Combined evaluation of a panel of protein and miRNA serum-exosome biomarkers for pancreatic cancer diagnosis increases sensitivity and specificity.
TL;DR: The concomitant evaluation of PaCIC and PaCa‐related miRNA marker panels awaits retrospective analyses of larger cohorts, as it should allow for a highly sensitive, minimally‐invasive PaCa diagnostics.
Abstract: Late diagnosis contributes to pancreatic cancer (PaCa) dismal prognosis, urging for reliable, early detection. Serum-exosome protein and/or miRNA markers might be suitable candidates, which we controlled for patients with PaCa. Protein markers were selected according to expression in exosomes of PaCa cell line culture supernatants, but not healthy donors' serum-exosomes. miRNA was selected according to abundant recovery in microarrays of patients with PaCa, but not healthy donors' serum-exosomes and exosome-depleted serum. According to these preselections, serum-exosomes were tested by flow cytometry for the PaCa-initiating cell (PaCIC) markers CD44v6, Tspan8, EpCAM, MET and CD104. Serum-exosomes and exosome-depleted serum was tested for miR-1246, miR-4644, miR-3976 and miR-4306 recovery by qRT-PCR. The majority (95%) of patients with PaCa (131) and patients with nonPa-malignancies reacted with a panel of anti-CD44v6, -Tspan8, -EpCAM and -CD104. Serum-exosomes of healthy donors' and patients with nonmalignant diseases were not reactive. Recovery was tumor grading and staging independent including early stages. The selected miR-1246, miR-4644, miR-3976 and miR-4306 were significantly upregulated in 83% of PaCa serum-exosomes, but rarely in control groups. These miRNA were also elevated in exosome-depleted serum of patients with PaCa, but at a low level. Concomitant evaluation of PaCIC and miRNA serum-exosome marker panels significantly improved sensitivity (1.00, CI: 0.95-1) with a specificity of 0.80 (CI: 0.67-0.90) for PaCa versus all others groups and of 0.93 (CI: 0.81-0.98) excluding nonPa-malignancies. Thus, the concomitant evaluation of PaCIC and PaCa-related miRNA marker panels awaits retrospective analyses of larger cohorts, as it should allow for a highly sensitive, minimally-invasive PaCa diagnostics.
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TL;DR: A review of the biophysical properties and physiological functions of extracellular vesicles, particularly their pro-metastatic effects, and highlight the utility of EVs for the development of cancer diagnostics and therapeutics can be found in this paper.
Abstract: The sustained growth, invasion, and metastasis of cancer cells depend upon bidirectional cell-cell communication within complex tissue environments. Such communication predominantly involves the secretion of soluble factors by cancer cells and/or stromal cells within the tumour microenvironment (TME), although these cell types have also been shown to export membrane-encapsulated particles containing regulatory molecules that contribute to cell-cell communication. These particles are known as extracellular vesicles (EVs) and include species of exosomes and shed microvesicles. EVs carry molecules such as oncoproteins and oncopeptides, RNA species (for example, microRNAs, mRNAs, and long non-coding RNAs), lipids, and DNA fragments from donor to recipient cells, initiating profound phenotypic changes in the TME. Emerging evidence suggests that EVs have crucial roles in cancer development, including pre-metastatic niche formation and metastasis. Cancer cells are now recognized to secrete more EVs than their nonmalignant counterparts, and these particles can be isolated from bodily fluids. Thus, EVs have strong potential as blood-based or urine-based biomarkers for the diagnosis, prognostication, and surveillance of cancer. In this Review, we discuss the biophysical properties and physiological functions of EVs, particularly their pro-metastatic effects, and highlight the utility of EVs for the development of cancer diagnostics and therapeutics.
925 citations
TL;DR: The multifaceted roles of exosomes, the small secreted particles, in communicating with other cells within tumor microenvironment are reviewed, suggesting they may provide promising biomarkers for cancer diagnosis and represent new targets for cancer therapy.
Abstract: Exosomes have emerged as a novel mode of intercellular communication. Exosomes can shuttle bioactive molecules including proteins, DNA, mRNA, as well as non-coding RNAs from one cell to another, leading to the exchange of genetic information and reprogramming of the recipient cells. Increasing evidence suggests that tumor cells release excessive amount of exosomes, which may influence tumor initiation, growth, progression, metastasis, and drug resistance. In addition, exosomes transfer message from tumor cells to immune cells and stromal cells, contributing to the escape from immune surveillance and the formation of tumor niche. In this review, we highlight the recent advances in the biology of exosomes as cancer communicasomes. We review the multifaceted roles of exosomes, the small secreted particles, in communicating with other cells within tumor microenvironment. Given that exosomes are cell type specific, stable, and accessible from body fluids, exosomes may provide promising biomarkers for cancer diagnosis and represent new targets for cancer therapy.
603 citations
TL;DR: The nature of EV subtypes, strategies for isolating EVs from both cell-culture media and body fluids, and procedures for quantifying EVs are discussed, as well as various applications of EVs in clinical diagnosis.
Abstract: Two broad categories of extracellular vesicles (EVs), exosomes and shed microvesicles (sMVs), which differ in size distribution as well as protein and RNA profiles, have been described. EVs are known to play key roles in cell-cell communication, acting proximally as well as systemically. This Review discusses the nature of EV subtypes, strategies for isolating EVs from both cell-culture media and body fluids, and procedures for quantifying EVs. We also discuss proteins selectively enriched in exosomes and sMVs that have the potential for use as markers to discriminate between EV subtypes, as well as various applications of EVs in clinical diagnosis.
