Exosomes derived from pancreatic cancer cells induce activation and profibrogenic activities in pancreatic stellate cells

The function of microRNA related to cancer-associated fibroblasts in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignant tumor characterized by a poor prognosis. A prominent feature of PDAC is the rich and dense stroma present in the tumor microenvironment (TME), which significantly hinders drug penetration. Cancer-associated fibroblasts (CAFs), activated fibroblasts originating from various cell sources, including pancreatic stellate cells (PSCs) and mesenchymal stem cells (MSCs), play a critical role in PDAC progression and TME formation. MicroRNAs (miRNAs) are small, single-stranded non-coding RNA molecules that are frequently involved in tumorigenesis and progression, exhibiting either oncolytic or oncogenic activity. Increasing evidence suggests that aberrant expression of miRNAs can mediate interactions between cancer cells and CAFs, thereby providing novel therapeutic targets for PDAC treatment. In this review, we will focus on the potential roles of miRNAs that target CAFs or CAFs-derived exosomes in PDAC progression, highlighting the feasibility of therapeutic strategies aimed at restoring aberrantly expressed miRNAs associated with CAFs, offering new pathways for the clinical management of PDAC.

Drug delivery based exosomes uptake pathways

Most cells secrete a material called extracellular vesicles (EVs), which play a crucial role in cellular communication. Exosomes are one of the most studied types of EVs. Recent research has shown the many functions and substrates of cellular exosomes. Multiple studies have shown the efficacy of exosomes in transporting a wide variety of cargo to their respective target cells. As a result, they are often utilized to transport medicaments to patients. Natural exosomes as well as exosomes modified with other compounds to enhance transport capabilities have been employed. In this article, we take a look at how different types of exosomes and modified exosomes may transport different types of cargo to their respective targets. Exosomes have a lot of potential as drug delivery vehicles for many synthetic compounds, proteins, nucleic acids, and gene repair specialists because they can stay in the body for a long time, are biocompatible, and can carry natural materials. A good way to put specific protein particles into exosomes is still not clear, though, and the exosomes can't be used in many situations yet. The determinants for exosome production, as well as ways for loading certain therapeutic molecules (proteins, nucleic acids, and small compounds), were covered in this paper. Further study and the development of therapeutic exosomes may both benefit from the information collected in this review.

New Insights into the Exosome-Induced Migration of Uveal Melanoma Cells and the Pre-Metastatic Niche Formation in the Liver

UM is an aggressive intraocular tumor characterized by high plasticity and a propensity to metastasize in the liver. However, the underlying mechanisms governing liver tropism remain poorly understood. Given the emerging significance of exosomes, we sought to investigate the contribution of UM-derived exosomes to specific steps of the metastatic process. Firstly, we isolated exosomes from UM cells sharing a common genetic background and different metastatic properties. A comparison of protein cargo reveals an overrepresentation of proteins related to cytoskeleton remodeling and actin filament-based movement in exosomes derived from the parental cells that may favor the detachment of cells from the primary site. Secondly, we assessed the role of macrophages in reprogramming the HHSCs by exosomes. The activation of HHSCs triggered a pro-inflammatory and pro-fibrotic environment through cytokine production, upregulation of extracellular matrix molecules, and the activation of signaling pathways. Finally, we found that activated HHSCs promote increased adhesion and migration of UM cells. Our findings shed light on the pivotal role of exosomes in pre-metastatic niche construction in the liver.

Pancreatic cancer cell- and cancer-associated fibroblast-derived exosomes in disease progression, metastasis, and therapy

Exosomes play a crucial role in the progression and spread of pancreatic cancer, serving not only as promoters of tumor growth and organ-specific metastasis but also as promising biomarkers and targets for treatment. These nano vesicles enhance intercellular communication by transferring bioactive molecules, such as proteins and RNAs, between cells. This process significantly affects cancer cell dynamics, including their proliferation, migration, and invasion, while also contributing to drug resistance. Our review focuses on the crucial interactions between cancer cells and fibroblasts mediated by exosomes within the pancreatic cancer microenvironment. We delve into how exosomes from both cancer-associated fibroblasts and the cancer cells themselves drive tumor progression through various mechanisms, such as epithelial-mesenchymal transition and facilitating metastasis to specific organs like the lungs and liver. The potential of leveraging exosomes for therapeutic interventions is also explored, highlighting the importance of understanding their role in cell communication as a step forward in developing more effective pancreatic cancer treatments.

MicroRNA-20a in extracellular vesicles derived from duodenal fluid is a possible biomarker for pancreatic ductal adenocarcinoma

Background

Pancreatic ductal adenocarcinoma (PDAC) has a high mortality rate owing to its late diagnosis and aggression. In addition, there are relatively few minimally invasive screening methods for the early detection of PDAC, making the identification of biomarkers for this disease a critical priority. Recent studies have reported that microRNAs in extracellular vesicles (EV-miRs) from bodily fluids can be useful for the diagnosis of PDACs. Given this, we designed this study to evaluate the utility of cancer EVs extracted from duodenal fluid (DF) and their resident EV-miRs as potential biomarkers for the detection of PDAC.

