special attention to epigenetic expression regulation by microRNA.

Effectiveness of urine fibronectin as a non-invasive diagnostic biomarker in bladder cancer patients: a systematic review and meta-analysis

Background

Previous researches pointed out that the measurement of urine fibronectin (Fn) could be a potential diagnostic test for bladder cancer (BCa). We conducted this meta-analysis to fully assess the diagnostic value of urine Fn for BCa detection.

Methods

A systematic literature search in PubMed, ISI Web of Science, EMBASE, Cochrane library, and CBM was carried out to identify eligible studies evaluating the urine Fn in diagnosing BCa. Pooled sensitivity, specificity, and diagnostic odds ratio (DOR) with their 95% confidence intervals (CIs) were calculated, and summary receiver operating characteristic (SROC) curves were established. We applied the STATA 13.0, Meta-Disc 1.4, and RevMan 5.3 software to the meta-analysis.

Results

Eight separate studies with 744 bladder cancer patients were enrolled in this meta-analysis. The pooled sensitivity, specificity, and DOR were 0.80 (95%CI = 0.77–0.83), 0.79 (95%CI = 0.73–0.84), and 15.18 (95%CI = 10.07–22.87), respectively, and the area under the curve (AUC) of SROC was 0.83 (95%CI = 0.79–0.86). The diagnostic power of a combined method (urine Fn combined with urine cytology) was also evaluated, and its sensitivity and AUC were significantly higher (0.86 (95%CI = 0.82–0.90) and 0.89 (95%CI = 0.86–0.92), respectively). Meta-regression along with subgroup analysis based on various covariates revealed the potential sources of the heterogeneity and the detailed diagnostic value of each subgroup. Sensitivity analysis supported that the result was robust. No threshold effect and publication bias were found in this meta-analysis.

Conclusions

Urine Fn may become a promising non-invasive biomarker for bladder cancer with a relatively satisfactory diagnostic power. And the combination of urine Fn with cytology could be an alternative option for detecting BCa in clinical practice. The potential value of urine Fn still needs to be validated in large, multi-center, and prospective studies.

Electronic supplementary material

The online version of this article (10.1186/s12957-018-1358-x) contains supplementary material, which is available to authorized users.

Inhibition of the receptor for advanced glycation promotes proliferation and repair of human periodontal ligament fibroblasts in response to high glucose via the NF-κB signaling pathway

OBJECTIVE

To observe if inhibition of the receptor for advanced glycation endproducts (RAGE) promotes proliferation and repair of human periodontal ligament fibroblasts (hPDLFs) stimulated by high glucose. In addition, we also discuss the effects of the NF-κB signaling pathway in relation to this process.

METHODS

Primary cultured hPDLFs were exposed to either low glucose (5.5 mmol/L) or high glucose (25 mmol/L), and RAGE expression was measured by Western blot analysis. Cells were cultured in high glucose with different concentrations of the RAGE inhibitor, FPS-ZM1. We measured cell proliferation using the Cell Counting Kit-8 and expression of collagen type 1 and fibronectin by real-time PCR and ELISA, respectively. The relative protein expression levels of NF-κB p65 and phosphorylated p65 were measured by Western blot analysis.

RESULTS

High glucose enhanced RAGE expression and suppressed cell growth. While FPS-ZM1 increased proliferation and expression of repair-related factors in high glucose, there was a concurrent decline in the phosphorylation level of NF-κB p65.

CONCLUSION

FPS-ZM1 rescued the proliferative capacity and repair capability of hPDLFs via the RAGE-NF-κB signaling pathway in response to high glucose.

