Identification Of Exosomes Research Articles

Circulating exosomal microRNAs as novel potential detection biomarkers in pancreatic cancer.

Circulating exosomal microRNAs (ex-miRNAs) are reflective of the characteristics of the tumor and are valuable biomarkers in different types of tumor. In addition, miRNAs serve important roles in tumor progression and metastasis. The present study aimed to investigate the circulating ex-miRNA-21 and miRNA-210 as novel biomarkers for patients with pancreatic cancer (PC). For this purpose, serum ex-miRNAs were extracted from the serum of patients with PC (n=30) and chronic pancreatitis (CP) (n=10) using an RNA isolation kit. For exosome identification in serum, transmission electron micrographs were used to determine crystalline structure, western blotting was used to identify exosomal markers, and NanoSight was used for nanoparticle characterization. The relative expression levels of ex-miRNAs were quantified using quantitative PCR and compared between patients with PC and CP. The expression levels of both ex-miRNA-21 and miRNA-210 were significantly higher in patients with PC compared with patients with CP (both P<0.001). However, no significant difference in the relative serum levels of free miR-21 and miR-210 was observed between the 2 groups of patients (both P>0.05). ex-miRNA-21 and miRNA-210 were associated with tumor stage, as well as other factors. The diagnostic potential of ex-miRNA-21 and miRNA-210 levels was 83 and 85%, respectively. In addition, when ex-miRNA and serum carbohydrate antigen 19-9 expression levels were combined, the accuracy increased to 90%. The present study identified that serum ex-miRNAs, miRNA-21 and miRNA-210 may be of value as potential biomarkers and therapeutic targets for the diagnosis and treatment of PC.

Paper-based ITP technology: An application to specific cancer-derived exosome detection and analysis

Exosomes derived from cancer cells/tissues have great potential for early cancer diagnostic use, but their clinical potential has not been fully explored because of a lack of cost-effective multiplex approaches capable of effectively isolating and identifying specific exosome populations and analyzing their content biomarkers. This study was aimed at overcoming the technical barrier by developing a paper-based isotachophoresis (ITP) technology capable of 1) rapid isolation and identification of exosomes from both malignant and healthy cells and 2) multiplex detection of selected exosomal protein biomarkers of the target exosomes. The technology integrates the focusing power of ITP and the multiplex capability of paper-based lateral flow to achieve on-board separation of target exosomes from large extracellular vesicles, followed by electrokinetic enrichment of the targets, leading to an ultrasensitive platform for comprehensive exosome analysis. For a proof of concept, the technology platform was tested with human serum samples spiked with exosomes derived from healthy human serum and a prostate cancer cell line. Under an anionic ITP condition, the device showed superior performance in simultaneous detection of the cancer exosomes and normal exosomes at concentrations as low as 1.2-2.0 × 106 exosomes/mL, which is equivalent to 2.0-3.0 × 10-18 M. The observed limit of detection was more than 30-fold better than that of enhanced ELISA. More importantly, in a subsequent step the technology was capable of the rapid profiling of a selected protein biomarker panel associated with the target exosomes. The results represent a significant step toward translating the detection of tumor-derived exosomes to a medical use at a point of care.

A Dual Antibody-modified Nanochannel Biosensor for Capture and Identification of Exosomes

Since exosomes carry the genetic information of their parental cells, there is an increasing need for new technologies capable of detecting exosomes with high sensitivity and accuracy. In this study, we propose a dual antibody-modified nanochannel biosensor for rapid, sensitive analysis of exosomes. Two antibodies (anti-CD63 and anti-EpCAM) were simultaneously immobilized on the surface of the porous anodic alumina (PAA) nanochannel to combine with proteins overexpressed on the exosomal membrane. As such, exosomes could be efficiently captured by the dual antibody-modified nanochannel. The captured exosomes effectively covered the nanochannel inlet, leading to remarkable block of ion flow through the channel. Based on this principle, the captured exosomes could be sensitively and accurately detected using a picoammeter. It was found that the use of two antibodies greatly increased the capture efficiency of exosomes compared to that of a single antibody. The results showed that exosomes down to 7.3 × 103 particles/mL were successfully detected by the nanochannel. Moreover, exosomes were successfully detected from plasma samples using a nanochannel biosensor modified with dual antibody, and the results showed significant differences in the exosomes content in plasma samples of cancer patients and healthy people, so as to initially distinguish cancer patients from healthy people.