Methods

EV-miRs were evaluated and identified in the supernatants of various pancreatic cancer cell lines (Panc-1, SUIT2, and MIAPaca2), human pancreatic duct epithelial cells, and the DF from patients with PDAC and healthy controls. EVs were extracted using ultracentrifugation and the relative expression of EV-miR-20a was quantified.

Results

We collected a total of 34 DF samples (27 PDAC patients and seven controls) for evaluation and our data suggest that the relative expression levels of EV-miR-20a were significantly higher in patients with PDAC than in controls (p = 0.0025). In addition, EV-miR-20a expression could discriminate PDAC from control patients regardless of the location of the tumor with an area under the curve values of 0.88 and 0.88, respectively.

Conclusions

We confirmed the presence of EVs in the DF and suggest that the expression of EV-miR-20a in these samples may act as a potential diagnostic biomarker for PDAC.

Exosomal non-coding RNA: A new frontier in diagnosing and treating pancreatic cancer: A review

Pancreatic cancer is the most fatal malignancy worldwide. Once diagnosed, most patients are already at an advanced stage because of their highly heterogeneous, drug-resistant, and metastatic nature and the lack of effective diagnostic markers. Recently, the study of proliferation, metastasis, and drug resistance mechanisms in pancreatic cancer and the search for useful diagnostic markers have posed significant challenges to the scientific community. Exosomes carry various biomolecules (DNA, non-coding RNAs (ncRNAs), proteins, and lipids) that mediate communication between tumors and other cells. ncRNAs can be transported through exosomes to numerous relevant receptor cells and regulate local epithelial-mesenchymal transition (EMT) in tumor tissue, proliferation, drug resistance, and the establishment of pre-metastatic ecological niches in distant organs. In summary, exosomal ncRNAs promote tumor cell proliferation, invasion, and metastasis through multiple EMT, immunosuppression, angiogenesis, and extracellular matrix remodeling pathways. Moreover, we discuss the significant therapeutic significance of exosomal ncRNAs as PC biomarkers.

Pancreatic cancer tumor microenvironment is a major therapeutic barrier and target

Pancreatic Ductal Adenocarcinoma (PDAC) is projected to become the 2nd leading cause of cancer-related deaths in the United States. Limitations in early detection and treatment barriers contribute to the lack of substantial success in the treatment of this challenging-to-treat malignancy. Desmoplasia is the hallmark of PDAC microenvironment that creates a physical and immunologic barrier. Stromal support cells and immunomodulatory cells face aberrant signaling by pancreatic cancer cells that shifts the complex balance of proper repair mechanisms into a state of dysregulation. The product of this dysregulation is the desmoplastic environment that encases the malignant cells leading to a dense, hypoxic environment that promotes further tumorigenesis, provides innate systemic resistance, and suppresses anti-tumor immune invasion. This desmoplastic environment combined with the immunoregulatory events that allow it to persist serve as the primary focus of this review. The physical barrier and immune counterbalance in the tumor microenvironment (TME) make PDAC an immunologically cold tumor. To convert PDAC into an immunologically hot tumor, tumor microenvironment could be considered alongside the tumor cells. We discuss the complex network of microenvironment molecular and cellular composition and explore how they can be targeted to overcome immuno-therapeutic challenges.

A Comprehensive Review of the Potential Role of Liquid Biopsy as a Diagnostic, Prognostic, and Predictive Biomarker in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma is one of the most lethal malignant diseases, with a mortality rate being close to incidence. Due to its heterogeneity and plasticity, as well as the lack of distinct symptoms in the early phases, it is very often diagnosed at an advanced stage, resulting in poor prognosis. Traditional tissue biopsies remain the gold standard for making a diagnosis, but have an obvious disadvantage in their inapplicability for frequent sampling. Blood-based biopsies represent a non-invasive method which potentially offers easy and repeated sampling, leading to the early detection and real-time monitoring of the disease and hopefully an accurate prognosis. Given the urgent need for a reliable biomarker that can estimate a patient's condition and response to an assigned treatment, blood-based biopsies are emerging as a potential new tool for improving patients' survival and surveillance. In this article, we discuss the current advances and challenges in using liquid biopsies for pancreatic cancer, focusing on circulating tumour DNA (ctDNA), extracellular vesicles (EVs), and circulating tumour cells (CTCs), and compare the performance and reliability of different biomarkers and combinations of biomarkers.

Exosomes: Emerging Modulators of Pancreatic Cancer Drug Resistance

Pancreatic cancer (PaC) is one of the most lethal tumors worldwide, difficult to diagnose, and with inadequate therapeutical chances. The most used therapy is gemcitabine, alone or in combination with nanoparticle albumin-bound paclitaxel (nab-paclitaxel), and the multidrug FOLFIRINOX. Unfortunately, PaC develops resistance early, thus reducing the already poor life expectancy of patients. The mechanisms responsible for drug resistance are not fully elucidated, and exosomes seem to be actively involved in this phenomenon, thanks to their ability to transfer molecules regulating this process from drug-resistant to drug-sensitive PaC cells. These extracellular vesicles are released by both normal and cancer cells and seem to be essential mediators of intercellular communications, especially in cancer, where they are secreted at very high numbers. This review illustrates the role of exosomes in PaC drug resistance. This manuscript first provides an overview of the pharmacological approaches used in PaC and, in the last part, focuses on the mechanisms exploited by the exosomes released by cancer cells to induce drug resistance.

