Tumor extracellular vesicles drive metastasis (it's a long way from home).

Among a plethora of functions, extracellular vesicles released by primary tumors spread in the organism and reach distant organs where they can induce the formation of a premetastatic niche. This constitutes a favorable microenvironment for circulating tumor cells which facilitates their seeding and colonization. In this review, we describe the journey of extracellular vesicles (EVs) from the primary tumor to the future metastatic organ, with a focus on the mechanisms used by EVs to target organs with a specific tropism (i.e., organotropism). We then highlight important tumor EV cargos in the context of premetastatic niche formation and summarize their known effects on extracellular matrix remodeling, angiogenesis, vessel permeabilization, resident cell activation, recruitment of foreign cells, and ultimately the formation of a pro-inflammatory and immuno-tolerant microenvironment. Finally, we discuss current experimental limitations and remaining opened questions in light of metastatic diagnosis and potential therapies targeting PMN formation.

Ral GTPases promote breast cancer metastasis by controlling biogenesis and organ targeting of exosomes.

Cancer extracellular vesicles (EVs) shuttle at distance and fertilize pre-metastatic niches facilitating subsequent seeding by tumor cells. However, the link between EV secretion mechanisms and their capacity to form pre-metastatic niches remains obscure. Using mouse models, we show that GTPases of the Ral family control, through the phospholipase D1, multi-vesicular bodies homeostasis and tune the biogenesis and secretion of pro-metastatic EVs. Importantly, EVs from RalA or RalB depleted cells have limited organotropic capacities in vivoand are less efficient in promoting metastasis. RalA and RalB reduce the EV levels of the adhesion molecule MCAM/CD146, which favors EV-mediated metastasis by allowing EVs targeting to the lungs. Finally, RalA, RalB, and MCAM/CD146, are factors of poor prognosis in breast cancer patients. Altogether, our study identifies RalGTPases as central molecules linking the mechanisms of EVs secretion and cargo loading to their capacity to disseminate and induce pre-metastatic niches in a CD146-dependent manner.

Live tracking of extracellular vesicles in larval zebrafish.

Formerly considered as insignificant cell debris, extracellular vesicles (EVs) have emerged as potent mediators of cell-cell communication, both in proximity and at distance from the producing cell. EVs are transported in body fluids and can be internalized by specific distant cells to ultimately deliver a functional message. Despite their striking importance in many physiological and pathological contexts, the exact mechanisms by which EVs impose local and distant modifications of the microenvironment in vivo remain to be fully understood. We realized that some conceptual gaps are direct consequences of the difficulty to visualize the shuttling and targeting of EVs in real time in vivo. The zebrafish larvae offered attractive features for live tracking of EVs, within circulating fluids. Here, we describe the experimental procedures that we have built for dissecting the dissemination of EVs at high spatio-temporal resolution in vivo.

Studying the Fate of Tumor Extracellular Vesicles at High Spatiotemporal Resolution Using the Zebrafish Embryo.

Tumor extracellular vesicles (EVs) mediate the communication between tumor and stromal cells mostly to the benefit of tumor progression. Notably, tumor EVs travel in the bloodstream, reach distant organs, and locally modify the microenvironment. However, visualizing these events in vivo still faces major hurdles. Here, we describe an approach for tracking circulating tumor EVs in a living organism: we combine chemical and genetically encoded probes with the zebrafish embryo as an animal model. We provide a first description of tumor EVs' hemodynamic behavior and document their intravascular arrest. We show that circulating tumor EVs are rapidly taken up by endothelial cells and blood patrolling macrophages and subsequently stored in degradative compartments. Finally, we demonstrate that tumor EVs activate macrophages and promote metastatic outgrowth. Overall, our study proves the usefulness and prospects of zebrafish embryo to track tumor EVs and dissect their role in metastatic niches formation in vivo.

Author Correction: Retinal progenitor cells release extracellular vesicles containing developmental transcription factors, microRNA and membrane proteins.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Retinal progenitor cells release extracellular vesicles containing developmental transcription factors, microRNA and membrane proteins.

A range of cell types, including embryonic stem cells, neurons and astrocytes have been shown to release extracellular vesicles (EVs) containing molecular cargo. Across cell types, EVs facilitate transfer of mRNA, microRNA and proteins between cells. Here we describe the release kinetics and content of EVs from mouse retinal progenitor cells (mRPCs). Interestingly, mRPC derived EVs contain mRNA, miRNA and proteins associated with multipotency and retinal development. Transcripts enclosed in mRPC EVs, include the transcription factors Pax6, Hes1, and Sox2, a mitotic chromosome stabilizer Ki67, and the neural intermediate filaments Nestin and GFAP. Proteomic analysis of EV content revealed retinogenic growth factors and morphogen proteins. mRPC EVs were shown to transfer GFP mRNA between cell populations. Finally, analysis of EV mediated functional cargo delivery, using the Cre-loxP recombination system, revealed transfer and uptake of Cre+ EVs, which were then internalized by target mRPCs activating responder loxP GFP expression. In summary, the data supports a paradigm of EV genetic material encapsulation and transfer within RPC populations. RPC EV transfer may influence recipient RPC transcriptional and post-transcriptional regulation, representing a novel mechanism of differentiation and fate determination during retinal development.