Aptamer-Cholesterol-Mediated Proximity Ligation Assay for Accurate Identification of Exosomes.

Accurate identification of exosomes plays an essential role in facilitating disease diagnosis and therapies. Herein, we proposed an Aptamer-cholesterol-mediated Proximity Ligation Assay (AcmPLA) for accurate identification of exosomes in a dual-probe strategy, one aptamer probe for recognition of exosomal innate surface protein CD63 and another cholesterol probe for biolipid layer targeting. By integrating a proximity ligation of probes bound with exosomal biomarkers for specific recognition and a rolling circle amplification (RCA) strategy for signal amplification, we have successfully developed an exosomes-surface approach that can perform "AND" logic analysis of dual biomarkers, which not only could be used for exosomes quantification, but also for exosomes tracing. Besides RCA-initiated signal amplification, CD9 antibody-labeled magnetic beads were used to capture exosomes for isolation and secondary signal enrichment. Our approach can achieve specific exosomes isolation and accurate identification and thus could be exploited for broad applications in biological science, biomedical engineering, and personalized medicine.

Development of a lateral flow aptamer assay strip for facile identification of theranostic exosomes isolated from human lung carcinoma cells

Exosomes are Extracellular Vesicles (EV) that own unique structural features and functions and have gradually become the hot research spot in recent years. The tumor-derived exosomes contain various types of useful biological information, and medical identification of exosomes relied on the specific characterization of membrane surface proteins. In this study, in order to rapidly identify non-small cell lung cancer (NSCLC)-derived exosomes, based on an aptamer against CD63 protein on exosome membrane, a low cost lateral flow aptamer assay (LFAA) test strip using nanogold particles as visualization probes was successfully developed for facile identification of A549 exosomes isolated from human lung carcinoma cells diluted from 6.4 × 109 particles/mL herein.

Exosomes transferring long non-coding RNA FAL1 to regulate ovarian cancer metastasis through the PTEN/AKT signaling pathway.

Tumor-derived exosomes have been repeatedly studied as tumor antigens, suppressing T-cell signaling molecules and promoting apoptosis in ovarian cancer (OC). Long non-coding RNAs (lncRNAs) have been recognized as major regulators in tumorigenesis, including OC. For this study, we try to find out the mechanism of exosomes and lncRNA FAL1 in OC. After the extraction and identification of exosomes, the internalization of exosomes was observed. Invasion and migration experiments were conducted to investigate the effect of SKOV3 cells-secreted exosomes on OC tumorigenesis and metastasis. Furthermore, the in vivo findings were verified via xenograft tumors in nude mice. FAL1 was knocked out on exosomes. OC cells treated with exosomes were co-cultured with lncRNA FAL1 or/and PTEN to measure cell invasion and migration. SKOV3-secreted exosomes were absorbed and internalized by OC cells. After exosome treatment, the migration and invasion of OC cells were enhanced, tumors in nude mice were larger and heavier, metastasis was increased, and lncRNA FAL1 expression was increased. When lncRNA FAL1 was knocked out, the promoting effects of SKOV3 cells-secreted exosomes on OC cell metastasis were weakened, along with increased PTEN level and decreased AKT phosphorylation level. In HO-8910PM cells treated with siRNA-FAL1 exosomes and siRNA-PTEN, cell invasion and migration, and AKT phosphorylation were restored. SKOV3-secreted exosomes inhibited the PTEN/AKT signaling pathway by transferring lncRNA FAL1, thus inhibiting OC cell metastasis in vitro and in vivo.

Fabrication of an Aptamer-Coated Liposome Complex for the Detection and Profiling of Exosomes Based on Terminal Deoxynucleotidyl Transferase-Mediated Signal Amplification.