Emerging role of pancreatic stellate cell-derived extracellular vesicles in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer that is characterised by a prominent collagenous stromal reaction/desmoplasia surrounding tumour cells. Pancreatic stellate cells (PSCs) are responsible for the production of this stroma and have been shown to facilitate PDAC progression. Recently, extracellular vesicles (EVs), in particular, small extracellular vesicles (exosomes) have been a topic of interest in the field of cancer research for their emerging roles in cancer progression and diagnosis. EVs act as a form of intercellular communication by carrying their molecular cargo from one cell to another, regulating functions of the recipient cells. Although the knowledge of the bi-directional interactions between the PSCs and cancer cells that promote disease progression has advanced significantly over the past decade, studies on PSC-derived EVs in PDAC are currently rather limited. This review provides an overview of PDAC, pancreatic stellate cells and their interactions with cancer cells, as well as the currently known role of extracellular vesicles derived from PSCs in PDAC progression.

Pancreatic cancer and exosomes: role in progression, diagnosis, monitoring, and treatment

Pancreatic cancer (PC) is one of the most dangerous diseases that threaten human life, and investigating the details affecting its progression or regression is particularly important. Exosomes are one of the derivatives produced from different cells, including tumor cells and other cells such as Tregs, M2 macrophages, and MDSCs, and can help tumor growth. These exosomes perform their actions by affecting the cells in the tumor microenvironment, such as pancreatic stellate cells (PSCs) that produce extracellular matrix (ECM) components and immune cells that are responsible for killing tumor cells. It has also been shown that pancreatic cancer cell (PCC)-derived exosomes at different stages carry molecules. Checking the presence of these molecules in the blood and other body fluids can help us in the early stage diagnosis and monitoring of PC. However, immune system cell-derived exosomes (IEXs) and mesenchymal stem cell (MSC)-derived exosomes can contribute to PC treatment. Immune cells produce exosomes as part of the mechanisms involved in the immune surveillance and tumor cell-killing phenomenon. Exosomes can be modified in such a way that their antitumor properties are enhanced. One of these methods is drug loading in exosomes, which can significantly increase the effectiveness of chemotherapy drugs. In general, exosomes form a complex intercellular communication network that plays a role in developing, progressing, diagnosing, monitoring, and treating pancreatic cancer.

Exosomes in metastasis of colorectal cancers: Friends or foes?

Colorectal cancer (CRC), the third most common type of cancer worldwide, threaten human health and quality of life. With multidisciplinary, including surgery, chemotherapy and/or radiotherapy, patients with an early diagnosis of CRC can have a good prognosis. However, metastasis in CRC patients is the main risk factor causing cancer-related death. To elucidate the underlying molecular mechanisms of CRC metastasis is the difficult and research focus on the investigation of the CRC mechanism. On the other hand, the tumor microenvironment (TME) has been confirmed as having an essential role in the tumorigenesis and metastasis of malignancies, including CRCs. Among the different factors in the TME, exosomes as extracellular vesicles, function as bridges in the communication between cancer cells and different components of the TME to promote the progression and metastasis of CRC. MicroRNAs packaged in exosomes can be derived from different sources and transported into the TME to perform oncogenic or tumor-suppressor roles accordingly. This article focuses on CRC exosomes and illustrates their role in regulating the metastasis of CRC, especially through the packaging of miRNAs, to evoke exosomes as novel biomarkers for their impact on the metastasis of CRC progression.

Exosomal cargos-mediated metabolic reprogramming in tumor microenvironment

Metabolic reprogramming is one of the hallmarks of cancer. As nutrients are scarce in the tumor microenvironment (TME), tumor cells adopt multiple metabolic adaptations to meet their growth requirements. Metabolic reprogramming is not only present in tumor cells, but exosomal cargos mediates intercellular communication between tumor cells and non-tumor cells in the TME, inducing metabolic remodeling to create an outpost of microvascular enrichment and immune escape. Here, we highlight the composition and characteristics of TME, meanwhile summarize the components of exosomal cargos and their corresponding sorting mode. Functionally, these exosomal cargos-mediated metabolic reprogramming improves the "soil" for tumor growth and metastasis. Moreover, we discuss the abnormal tumor metabolism targeted by exosomal cargos and its potential antitumor therapy. In conclusion, this review updates the current role of exosomal cargos in TME metabolic reprogramming and enriches the future application scenarios of exosomes.

The role of microRNAs in the modulation of cancer-associated fibroblasts activity during pancreatic cancer pathogenesis

Pancreatic ductal adenocarcinoma (PDAC) is the deadliest of the common cancers. A major hallmark of PDAC is an abundant and dense fibrotic stroma, the result of a disproportionate deposition of extracellular matrix (ECM) proteins. Cancer-associated fibroblasts (CAFs) are the main mediators of PDAC desmoplasia. CAFs represent a heterogenous group of activated fibroblasts with different origins and activation mechanisms. microRNAs (miRNAs) are small non-coding RNAs with critical activity during tumour development and resistance to chemotherapy. Increasing evidence has revealed that miRNAs play a relevant role in the differentiation of normal fibroblasts into CAFs in PDAC. In this review, we discuss recent findings on the role of miRNAs in the activation of CAFs during the progression of PDAC and its response to therapy, as well as the potential role that PDAC-derived exosomal miRNAs may play in the activation of hepatic stellate cells (HSCs) and formation of liver metastasis. Since targeting of CAF activation may be a viable strategy for PDAC therapy, and miRNAs have emerged as potential therapeutic targets, understanding the biology underpinning miRNA-mediated tumour cell-CAF interactions is an important component in guiding rational approaches to treating this deadly disease.