Analysis of killer cell immunoglobulin-like receptors (KIRs) and their HLA ligand genes polymorphisms in Iranian patients with systemic sclerosis.

Genetic factors have a great role in the pathogenesis of autoimmune diseases by cooperating with environmental stimuli. Killer immunoglobulin-like receptors (KIRs) are cell surface proteins on NK cells whose association with major histocompatibility complex-I regulates their killing function. The aim of this study was to provide information on the possible association between KIR and human leukocyte antigen (HLA) genes with systemic sclerosis disease in Iranian population. A total of 279 systemic sclerosis patients and 451 healthy controls were enrolled in this case-control study in order to determine the presence or absence of 19 KIR genes and 6 specific HLA class I ligands. DNA was analyzed by polymerase chain reaction using the specific sequence primer method (PCR-SSP). Among 11 discovered KIR genotypes, 6 genotypes showed a considerable role and 4 genotypes could preclude the risk of systemic sclerosis (SSc) disease. The gene-gene interactions were also analyzed, and significant confounding effects were seen between involved genes in these two combinations: "KIR3DL1; HLA-BW4-Thr80" and "KIR3DL1 -HLA-BW4-A1." None of single KIR genes showed significant effect on the risk of SSc. We conclude that there is an important relationship between KIR genes and their HLA ligands with incidence rate of systemic sclerosis in Iranian population. The powerful role of a number of discovered KIR/HLA compounds such as activating KIR genotype 3 and HLA-BW4-A1 confirmed the provocative hypothesis of the interplay between activating or inhibitory KIR genes with HLA ligands as a critical index of systemic sclerosis predisposition.

Anxiety and depression in rheumatoid arthritis: an epidemiologic survey and investigation of clinical correlates in Iranian population.

Psychiatric disorders occur in a considerable proportion of patients with rheumatoid arthritis (RA). This study was conducted in order to evaluate the prevalence of anxiety and depression in Iranian RA patients. In the cross sectional study, 414 RA patients were enrolled prospectively during a period of 6 months from RA clinic of Rheumatology Research Center. Beck's and Cattell's inventories were applied to investigate depression and anxiety in RA patients. RA activity was measured by Disease Activity Score and patients' disability was assessed by Health Assessment Questionnaire. Levels of pain perception were stratified based on Visual Analog Scale. The prevalence of depression was 63.6 % and anxiety was in 84.1 % among RA patients. Mixed anxiety and depression was detected in 60.2 % of the study population. Functional disability was significantly associated with severity of depressive and anxiety symptoms (p < 0.001); however there was no association between disease activity and depression or anxiety (p = 0.420). There was weak correlation between disease activity score and functional disability (Spearman's rho = 0.33; p < 0.01). Severe levels of depression and anxiety were associated with higher levels of pain perception (p < 0.001). Our study stressed the impact of depressive and anxiety symptoms in functional disability and pain perception of RA patients. Our results point out the multidisciplinary management of RA.

Chronic hepatitis B infection is not associated with increased risk of vascular mortality while having an association with metabolic syndrome.

This study aimed to assess the association of chronic hepatitis B (CHB) with vascular mortality and metabolic syndrome (MS) using data from a large population-based cohort study in Iran. A total of 12,781 participants (2249 treatment-naïve CHB and 10,532 without CHB) were studied. Logistic regression model was used to assess the association between MS and CHB with adjustment for age, ALT, PLT, alcohol intake, smoking, exercise, and socioeconomic status. MS was defined according to the ATPIII guidelines. Cox proportional hazards model was used to assess the hazard ratios for overall and vascular related mortality. There was a significant association between CHB infection and overall mortality (hazard ratio (95%CI) of 1.44 (1.16-1.79), P < 0.001) after adjusting for other confounders. However, we found no association between CHB infection and mortality from vascular events (hazard ratio (95%CI) of 1.31 (0.93-1.84), P = 0.124) even after subgroup analysis by ALT. Furthermore, increased risk of overall mortality in CHB infected individuals was not related to MS and vice versa (P for interaction = 0.06). We noted a significant direct association between CHB infection and MS in women (OR (95%CI); 1.23 (1.07-1.42), P < 0.004). However, CHB was inversely associated with MS in men (OR (95%CI), 0.85 (0.79-0.99). This gender dependent association was related to high BP levels in women. In this study no association between CHB infection and mortality from vascular events was found. Further longitudinal studies should be done to investigate the exact impact of HBV infection on metabolic parameters and vascular pathology.

