Early Detection and Investigation of Extracellular Vesicles Biomarkers in Breast Cancer

miRNA and piRNA differential expression profiles in Alzheimer's disease: A potential source of pathology and tool for diagnosis

Alzheimer's Disease (AD) is the most prevalent form of dementia and one of the leading causes of death in the United States, and despite our best efforts and recent advancements, a treatment that stops or substantially slows its progression has remained elusive. Small extracellular vesicles (sEVs), hold the potential to alleviate some of the common issues in the field by serving to better differentiate AD and non-AD individuals. These vesicles could provide insights into therapeutic targets, and potentially an avenue towards early detection. We compared the sEV cargo profiles of AD and non-AD brains (n = 6) and identified significant differences in both the micro RNA (miRNA) and Piwi-interacting RNA (piRNA) cargo through sEV isolation from temporal cortex tissue, followed by small RNA sequencing, and differential expression analysis. Differentially expressed miRNAs targeting systems relevant to AD included miR-206, miR-4516, miR-219a-5p, and miR-486-5p. Significant piRNAs included piR-6,565,525, piR-2,947,194, piR-7,181,973, and piR-7,326,987. These targets warrant further study for their potential role in the progression of AD pathology by dysregulating cellular activity; additionally, future large-scale studies of neuronal sEV miRNA profiles may facilitate the development of diagnostic tools which can aid in clinical trial design and recruitment. Longitudinal analysis of sEV data, perhaps accessible through plasma surveyance, will help determine at what point these miRNA and/or piRNA profiles begin to diverge between AD and non-AD individuals.

Distinctive features of blood- and ascitic fluid-derived extracellular vesicles in ovarian cancer patients

BACKGROUND

Ovarian cancer (OC) is a highly aggressive malignancy characterized by early dissemination of cancer cells from the surface of the ovary to the peritoneum. To gain a deeper understanding of the mechanisms associated with this intraperitoneal spread, we aimed to characterize the role of extracellular vesicles (EVs) in metastatic colonization in OC.

METHODS

To this purpose, a total of 150 samples of ascitic fluids, blood serum, tumor and normal tissues from 60 OC patients, were extensively analyzed to characterize the EVs released in blood and ascitic fluids of OC patients, in terms of size, expression of superficial epitopes and abundance of miRNAs biocargo.

RESULTS

A statistically significant difference in the size of EVs derived from ascitic fluid and serum was identified. Analysis of surface protein expression highlighted twenty epitopes with a significant difference between the two biological matrices, of which 18 were over- and two were under-expressed in ascitic fluid. With regard to miRNA levels, Principal Component Analysis (PCA) assessed four distinct clusters representing tumor tissue, normal tissue, ascitic fluid, and serum. A prominent difference in circulating miRNAs was observed in serum and ascitic fluid highlighting 98 miRNAs significantly deregulated (P-adj < 0.05) between the two bodily fluids. Deregulated miRNAs and epitopes underline an enrichment in ascites in components contributing to the metastatic spread.

CONCLUSION

The results highlight a clear difference between the two biological fluids, suggesting that tumor selectively releases specific EVs populations in serum or ascites. In this context, it seems that ascites-derived EVs play a major role in modulating EMT and metastatic cascade, which is a key feature of OC.

From Cell Lines to Patients: Dissecting the Proteomic Landscape of Exosomes in Breast Cancer

Background: Breast cancer (BC) is the most common cancer among women worldwide; therefore, the efforts of many scientists are aimed at finding effective biomarkers for this disease. It is known that exosomes are nanosized extracellular vesicles (EVs) that are released from various cell types, including cancer cells. Exosomes are directly involved in governing the physiological and pathological processes of an organism through the horizontal transfer of functional molecules (proteins, microRNA, etc.) from producing to receiving cells. Since the diagnosis and treatment of BC have been improved substantially with exosomes, in this study, we isolated breast carcinoma cell-derived exosomes, primary endotheliocyte-derived exosomes, and blood exosomes from BC patients (BCPs) in the first stage of disease and investigated their proteomic profiles. Methods: Exosomes were isolated from the samples by ultrafiltration and ultracentrifugation, followed by mass spectrometric and bioinformatics analyses of the data. The exosomal nature of vesicles was verified using transmission electron microscopy and flow cytometry. Results: Exosome proteins secreted by MCF-7 and BT-474 cells were found to form two clusters, one of which enhanced the malignant potential of cancer cells, while the other coincided with a cluster of HUVEC-derived exosome proteins. Despite the different ensembles of proteins in exosomes from the MCF-7 and BT-474 lines, the relevant portions of these proteins are involved in similar biological pathways. Comparison analysis revealed that more BC-associated proteins were found in the exosomal fraction of blood from BCPs than in the exosomal fraction of conditioned medium from cells mimicking the corresponding cancer subtype (89% and 81% for luminal A BC and MCF-7 cells and 86% and 80% for triple-positive BC and BT-474 cells, respectively). Conclusions: Tumor-associated proteins should be sought not in exosomes secreted by cell lines but in the composition of blood exosomes from cancer patients, while the contribution of endotheliocyte exosomes to the total pool of blood exosomes can be neglected.