The exosome is a promising biomarker carrying many kinds of membrane proteins with huge heterogeneity, so the sensitive and multiplex analysis of exosomes is very significant for disease diagnosis and exploration of their biological functions. Herein, we propose an efficient method for highly sensitive detection and heterogeneity identification of exosomes based on the design and fabrication of an aptamer-coated liposome complex coupled with terminal deoxynucleotidyl transferase (TdT)-mediated polymerization. Specifically, in the presence of target exosomes, the aptamers immobilized on the surface of 1,2-dioleoyl-3-trimethylammonium-propane liposomes prefer to bind with exosomal membrane proteins due to the high affinity. The resulting aptamer-exosome complex will be accessible to TdT to switch on the polymerization reaction for signal amplification, achieving highly sensitive detection of exosomes. Furthermore, the proposed method can be employed to profile different exosomal membrane proteins by making use of a cluster of corresponding aptamers and obtain a fingerprint map of various cancer cell-derived exosomes. Thus, our approach may provide a highly sensitive and robust strategy for the identification of exosome heterogeneity with advantages of being label-free and having no separation, potentially enabling the precise subpopulation of exosomes with practical value in clinical applications.

Platelet Factor 4 as a Novel Exosome Marker in MALDI-MS Analysis of Exosomes from Human Serum.

Exosomes are nanosized vesicles commonly found in biological fluids as a result of a secretion process involving endosomes and multivesicular bodies. The isolation and analysis of exosomes can be useful for noninvasive clinical diagnosis of a variety of human diseases. We investigated the utility of analyzing exosomal proteins, using matrix-assisted laser desorption/ionization combined with Fourier-transform ion cyclotron resonance mass spectrometry (MALDI-FTICR-MS), as a means of determining the presence of exosomes. MALDI-FTICR-MS analyses of exosomes enriched from human serum via centrifugation in a mass range of m/z 1000-20 000 yielded a distinctive protein around m/z 7766. The high mass accuracy and resolution of MALDI-FTICR-MS allowed for reliable comparisons against a protein database, through which the protein was identified as platelet factor 4 (PLF4), whose singly charged protein peak has an elemental composition of C341H577N96O101S4+, with a theoretical most abundant isotopic peak at m/z 7765.194 and a theoretical average peak at m/z 7766. The MALDI-TOF MS analysis of exosomes from the serum of 27 patients with different states of liver diseases provided the most abundant PLF4 peak for each mass spectrum, along with several additional minor peaks. In conclusion, MALDI-MS is suitable as an alternative exosome detection method, serving as a valuable confirmation tool, greatly decreasing the time and workload associated with exosome identification.

Abstract 1341: Magnetic isolation and identification of exosomes using Fe/Au nanowires

Abstract We are developing segmented magnetic nanowires (MNWs) as a new platform for highly specific biolabels. We found that cancer cells internalize MNWs and package them into exosomes, which are then secreted for several days. These MNWs thus enable magnetic isolation of exosomes, which could prove useful in future diagnosis. Our immediate goals are to study how cells internalize MNWs, to determine the timing and reproducibility of exosome secretion, and to improve the magnetic isolation of exosomes. Following this work, we aim to use ferromagnetic resonance (FMR) to identify specific MNW biolabels, similar to radio frequency identification (RFID). In this study, we incubated osteosarcoma (OSCA-8) cells with Fe/Au segmented MNWs with and without PEG coating for 48 hours. Internalization of MNWs as a function of concentration (5-40 µg/ml) was followed by fluorescence and transmission electron microscopy (TEM). We obtained quantitative estimates of MNW internalization by magnetic measurements. Our experiments indicated better internalization of the MNWs using PEG as a capping agent. As we increased the concentration of MNWs, both the number of cells with MNWs and the number of MNWs per cell increased. TEM images show that after uptake by cancer cells, MNWs were predominantly located within lysosomes, and they appeared to be fragmented into small segments of similar size as exosomes. These segments were mostly composed of either Fe or Au, suggesting that fragmentation occurred at or near the boundary of segments. We used two different methods for exosome isolation: non-magnetic isolation (centrifuge and ExoQuick TC) as a control and magnetic isolation. We incubated OSCA-8 cells with different concentrations of MNWs (0 to 35 µg/ml), and exosomes were isolated for up to 11 days. We analyzed the exosome size distribution using a nanoparticle tracking analyzer (NanoSight) and found that exosomes isolated magnetically had similar size distributions as those isolated non-magnetically. A minimum concentration of 25 µg/ml MNWs in 3×105 cells was required for appreciable magnetic isolation. Increasing the concentration of MNWs progressively; however, isolated microvesicles that had wider and more heterogeneous size distributions. Next, we successfully identified two different types of MNW biolabels by FMR. MNWs were fixed in a polymer that was placed onto an RFID chip. Each type of MNW exhibited a unique RF signature as the sample was exposed to an external magnetic field. Our preliminary data show that MNWs appear to allow fast, inexpensive magnetic exosome isolation and is our future goal is MNW identification of exosomes. The methodology developed in this study should be transferable to develop comparable approaches to isolate and identify exosomes from virtually any type of cell. Citation Format: Zohreh Nemati, Thomas Gage, Mohammad Reza Zamani Kouhpanji, Joseph Um, Alicia Donnelly, Daniel Shore, Kelly Makielski, Yali Zhang, Rhonda Franklin, Jaime F. Modiano, Bethanie J. Stadler. Magnetic isolation and identification of exosomes using Fe/Au nanowires [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1341.