Pancreatic cancer, stroma, and exosomes

In the pathogenesis of pancreatic adenocarcinoma, tumor stroma plays a key role in both aggressiveness, immune evasion, resistance to chemotherapy, and the ability to metastasize. Among the elements that characterize the behavior of the stroma, extracellular vesicles and, in particular, exosomes play an important role. These extracellular vesicles carry a wide range of bioactive molecules, from transcription factors to microRNAs, which can substantially alter the phenotype of the cellular components of the stroma. Exosomes are involved in the exchange of signals between tumor cells, tumor-associated macrophages, cancer-associated fibroblasts, and also with the healthy cells surrounding the tumor. They can transfer resistance to chemotherapeutic drugs, promote the epithelial-mesenchymal transition, modify the phenotype of macrophages, or induce the expression of molecules that alter the extracellular matrix to facilitate migration and metastasis. On the other hand, all these characteristics make these vesicles first-rate therapeutic targets, as controlling their functionality could greatly enhance the effectiveness of treatments that, today, are still far from be satisfactory.

Therapeutic Strategies to Overcome Fibrotic Barriers to Nanomedicine in the Pancreatic Tumor Microenvironment

Pancreatic cancer is notorious for its dismal prognosis. The enhanced permeability and retention (EPR) effect theory posits that nanomedicines (therapeutics in the size range of approximately 10-200 nm) selectively accumulate in tumors. Nanomedicine has thus been suggested to be the "magic bullet"-both effective and safe-to treat pancreatic cancer. However, the densely fibrotic tumor microenvironment of pancreatic cancer impedes nanomedicine delivery. The EPR effect is thus insufficient to achieve a significant therapeutic effect. Intratumoral fibrosis is chiefly driven by aberrantly activated fibroblasts and the extracellular matrix (ECM) components secreted. Fibroblast and ECM abnormalities offer various potential targets for therapeutic intervention. In this review, we detail the diverse strategies being tested to overcome the fibrotic barriers to nanomedicine in pancreatic cancer. Strategies that target the fibrotic tissue/process are discussed first, which are followed by strategies to optimize nanomedicine design. We provide an overview of how a deeper understanding, increasingly at single-cell resolution, of fibroblast biology is revealing the complex role of the fibrotic stroma in pancreatic cancer pathogenesis and consider the therapeutic implications. Finally, we discuss critical gaps in our understanding and how we might better formulate strategies to successfully overcome the fibrotic barriers in pancreatic cancer.

Pancreatic cancer and fibrosis: Targeting metabolic reprogramming and crosstalk of cancer-associated fibroblasts in the tumor microenvironment

Pancreatic cancer is one of the most dangerous types of cancer today, notable for its low survival rate and fibrosis. Deciphering the cellular composition and intercellular interactions in the tumor microenvironment (TME) is a necessary prerequisite to combat pancreatic cancer with precision. Cancer-associated fibroblasts (CAFs), as major producers of extracellular matrix (ECM), play a key role in tumor progression. CAFs display significant heterogeneity and perform different roles in tumor progression. Tumor cells turn CAFs into their slaves by inducing their metabolic dysregulation, exacerbating fibrosis to acquire drug resistance and immune evasion. This article reviews the impact of metabolic reprogramming, effect of obesity and cellular crosstalk of CAFs and tumor cells on fibrosis and describes relevant therapies targeting the metabolic reprogramming.

Crosstalk between Pancreatic Cancer Cells and Cancer-Associated Fibroblasts in the Tumor Microenvironment Mediated by Exosomal MicroRNAs

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant digestive tumors, characterized by a low rate of early diagnosis, strong invasiveness, and early metastasis. The abundant stromal cells, dense extracellular matrix, and lack of blood supply in PDAC limit the penetration of chemotherapeutic drugs, resulting in poor efficacy of the current treatment regimens. Cancer-associated fibroblasts (CAFs) are the major stromal cells in the tumor microenvironment. Tumor cells can secrete exosomes to promote the generation of activated CAFs, meanwhile exosomes secreted by CAFs help promote tumor progression. The aberrant expression of miRNAs in exosomes is involved in the interaction between tumor cells and CAFs, which provides the possibility for the application of exosomal miRNAs in the diagnosis and treatment of PDAC. The current article reviews the mechanism of exosomal miRNAs in the crosstalk between PDAC cells and CAFs in the tumor microenvironment, in order to improve the understanding of TME regulation and provide evidence for designing diagnostic and therapeutic targets against exosome miRNA in human PDAC.