Characterization of Induced Pluripotent Stem Cell Microvesicle Genesis, Morphology and Pluripotent Content.

Microvesicles (MVs) are lipid bilayer-covered cell fragments that range in diameter from 30 nm-1 uM and are released from all cell types. An increasing number of studies reveal that MVs contain microRNA, mRNA and protein that can be detected in the extracellular space. In this study, we characterized induced pluripotent stem cell (iPSC) MV genesis, content and fusion to retinal progenitor cells (RPCs) in vitro. Nanoparticle tracking revealed that iPSCs released approximately 2200 MVs cell/hour in the first 12 hrs with an average diameter of 122 nm. Electron and light microscopic analysis of iPSCs showed MV release via lipid bilayer budding. The mRNA content of iPSC MVs was characterized and revealed the presence of the transcription factors Oct-3/4, Nanog, Klf4, and C-Myc. The protein content of iPSCs MVs, detected by immunogold electron microscopy, revealed the presence of the Oct-3/4 and Nanog. Isolated iPSC MVs were shown to fuse with RPCs in vitro at multiple points along the plasma membrane. These findings demonstrate that the mRNA and protein cargo in iPSC MVs have established roles in maintenance of pluripotency. Building on this work, iPSC derived MVs may be shown to be involved in maintaining cellular pluripotency and may have application in regenerative strategies for neural tissue.

Association of STAT4 rs7574865 with susceptibility to systemic lupus erythematosus in Iranian population.

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease with complex genetic inheritance that affecting different organs and systems. STAT4 has been newly identified as a susceptible gene in the development of SLE. According to recent studies, STAT4 has been associated with SLE in various populations. We investigated whether STAT4 single nucleotide polymorphisms (SNPs) were associated with susceptibility and clinical features of SLE in Iranian patients. The study group comprised 280 patients with SLE and 281 sex-, age-, and ethnicity-matched healthy controls of Iranian ancestry. Two SNPs (rs7574865 and rs7601754) were genotyped using the TaqMan MGB Allelic Discrimination method. Our results showed a significant association between rs7574865 T allele (odds ratio (OR) = 1.50, 95 % CI = 1.18-1.92, P = 0.002) and susceptibility to SLE. The rs7574865TT genotype (P = 0.02, OR = 1.94, 95 % CI = 1.74-3.19) and GT genotype (P = 0.008, OR = 1.71, 95 % CI = 1.19-2.45) showed a significant association with the risk of SLE in the Iranian population. We concluded that STAT4 rs7574865 is associated with SLE susceptibility in the Iranian population and this SNP might be a factor in the pathogenesis of SLE. However, further studies are required to investigate the mechanism by which polymorphisms in this gene lead to SLE.

Interleukin-1 gene cluster and IL-1 receptor polymorphisms in Iranian patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease of unknown etiology with a complex pathogenesis involving multiple genetic and environmental contributions. Single-nucleotide polymorphisms (SNPs) in cytokine genes are associated with higher or lower cytokine activity, which can alter the susceptibility to certain diseases or their clinical outcomes. We investigated SNPs of the IL-1 family in Iranian SLE patients and normal individuals. We obtained blood samples from 207 SLE patients and 213 healthy controls. Cytokine genotyping was performed by polymerase chain reaction with sequence-specific primers. The following SNPs were assessed: IL-1A rs1800587, IL-1B rs16944 and rs1143634, IL-1R1 rs2234650 and IL-1RN rs315952. The frequency of the IL-1RN rs315952 CT genotype was significantly lower among patients with SLE compared with healthy controls (OR = 0.63, 95 % CI = 0.42-0.95; P < 0.05 relative to reference genotype and OR = 0.62, CI = 0.42-0.93; P < 0.05 relative to homozygous genotypes). For all other studied alleles and genotypes, there were no significant differences concerning genotype frequencies between patients and controls. A significant increase in IL-1RN rs315952 T allele frequency was noted in patients with a hematologic manifestation (OR = 1.75; 95 % CI = 1.07-2.84; P = 0.033). Polymorphism in IL-1RN rs315952 was significantly associated with SLE in Iranian patients, rs315952CT genotype being a protective factor. We found that IL-1RN rs315952 T allele frequency was significantly higher in patients with hematologic manifestations. Variation at this locus may affect IL-1 receptor antagonist activity, supporting the hypothesis that altered or imbalanced IL1 production may affect the risk of developing SLE.