TLR4 Ligands Selectively Synergize to Induce Expression of IL-8

Objective: Dysfunctional remodeling of the extracellular matrix contributes to the formation of TLR-dependent feed forward loops that drive chronic inflammation. We have previously shown that two Type III domains of Fibronectin, FnEDA and FnIII-1c, cooperate to induce the synergistic release of interleukin 8 (IL-8) from dermal fibroblasts. We now identify steps in the TLR4 pathway where synergy can be demonstrated as well as additional kinases functioning in fibronectin activation of TLR4 signaling. We also evaluate the ligand and cell-type specificity of this synergistic response. Approach: FnEDA, FnIII-1c, and lipopolysaccharide (LPS)-induced genes in fibroblasts were analyzed by a quantitative reverse transcription-polymerase chain reaction (qPCR) and protein was measured by an enzyme-linked immunosorbent assay (ELISA). Kinases functioning in gene expression were identified by using specific inhibitors. Activated TLR4-dependent effector molecules were identified by cell fractionation and Western blot and quantified by image analysis. Results: The addition of FnEDA and FnIII-1c to dermal fibroblasts resulted in a synergistic increase in the expression of IL-8, tumor necrosis factor alpha (TNF-α), and vascular cell adhesion molecule (VCAM-1). Synergy between these domains was detected at the level of nuclear factor kappa-light chain enhancer of activated B cells (NF-κB) and inhibitor of kappa B kinase (IKK) activation. Induction of IL-8 by fibronectin ligands was partially attenuated in the presence of inhibitors to either epidermal growth factor receptor or Src kinases. FnIII-1c also synergized with LPS to induce IL-8 in dermal fibroblasts, whereas the combined effect of FnEDA and LPS on IL-8 synthesis was additive. In contrast, synergistic responses to these ligands were not observed in THP-1 monocytic cells. Innovation: The data suggest that chronic inflammation may be driven by matrix- and pathogen-derived TLR4 ligands that work in synergy to promote an exuberant innate response. Conclusion: The data suggest that the molecular mechanism underlying synergistic responses to TLR4 ligands lies upstream of IKK activation, likely in the molecular composition of the TLR4 receptor complex that assembles in response to each ligand. In addition, synergistic responses to TLR4 activation may be both cell-type and ligand specific.

Tumor p38MAPK signaling enhances breast carcinoma vascularization and growth by promoting expression and deposition of pro-tumorigenic factors

The breast carcinoma microenvironment strikingly influences cancer progression and response to therapy. Various cell types in the carcinoma microenvironment show significant activity of p38 mitogen-activated protein kinase (MAPK), although the role of p38MAPK in breast cancer progression is still poorly understood. The present study examined the contribution of tumor p38MAPK to breast carcinoma microenvironment and metastatic capacity. Inactivation of p38MAPK signaling in metastatic breast carcinoma cells was achieved by forced expression of the kinase-inactive mutant of p38/MAPK14 (a dominant-negative p38, dn-p38). Disruption of tumor p38MAPK signaling reduced growth and metastases of breast carcinoma xenografts. Importantly, dn-p38 markedly decreased tumor blood-vessel density and lumen sizes. Mechanistic studies revealed that p38 controls expression of pro-angiogenic extracellular factors such as matrix protein Fibronectin and cytokines VEGFA, IL8, and HBEGF. Tumor-associated fibroblasts enhanced tumor growth and vasculature as well as increased expression of the pro-angiogenic factors. These effects were blunted by dn-p38. Metadata analysis showed elevated expression of p38 target genes in breast cancers and this was an unfavorable marker of disease recurrence and poor-outcome. Thus, our study demonstrates that tumor p38MAPK signaling promotes breast carcinoma growth, invasive and metastatic capacities. Importantly, p38 enhances carcinoma vascularization by facilitating expression and deposition of pro-angiogenic factors. These results argue that p38MAPK is a valuable target for anticancer therapy affecting tumor vasculature. Anti-p38 drugs may provide new therapeutic strategies against breast cancer, including metastatic disease.