The value of exosome-derived noncoding RNAs in colorectal cancer proliferation, metastasis, and clinical applications

Colorectal cancer (CRC) is the third most common cancer in the world today, and its incidence and mortality rates are increasing every year. The ease of proliferation and metastasis of CRC has long been an important reason for its high mortality rate. Exosomes serve as key mediators that mediate communication between tumor cells and various other cells. Non-coding RNAs (ncRNAs) have been shown to play a key role in apoptosis, immunosuppression and proliferation metastasis in cancer. ncRNAs are loaded on exosomes and initiate the onset of metastasis by promoting epithelial-mesenchymal transition (EMT) at the primary site of the tumor. Meanwhile, exosome-derived ncRNAs construct a pre-metastatic niche (PMN) for CRC metastasis by forming an inflammatory microenvironment in distant organs, immunosuppression, and promoting angiogenesis and remodeling of the extracellular matrix. Here, we summarize the specific mechanisms associated with exosome-derived ncRNAs promoting local invasion and metastasis in CRC. Finally, we focus on their value for clinical application in future CRC diagnosis and treatment.

Proteomes of Extracellular Vesicles From Pancreatic Cancer Cells and Cancer-Associated Fibroblasts

OBJECTIVES

Extracellular vesicles (EVs) are lipid bound vesicles secreted by cells into the extracellular environment. Studies have implicated EVs in cell proliferation, epithelial-mesenchymal transition, metastasis, angiogenesis, and mediating the interaction of tumor cells and microenvironment. A systematic characterization of EVs from pancreatic cancer cells and cancer-associated fibroblasts (CAFs) would be valuable for studying the roles of EV proteins in pancreatic tumorigenesis.

METHODS

Proteomic and functional analyses were applied to characterize the proteomes of EVs released from 5 pancreatic cancer lines, 2 CAF cell lines, and a normal pancreatic epithelial cell line (HPDE).

RESULTS

More than 1400 nonredundant proteins were identified in each EV derived from the cell lines. The majority of the proteins identified in the EVs from the cancer cells, CAFs, and HPDE were detected in all 3 groups, highly enriched in the biological processes of vesicle-mediated transport and exocytosis. Protein networks relevant to pancreatic tumorigenesis, including epithelial-mesenchymal transition, complement, and coagulation components, were significantly enriched in the EVs from cancer cells or CAFs.

CONCLUSIONS

These findings support the roles of EVs as a potential mediator in transmitting epithelial-mesenchymal transition signals and complement response in the tumor microenvironment and possibly contributing to coagulation defects related to cancer development.

Extracellular vesicles in pancreatic cancer immune escape: Emerging roles and mechanisms

Pancreatic cancer (PC) is the most lethal malignancy worldwide due to its delayed diagnosis and limited treatment options. Despite great progress in clinical trials of immunotherapies for various cancers, their effectiveness in PC is very low, indicating that immune evasion is still a major obstacle to immunotherapy in PC. However, the mechanism of immune escape in PC is not fully understood, which substantially restricts the development of immunotherapy. As an important component of intercellular communication networks, extracellular vesicles (EVs) have attracted increasing attention in relation to immune escape. This review aims to provide a better understanding of the roles of EVs in tumor immune escape and the potential to expand their application in cancer immunotherapy. The relationship between PC and the tumor immune microenvironment is briefly introduced. Then, the mechanism by which EVs are involved in immune regulation is summarized, and the latest progress in determining the role of EVs in regulating PC immune escape is highlighted.

Emerging role of exosomes in cancer progression and tumor microenvironment remodeling

Cancer is one of the leading causes of death worldwide, and the factors responsible for its progression need to be elucidated. Exosomes are structures with an average size of 100 nm that can transport proteins, lipids, and nucleic acids. This review focuses on the role of exosomes in cancer progression and therapy. We discuss how exosomes are able to modulate components of the tumor microenvironment and influence proliferation and migration rates of cancer cells. We also highlight that, depending on their cargo, exosomes can suppress or promote tumor cell progression and can enhance or reduce cancer cell response to radio- and chemo-therapies. In addition, we describe how exosomes can trigger chronic inflammation and lead to immune evasion and tumor progression by focusing on their ability to transfer non-coding RNAs between cells and modulate other molecular signaling pathways such as PTEN and PI3K/Akt in cancer. Subsequently, we discuss the use of exosomes as carriers of anti-tumor agents and genetic tools to control cancer progression. We then discuss the role of tumor-derived exosomes in carcinogenesis. Finally, we devote a section to the study of exosomes as diagnostic and prognostic tools in clinical courses that is important for the treatment of cancer patients. This review provides a comprehensive understanding of the role of exosomes in cancer therapy, focusing on their therapeutic value in cancer progression and remodeling of the tumor microenvironment.

Extracellular vesicle-mediated crosstalk between pancreatic cancer and stromal cells in the tumor microenvironment

Pancreatic ductal adenocarcinoma (PDAC) interacts closely with the tumor microenvironment (TME). The TME is remodeled by crosstalk between pancreatic cancer cells and stromal cells, and is critical for cancer progression. Extracellular vesicles (EVs), including exosomes and microvesicles, help facilitate an exchange of information both within the TME and to distant organs. EVs have also been identified as potential diagnostic biomarkers, therapeutic targets, and drug carriers for pancreatic cancer treatment. Thus, understanding the selective packaging of EVs cargo and its mechanistic impact will increase our understanding of cancer biology. In this review, we collect and analyze recent findings of the pancreatic cancer-stromal cell interactions mediated by EVs and the mechanisms involved in cancer-related immunity and chemoresistance. These studies demonstrate the vital role of EVs in pancreatic cancer reprogramming and TME remodeling. We also summarize the EVs identified as potential PDAC diagnostic biomarkers and possible therapeutic targets. This greater understanding is a promising avenue for transitioning EVs from bench to bedside.