MicroRNA Shuttle from Cell-To-Cell by Exosomes and Its Impact in Cancer.

The identification of exosomes, their link to multivesicular bodies and their potential role as a messenger vehicle between cancer and healthy cells opens up a new approach to the study of intercellular signaling. Furthermore, the fact that their main cargo is likely to be microRNAs (miRNAs) provides the possibility of the transfer of such molecules to control activities in the recipient cells. This review concerns a brief overview of the biogenesis of both exosomes and miRNAs together with the movement of such structures between cells. The possible roles of miRNAs in the development and progression of breast, ovarian and prostate cancers are discussed.

A Label-Free Platform for Identification of Exosomes from Different Sources.

Exosomes contain cell- and cell-state-specific cargos of proteins, lipids, and nucleic acids and play significant roles in cell signaling and cell-cell communication. Current research into exosome-based biomarkers has relied largely on analyzing candidate biomarkers, i.e., specific proteins or nucleic acids. However, this approach may miss important biomarkers that are yet to be identified. Alternative approaches are to analyze the entire exosome system, either by "omics" methods or by techniques that provide "fingerprints" of the system without identifying each individual biomolecule component. Here, we describe a platform of the latter type, which is based on surface-enhanced Raman spectroscopy (SERS) in combination with multivariate analysis, and demonstrate the utility of this platform for analyzing exosomes derived from different biological sources. First, we examined whether this analysis could use exosomes isolated from fetal bovine serum using a simple, commercially available isolation kit or necessitates the higher purity achieved by the "gold standard" ultracentrifugation/filtration procedure. Our data demonstrate that the latter method is required for this type of analysis. Having established this requirement, we rigorously analyzed the Raman spectral signature of individual exosomes using a unique, hybrid SERS substrate made of a graphene-covered Au surface containing a quasi-periodic array of pyramids. To examine the source of the Raman signal, we used Raman mapping of low and high spatial resolution combined with morphological identification of exosomes by scanning electron microscopy. Both approaches suggested that the spectra were collected from single exosomes. Finally, we demonstrate for the first time that our platform can distinguish among exosomes from different biological sources based on their Raman signature, a promising approach for developing exosome-based fingerprinting. Our study serves as a solid technological foundation for future exploration of the roles of exosomes in various biological processes and their use as biomarkers for disease diagnosis and treatment monitoring.

Direct isolation and characterization of circulating exosomes from biological samples using magnetic nanowires

BackgroundTumor-derived exosomes are gaining attention as important factors that facilitate communication between neighboring cells and manipulate cellular processes associated with cancer development or progression. The conventional techniques for the isolation and detection of exosomes face several limitations, restricting their clinical applications. Hence, a highly efficient technique for the isolation and identification of exosomes from biological samples may provide critical information about exosomes as biomarkers and improve our understanding of their unique role in cancer research. Here, we describe the use of antibody cocktail-conjugated magnetic nanowires to isolate exosomes from plasma of breast and lung cancer patients.MethodsThe isolated exosomes were characterized based on size and concentration using nanoparticle tracking analysis. Levels of exosomal proteins were measured by bicinchoninic acid assay and enzyme-linked immunosorbent assay. Morphology was visualized by transmission electron microscopy. Immunoblotting (Western blotting) was used to detect the presence of exosomal markers.ResultsThe use of antibody cocktail-conjugated magnetic nanowires resulted in approximately threefold greater yield when compared to the conventional methods. The elongated feature of nanowires significantly improved the efficiency of exosome isolation, suggesting its potential to be translated in diverse clinical applications, including cancer diagnosis and treatment.ConclusionsThe nanowire-based method allows rapid isolation of homogeneous population of exosomes with relatively high yield and purity from even small amounts of sample. These results suggest that this method has the potential for clinical applications requiring highly purified exosomes for the analysis of protein, lipid, mRNA, and miRNA.