Role of the extracellular matrix in cancer-associated epithelial to mesenchymal transition phenomenon

The epithelial to mesenchymal transition (EMT) program is a crucial component in the processes of morphogenesis and embryonic development. The transition of epithelial to mesenchymal phenotype is associated with numerous structural and functional changes, including loss of cell polarity and tight cell-cell junctions, the acquisition of invasive abilities, and the expression of mesenchymal proteins. The switch between the two phenotypes is involved in human pathology and is crucial for cancer progression. Extracellular matrices (ECMs) are multi-component networks that surround cells in tissues. These networks are obligatory for cell survival, growth, and differentiation as well as tissue organization. Indeed, the ECM suprastructure, in addition to its supportive role, can process and deliver a plethora of signals to cells, which ultimately regulate their behavior. Importantly, the ECM derived signals are critically involved in the process of EMT during tumorigenesis. This review discusses the multilayer interaction between the ECM and the EMT process, focusing on contributions of discrete mediators, a strategy that may identify novel potential target molecules. Developmental Dynamics 247:368-381, 2018. © 2017 Wiley Periodicals, Inc.

Runx3 inhibits melanoma cell migration through regulation of cell shape change

The transcription factor Runx3 is a known tumor suppressor gene, and its expression is frequently lost in melanoma. However, the potential contribution of the loss of Runx3 expression to melanoma development and progression remains unclear. In this in vitro study, we demonstrated that ectopic Runx3 re-expression in B16-F10 melanoma cells changed the cell shape from elongated and branched to spread and unbranched, which enhanced stress fiber formation, increased the number of mature and fibrillar focal adhesions, and up-regulated fibronectin expression. In association with the cell shape change, the Runx3 re-expression in B16-F10 melanoma cells inhibited cell migration. Moreover, the phenotype of the Runx3 induced cell shape change was partially resembled when the melanoma cells were cultured on a fibronectin-coated coverslip, suggesting that fibronectin may mediate the Runx3 induced cell shape change of the melanoma cells. Taken together, our findings suggest that Runx3 may regulate cell shape to inhibit melanoma cell migration partly through enhancing stress fiber formation and ECM protein production. Our present study provides further evidence for the idea that cell shape change is potentially correlated with melanoma development and progression.

Patterns and functional implications of platelets upon tumor "education"

While platelets are traditionally recognized to play a predominant role in hemostasis and thrombosis, increasing evidence verifies its involvement in malignancies. As a component of the tumor microenvironment, platelets influence carcinogenesis, tumor metastasis and chemotherapy efficiency. Platelets status is thus predictable as a hematological biomarker of cancer prognosis and a hot target for therapeutic intervention. On the other hand, the role of circulating tumor cells (CTCs) as an inducer of platelet activation and aggregation has been well acknowledged. The cross-talk between platelets and CTCs is reciprocal on that the CTCs activate platelets while platelets contribute to CTCs' survival and dissemination. This review covers some of the current issues related to the loop between platelets and tumor aggression, including the manners of tumor cells in "educating" platelets and biofunctional alterations of platelets upon tumor "education". We also highlight the potential clinical applications on the interplay between tumors and platelets. Further studies with well-designed prospective multicenter trials may contribute to clinical "liquid biopsy" diagnosis by evaluating the global changes of platelets.

Epithelial-to-Mesenchymal Transition in the Pathogenesis and Therapy of Head and Neck Cancer

Head and neck cancer (HNC) is one of the most prevalent human malignancies worldwide, with a high morbidity and mortality. Implementation of interdisciplinary treatment modalities has improved the quality of life, but only minor changes in overall survival have been achieved over the past decades. Main causes for treatment failure are an aggressive and invasive tumor growth in combination with a high degree of intrinsic or acquired treatment resistance. A subset of tumor cells gain these properties during malignant progression by reactivating a complex program of epithelia-to-mesenchymal transition (EMT), which is integral in embryonic development, wound healing, and stem cell behavior. EMT is mediated by a core set of key transcription factors, which are under the control of a large range of developmental signals and extracellular cues. Unraveling molecular principles that drive EMT provides new concepts to better understand tumor cell plasticity and response to established as well as new treatment modalities, and has the potential to identify new drug targets for a more effective, less toxic, and individualized therapy of HNC patients. Here, we review the most recent findings on the clinical relevance of a mesenchymal-like phenotype for HNC patients, including more rare cases of mucosal melanoma and adenoid cystic carcinoma.