Small extracellular vesicles (exosomes) and their cargo in pancreatic cancer: Key roles in the hallmarks of cancer

Pancreatic cancer (PC) is a devastating disease, offering poor mortality rates for patients. The current challenge being faced is the inability to diagnose patients in a timely manner, where potentially curative resection provides the best chance of survival. Recently, small/nanosized extracellular vesicles (sEVs), including exosomes, have gained significant preclinical and clinical attention due to their emerging roles in cancer progression and diagnosis. Extracellular vesicles (EVs) possess endogenous properties that offer stability and facilitate crossing of biological barriers for delivery of molecular cargo to cells, acting as a form of intercellular communication to regulate function and phenotype of recipient cells. This review provides an overview of the role of EVs, their subtypes and their oncogenic cargo (as characterised by targeted studies as well as agnostic '-omics' analyses) in the pathobiology of pancreatic cancer. The discussion covers the progress of 'omics technology' that has enabled elucidation of the molecular mechanisms that mediate the role of EVs and their cargo in pancreatic cancer progression.

Cancer cell's internal and external warriors: Autophagosomes and exosomes

"That survival instinct, that will to live, that need to get back to life again, is more powerful than any consideration of taste, decency, politeness, manners, civility, anything. It's such a powerful force." This quote by famous director Danny Boyle is a perfect analogy to describe the cancer cell's inexhaustible drive to persist against all odds. In order to adapt to a hostile environment, the cancer cells rely on multiple mechanisms including immune escape, epithelial to mesenchymal transition, angiogenesis, extravasation, autophagy, exosome release among others. Cancer cells depute their internal and external warriors, autophagosomes and exosomes, to dwell in the belligerent tumor microenvironment. It is quite reasonable for a cancer cell, striving to survive, to invest in pathways that will provide the maximum advantage. Autophagy is an important cellular degradation pathway, while the exosome pathway provides an alternative cargo disposal mechanism to maintain the homeostasis and cell survival. While autophagic degradation provides the essential nutrients to rapidly dividing cells, exosomal secretion ensures that the tumor microenvironment is attuned to accommodate the swiftly expanding tumor mass. Studies have revealed that exosomes secreted by cancer cells can modulate autophagy in recipient cells, while autophagy can influence the biogenesis of exosomes. Autophagy and exosome crosstalk is extremely complex and it is only beginning to be recognized and documented. This review is focused on discussing the roles of autophagy and exosomes in the cancer cell's adaptation to the tumor microenvironment and how the two pathways are coordinately regulated to facilitate cancer cell survival.

An Insight into miR-1290: An Oncogenic miRNA with Diagnostic Potential

For more than two decades, the view of the roles of non-coding RNAs (ncRNAs) has been radically changing. These RNA molecules that are transcribed from our genome do not have the capacity to encode proteins, but are critical regulators of gene expression at different levels. Our knowledge is constantly enriched by new reports revealing the role of these new molecular players in the development of many pathological conditions, including cancer. One of the ncRNA classes includes short RNA molecules called microRNAs (miRNAs), which are involved in the post-transcriptional control of gene expression affecting various cellular processes. The aberrant expression of miRNAs with oncogenic and tumor-suppressive function is associated with cancer initiation, promotion, malignant transformation, progression and metastasis. Oncogenic miRNAs, also known as oncomirs, mediate the downregulation of tumor-suppressor genes and their expression is upregulated in cancer. Nowadays, miRNAs show promising application in diagnosis, prediction, disease monitoring and therapy response. Our review presents a current view of the oncogenic role of miR-1290 with emphasis on its properties as a cancer biomarker in clinical medicine.

Exosomes: the key of sophisticated cell-cell communication and targeted metastasis in pancreatic cancer

Pancreatic cancer is one of the most common malignancies. Unfortunately, the lack of effective methods of treatment and diagnosis has led to poor prognosis coupled with a very high mortality rate. So far, the pathogenesis and progression mechanisms of pancreatic cancer have been poorly characterized. Exosomes are small vesicles secreted by most cells, contain lipids, proteins, and nucleic acids, and are involved in diverse functions such as intercellular communications, biological processes, and cell signaling. In pancreatic cancer, exosomes are enriched with multiple signaling molecules that mediate intercellular communication with control of immune suppression, mutual promotion between pancreas stellate cells and pancreatic cancer cells, and reprogramming of normal cells. In addition, exosomes can regulate the pancreatic cancer microenvironment and promote the growth and survival of pancreatic cancer. Exosomes can also build pre-metastatic micro-ecological niches and facilitate the targeting of pancreatic cancer. The ability of exosomes to load cargo and target allows them to be of great clinical value as a biomarker mediator for targeted drugs in pancreatic cancer. Video Abstract.

