Cleavage of L1 in exosomes and apoptotic membrane vesicles released from ovarian carcinoma cells

The dynamic TRPV2 ion channel proximity proteome reveals functional links of calcium flux with cellular adhesion factors NCAM and L1CAM in neurite outgrowth

TRPV2 voltage-insensitive, calcium-permeable ion channels play important roles in cancer progression, immune response, and neuronal development. Despite TRPV2's physiological impact, underlying endogenous proteins mediating TRPV2 responses and affected signaling pathways remain elusive. Using quantitative peroxidase-catalyzed (APEX2) proximity proteomics we uncover dynamic changes in the TRPV2-proximal proteome and identify calcium signaling and cell adhesion factors recruited to the molecular channel neighborhood in response to activation. Quantitative TRPV2 proximity proteomics further revealed activation-induced enrichment of protein clusters with biological functions in neural and cellular projection. We demonstrate a functional connection between TRPV2 and the neural immunoglobulin cell adhesion molecules NCAM and L1CAM. NCAM and L1CAM stimulation robustly induces TRPV2 [Ca2+]I flux in neuronal PC12 cells and this TRPV2-specific [Ca2+]I flux requires activation of the protein kinase PKCα. TRPV2 expression directly impacts neurite lengths that are modulated by NCAM or L1CAM stimulation. Hence, TRPV2's calcium signaling plays a previously undescribed, yet vital role in cell adhesion, and TRPV2 calcium flux and neurite development are intricately linked via NCAM and L1CAM cell adhesion proteins.

Exosomes biogenesis was increased in metformin-treated human ovary cancer cells; possibly to mediate resistance

BACKGROUND

Exosomes derived from tumor cells contribute to the pathogenesis of cancers. Metformin, the most usually used drug for type 2 diabetes, has been frequently investigated for anticancer effects. Here, we examined whether metformin affects exosomes signaling in human ovary cancer cells in vitro.

METHODS

Human ovary cancer cells, including A2780 and Skov3 cells, were treated with metformin for either 24-48 h. Cell viability and caspase-3 activity were determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) and colorimetric assays respectively. Oil-Red-O staining and in vitro, scratch assays were used to examine cellular toxicity and wound healing rate. After treatment with metformin, exosomes were isolated from cells and quantified by acetylcholinesterase (AChE) assay, Dynamic Light Scattering (DLS), and their markers. Genes related to exosomes signaling were analyzed by real-time PCR or western blotting.

RESULTS

Our results showed that metformin decreased the viability of both cells dose/time-dependently (P < 0.05). Metformin increased the activity of caspase-3 (P < 0.05) as well as the number of Oil-Red-O positive cells in both cell lines. In vitro scratch assay showed that the cell migration rate of metformin-treated cells was decreased (P < 0.05), whereas AChE activity of exosomes from metformin-treated cells was increased (P < 0.05). Concurrent with an increase in CD63 protein levels, expression of Alix, CD63, CD81, Lamp-2, and Rab27b up-regulated in treated cells (P < 0.05).

CONCLUSION

Results indicated that metformin had a cytotoxic effect on ovary cancer cells and enhanced exosome biogenesis and secretion.

Emergence of Extracellular Vesicles as "Liquid Biopsy" for Neurological Disorders: Boom or Bust

Extracellular vesicles (EVs) have emerged as an attractive liquid biopsy approach in the diagnosis and prognosis of multiple diseases and disorders. The feasibility of enriching specific subpopulations of EVs from biofluids based on their unique surface markers has opened novel opportunities to gain molecular insight from various tissues and organs, including the brain. Over the past decade, EVs in bodily fluids have been extensively studied for biomarkers associated with various neurological disorders, such as Alzheimer's disease, Parkinson's disease, schizophrenia, bipolar disorder, major depressive disorders, substance use disorders, human immunodeficiency virus-associated neurocognitive disorder, and cancer/treatment-induced neurodegeneration. These studies have focused on the isolation and cargo characterization of either total EVs or brain cells, such as neuron-, astrocyte-, microglia-, oligodendrocyte-, pericyte-, and endothelial-derived EVs from biofluids to achieve early diagnosis and molecular characterization and to predict the treatment and intervention outcomes. The findings of these studies have demonstrated that EVs could serve as a repetitive and less invasive source of valuable molecular information for these neurological disorders, supplementing existing costly neuroimaging techniques and relatively invasive measures, like lumbar puncture. However, the initial excitement surrounding blood-based biomarkers for brain-related diseases has been tempered by challenges, such as lack of central nervous system specificity in EV markers, lengthy protocols, and the absence of standardized procedures for biological sample collection, EV isolation, and characterization. Nevertheless, with rapid advancements in the EV field, supported by improved isolation methods and sensitive assays for cargo characterization, brain cell-derived EVs continue to offer unparallel opportunities with significant translational implications for various neurological disorders. SIGNIFICANCE STATEMENT: Extracellular vesicles present a less invasive liquid biopsy approach in the diagnosis and prognosis of various neurological disorders. Characterizing these vesicles in biofluids holds the potential to yield valuable molecular information, thereby significantly impacting the development of novel biomarkers for various neurological disorders. This paper has reviewed the methodology employed to isolate extracellular vesicles derived from various brain cells in biofluids, their utility in enhancing the molecular understanding of neurodegeneration, and the potential challenges in this research field.

An immune-related exosome signature predicts the prognosis and immunotherapy response in ovarian cancer

BACKGROUND

Cancer-derived exosomes contribute significantly in intracellular communication, particularly during tumorigenesis. Here, we aimed to identify two immune-related ovarian cancer-derived exosomes (IOCEs) subgroups in ovarian cancer (OC) and establish a prognostic model for OC patients based on immune-related IOCEs.

METHODS

The Cancer Genome Atlas (TCGA) database was used to obtain RNA-seq data, as well as clinical and prognostic information. Consensus clustering analysis was performed to identify two IOCEs-associated subgroups. Kaplan-Meier analysis was used to compare the overall survival (OS) between IOCEs-high and IOCEs-low subtype. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted to investigate the mechanisms and biological effects of differentially expressed genes (DEGs) between the two subtypes. Besides, an IOCE-related prognostic model of OC was constructed by Lasso regression analysis, and the signature was validated using GSE140082 as the validation set.

RESULTS

In total, we obtained 21 differentially expressed IOCEs in OC, and identified two IOCE-associated subgroups by consensus clustering. IOCE-low subgroup showed a favorable prognosis while IOCE-high subgroup had a higher level of immune cell infiltration and immune response. GSEA showed that pathways in cancer and immune response were mainly enriched in IOCE-high subgroup. Thus, IOCE-high subgroup may benefit more in immunotherapy treatment. In addition, we constructed a risk model based on nine IOCE-associated genes (CLDN4, AKT2, CSPG5, ALDOC, LTA4H, PSMA2, PSMA5, TCIRG1, ANO6).

CONCLUSION

We developed a novel stratification system for OV based on IOCE signature, which could be used to estimate the prognosis as well as immunotherapy for OC patient.

Clinical significance of L1CAM expression in metastatic tubo-ovarian high-grade serous carcinoma

OBJECTIVE

To analyze the expression and prognostic role of L1CAM in tubo-ovarian high-grade serous carcinoma (HGSC).

METHODS

L1CAM protein expression by immunohistochemistry was analyzed in 644 HGSC (413 effusions, 231 surgical specimens). Expression was analyzed for association with clinicopathologic parameters and survival.