Fibronectin promotes directional persistence in fibroblast migration through interactions with both its cell-binding and heparin-binding domains

The precise mechanisms through which insoluble, cell-adhesive ligands induce and regulate directional cell migration remain obscure. We recently demonstrated that elevated surface density of physically adsorbed plasma fibronectin (FN) promotes high directional persistence in fibroblast migration. While cell-FN association through integrins α₅β₁ and α_vβ₃ was necessary, substrates that selectively engaged these integrins did not support the phenotype. We here show that high directional persistence necessitates a combination of the cell-binding and C-terminal heparin-binding domains of FN, but does not require the engagement of syndecan-4 or integrin α₄β₁. FN treatment with various fixation agents indicated that associated changes in fibroblast motility were due to biochemical changes, rather than alterations in its physical state. The nature of the coating determined the ability of fibroblasts to assemble endogenous or exogenous FN, while FN fibrillogenesis played a minor, but significant, role in regulating directionality. Interestingly, knockdown of cellular FN abolished cell motility altogether, demonstrating a requirement for intracellular processes in enabling fibroblast migration on FN. Lastly, kinase inhibition experiments revealed that regulation of cell speed and directional persistence are decoupled. Hence, we have identified factors that render full-length FN a promoter of directional migration and discuss the possible, relevant mechanisms.

Anti-Obesity Effect of Bombus ignitus Queen Glycosaminoglycans in Rats on a High-Fat Diet

The mechanism of functional insect glycosaminoglycan (GAG) on obesity caused a high fat diet has not yet been elucidated. Therefore, insect glycosaminoglycans derived from Isaria sinclairii, Bombus ignitus (a type of bumblebee) queen, and Gryllus bimaculatus were purified and investigated as a potential functional food. 14-week old male Wistar rats were fed a high-fat diet (HFD) for 6 weeks. There were five groups that received daily intraperitoneal administration of phosphate buffered saline (PBS, control), GbG (GAG from Gryllus bimaculatus) 10 mg/kg, ISG (GAG from Isaria sinclairii) 10 mg/kg, IQG (GAG from Bombus ignites) 10 mg/kg, or Pravastatin (2 mg/kg). All treatments were performed for one month. IQG produced a potential anti-inflammatory effect with the inhibition of c-reactive protein and sero-biochemical parameters of phospholipids and free fatty acids indicative of an anti-hyperlipidemic effect. Abdominal and epididymidal fat weight were reduced in conjunction with a mild increase in body weight. The level of laminin in HMVEC-C cells or fibronectin in HFD rat hepatocytes was significantly affected by these GAG treatments, which regulated adipogenesis and adipocyte function. Compared to the control rats, IQG-treated rats displayed up-regulation of 87 genes (test:control ratio >2.0) including fatty acid synthase and 3-hydroxy-3-methylglutaryl-coenzyme A reductase, with the down-regulation of 47 genes including the uridine diphosphate (UDP) glycosyltransferase 2 families, polypeptidase B, and insulin-like growth factor binding protein 1. The data suggest that IQG could potentially prevent or treat fatty liver or hyperlipidemia.