Small extracellular vesicles: from mediating cancer cell metastasis to therapeutic value in pancreatic cancer

Pancreatic cancer is a highly malignant tumor and, is extremely difficult to diagnose and treat. Metastasis is one of the critical steps in the development of cancer and uses cell to cell communication to mediate changes in the microenvironment. Small extracellular vesicles (sEVs)-carry proteins, nucleic acids and other bioactive substances, and are important medium for communication between cells. There are two primary steps in sVEs-mediated metastasis: communication between pancreatic cancer cells and their surrounding microenvironment; and the communication between primary tumor cells and distant organ cells in distant organs that promotes angiogenesis, reshaping extracellular matrix, forming immunosuppressive environment and other ways to form appropriate pre-metastasis niche. Here, we explore the mechanism of localization and metastasis of pancreatic cancer and use sEVs as early biomarkers for the detection and treatment of pancreatic cancer. Video Abstract.

Pancreatic stellate cells - rising stars in pancreatic pathologies

Pluripotent pancreatic stellate cells (PSCs) receive growing interest in past decades. Two types of PSCs are recognized –vitamin A accumulating quiescent PSCs and activated PSCs- the main producents of extracellular matrix in pancreatic tissue. PSCs plays important role in pathogenesis of pancreatic fibrosis in pancreatic cancer and chronic pancreatitis. PSCs are intensively studied as potential therapeutical target because of their important role in developing desmoplastic stroma in pancreatic cancer. There also exists evidence that PSC are involved in other pathologies like type-2 diabetes mellitus. This article brings brief characteristics of PSCs and recent advances in research of these cells.

The potential role of miR-1290 in cancer progression, diagnosis, prognosis, and treatment: An oncomiR or onco-suppressor microRNA?

Cancer is one of the leading causes of death in humans because of the lack of early diagnosis, distant metastases, and the resistance to adjuvant therapies, including chemotherapy and radiotherapy. In addition to playing an essential role in tumor progression and development, microRNAs (miRNAs) can be used as a robust biomarker in the early detection of cancer. MiR-1290 was discovered for the first time in human embryonic stem cells, and under typical physiological situations, plays an essential role in neuronal differentiation and neural stem cell proliferation. Its coding sequence is located at the 1p36.13 regions in the first intron of the aldehyde dehydrogenase 4 gene member A1. miR-1290 is out of control in many cancers such as breast cancer, colorectal cancer, esophageal squamous cell carcinoma, gastric cancer, lung cancer, pancreatic cancer, and plays a vital role in their development. Therefore, it is suggested that miR-1290 can be considered as a potential diagnostic and therapeutic target in many cancers. In addition to the importance of miR-1290 in the noninvasive diagnosis of various cancers, this systematic review study discussed the role of miR-1290 in altering the expression of different genes involved in cancer development and chemo-radiation resistance. Moreover, it considered the regulatory effect of natural products on miR-1290 expression and the interaction of lncRNAs by miR-1290.

Current theranostic approaches for metastatic cancers through hypoxia-induced exosomal packaged cargo

Tumour cells exhibit numerous defence mechanisms against various therapeutic strategies and help in developing drug resistance. These defence strategies help cancer cells prevent their elimination from an organism and prosper at a specific location. In recent times it's been observed that there is a significant contribution of secreted extracellular vesicles (EVs) from such tumorigenic sites in the development and prognosis of cancer. Amongst the various types of EVs, exosomes behave like biological carriers, play a crucial role in transporting the content between different cells, and had such an underrated defence mode by getting induced due to the hypoxia secreted highly specialised double-membrane structures. These small structure vesicles play a critical part in regulating local microenvironment and intracellular communications, cited by many research studies. Exosomes are a potential carrier of several cargo biomolecules like proteins, lipids, miRNAs, mRNAs etc., facilitating better communication within the microenvironment of cancer cells, enhancing the metastatic rate along with cancer progression. Several studies have extensively researched elucidating exosomes mediated radiation-induced bystander effects: multidrug resistance, epithelial-mesenchymal transition, and help cancer cells escape from the immune system apart from playing a critical role in angiogenesis too. Due to its natural tendency to carry different biomolecules, it can also be used to haul chemical drugs and efficiently deliver the drug molecules to the targeted site of cancer. The current review aims to explore the vivid role of hypoxia-induced exosomes in tumour progression along with its application and challenges in cancer therapeutics.

Comprehensive Analysis of microRNA Profiles in Organoids Derived from Human Colorectal Adenoma and Cancer

INTRODUCTION

Exosomes are membrane-enclosed nanovesicles, which are increasingly being recognized as important cell communication components for their role in transmitting microRNAs (miRNAs). No previous study has addressed the exosomal miRNA profile in colorectal adenomas (CRAs) because the long-term culture of CRA is challenging. This study aimed to identify the miRNA signature in organoid exosomes derived from human CRA and colorectal cancer (CRC) samples.

METHODS

Organoid cultures were developed from resected colorectal tissues of patients with CRA or CRC undergoing surgery or endoscopic mucosal resection. Exosomes were prepared from the conditioned medium of the organoids. miRNAs were prepared from the exosomes and their source organoids. The miRNA expression profiles were compared using microarray analysis. The impact of alteration of miRNA expression on cell proliferation was examined using miRNA mimics or inhibitors in HT-29 human CRC cells.