RESULTS

L1CAM protein expression was found in 401/413 (97%) effusions and 209/231 (90%) surgical specimens, with significantly higher staining extent in effusions (p < 0.001). L1CAM protein expression in effusions was unrelated to clinicopathologic parameters (p > 0.05). In surgical specimens, higher L1CAM expression was significantly related to primary (intrinsic) chemoresistance (p = 0.017). High (>25%) L1CAM expression in HGSC effusions (p = 0.02), older patient age (p = 0.013), FIGO stage IV disease (p < 0.001) and larger residual disease volume (p = 0.001) were significantly associated with shorter overall survival (OS) in univariate analysis. In Cox multivariate analysis, only FIGO stage (p = 0.001) and residual disease volume (p = 0.003) were independent prognosticators of OS. L1CAM expression in effusions was unrelated to progression-free survival (PFS). There was no association between L1CAM expression in surgical specimens and survival.

CONCLUSION

L1CAM is overexpressed in HGSC effusions compared to surgical specimens. Its overexpression in effusions is significantly associated with shorter OS, but not independently of established prognostic factors such as FIGO stage and residual disease volume.

"DEPHENCE" system-a novel regimen of therapy that is urgently needed in the high-grade serous ovarian cancer-a focus on anti-cancer stem cell and anti-tumor microenvironment targeted therapies

Ovarian cancer, especially high-grade serous type, is the most lethal gynecological malignancy. The lack of screening programs and the scarcity of symptomatology result in the late diagnosis in about 75% of affected women. Despite very demanding and aggressive surgical treatment, multiple-line chemotherapy regimens and both approved and clinically tested targeted therapies, the overall survival of patients is still unsatisfactory and disappointing. Research studies have recently brought some more understanding of the molecular diversity of the ovarian cancer, its unique intraperitoneal biology, the role of cancer stem cells, and the complexity of tumor microenvironment. There is a growing body of evidence that individualization of the treatment adjusted to the molecular and biochemical signature of the tumor as well as to the medical status of the patient should replace or supplement the foregoing therapy. In this review, we have proposed the principles of the novel regimen of the therapy that we called the "DEPHENCE" system, and we have extensively discussed the results of the studies focused on the ovarian cancer stem cells, other components of cancer metastatic niche, and, finally, clinical trials targeting these two environments. Through this, we have tried to present the evolving landscape of treatment options and put flesh on the experimental approach to attack the high-grade serous ovarian cancer multidirectionally, corresponding to the "DEPHENCE" system postulates.

L1CAM deployed perivascular tumor niche promotes vessel wall invasion of tumor thrombus and metastasis of renal cell carcinoma

The survival of tumor cells in the bloodstream, and vasculature adhesion at metastatic sites are crucial for tumor metastasis. Perivascular invasion aids tumor cell self-renewal, survival, and formation of metastases by facilitating readily available oxygen, nutrients, and endothelial-derived paracrine factors. Renal cell carcinoma (RCC) is among the most prevalent tumors of the urinary system, and the formation of venous tumor thrombus (VTT) is a characteristic feature of RCC. We observed high expression of L1CAM in the VTT with vessel wall invasion. L1CAM promotes the adhesion, migration, and invasion ability of RCC and enhances metastasis by interacting with ITGA5, which elicits activation of signaling downstream of integrin α5β1. L1CAM promotes ADAM17 transcription to facilitate transmembrane ectodomain cleavage and release of soluble L1CAM. In response to soluble L1CAM, vascular endothelial cells release several cytokines and chemokines. Endothelial-derived CXCL5 and its receptor CXCR2 promote the migration and intravasation of RCC toward endothelial cells suggesting that crosstalk between endothelial cells and tumor cells has a direct guiding role in driving the metastatic spread of RCC. LICAM plays a crucial role in the invasive ability of RCC, and regulation of L1CAM expression may contribute therapeutically to preventing RCC progression.

Hybrid exosomes, exosome-like nanovesicles and engineered exosomes for therapeutic applications

Exosomes are endosome-derived nanovesicles involved in cellular communication. They are natural nanocarriers secreted by various cells, making them suitable candidates for diverse drug delivery and therapeutic applications from a material standpoint. They have a phospholipid bilayer decorated with functional molecules and an enclosed parental matrix, which has attracted interest in developing designer/hybrid engineered exosome nanocarriers. The structural versatility of exosomes allows the modification of their original configuration using various methods, including genetic engineering, chemical procedures, physical techniques, and microfluidic technology, to load exosomes with additional cargo for expanded biomedical applications. Exosomes show enormous potential for overcoming the limitations of conventional nanoparticle-based techniques in targeted therapy. This review highlights the exosome sources, characteristics, state of the art in the field of hybrid exosomes, exosome-like nanovesicles and engineered exosomes as potential cargo delivery vehicles for therapeutic applications.

Message in the bottle: regulation of the tumor microenvironment via exosome-driven proteolysis

Exosomes comprise a subtype of extracellular vesicles involved in cell-to-cell communication, specifically by transporting biological molecules, such as proteins and nucleic acids, to either local or more distant recipient cells, thus triggering distinct biological behaviors. Included in the exosome cargo is frequently a wide range of proteolytic enzymes, such as the matrix metalloproteinases (MMPs), the disintegrin and metalloproteinases (ADAMs), and the ADAM with thrombospondin-like motifs (ADAMTSs), whose functions contribute to the development and progression of cancer. In recent years, extensive research on the potential use of exosomes in diagnostic and therapeutic applications for personalized medicine has emerged, but the targeting of the proteolytic cargo of exosomes has not been fully exploited in this direction. In this review, we aim to explore both the mechanistic and the translational importance of proteolytic enzymes carried by the tumor cell-derived exosomes, as well as their role in the acquisition and support of certain hallmarks of cancer.

Role of the Hypoxic-Secretome in Seed and Soil Metastatic Preparation

During tumor growth, the delivery of oxygen to cells is impaired due to aberrant or absent vasculature. This causes an adaptative response that activates the expression of genes that control several essential processes, such as glycolysis, neovascularization, immune suppression, and the cancer stemness phenotype, leading to increased metastasis and resistance to therapy. Hypoxic tumor cells also respond to an altered hypoxic microenvironment by secreting vesicles, factors, cytokines and nucleic acids that modify not only the immediate microenvironment but also organs at distant sites, allowing or facilitating the attachment and growth of tumor cells and contributing to metastasis. Hypoxia induces the release of molecules of different biochemical natures, either secreted or inside extracellular vesicles, and both tumor cells and stromal cells are involved in this process. The mechanisms by which these signals that can modify the premetastatic niche are sent from the primary tumor site include changes in the extracellular matrix, recruitment and activation of different stromal cells and immune or nonimmune cells, metabolic reprogramming, and molecular signaling network rewiring. In this review, we will discuss how hypoxia might alter the premetastatic niche through different signaling molecules.

Biomarker and therapeutic potential of peripheral extracellular vesicles in Alzheimer's disease

Extracellular vesicles (EVs) are cell-derived nanoparticles with an important role in intercellular communication, even across brain barriers. The bidirectional brain-barrier crossing capacity of EVs is supported by research identifying neuronal markers in peripheral EVs, as well as the brain delivery of peripherally administered EVs. In addition, EVs are reflective of their cellular origin, underlining their biomarker and therapeutic potential when released by diseased and regenerative cells, respectively. Both characteristics are of interest in Alzheimer's disease (AD) where the current biomarker profile is solely based on brain-centered readouts and effective therapeutic options are lacking. In this review, we elaborate on the role of peripheral EVs in AD. We focus on bulk EVs and specific EV subpopulations including bacterial EVs (bEVs) and neuronal-derived EVs (nEVs), which have mainly been studied from a biomarker perspective. Furthermore, we highlight the therapeutic potential of peripherally administered EVs whereby research has centered around stem cell derived EVs.