589 citations
TL;DR: It is found that hypoxic exosomes derived from pancreatic cancer cells activate macrophages to the M2 phenotype in a HIF1a or HIF2a-dependent manner, which then facilitates the migration, invasion, and epithelial-mesenchymal transition of pancreaticcancer cells.
Abstract: Exosomes are emerging as important mediators of the cross-talk between tumor cells and the microenvironment. However, the mechanisms by which exosomes modulate tumor development under hypoxia in pancreatic cancer remain largely unknown. Here, we found that hypoxic exosomes derived from pancreatic cancer cells activate macrophages to the M2 phenotype in a HIF1a or HIF2a-dependent manner, which then facilitates the migration, invasion, and epithelial-mesenchymal transition of pancreatic cancer cells. Given that exosomes have been shown to transport miRNAs to alter cellular functions, we discovered that miR-301a-3p was highly expressed in hypoxic pancreatic cancer cells and enriched in hypoxic pancreatic cancer cell-derived exosomes. Circulating exosomal miR-301a-3p levels positively associated with depth of invasion, lymph node metastasis, late TNM stage, and poor prognosis of pancreatic cancer. Hypoxic exosomal miR-301a-3p induced the M2 polarization of macrophages via activation of the PTEN/PI3Kγ signaling pathway. Coculturing of pancreatic cancer cells with macrophages in which miR-301a-3p was upregulated or treated with hypoxic exosomes enhanced their metastatic capacity. Collectively, these data indicate that pancreatic cancer cells generate miR-301a-3p-rich exosomes in a hypoxic microenvironment, which then polarize macrophages to promote malignant behaviors of pancreatic cancer cells. Targeting exosomal miR-301a-3p may provide a potential diagnosis and treatment strategy for pancreatic cancer.Significance: These findings identify an exosomal miRNA critical for microenvironmental cross-talk that may prove to be a potential target for diagnosis and treatment of pancreatic cancer.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/16/4586/F1.large.jpg Cancer Res; 78(16); 4586-98. ©2018 AACR.
446 citations
TL;DR: The results demonstrate that certain microRNAs species, such as miR-21 and mi-1246, are selectively enriched in human breast cancer exosomes and significantly elevated in the plasma of patients with breast cancer.
Abstract: microRNAs are promising candidate breast cancer biomarkers due to their cancer-specific expression profiles. However, efforts to develop circulating breast cancer biomarkers are challenged by the heterogeneity of microRNAs in the blood. To overcome this challenge, we aimed to develop a molecular profile of microRNAs specifically secreted from breast cancer cells. Our first step towards this direction relates to capturing and analyzing the contents of exosomes, which are small secretory vesicles that selectively encapsulate microRNAs indicative of their cell of origin. To our knowledge, circulating exosome microRNAs have not been well-evaluated as biomarkers for breast cancer diagnosis or monitoring. Exosomes were collected from the conditioned media of human breast cancer cell lines, mouse plasma of patient-derived orthotopic xenograft models (PDX), and human plasma samples. Exosomes were verified by electron microscopy, nanoparticle tracking analysis, and western blot. Cellular and exosome microRNAs from breast cancer cell lines were profiled by next-generation small RNA sequencing. Plasma exosome microRNA expression was analyzed by qRT-PCR analysis. Small RNA sequencing and qRT-PCR analysis showed that several microRNAs are selectively encapsulated or highly enriched in breast cancer exosomes. Importantly, the selectively enriched exosome microRNA, human miR-1246, was detected at significantly higher levels in exosomes isolated from PDX mouse plasma, indicating that tumor exosome microRNAs are released into the circulation and can serve as plasma biomarkers for breast cancer. This observation was extended to human plasma samples where miR-1246 and miR-21 were detected at significantly higher levels in the plasma exosomes of 16 patients with breast cancer as compared to the plasma exosomes of healthy control subjects. Receiver operating characteristic curve analysis indicated that the combination of plasma exosome miR-1246 and miR-21 is a better indicator of breast cancer than their individual levels. Our results demonstrate that certain microRNA species, such as miR-21 and miR-1246, are selectively enriched in human breast cancer exosomes and significantly elevated in the plasma of patients with breast cancer. These findings indicate a potential new strategy to selectively analyze plasma breast cancer microRNAs indicative of the presence of breast cancer.
410 citations
Cites background from "Combined evaluation of a panel of p..."
...In addition, miR-1246 has also been found to be elevated in serum from patients with esophageal cancer [36], colon cancer [37], and pancreatic cancer [38]....
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...It is important to note that recent studies have evaluated exosome microRNA expression and their association with cancer, including those of the prostate [39], lung [40], ovary [11], liver [41], colorectal [42], skin [32], pancreas [38], and glioblastoma [43]....
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References
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TL;DR: It is shown that exosomes contain both mRNA and microRNA, which can be delivered to another cell, and can be functional in this new location, and it is proposed that this RNA is called “exosomal shuttle RNA” (esRNA).
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10,484 citations
"Combined evaluation of a panel of p..." refers background in this paper
...Interest in Exo increased with the discovery of exosomal mRNA and miRNA.(8) Coupling of RNA-...
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2,900 citations
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2,093 citations
"Combined evaluation of a panel of p..." refers background in this paper
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1,737 citations
"Combined evaluation of a panel of p..." refers background in this paper
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TL;DR: Strategies for exosome isolation, the understanding to date of exosomes composition, functions, and pathways, and their potential for diagnostic and therapeutic applications are summarized.
1,639 citations
"Combined evaluation of a panel of p..." refers background in this paper
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