Different signatures of miR-16, miR-30b and miR-93 in exosomes from breast cancer and DCIS patients

Loading of microRNAs (miRNAs) into exosomes that are involved in cellular communication is a selective process. The current study investigates whether the enrichment of miRNAs in exosomes reflects the pathogenesis of breast cancer (BC) and ductal carcinoma in situ (DCIS). The levels of miRNAs were quantified in exosomes from plasma of 32 BC patients, 8 DCIS patients and 8 healthy women by TaqMan real-time PCR-based miRNA array cards containing 47 different miRNAs. Then, exosomal miR-16, miR-30b and miR-93 that displayed deregulation in the arrays were selected and analyzed in 111 BC patients, 42 DCIS patients and 39 healthy women by TaqMan real-time PCR. Identification of exosomes was performed by Western blot. The levels of exosomal miR-16 were higher in plasma of BC (p = 0.034) and DCIS (p = 0.047) patients than healthy women, and were associated with estrogen (p = 0.004) and progesterone (p = 0.008) receptor status. Particularly, in estrogen-positive patients miR-16 was significantly enriched in exosomes (p = 0.0001). Lower levels of exosomal miR-30b were associated with recurrence (p = 0.034). Exosomal miR-93 was upregulated in DCIS patients (p = 0.001). Our findings suggest that different signatures of miR-16, miR-30b and miR-93 in exosomes from BC and DCIS patients are associated with a particular biology of breast tumors.

Isolation and identification of exosomes secreted from HK-2 cells exposed to high oxalate

Objective To investigate the method for isolating and identification exosomes from the HK-2 cells exposed to high oxalate. Methods HK-2 cells were cultured to serum-free culture medium and treated with oxalate at the concentration from 0 mmol/L to 10.00 mmol/L for 48 h. CCK-8 assays were performed to measure the cells proliferation.Combined the cell morphology, observed under inverted microscope with statistical analysis, we finally 2.00 mmol/L oxalic acid as the experimental concentration. The HK-2 cell was exposed to 2.00 mmol/L oxalate for 48 h. The supernatants were collected. Exosomes were isolated and purified from the supernatants by ultracentrifugation. Transmission electron microscopy (TEM) was used to observe the morphology of isolated exosomes. Particle size of exosomes were detected with Nanosight technology. Western blot analysis was used to examine the experession of HSP70, CD63. Results CCK-8 assay showed that the cell viability in each group, including (100.0±4.0)% in 0 mmol/L group ; (97.7±1.5)% in the 0.25 mmol/L group; (97.3±2.1)% in the 0.50 mmol/L group; (87.7±2.1)% in the 1.00 mmol/L group; (76.0±1.0)% in the 2.00 mmol/L group; (58.1±2.6)% in the 4.00 mmol/L group; (52.7±1.5)% in the 5.00 mmol/L group; (37.7±3.2)% in the 8.00 mmol/L group ; (31.3±2.0)% in the 10.00 mmol/L group.The isolated exosomes demonstrated round or oval shape under TEM. The peak particle size was 56 nm, which the overall mean particle size was 87 nm. Those and particles with a diameter between 30-150 nm accounted for 91.2%. In this experiment, The expression of HSP70, CD63 could be detected in the isolated exosomes.However, only the expression of HSP70 could be detected in the HK-2 cells. Conclusions Under the treatment of 2 mmol/l oxalate for 48 hours, Ultracentrifugation can be used to isolate and purify exosomes efficiently from the HK-2 cells. This is helpful for further study of exosome as mediator of cell-to-cell communication. Key words: Exosomes; Kidney stone; Oxalate.