Diagnostic and prognostic significance of SLC50A1 expression in patients with primary early breast cancer

There is a lack of validated biomarkers for the diagnosis of early breast cancer (EBC). The current study aimed to determine the diagnostic and prognostic value of solute carrier family 50 member 1 (SLC50A1) in patients with EBC. Therefore, 123 patients with EBC, 30 patients with benign breast disease (BBD) and 26 healthy controls (HCs) were recruited. The serum levels of SLC50A1 in paired sera of 40 postoperative patients were assessed by ELISA. Immunohistochemical staining for SLC50A1 was performed in surgical tissue derived from 83 patients with EBC and 30 patients with BBD. mRNA expression of SLC50A1 and its diagnostic and prognostic value in patients with EBC was evaluated using an RNA-sequencing database. The results showed that serum levels of SLC50A1 in patients with EBC were significantly higher compared with those in patients with BBD and HCs (both P<0.001). Additionally, receiver operating characteristic curve analysis revealed that the serum levels of SLC50A1 distinguished patients with EBC from patients with BBD and HCs with a sensitivity of 76.42% and specificity of 76.79% [area under the curve (AUC)=0.783; P<0.001]. The diagnostic value of SLC50A1 was significantly greater than that of carcinoembryonic (P<0.005) and carbohydrate antigen 15-3 (P<0.029). Furthermore, the number of SLC50A1 positive cells significantly increased in tissue of patients with EBC compared with patients with BBD (P<0.001). A positive association between serum levels of SLC50A1 and its expression in tissue samples was observed in patients with EBC (ρ=0.700; P<0.001). Additionally, bioinformatics analysis verified the diagnostic value of SLC50A1, with an AUC of 0.983 (P<0.001). Multivariate analysis demonstrated that SLC50A1 was an independent prognostic factor in patients with EBC with a hazard ratio of 1.917 (P=0.013). These findings indicated that SLC50A1 may be a potential diagnostic biomarker for primary EBC and that SLC50A1 upregulation may be associated with unfavorable prognosis in patients with EBC.

Composition, Biogenesis, and Role of Exosomes in Tumor Development

The role of exosomes and their mechanism of action at the tumor site have received increasing attention. These microvesicles are produced by a wide range of cells including mesenchymal stem cells (MSCs) and immune cells. In particular, tumor cells release remarkable amounts of exosomes which spread to distant organs through the blood and enhance the possibility of tumor metastasis. In spite of results on tumor promoting properties, there are reports demonstrating the tumor inhibiting effects of exosomes depending on the type of the tumor and cell source. This review aims to have a comprehensive appraisal on the biogenesis, composition, and isolation of exosomes and then highlights the current knowledge of their role in cancer progression or inhibition by special focusing on MSC's exosomes (MSC-EXOs).

Distinct functions of dimeric and monomeric scaffold protein Alix in regulating F-actin assembly and loading of exosomal cargo

Alix is a ubiquitously expressed scaffold protein that participates in numerous cellular processes related to the remodeling/repair of membranes and the actin cytoskeleton. Alix exists in monomeric and dimeric/multimeric configurations, but how dimer formation occurs and what role the dimer has in Alix-mediated processes are still largely elusive. Here, we reveal a mechanism for Alix homodimerization mediated by disulfide bonds under physiological conditions, and demonstrate that the Alix dimer is enriched in exosomes and F-actin cytoskeleton subcellular fractions. Proteomic analysis of exosomes derived from Alix^-/- primary cells underlined the indispensable role of Alix in loading syntenin into exosomes, thereby regulating the cellular levels of this protein. Using a set of deletion mutants, we define the function of Alix Bro1 domain, which is solely required for its exosomal localization, and that of the V domain, which is needed for recruiting syntenin into exosomes. We reveal an essential role for Cys⁸¹⁴ within the disordered proline rich domain (PRD) for Alix dimerization. By mutating this residue, we show that Alix remains exclusively monomeric and, in this configuration, is effective in loading syntenin into exosomes. In contrast, loss of dimerization affects the ability of Alix to associate with F-actin, thereby compromising Alix-mediated cytoskeleton remodeling. We propose that dimeric and monomeric forms of Alix selectively execute two of the protein's main functions: exosomal cargo loading and cytoskeleton remodeling.

Extracellular Vesicles-ceRNAs as Ovarian Cancer Biomarkers: Looking into circRNA-miRNA-mRNA Code

Simple Summary

Patients with ovarian cancer have a very poor chance of long-term survival, usually due to advanced disease at the time of diagnosis. Emerging evidence suggests that extracellular vesicles contain noncoding RNAs such as microRNAs, piwiRNAs, circular RNAs, and long noncoding RNAs, with regulatory effects on ovarian cancer. In this review, we focus on ovarian cancer-associated circular RNA shuttled by extracellular vesicles as mediators of cancer progression and novel biomarkers in liquid biopsy. We propose a circular-RNA–microRNA-mRNA code that can reveal the regulatory network created by extracellular vesicles, noncoding RNAs, and mRNAs in ovarian cancer. Future research in this field will help to identify novel diagnostic biomarkers and druggable therapeutic targets, which will ultimately benefit patients.

Abstract

Ovarian cancer (OC) is one of the most lethal gynecologic malignancies in females worldwide. OC is frequently diagnosed at an advanced stage due to a lack of specific symptoms and effective screening tests, resulting in a poor prognosis for patients. Age, genetic alterations, and family history are the major risk factors for OC pathogenesis. Understanding the molecular mechanisms underlying OC progression, identifying new biomarkers for early detection, and discovering potential targets for new drugs are urgent needs. Liquid biopsy (LB), used for cancer detection and management, consists of a minimally invasive approach and practical alternative source to investigate tumor alterations by testing extracellular vesicles (EVs), circulating tumor cells, tumor-educated platelets, and cell-free nucleic acids. EVs are nanosize vesicles shuttling proteins, lipids, and nucleic acids, such as DNA, RNA, and non-coding RNAs (ncRNAs), that can induce phenotypic reprogramming of target cells. EVs are natural intercellular shuttles for ncRNAs, such as microRNAs (miRNAs) and circular-RNAs (circRNAs), known to have regulatory effects in OC. Here we focus on the involvement of circRNAs and miRNAs in OC cancer progression. The circRNA-microRNA-mRNA axis has been investigated with Circbank and miRwalk analysis, unraveling the intricate and detailed regulatory network created by EVs, ncRNAs, and mRNAs in OC.

Vesicle Induced Receptor Sequestration: Mechanisms behind Extracellular Vesicle-Based Protein Signaling

Extracellular vesicles (EVs) are fundamental for proper physiological functioning of multicellular organisms. By shuttling nucleic acids and proteins between cells, EVs regulate a plethora of cellular processes, especially those involved in immune signalling. However, the mechanistic understanding concerning the biophysical principles underlying EV-based communication is still incomplete. Towards holistic understanding, particular mechanisms explaining why and when cells apply EV-based communication and how protein-based signalling is promoted by EV surfaces are sought. Here, the authors study vesicle-induced receptor sequestration (VIRS) as a universal mechanism augmenting the signalling potency of proteins presented on EV-membranes. By bottom-up reconstitution of synthetic EVs, the authors show that immobilization of the receptor ligands FasL and RANK on EV-like vesicles, increases their signalling potential by more than 100-fold compared to their soluble forms. Moreover, the authors perform diffusion simulations within immunological synapses to compare receptor activation between soluble and EV-presented proteins. By this the authors propose vesicle-triggered local clustering of membrane receptors as the principle structural mechanism underlying EV-based protein presentation. The authors conclude that EVs act as extracellular templates promoting the local aggregation of membrane receptors at the EV contact site, thereby fostering inter-protein interactions. The results uncover a potentially universal mechanism explaining the unique structural profit of EV-based intercellular signalling.