Gastroesophageal circulating tumor cell crosstalk with peripheral immune system guides CTC survival and proliferation

Tumor dissemination is a key event in tumor progression. During this event, a main role is played by circulating tumor cells (CTCs), immune cells, and their interaction. How the immune system supports the survival and proliferation of CTCs is not fully elucidated. In this study we established an in-vitro co-culture system consisting of immune cells and CTCs from the same patient, which increased the success rate in the establishment of CTC-derived long-term cell cultures. In this system, we characterized the immune cells of successful co-cultures and the signals they exchange with cancer cells, including cytokines and extracellular vesicle (EV) content. Using this protocol, we stabilized four CTC-derived cell lines from patients with metastatic gastroesophageal cancer, which were cultured for over a year and characterized from a genetic and molecular point of view. The four cell lines harbor shared chromosomal aberrations including the amplification at 8q24.21 containing MYC and deletion 9p21.3 containing CDKN2A/B and the IFN type I cluster. The transcriptomic profile of CTC cell lines is distinct from primary tumors, and we detected the activation of E2F, G2M and MYC pathways and the downregulation of interferon response pathway. Each cell line shows a degree of invasiveness in zebrafish in-vivo, and the most invasive ones share the same mutation in RAB14 gene. In addition, the four cell lines secrete cell-line specific EVs containing microRNAs that target YAP, BRG1-AKT1, TCF8-HDAC pathways. Overall, we highlight how the immune system plays a key role in the proliferation of CTCs through EV signaling, and how CTC cell line genomic and transcriptomic alterations make these cells less visible from the immune system and likely responsible for the survival advantage in sites distant from the microenvironment of origin.

Extracellular vesicle-mediated drug delivery in breast cancer theranostics

Breast cancer (BC) continues to be a significant global challenge due to drug resistance and severe side effects. The increasing prevalence is alarming, requiring new therapeutic approaches to address these challenges. At this point, Extracellular vesicles (EVs), specifically small endosome-released nanometer-sized EVs (SEVs) or exosomes, have been explored by literature as potential theranostics. Therefore, this review aims to highlight the therapeutic potential of exosomes in BC, focusing on their advantages in drug delivery and their ability to mitigate metastasis. Following the review, we identified exosomes' potential in combination therapies, serving as miRNA carriers and contributing to improved anti-tumor effects. This is evident in clinical trials investigating exosomes in BC, which have shown their ability to boost chemotherapy efficacy by delivering drugs like paclitaxel (PTX) and doxorubicin (DOX). However, the translation of EVs into BC therapy is hindered by various challenges. These challenges include the heterogeneity of EVs, the selection of the appropriate parent cell, the loading procedures, and determining the optimal administration routes. Despite the promising therapeutic potential of EVs, these obstacles must be addressed to realize their benefits in BC treatment.

Surface protein profiling of milk and serum extracellular vesicles unveils body fluid-specific signatures

Cell-derived extracellular vesicles (EVs) are currently in the limelight as potential disease biomarkers. The promise of EV-based liquid biopsy resides in the identification of specific disease-associated EV signatures. Knowing the reference EV profile of a body fluid can facilitate the identification of such disease-associated EV-biomarkers. With this aim, we purified EVs from paired human milk and serum samples and used the MACSPlex bead-based flow-cytometry assay to capture EVs on bead-bound antibodies specific for a certain surface protein, followed by EV detection by the tetraspanins CD9, CD63, and CD81. Using this approach we identified body fluid-specific EV signatures, e.g. breast epithelial cell signatures in milk EVs and platelet signatures in serum EVs, as well as body fluid-specific markers associated to immune cells and stem cells. Interestingly, comparison of pan-tetraspanin detection (simultaneous CD9, CD63 and CD81 detection) and single tetraspanin detection (detection by CD9, CD63 or CD81) also unveiled body fluid-specific tetraspanin distributions on EVs. Moreover, certain EV surface proteins were associated with a specific tetraspanin distribution, which could be indicative of the biogenesis route of this EV subset. Altogether, the identified body fluid-specific EV profiles can contribute to study EV profile deviations in these fluids during disease processes.