Identification of exosomes and its signature miRNAs of male and female Cynoglossus semilaevis

Exosomes are small membrane particles which are widely found in various cell lines and physiological fluids in mammalian. MicroRNAs (miRNAs) enclosed in exosomes have been identified as proper signatures for many diseases and response to therapies. However, the composition of exosomes and enclosed miRNAs in fishes has not been investigated. Cynoglossus semilaevis is an important commercial flatfish with ambiguous distinction between males and females before sex maturation, which leads to screening difficulty in reproduction and cultivation. An effective detection method was required for sex differentiation of C. semilaevis. In this work, we successfully identified exosomes in C. semilaevis serum. The analysis of nucleotide composition showed that miRNA dominated in exosomes. Thereafter the miRNA profiles in exosomes from males and females were sequenced and compared to identify the signature miRNAs corresponding to sex differentiation. The functions of signature miRNAs were analyzed by target matching and annotation. Furthermore, 7 miRNAs with high expression in males were selected from signature miRNAs as the markers for sex identification with their expression profiles verified by real time quantitative PCR. Exosomes were first found in fish serum in this work. Investigation of marker miRNAs supplies an effective index for the filtration of male and female C. semilaevis in cultivation.

Increased Circulating Exosomal miRNA-223 Is Associated with Acute Ischemic Stroke.

Recent studies have demonstrated that exosomal microRNAs (miRNAs) are novel biomarkers and therapeutic targets for various diseases including vascular disease. However, specific exosomal miRNAs expression in stroke patients has not been reported yet. Here, we explored whether circulating exosomal miRNAs can serve as potential biomarkers for the diagnosis of acute ischemic stroke and discussed the potential for clinical application. Blood samples were collected from acute ischemic stroke patients within the first 72 h (n = 50). Circulating exosomes were exacted by Exoquick exosome isolation kit and characterized by transmission electron microscopy. Western blot was performed to assess the expression of exosomal protein makers. Exosomal miRNA-223 (miR-223) was detected by RT-PCR assay. The relationship between the expression levels of miR-223 and National Institutes of Health Stroke Scale (NIHSS) scores, brain infarct volume, and neurological outcomes were analyzed. Circulating exosomes were isolated and the size of vesicles ranged between 30 and 100 nm. The identification of exosomes was further confirmed by the detection of specific exosomal protein markers CD9, CD63, and Tsg101. Exosomal miR-223 in acute ischemic stroke patients was significantly upregulated compared to control group (p < 0.001). Exosomal miR-223 level was positively correlated with NIHSS scores (r = 0.31, p = 0.03). Exosomal miR-223 expression in stroke patients with poor outcomes was higher than those with good outcomes (p < 0.05). Increased exosomal miR-223 was associated with acute ischemic stroke occurrence, stroke severity, and short-term outcomes. Future studies with large sample are needed to assess the clinical application of exosomal miR-223 as a novel biomarker for ischemic stroke diagnosis.

924P - Identification of exosomes in non-Hodgkin B-cell lymphomas. Prognostic usefulness in patients treated with rituximab-chemotherapy: a prospective, multicenter correlation study by the Spanish Lymphoma Oncology Group (GOTEL)

924P - Identification of exosomes in non-Hodgkin B-cell lymphomas. Prognostic usefulness in patients treated with rituximab-chemotherapy: a prospective, multicenter correlation study by the Spanish Lymphoma Oncology Group (GOTEL)

Isolation and identification of exosomes of hepatocellular carcinoma cells

AIM:To seek a new method for isolating and purifying exosomes from the supernatants of cultured human hepato cellular carcinoma cells.METHODS:Human hepatocellular carcinoma cells SMMC-7721 were cultured to adapt to continuous serum-free culture,and the culture supernatants were collected.Exosomes derived from SMMC-7721 were isolated and purified from the supernatants by improved ultracentrifugation.Transmission electron microscopy(TEM) was used to observe the morphology of isolated exosomes.Particle size of exosomes was detected with Nanosight technology.Western blot analysis was used to examine CD63,CD9,and Alix exosomal protein expression and SDS-PAGE was used for exosomal protein analysis.RESULTS:The isolated exosomes were round or oval in shape under TEM.The peak diameter of exosomes was 122 nm,and particles with a diameter between 30-150 nm accounted for 72.16%.The expression of Alix,CD63 and CD9 could be detected in the supernatants of cultured cells and isolated exosomes.SDS-PAGE showed that the abundant macromolecular structure proteins were significantly less in exosomes than in SMMC-7721 cells.CONCLUSION:Continuous adaptation to serum-free culture combined with improved ultracentrifugation can be used to isolate and purify exosomes efficiently.This is helpful for further study of exosome markers of hepatocellular carcinoma cells.