L1CAM-associated extracellular vesicles: A systematic review of nomenclature, sources, separation, and characterization

When released into biological fluids like blood or saliva, brain extracellular vesicles (EVs) might provide a window into otherwise inaccessible tissue, contributing useful biomarkers of neurodegenerative and other central nervous system (CNS) diseases. To enrich for brain EVs in the periphery, however, cell-specific EV surface markers are needed. The protein that has been used most frequently to obtain EVs of putative neuronal origin is the transmembrane L1 cell adhesion molecule (L1CAM/CD171). In this systematic review, we examine the existing literature on L1CAM and EVs, including investigations of both neurodegenerative disease and cancer through the lens of the minimal information for studies of EVs (MISEV), specifically in the domains of nomenclature usage, EV sources, and EV separation and characterization. Although numerous studies have reported L1CAM-associated biomarker signatures that correlate with disease, interpretation of these results is complicated since L1CAM expression is not restricted to neurons and is also upregulated during cancer progression. A recent study has suggested that L1CAM epitopes are present in biofluids mostly or entirely as cleaved, soluble protein. Our findings on practices and trends in L1CAM-mediated EV separation, enrichment, and characterization yield insights that may assist with interpreting results, evaluating rigor, and suggesting avenues for further exploration.

Cancer Stem Cells in Ovarian Cancer-A Source of Tumor Success and a Challenging Target for Novel Therapies

Ovarian cancer is the most lethal neoplasm of the female genital organs. Despite indisputable progress in the treatment of ovarian cancer, the problems of chemo-resistance and recurrent disease are the main obstacles for successful therapy. One of the main reasons for this is the presence of a specific cell population of cancer stem cells. The aim of this review is to show the most contemporary knowledge concerning the biology of ovarian cancer stem cells (OCSCs) and their impact on chemo-resistance and prognosis in ovarian cancer patients, as well as to present the treatment options targeted exclusively on the OCSCs. The review presents data concerning the role of cancer stem cells in general and then concentrates on OCSCs. The surface and intracellular OCSCs markers and their meaning both for cancer biology and clinical prognosis, signaling pathways specifically activated in OCSCs, the genetic and epigenetic regulation of OCSCs function including the recent studies on the non-coding RNA regulation, cooperation between OCSCs and the tumor microenvironment (ovarian cancer niche) including very specific environment such as ascites fluid, the role of shear stress, autophagy and metabolic changes for the function of OCSCs, and finally mechanisms of OCSCs escape from immune surveillance, are described and discussed extensively. The possibilities of anti-OCSCs therapy both in experimental settings and in clinical trials are presented, including the recent II phase clinical trials and immunotherapy. OCSCs are a unique population of cancer cells showing a great plasticity, self-renewal potential and resistance against anti-cancer treatment. They are responsible for the progression and recurrence of the tumor. Several completed and ongoing clinical trials have tested different anti-OCSCs drugs which, however, have shown unsatisfactory efficacy in most cases. We propose a novel approach to ovarian cancer diagnosis and therapy.

Scramblases as Regulators of Proteolytic ADAM Function

Proteolytic ectodomain release is a key mechanism for regulating the function of many cell surface proteins. The sheddases ADAM10 and ADAM17 are the best-characterized members of the family of transmembrane disintegrin-like metalloproteinase. Constitutive proteolytic activities are low but can be abruptly upregulated via inside-out signaling triggered by diverse activating events. Emerging evidence indicates that the plasma membrane itself must be assigned a dominant role in upregulation of sheddase function. Data are discussed that tentatively identify phospholipid scramblases as central players during these events. We propose that scramblase-dependent externalization of the negatively charged phospholipid phosphatidylserine (PS) plays an important role in the final activation step of ADAM10 and ADAM17. In this manuscript, we summarize the current knowledge on the interplay of cell membrane changes, PS exposure, and proteolytic activity of transmembrane proteases as well as the potential consequences in the context of immune response, infection, and cancer. The novel concept that scramblases regulate the action of ADAM-proteases may be extendable to other functional proteins that act at the cell surface.

Cancer Stem Cells: An Ever-Hiding Foe

Cancer stem cells are a population of cells enable to reproduce the original phenotype of the tumor and capable to self-renewal, which is crucial for tumor proliferation, differentiation, recurrence, and metastasis, as well as chemoresistance. Therefore, the cancer stem cells (CSCs) have become one of the main targets for anticancer therapy and many ongoing clinical trials test anti-CSCs efficacy of plenty of drugs. This chapter describes CSCs starting from general description of this cell population, through CSCs markers, signaling pathways, genetic and epigenetic regulation, role of epithelial-mesenchymal transition (EMT) transition and autophagy, cooperation with microenvironment (CSCs niche), and finally role of CSCs in escaping host immunosurveillance against cancer.

Exosomes in the Healthy and Malignant Bone Marrow Microenvironment

The bone marrow (BM) is a complex organ that sustains hematopoiesis via mechanisms involving the microenvironment. The microenvironment includes several cell types, neurotransmitters from innervated fibers, growth factors, extracellular matrix proteins, and extracellular vesicles. The main function of the BM is to regulate hematopoietic function to sustain the production of blood and immune cells. However, the BM microenvironment can also accommodate the survival of malignant cells. A major mechanism by which the cancer cells communicate with cells of the BM microenvironment is through the exchange of exosomes, a subset of extracellular vesicles that deliver molecular signals bidirectionally between malignant and healthy cells. The field of exosomes is an active area of investigation since an understanding of how the exosomal packaging, cargo, and production can be leveraged therapeutically to deter cancer progression and sensitize malignant cells to other therapies. Altogether, this chapter discusses the crucial role of exosomes in the development and progression of BM-associated cancers, such as hematologic malignancies and marrow-metastatic breast cancer. Exosome-based therapeutic strategies and their limitations are also considered.

Cell adhesion molecule L1 interacts with the chromo shadow domain of heterochromatin protein 1 isoforms α, β, and ɣ via its intracellular domain

Cell adhesion molecule L1 regulates multiple cell functions and L1 deficiency is linked to several neural diseases. Proteolytic processing generates functionally decisive L1 fragments, which are imported into the nucleus. By computational analysis, we found at L1's C-terminal end the chromo shadow domain-binding motif PxVxL, which directs the binding of nuclear proteins to the heterochromatin protein 1 (HP1) isoforms α, β, and ɣ. By enzyme-linked immunosorbent assay, we show that the intracellular L1 domain binds to all HP1 isoforms. These interactions involve the HP1 chromo shadow domain and are mediated via the sequence ₁₁₅₈ KDET₁₁₆₁ in the intracellular domain of murine L1, but not by L1's C-terminal PxVxL motif. Immunoprecipitation using nuclear extracts from the brain and from cultured cerebellar and cortical neurons indicates that HP1 isoforms interact with a yet unknown nuclear L1 fragment of approximately 55 kDa (L1-55), which carries ubiquitin residues. Proximity ligation indicates a close association between L1-55 and the HP1 isoforms in neuronal nuclei. This association is reduced after the treatment of neurons with inhibitors of metalloproteases, β-site of amyloid precursor protein cleaving enzyme (BACE1), or ɣ-secretase, suggesting that cleavage of full-length L1 by these proteases generates L1-55. Reduction of HP1α, -β, or -ɣ expression by siRNA decreases L1-dependent neurite outgrowth from cultured cortical neurons and decreases the L1-dependent migration of L1-transfected HEK293 cells in a scratch assay. These findings indicate that the interaction of the novel fragment L1-55 with HP1 isoforms in nuclei affects L1-dependent functions, such as neurite outgrowth and neuronal migration.