Cancer Biomarkers in Liquid Biopsy for Early Detection of Breast Cancer: A Systematic Review

Background:

Breast cancer (BC) is the most common neoplasm in women worldwide. Liquid biopsy (LB) is a non-invasive diagnostic technique that allows the analysis of biomarkers in different body fluids, particularly in peripheral blood and also in urine, saliva, nipple discharge, volatile respiratory fluids, nasal secretions, breast milk, and tears. The objective was to analyze the available evidence related to the use of biomarkers obtained by LB for the early diagnosis of BC.

Methods:

Articles related to the use of biomarkers for the early diagnosis of BC due to LB, published between 2010 and 2022, from the databases (WoS, EMBASE, PubMed, and SCOPUS) were included. The MInCir diagnostic scale was applied in the articles to determine their methodological quality (MQ). Descriptive statistics were used, as well as determination of weighted averages of each variable, to analyze the extracted data. Sensitivity, specificity, and area under the curve values for specific biomarkers (individual or in panels) are described.

Results:

In this systematic review (SR), 136 articles met the selection criteria, representing 17 709 patients with BC. However, 95.6% were case-control studies. In 96.3% of cases, LB was performed in peripheral blood samples. Most of the articles were based on microRNA (miRNA) analysis. The mean MQ score was 25/45 points. Sensitivity, specificity, and area under the curve values for specific biomarkers (individual or in panels) have been found.

Conclusions:

The determination of biomarkers through LB is a useful mechanism for the diagnosis of BC. The analysis of miRNA in peripheral blood is the most studied methodology. Our results indicate that LB has a high sensitivity and specificity for the diagnosis of BC, especially in early stages.

Extracellular vesicle isolation, purification and evaluation in cancer diagnosis

Strategies for non-invasive biomarker discovery in early detection of cancer are an urgent need. Extracellular vesicles (EVs) have generated increasing attention from the scientific community and are under intensive investigations due to their unique biological profiles and their non-invasive nature. EVs are membrane-enclosed vesicles with variable sizes and function. Such vesicles are actively secreted from multiple cell types and are considered as key vehicles for inter-cellular communications and signalling. The stability and potential to easily cross biological barriers enable EVs for exerting durable effects on target cells. These along with easy access to such vesicles, the consistent secretion from tumour during all stages of tumorigenesis and their content providing a reservoir of molecules as well as mirroring the identity of the cell of origin are virtues that have made EVs appealing to be assessed in liquid biopsy approaches and for using as a promising resource of biomarkers in cancer diagnosis and therapy and monitoring targeted cancer therapy. Early detection of EVs will guide time-scheduled personalised therapy. Surveying reliable and sensitive methods for rapid isolation of EVs from biofluids, the purity of isolated vesicles and their molecular profiling and marker specification for clinical translation in patients with cancer are issues in the area and the hot topics of many recent studies. Here, the focus is over methods for EV isolation and stratification for digging more information about liquid biopsy-based diagnosis. Extending knowledge regarding EV-based strategies is a key to validate independent patient follow-up for cancer diagnosis at early stages and inspecting the efficacy of therapeutics.

Extracellular Vesicles as Mediators of Therapy Resistance in the Breast Cancer Microenvironment

Resistance to various therapies, including novel immunotherapies, poses a major challenge in the management of breast cancer and is the leading cause of treatment failure. Bidirectional communication between breast cancer cells and the tumour microenvironment is now known to be an important contributor to therapy resistance. Several studies have demonstrated that crosstalk with the tumour microenvironment through extracellular vesicles is an important mechanism employed by cancer cells that leads to drug resistance via changes in protein, lipid and nucleic acid cargoes. Moreover, the cargo content enables extracellular vesicles to be used as effective biomarkers for predicting response to treatments and as potential therapeutic targets. This review summarises the literature to date regarding the role of extracellular vesicles in promoting therapy resistance in breast cancer through communication with the tumour microenvironment.