Traumatic brain injury: recent advances in plasticity and regeneration.

There is an urgent need for effective therapies to restore neurologic function and decrease disability following traumatic brain injury (TBI). Here, emerging findings on the mechanisms of post-TBI neural repair and regeneration, as well as therapeutic implications, are selectively reviewed. Recent discoveries include the characterization of the inhibitory signaling systems within the injury site, postinjury stem cell niche activation, the role of serotonin signaling in repair, and environment enrichment. A potentially transformative finding has been the identification of exosomes, nano-sized extracellular vesicles which have key roles in cell signaling, and might serve as novel biomarkers and as vehicles for targeted delivery of repair-inducing molecules. In the experimental setting, post-TBI repair can be promoted by modulation of inhibitory signaling, neurotrophic factor administration, and amplified serotonin signaling; additional strategies include mobilization of endogenous stem cell populations, exogenous cell-based therapies, and environmental enhancement. Feasibility, safety, and efficacy of these approaches need further investigation in humans. Studies are also needed to evaluate biomarkers based on molecular traces of neural repair and regeneration, which could transform prognostic and predictive modeling of post-TBI recovery trajectories.

Abstract 3382: Exosomes analysis in non-small cell lung cancer: looking for a clinical application

Abstract BACKGROUND Cancer cells produce a heterogeneous mixture of vesicular, organelle-like structures (microvesicles or MVs) into their surroundings including blood and body fluid. In particular exosomes are biological nanovescicles (40-100 nm) that are formed by the inward budding of multivescicular bodies (MVB), as a component of the endocytic pathway. They are released from different cell types under both normal and pathological conditions. Exosomal content is composed by proteins, DNA, mRNA and microRNA (miRNA) that are transferred to distant site and mediate inter-cellular communication. PURPOSE OF THE STUDY The aim of this pilot study is to investigate whether exosomes isolation from clinical samples (plasma from NSCLC patients) is feasible. Furthermore we have analyzed a panel of 7 miRNA related to NSCLC. EXPERIMENTAL DESIGN AND METHODS The study population was selected among lung cancer patients diagnosed with NSCLC, histotype adenocarcinoma, in the Oncology department of Antwerp University Hospital. A total of 12 patients participated in the project. Six blood samples from healthy volunteers were also collected. After obtaining the informed consent, blood samples (10 ml) were stored in the UZA-tumor biobank. Clinical data were also collected from patients’ medical records. Exosomes were isolated by means of both Density Gradient (DG) centrifugation and the Total Exosome Isolation kit (from plasma) (Invitrogen) according to manufacturers’ instructions. The Total exosome RNA and protein isolation kit (Invitrogen) was used for proteins recovery from exosome. Extracted proteins are used for western blot analysis aimed at the identification of specific exosome protein markers: CD63, ALIX and TSG101. Nanoparticle Tracking Analysis (NTA) was performed by means of the NanoSight NS500 instrument. In order to visualize the isolated exosomes a TEM (Transmission Electron Microscopy) analysis was performed. The total exosome RNA and protein isolation kit (Invitrogen) was used to extract small-RNA from exosomal samples. The analysis of 7 miRNAs (miR-30b, -30c, -103, -122, -195, -221, -222) was performed on the LightCycler 480 (Roche) and the fold change was calculated according to the formula 2ααCq. miR-1228 was used has endogenous control to normalize the reaction. RESULTS • ALIX protein is a reliable protein marker for exosome identification • TEM analysis have shown that exosomes can be isolated in NSCLC plasma samples • 7 selected miRNAs are strongly deregulated in our clinical samples and seem related to staging • miR30b and -30c might be related to squamous cell carcinoma histotype CONCLUSION The analysis of exosomes in NSCLC could represent a noninvasive test for patients’ management. With this pilot study we have demonstrated that exosome analysis and exosomal miRNA profiling is feasible. Due to the small sample size we cannot make significant statistic conclusion. Further analyses in a larger series are needed. Citation Format: Christian D. Rolfo, Marta Castiglia, Marco Giallombardo, Jorge Chacartegui, Nele Van Der Steen, Inge Mertens, Marc Peeters, Antonio Russo, Patrick Pauwels. Exosomes analysis in non-small cell lung cancer: looking for a clinical application. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3382. doi:10.1158/1538-7445.AM2015-3382