Role of L1CAM in retinoblastoma tumorigenesis: identification of novel therapeutic targets

The study presented focuses on the role of the neuronal cell adhesion molecule L1 cell adhesion molecule (L1CAM) in retinoblastoma (RB), the most common malignant intraocular childhood tumor. L1CAM is differentially expressed in a variety of human cancers and has been suggested as a promising therapeutic target. We likewise observed differential expression patterns for L1CAM in RB cell lines and patient samples. The two proteases involved in ectodomain shedding of L1CAM (L1CAM sheddases: ADAM10 and ADAM17) were likewise differentially expressed in the RB cell lines investigated, and an involvement in L1CAM processing in RB cells could be verified. We also identified ezrin, galectin-3, and fibroblast growth factor basic as L1CAM signaling target genes in RB cells. Lentiviral L1CAM knockdown induced apoptosis and reduced cell viability, proliferation, growth, and colony formation capacity of RB cells, whereas L1CAM-overexpressing RB cells displayed the opposite effects. Chicken chorioallantoic membrane assays revealed that L1CAM depletion decreases the tumorigenic and migration potential of RB cells in vivo. Moreover, L1CAM depletion decreased viability and tumor growth of etoposide-resistant RB cell lines upon etoposide treatment in vitro and in vivo. Thus, L1CAM and its processing sheddases are potential novel targets for future therapeutic RB approaches.

Multi-Omics Data Integration in Extracellular Vesicle Biology-Utopia or Future Reality?

Extracellular vesicles (EVs) are membranous structures derived from the endosomal system or generated by plasma membrane shedding. Due to their composition of DNA, RNA, proteins, and lipids, EVs have garnered a lot of attention as an essential mechanism of cell-to-cell communication, with various implications in physiological and pathological processes. EVs are not only a highly heterogeneous population by means of size and biogenesis, but they are also a source of diverse, functionally rich biomolecules. Recent advances in high-throughput processing of biological samples have facilitated the development of databases comprised of characteristic genomic, transcriptomic, proteomic, metabolomic, and lipidomic profiles for EV cargo. Despite the in-depth approach used to map functional molecules in EV-mediated cellular cross-talk, few integrative methods have been applied to analyze the molecular interplay in these targeted delivery systems. New perspectives arise from the field of systems biology, where accounting for heterogeneity may lead to finding patterns in an apparently random pool of data. In this review, we map the biological and methodological causes of heterogeneity in EV multi-omics data and present current applications or possible statistical methods for integrating such data while keeping track of the current bottlenecks in the field.

The cell adhesion molecule L1 interacts with nuclear proteins via its intracellular domain

Proteolytic cleavage of the cell adhesion molecule L1 (L1) in brain tissue and in cultured cerebellar neurons results in the generation and nuclear import of a 30 kDa fragment comprising most of L1's C-terminal, intracellular domain. In search of molecules that interact with this domain, we performed affinity chromatography with the recombinant intracellular L1 domain and a nuclear extract from mouse brains, and identified potential nuclear L1 binding partners involved in transcriptional regulation, RNA processing and transport, DNA repair, chromatin remodeling, and nucleocytoplasmic transport. By co-immunoprecipitation and enzyme-linked immunosorbent assay using recombinant proteins, we verified the direct interaction between L1 and the nuclear binding partners non-POU domain containing octamer-binding protein and splicing factor proline/glutamine-rich. The proximity ligation assay confirmed this close interaction in cultures of cerebellar granule cells. Our findings suggest that L1 fragments regulate multiple nuclear functions in the nervous system. We discuss possible physiological and pathological roles of these interactions in regulation of chromatin structure, gene expression, RNA processing, and DNA repair.

Distinct Cargos of Small Extracellular Vesicles Derived from Hypoxic Cells and Their Effect on Cancer Cells

Hypoxia is a common hallmark of solid tumors and is associated with aggressiveness, metastasis and poor outcome. Cancer cells under hypoxia undergo changes in metabolism and there is an intense crosstalk between cancer cells and cells from the tumor microenvironment. This crosstalk is facilitated by small extracellular vesicles (sEVs; diameter between 30 and 200 nm), including exosomes and microvesicles, which carry a cargo of proteins, mRNA, ncRNA and other biological molecules. Hypoxia is known to increase secretion of sEVs and has an impact on the composition of the cargo. This sEV-mediated crosstalk ultimately leads to various biological effects in the proximal tumor microenvironment but also at distant, future metastatic sites. In this review, we discuss the changes induced by hypoxia on sEV secretion and their cargo as well as their effects on the behavior and metabolism of cancer cells, the tumor microenvironment and metastatic events.

Exosomes in Sepsis and Inflammatory Tissue Injury

Sepsis is the leading cause of death in medical intensive care units, and thus represents a serious healthcare problem worldwide. Sepsis is often caused by the aberrant host responses to infection, which induce dysregulated inflammation that leads to life-threatening multiple organ failures. Mediators such as proinflammatory cytokines that drive the sepsis pathogenesis have been extensively studied. Exosomes, biological lipid bilayer nanoparticles secreted via the endosomal pathway of cells, have recently emerged as important cargos that carry multiple mediators critical for the pathogenesis of sepsis-associated organ dysfunctions. Here we will review current knowledge on the exosomes in sepsis and relevant inflammatory tissue injuries.

Targeting Cancer Stem Cells to Overcome Therapy Resistance in Ovarian Cancer

Ovarian cancer is the most lethal gynecological malignancy due to its late detection and high recurrence rate. Resistance to conventional platinum-based therapies and metastasis are attributed to a population of cells within tumors called cancer stem cells, which possess stem-like features and are able to recapitulate new tumors. Recent studies have deepened the understanding of the biology of ovarian cancer stem cells and their special properties and have identified multiple markers and signaling pathways responsible for their self-renewal abilities. Targeting cancer stem cells represents the most promising strategy for overcoming therapy resistance and reducing mortality in ovarian cancer, but further efforts must be made to improve our understanding of the mechanisms involved in therapy resistance. In this review, we summarize our current knowledge about ovarian cancer stem cells, their involvement in metastasis and their interactions with the tumor microenvironment; we also discuss the therapeutic approaches that are being developed to target them to prevent tumor relapse.

Expression and serum levels of the neural cell adhesion molecule L1-like protein (CHL1) in gastrointestinal stroma tumors (GIST) and its prognostic power

INTRODUCTION

Diagnosis of gastrointestinal stroma tumors (GIST) is based on the histological evaluation of tissue specimens. Reliable systemic biomarkers are lacking. We investigated the local expression of the neural cell adhesion molecule L1-like protein (CHL1) in GIST and determined whether soluble CHL1 proteoforms could serve as systemic biomarkers.

MATERIAL AND METHODS

Expression of CHL1 was analyzed in primary tumor specimens and metastases. 58 GIST specimens were immunohistochemically stained for CHL1 on a tissue microarray (TMA). Systemic CHL1 levels were measured in sera derived from 102 GIST patients and 91 healthy controls by ELISA. Results were statistically correlated with clinicopathological parameters.

RESULTS

CHL1 expression was detected in GIST specimens. Reduced tissue expression was significantly associated with advanced UICC stages (p = 0.036) and unfavorable tumor localization (p = 0.001). CHL1 serum levels are significantly elevated in GIST patients (p < 0.010). Elevated CHL1 levels were significantly associated with larger tumors (p = 0.023), advanced UICC stage (p = 0.021), and an increased Fletcher score (p = 0.041). Moreover, patients with a higher CHL1 serum levels displayed a significantly shortened recurrence free survival independent of other clinicopathological variables.

CONCLUSION

Local CHL1 expression and serum CHL1 levels show a reverse prognostic behavior, highlighting the relevance of proteolytic shedding of the molecule. The results of the study indicate a potential role of serum CHL1 as a diagnostic and prognostic marker in GIST.

Pathophysiological Role and Potential Therapeutic Exploitation of Exosomes in Ovarian Cancer

Exosomes are extracellular vesicles involved in several biological and pathological molecules and can carry many bioactive materials to target cells. They work as important mediators of cell-cell communication and play essential roles in many diseases, especially in cancer. Ovarian cancer is one of the most common gynecological malignancies. Most patients are diagnosed at advanced stages involving widespread peritoneal dissemination, resulting in poor prognosis. Emerging evidence has shown that exosomes play vital roles throughout the progression of ovarian cancer. Moreover, the development of engineered exosome-based therapeutic applications— including drug delivery systems, biomolecular targets and immune therapy—has increased drastically. Herein, we review the functional features of exosomes in ovarian cancer progression and the therapeutic application potential of exosomes as novel cancer treatments.