Proteomic profiles of thyroid tumors by mass spectrometry-imaging on tissue microarrays

The current study proposes the successful use of a mass spectrometry-imaging technology that explores the composition of biomolecules and their spatial distribution directly on-tissue to differentially classify benign and malignant cases, as well as different histotypes. To identify new specific markers, we investigated with this technology a wide histological Tissue Microarray (TMA)-based thyroid lesion series. Results showed specific protein signatures for malignant and benign specimens and allowed to build clusters comprising several proteins with discriminant capabilities. Among them, FINC, ACTB1, LMNA, HSP7C and KAD1 were identified by LC-ESI-MS/MS and found up-expressed in malignant lesions. These findings represent the opening of further investigations for their translation into clinical practice, e.g. for setting up new immunohistochemical stainings, and for a better understanding of thyroid lesions. This article is part of a Special Issue entitled: MALDI Imaging, edited by Dr. Corinna Henkel and Prof. Peter Hoffmann.

Breast cancer cells alter the dynamics of stromal fibronectin-collagen interactions

Breast cancer cells recruit surrounding stromal cells, such as cancer-associated fibroblasts (CAFs), to remodel their extracellular matrix (ECM) and promote invasive tumor growth. Two major ECM components, fibronectin (Fn) and collagen I (Col I), are known to interact with each other to regulate cellular behavior. In this study, we seek to understand how Fn and Col I interplay and promote a dysregulated signaling pathway to facilitate tumor progression. Specifically, we investigated the evolution of tumor-conditioned stromal ECM composition, structure, and relaxation. Furthermore, we assessed how evolving Fn-Col I interactions gradually affected pro-angiogenic signaling. Our data first indicate that CAFs initially assembled a strained, viscous, and unfolded Fn matrix. This early altered Fn matrix was later remodeled into a thick Col I-rich matrix that was characteristic of a dense tumor mass. Next, our results suggest that this ECM remodeling was primarily mediated by matrix metalloproteinases (MMPs). This MMP activity caused profound structural and mechanical changes in the developing ECM, which then modified vascular endothelial growth factor (VEGF) secretion by CAFs and matrix sequestration. Collectively, these findings enhance our understanding of the mechanisms by which Fn and Col I synergistically interplay in promoting a sustained altered signaling cascade to remodel the breast tumor stroma for invasive breast tumor growth.

The fibronectin III-1 domain activates a PI3-Kinase/Akt signaling pathway leading to αvβ5 integrin activation and TRAIL resistance in human lung cancer cells

Background

Fibronectin is a mechanically sensitive protein which is organized in the extracellular matrix as a network of interacting fibrils. The lung tumor stroma is enriched for fibronectin which is thought to contribute to metastasis and drug resistance. Fibronectin is an elastic, multi-modular protein made up of individually folded domains, some of which can stretch in response to increased mechanical tension. Very little is known about the relationship of fibronectin’s unfolded domains to lung cancer resistance to chemotherapy. In the present study, we evaluated the impact of unfolding the first Type III domain of fibronectin (FnIII-1c) on TNF-related apoptosis inducing ligand (TRAIL) resistance.

Methods

NCI-H460 non-small cell lung cancer cells were treated with FnIII-1c then assessed for TRAIL-induced apoptosis. Subsequent analysis of FnIII-1c-mediated signaling pathways was also completed. Human non-small cell lung cancer tissue sections were assessed for the expression of vitronectin by immunohistochemistry.

Results

FnIII-1c inhibited TRAIL-induced activation of caspase 8 and subsequent apoptosis in NCI-H460 lung cancer cells. FnIII-1c treatment was associated with the activation of the phosphatidylinositol-3-kinase/alpha serine/threonine kinase (PI3K/Akt) pathway and the αvβ5 integrin receptor for vitronectin, both of which were required for TRAIL resistance. Immunohistochemical staining of sections from non-small cell lung cancers showed that vitronectin was localized around blood vessels and in the tumor-stroma interface.

Conclusions

Unfolding of Type III domains within the fibronectin matrix may promote TRAIL resistance through the activation of a PI3K/Akt/αvβ5 signaling axis and point to a novel mechanism by which changes in secondary structure of fibronectin contribute to cancer cell resistance to apoptosis.