Overview of current microRNA biomarker signatures as potential diagnostic tools for leukaemic conditions

Haematological malignancies encompass all variations of leukaemia at both the chronic and acute level, together with the specific cell type induced into tumourigenesis. Current diagnostic protocols for leukaemic conditions rely heavily on cytomorphology and other histological examinations from bone marrow aspirates, with the latter being a highly invasive surgical procedure for the patient. The discovery of microRNAs as one of the key gene regulatory networks in the past two decades has enabled researchers to investigate the possibility of exploiting the identification of dysregulated expression profiles for specific microRNAs present in the leukaemic patient's bloodstream as novel liquid biopsy diagnostic tools. This review article serves to consolidate recent global research efforts aiming to achieve such scopes.

Exosomes derived from Piwil2‑induced cancer stem cells transform fibroblasts into cancer‑associated fibroblasts

Recently, several studies have demonstrated that cancer cell‑derived exosomes can facilitate tumor development and metastasis formation. However, the detailed function of exosomes released by cancer stem cells (CSCs) requires further investigation. The aim of the present study was to investigate the role of CSC‑derived exosomes in tumor development. For this purpose, Piwil2‑induced cancer stem cells (Piwil2‑iCSCs) were used as exosome‑generating cells, while fibroblasts (FBs) served as recipient cells. Exosomes were isolated by the ultracentrifugation of Piwil2‑iCSC‑conditioned medium and identified by transmission electron microscopy, nanoparticle tracking analysis and western blot analysis. To evaluate the effects of the exosomes on cell proliferation, migration and invasion, cell counting assay (CCK‑8), a wound healing assay and a Transwell assay were performed. Protein expression [matrix metalloproteinase (MMP)2, MMP9, α‑smooth muscle actin (α‑SMA) and vimentin and fibroblast‑activating protein (FAP)] was examined in FBs by western blot analysis. It was found that the Piwil2‑iCSC‑derived exosomes (Piwil2‑iCSC‑Exo) were oval or spherical, membrane‑coated vesicles with a uniform size (30‑100 nm in diameter). They are characterized by the surface expression of CD9, CD63, Hsp70 and Piwil2 proteins. Additional results from functional analyses revealed that Piwil2‑iCSC‑Exo enhanced the proliferative, migratory and invasive abilities of FBs, accompanied by the upregulated expression of MMP2 and MMP9. In addition, the increased expression of α‑SMA (P<0.05), vimentin (P<0.01 vs. control group, P<0.05 vs. PBS group) and FAP (P<0.001 vs. control group, P<0.01 vs. PBS group) following exposure to Piwil2‑iCSC‑Exo suggested that the exosomes induced FB transformation into cancer‑associated fibroblasts (CAFs). On the whole, the findings of this study demonstrate that Piwil2‑iCSC‑Exo induce the cancer‑associated phenotype in fibroblasts in vitro, suggesting that CSCs can promote tumor development through the modulation of the tumor microenvironment.

Circulating Levels of L1-cell Adhesion Molecule as a Serum Biomarker for Early Detection of Gastric Cancer and Esophagogastric Junction Adenocarcinoma

Background: Low serum L1 cell adhesion molecule (L1CAM) has been found in several malignant tumors. Here, we aimed to evaluate the diagnostic potential for serum L1CAM in patients with gastric cancers (GC) and esophagogastric junction adenocarcinoma (EJA). Methods: Enzyme-linked immunosorbent assay (ELISA) was carried out to detect L1CAM level in sera of 148 GC patients, 59 EJA patients and 148 healthy controls. Receiver operating characteristics (ROC) was employed to evaluate diagnostic accuracy. Results: The concentrations of serum L1CAM were significantly lower in GC and EJA than those in healthy controls (P<0.001). Detection of L1CAM provided a sensitivity of 83.1%, a specificity of 62.2%, and an area under the curve (AUC) of 0.769 (95% CI: 0.715-0.823) in diagnosing GC, and a sensitivity of 66.1%, a specificity of 62.2%, and an AUC of 0.672 (95% CI: 0.590-0.755) in diagnosing EJA. Similar results were observed in the diagnosis of early-stage GC (0.681 (95%CI: 0.596-0.766)) and early-stage EJA (0.674 (95%CI: 0.528-0.820)). Analysis of clinical data showed that the levels of L1CAM were significantly associated with lymph node metastasis in GC (P<0.05). Conclusions: Our study showed that serum L1CAM might be a diagnostic biomarker for GC and EJA.

Role of Matrix Metalloproteinases in Angiogenesis and Cancer

During angiogenesis, new vessels emerge from existing endothelial lined vessels to promote the degradation of the vascular basement membrane and remodel the extracellular matrix (ECM), followed by endothelial cell migration, and proliferation and the new generation of matrix components. Matrix metalloproteinases (MMPs) participate in the disruption, tumor neovascularization, and subsequent metastasis while tissue inhibitors of metalloproteinases (TIMPs) downregulate the activity of these MMPs. Then, the angiogenic response can be directly or indirectly mediated by MMPs through the modulation of the balance between pro- and anti-angiogenic factors. This review analyzes recent knowledge on MMPs and their participation in angiogenesis.

Membrane-bound Gaussia luciferase as a tool to track shedding of membrane proteins from the surface of extracellular vesicles

Extracellular vesicles (EVs) released by cells play a role in intercellular communication. Reporter and targeting proteins can be modified and exposed on the surface of EVs to investigate their half-life and biodistribution. A characterization of membrane-bound Gaussia luciferase (mbGluc) revealed that its signal was detected also in a form smaller than common EVs (<70 nm). We demonstrated that mbGluc initially exposed on the surface of EVs, likely undergoes proteolytic cleavage and processed fragments of the protein are released into the extracellular space in active form. Based on this observation, we developed a new assay to quantitatively track shedding of membrane proteins from the surface of EVs. We used this assay to show that ectodomain shedding in EVs is continuous and is mediated by specific proteases, e.g. metalloproteinases. Here, we present a novel tool to study membrane protein cleavage and release using both in vitro and in vivo models.

Exosomes: Current use and future applications

Exosomes are endosomal-derived vesicles that play a critical role in cell-to-cell communication and are secreted in several biological fluids including serum, saliva, urine, ascites, and cerebro-spinal fluid amongst others. Exosomes are small (30-150 nm diameter) with a distinctive bilipid protein structure. They can carry and exchange various cargos between cells and are used as a non-invasive biomarker for several diseases. Exosomes are considered the best biomarkers for cancer diagnosis, owing to their unique characteristics. Here, we provide a review of the up-to-date applications of exosomes, derived from various sources, in the prognosis and diagnosis of several diseases including cancer, cardiovascular and regenerative diseases as well as, arthritis, neurological diseases, and diabetes mellitus. The role of exosomes and their applications in biomedical research and preclinical trials have also been briefly discussed.

L1 Cell Adhesion Molecule in Cancer, a Systematic Review on Domain-Specific Functions

L1 cell adhesion molecule (L1CAM) is a glycoprotein involved in cancer development and is associated with metastases and poor prognosis. Cellular processing of L1CAM results in expression of either full-length or cleaved forms of the protein. The different forms of L1CAM may localize at the plasma membrane as a transmembrane protein, or in the intra- or extracellular environment as cleaved or exosomal forms. Here, we systematically analyze available literature that directly relates to L1CAM domains and associated signaling pathways in cancer. Specifically, we chart its domain-specific functions in relation to cancer progression, and outline pre-clinical assays used to assess L1CAM. It is found that full-length L1CAM has both intracellular and extracellular targets, including interactions with integrins, and linkage with ezrin. Cellular processing leading to proteolytic cleavage and/or exosome formation results in extracellular soluble forms of L1CAM that may act through similar mechanisms as compared to full-length L1CAM, such as integrin-dependent signals, but also through distinct mechanisms. We provide an algorithm to guide a step-wise analysis on L1CAM in clinical samples, to promote interpretation of domain-specific expression. This systematic review infers that L1CAM has an important role in cancer progression that can be attributed to domain-specific forms. Most studies focus on the full-length plasma membrane L1CAM, yet knowledge on the domain-specific forms is a prerequisite for selective targeting treatment.

Role of the Exosome in Ovarian Cancer Progression and Its Potential as a Therapeutic Target

Peritoneal dissemination is a distinct form of metastasis in ovarian cancer that precedes hematogenic or lymphatic metastasis. Exosomes are extracellular vesicles of 30–150 nm in diameter secreted by different cell types and internalized by target cells. There is emerging evidence that exosomes facilitate the peritoneal dissemination of ovarian cancer by mediating intercellular communication between cancer cells and the tumor microenvironment through the transfer of nucleic acids, proteins, and lipids. Furthermore, therapeutic applications of exosomes as drug cargo delivery are attracting research interest because exosomes are stabilized in circulation. This review highlights the functions of exosomes in each process of the peritoneal dissemination of ovarian cancer and discusses their potential for cancer therapeutics.

Ovarian Cancer Stem Cells: Role in Metastasis and Opportunity for Therapeutic Targeting

Ovarian cancer (OC) is a heterogeneous disease usually diagnosed at a late stage. Cancer stem cells (CSCs) that exist within the bulk tumor survive first-line chemotherapy and contribute to resistant disease with metastasis. Understanding the key features of CSC biology provides valuable opportunities to develop OCSC-directed therapeutics, which will eventually improve the clinical outcomes of patients. Although significant developments have occurred since OCSCs were first described, the involvement of CSCs in ovarian tumor metastasis is not fully understood. Here, we discuss putative CSC markers and the fundamental role of CSCs in facilitating tumor dissemination in OC. Additionally, we focus on promising CSC-targeting strategies in preclinical and clinical studies of OC and discuss potential challenges in CSC research.

Exosome-orchestrated hypoxic tumor microenvironment

Hypoxic tumor microenvironment is a common feature of solid tumors and is associated with aggressiveness and poor patient outcomes. A continuous interference between cancer cells and stromal cells within the hypoxic microenvironment has been uncovered for its importance in cancer development and treatment responsiveness. Exosomes, initially considered as “garbage bins” for unwanted material from cells, are now elucidated to perform a variety of functions that involve interactions within the cellular microenvironment due to their ability to carry numerous cargoes, including lipids, proteins, nucleic acids, and metabolites. Exosome-mediated continuous interference between cancer cells and stroma are believed to regulate hypoxia-adaptation and to rebuild the microenvironment in return. In this review, we will discuss the knowledge in literature with respect to the exosome-mediated multi-directional and mutual signal transmission among the variety of cell types within hypoxic cancer microenvironment.

Metalloproteinases at the surface of small extrcellular vesicles in advanced ovarian cancer: Relationships with ascites volume and peritoneal canceromatosis index

Metalloproteinases and their extracellular matrix metalloproteinase inducer (EMMPRIN) play an essential role in the regulation of signaling from growth factors receptors and adhesion molecules, cell motility and extracellular matrix degradation. The aim of the study was to evaluate the relationship between the levels of small extracellular vesicles (sEVs) metalloproteinases, such as ADAM10, ADAM17, MMP2, MMP9 and EMMPRIN and ascites volume and peritoneal canceromatosis index in advanced ovarian cancer patients (OCPs). The subpopulations of metalloproteinases at the surface of sEVs of borderline ovarian tumor patients (BOTPs) (n = 20, 36.5 ± 2.5 years) and previously untreated advanced OCPs (n = 35, 56.5 ± 2.5 years) were evaluated using flow cytometry. The metalloproteinase subpopulations of CD9-positive sEVs isolated from plasma of BOTPs and OCPs appeared to be quite similar. However, a significant difference in the expression of ADAM-metalloproteinases in ascites sEVs was found between BOTPs and OCPs. The level of sEVs metalloproteinases in OCPs significantly depended on the ascites volume. A statistically significant relationship between the level of ADAM10+/ADAM17- subpopulation in plasma sEVs and the peritoneal canceromatosis index was found (R = 0.66, p < .05). The levels of metalloproteinases and EMMPRIN in circulating sEVs, as well as the assessment of individual subpopulations may be promising approaches to OCPs managing.

Diagnostic and prognostic value of serum L1-cell adhesion molecule in esophageal squamous cell carcinoma

OBJECTIVE

L1 cell adhesion molecule (L1CAM) has been found to be dysregulated in several types of human cancers. Here, we aimed to determine the level of soluble L1CAM in serum of patients with esophageal squamous cell carcinoma (ESCC).

METHODS

Serum levels of L1CAM were determined by an enzyme-linked immunosorbent assay (ELISA) in 191 patients with ESCC and 94 normal controls. Receiver operating characteristics (ROC) was employed to calculate diagnostic accuracy. Cumulative survival time was calculated by the Kaplan-Meier method and analyzed by the logrank test.

RESULTS

Levels of L1CAM were significantly lower in all ESCC patients than in normal controls (P < 0.001). Detection of serum L1CAM provided a sensitivity of 28.3%, a specificity of 90.4% and an area under the curve (AUC) of 0.644 (95% CI: 0.579-0.710) in diagnosing ESCC. Similar results were observed in the diagnosis of early-stage ESCC (26.2% sensitivity, 90.4% specificity, and an AUC of 0.629). Moreover, decreased level of L1CAM was correlated with depth of tumor invasion (P < 0.05). Kaplan-Meier analysis showed that lower serum L1CAM level was significantly related to shorter overall survival time (P = 0.036) and disease-free survival time (P = 0.021) of ESCC patients.

CONCLUSIONS

Our study demonstrated that serum L1CAM might serve as a potential biomarker for the diagnosis and prognosis of ESCC.

Exosomes and Exosome-Inspired Vesicles for Targeted Drug Delivery

The similarities between exosomes and liposomes, together with the high organotropism of several types of exosomes, have recently prompted the development of engineered-exosomes or exosome-mimetics, which may be artificial (liposomal) or cell-derived vesicles, as advanced platforms for targeted drug delivery. Here, we provide the current state-of-the-art of using exosome or exosome-inspired systems for drug delivery. We review the various approaches investigated and the shortcomings of each approach. Finally the challenges which have been identified to date in this field are summarized.

Extracellular Vesicles and Matrix Remodeling Enzymes: The Emerging Roles in Extracellular Matrix Remodeling, Progression of Diseases and Tissue Repair

Extracellular vesicles (EVs) are membrane enclosed micro- and nano-sized vesicles that are secreted from almost every species, ranging from prokaryotes to eukaryotes, and from almost every cell type studied so far. EVs contain repertoire of bioactive molecules such as proteins (including enzymes and transcriptional factors), lipids, carbohydrates and nucleic acids including DNA, coding and non-coding RNAs. The secreted EVs are taken up by neighboring cells where they release their content in recipient cells, or can sail through body fluids to reach distant organs. Since EVs transport bioactive cargo between cells, they have emerged as novel mediators of extra- and intercellular activities in local microenvironment and inter-organ communications distantly. Herein, we review the activities of EV-associated matrix-remodeling enzymes such as matrix metalloproteinases, heparanases, hyaluronidases, aggrecanases, and their regulators such as extracellular matrix metalloproteinase inducers and tissue inhibitors of metalloproteinases as novel means of matrix remodeling in physiological and pathological conditions. We discuss how such EVs act as novel mediators of extracellular matrix degradation to prepare a permissive environment for various pathological conditions such as cancer, cardiovascular diseases, arthritis and metabolic diseases. Additionally, the roles of EV-mediated matrix remodeling in tissue repair and their potential applications as organ therapies have been reviewed. Collectively, this knowledge could benefit the development of new approaches for tissue engineering.

L1 Cell Adhesion Molecule and Its Soluble Form sL1 Exhibit Poor Prognosis in Primary Breast Cancer Patients

INTRODUCTION

The L1 cell adhesion molecule (L1-CAM) and its soluble form sL1 play a prominent role in invasion and metastasis in several cancers. However, its association with breast cancer is still unclear.

PATIENTS AND METHODS

We analyzed L1-CAM expression and serum sL1 levels in cancer and para-carcinoma tissues from 162 consecutive patients with primary invasive breast cancer (PBC) using immunohistochemistry and an enzyme-linked immunosorbent assay, respectively. The serum sL1 levels were also examined in 38 patients with benign breast disease and 36 healthy controls.

RESULTS

L1-CAM was expressed more frequently in cancer tissues than in para-carcinoma tissues (24.1% vs. 5.6%; P < .001), and the mean sL1 levels were significantly greater in PBC than in those with benign breast disease and healthy controls (P = .027). Both L1-CAM⁺ expression and higher mean sL1 levels correlated significantly with larger tumor size, lymph node involvement, higher histologic grade, advanced TNM stage, and shorter disease-free survival for PBC patients. Moreover, higher mean sL1 levels were also significantly associated with estrogen receptor-α-negative expression, human epidermal growth factor receptor 2-positive (HER2⁺) expression, HER2-enriched and triple-negative molecular subtypes, and L1-CAM⁺ expression (P < .05). On multivariate analysis, larger tumor size, nodal involvement, HER2⁺, and higher sL1 levels (≥ 0.7 ng/mL) were independent factors associated with L1-CAM⁺ expression (P < .05). No association was found between L1-CAM expression or sL1 level with age, gender, histologic type, or expression of progesterone receptor, Ki-67, p53, or vascular endothelial growth factor C (P > .05).

CONCLUSION

These results indicate that L1-CAM and sL1 are elevated in PBC and both might affect the prognosis of PBC patients. In addition, sL1 might be a useful marker for screening and diagnosis.

A Fragment of Adhesion Molecule L1 Binds to Nuclear Receptors to Regulate Synaptic Plasticity and Motor Coordination

Proteolytic cleavage of the neuronal isoform of the murine cell adhesion molecule L1, triggered by stimulation of the cognate L1-dependent signaling pathways, results in the generation and nuclear import of an L1 fragment that contains the intracellular domain, the transmembrane domain, and part of the extracellular domain. Here, we show that the LXXLL and FXXLF motifs in the extracellular and transmembrane domain of this L1 fragment mediate the interaction with the nuclear estrogen receptors α (ERα) and β (ERβ), peroxisome proliferator-activated receptor γ (PPARγ), and retinoid X receptor β (RXRβ). Mutations of the LXXLL motif in the transmembrane domain and of the FXXLF motif in the extracellular domain disturb the interaction of the L1 fragment with these nuclear receptors and, when introduced by viral transduction into mouse embryos in utero, result in impaired motor coordination, learning and memory, as well as synaptic connectivity in the cerebellum, in adulthood. These impairments are similar to those observed in the L1-deficient mouse. Our findings suggest that the interplay of nuclear L1 and distinct nuclear receptors is associated with synaptic contact formation and plasticity.

Soluble E-cadherin promotes tumor angiogenesis and localizes to exosome surface

The limitations of current anti-angiogenic therapies necessitate other targets with complimentary mechanisms. Here, we show for the first time that soluble E-cadherin (sE-cad) (an 80-kDa soluble form), which is highly expressed in the malignant ascites of ovarian cancer patients, is a potent inducer of angiogenesis. In addition to ectodomain shedding, we provide further evidence that sE-cad is abundantly released in the form of exosomes. Mechanistically, sE-cad-positive exosomes heterodimerize with VE-cadherin on endothelial cells and transduce a novel sequential activation of β-catenin and NFκB signaling. In vivo and clinical data prove the relevance of sE-cad-positive exosomes for malignant ascites formation and widespread peritoneal dissemination. These data advance our understanding of the molecular regulation of angiogenesis in ovarian cancer and support the therapeutic potential of targeting sE-cad. The exosomal release of sE-cad, which represents a common route for externalization in ovarian cancer, could potentially be biomarkers for diagnosis and prognosis.

A soluble form E-cadherin is highly expressed in ovarian cancer. Here, the authors show that soluble E-cadherin is released by ovarian cancer cells packaged in exosomes and promotes tumor angiogenesis through β-catenin and NFkB signaling activation.

Soluble CD157 in pleural effusions: a complementary tool for the diagnosis of malignant mesothelioma

Background

CD157/Bst1 glycoprotein is expressed in >85% of malignant pleural mesotheliomas and is a marker of enhanced tumor aggressiveness.

Results

In vitro, mesothelial cells (malignant and non-malignant) released CD157 in soluble form or as an exosomal protein. In vivo, sCD157 is released and can be measured in pleural effusions by ELISA. Significantly higher levels of effusion sCD157 were detected in patients with malignant pleural mesothelioma than in patients with non-mesothelioma tumors or with non-malignant conditions. In our patient cohort, the area under the receiver-operating characteristic curve for sCD157 that discriminated malignant pleural mesothelioma from all other causes of pleural effusion was 0.685, cut-off (determined by the Youden Index) = 23.66 ng/ml (62.3% sensitivity; 73.93% specificity). Using a cut-off that yielded 95.58% specificity, measurement of sCD157 in cytology-negative effusions increased sensitivity of malignant pleural mesothelioma diagnosis from 34.42% to 49.18%.

Conclusions

Evaluation of soluble CD157 in pleural effusions provides a diagnostic aid in malignant mesothelioma.

Methods

Soluble CD157 (sCD157) was detected biochemically in culture supernatants of malignant and non-malignant mesothelial cells, and in pleural effusions from various pathological conditions. An ELISA system was established to measure the concentration of sCD157 in fluids, and extended to analyze sCD157 in pleural effusions from a cohort of 295 patients.

Tumor cells derived exosomes contain hTERT mRNA and transform nonmalignant fibroblasts into telomerase positive cells

Exosomes are small (30-100nm) vesicles secreted from all cell types serving as inter-cell communicators and affecting biological processes in “recipient” cells upon their uptake. The current study demonstrates for the first time that hTERT mRNA, the transcript of the enzyme telomerase, is shuttled from cancer cells via exosomes into telomerase negative fibroblasts, where it is translated into a fully active enzyme and transforms these cells into telomerase positive, thus creating a novel type of cells; non malignant cells with telomerase activity. All tested telomerase positive cells, including cancer cells and non malignant cells with overexpressed telomerase secreted exosomal hTERT mRNA in accordance with the endogenous levels of their hTERT mRNA and telomerase activity. Similarly exosomes isolated from sera of patients with pancreatic and lung cancer contained hTERT mRNA as well. Telomerase activity induced phenotypic changes in the recipient fibroblasts including increased proliferation, extension of life span and postponement of senescence. In addition, telomerase activity protected the fibroblasts from DNA damage induced by phleomycin and from apoptosis, indicating that also telomerase “extracurricular” activities are manifested in the recipient cells. The shuttle of telomerase from cancer cells into fibroblasts and the induction of these changes may contribute to the alterations of cancer microenvironment and its role in cancer. The described process has an obvious therapeutic potential which will be explored in further studies.