RESULTS

We established 6 organoid lines from CRC and 8 organoid lines from CRA. Exosomal miRNA signatures were different between the organoids derived from CRA and CRC. Both exosomal and cellular miR-1246 expressions were upregulated in CRC-derived organoids compared to their expression in CRA-derived organoids. Alteration of miR-1246 expression by the miR-1246 mimic or inhibitor increased or decreased cell proliferation in HT-29 cells, respectively.

CONCLUSIONS

We report for the first time the miRNA profiles of exosomes in CRA- and CRC-derived organoids. The upregulation of miR-1246 might play a role in increased cell proliferation in the process of CRA-carcinoma transition.

Extracellular vesicles in pancreatic cancer progression and therapies

Pancreatic cancer (PC) is one of the leading causes of cancer-related death worldwide due to delayed diagnosis and limited treatments. More than 90% of all pancreatic cancers are pancreatic ductal adenocarcinoma (PDAC). Extensive communication between tumour cells and other cell types in the tumour microenvironment have been identified which regulate cancer hallmarks during pancreatic tumorigenesis via secretory factors and extracellular vesicles (EVs). The EV-capsuled factors not only facilitate tumour growth locally, but also enter circulation and reach distant organs to construct a pre-metastatic niche. In this review, we delineate the key factors in pancreatic ductal adenocarcinoma derived EVs that mediate different tumour processes. Also, we highlight the factors that are related to the crosstalk with cancer stem cells/cancer-initiating cells (CSC/CIC), the subpopulation of cancer cells that can efficiently metastasize and resist currently used chemotherapies. Lastly, we discuss the potential of EV-capsuled factors in early diagnosis and antitumour therapeutic strategies.

Pancreatic Cancer Small Extracellular Vesicles (Exosomes): A Tale of Short- and Long-Distance Communication

Simple Summary

Even today, pancreatic cancer still has a dismal prognosis. It is characterized by a lack of early symptoms and thus late diagnosis as well as early metastasis. The majority of patients suffer from pancreatic ductal adenocarcinoma (PDAC). PDACs communicate extensively with cellular components of their microenvironment, but also with distant metastatic niches to facilitate tumor progression and dissemination. This crosstalk is substantially enabled by small extracellular vesicles (sEVs, exosomes) with a size of 30–150 nm that are released from the tumor cells. sEVs carry bioactive cargos that reprogram target cells to promote tumor growth, migration, metastasis, immune evasion, or chemotherapy resistance. Interestingly, sEVs also carry novel diagnostic, prognostic and potentially also predictive biomarkers. Moreover, engineered sEVs may be utilized as therapeutic agents, improving treatment options. The role of sEVs for PDAC development, progression, diagnosis, prognosis, and treatment is the focus of this review.

Abstract

Even with all recent advances in cancer therapy, pancreatic cancer still has a dismal 5-year survival rate of less than 7%. The most prevalent tumor subtype is pancreatic ductal adenocarcinoma (PDAC). PDACs display an extensive crosstalk with their tumor microenvironment (TME), e.g., pancreatic stellate cells, but also immune cells to regulate tumor growth, immune evasion, and metastasis. In addition to crosstalk in the local TME, PDACs were shown to induce the formation of pre-metastatic niches in different organs. Recent advances have attributed many of these interactions to intercellular communication by small extracellular vesicles (sEVs, exosomes). These nanovesicles are derived of endo-lysosomal structures (multivesicular bodies) with a size range of 30–150 nm. sEVs carry various bioactive cargos, such as proteins, lipids, DNA, mRNA, or miRNAs and act in an autocrine or paracrine fashion to educate recipient cells. In addition to tumor formation, progression, and metastasis, sEVs were described as potent biomarker platforms for diagnosis and prognosis of PDAC. Advances in sEV engineering have further indicated that sEVs might once be used as effective drug carriers. Thus, extensive sEV-based communication and applications as platform for biomarker analysis or vehicles for treatment suggest a major impact of sEVs in future PDAC research.

Small extracellular vesicle non-coding RNAs in pancreatic cancer: molecular mechanisms and clinical implications

Pancreatic cancer has the worst prognosis among common tumors which is attributed to its aggressive phenotype, diagnosis at advanced, inoperable stages, and resistance to systemic therapy. Non-coding RNAs (ncRNAs) such as microRNAs, long non-coding RNAs, and circular RNAs have been established as important regulators of gene expression and their deregulation has been implicated in multiple diseases and foremost cancer. In the tumor microenvironment, non-coding RNAs can be distributed among cancer cells, stromal cells, and immune cells via small extracellular vesicles (sEVs), thereby facilitating intercellular communication and influencing major cancer hallmarks such as angiogenesis, evasion of the immune system, and metastatic dissemination. Furthermore, sEV-ncRNAs have shown promising potential as liquid biopsies with diagnostic and prognostic significance. In this review, we summarize the role of sEVs as carriers of ncRNAs and underlying molecular mechanisms in pancreatic cancer. Moreover, we review the potential of sEV-ncRNAs as biomarkers and highlight the suitability of sEVs as delivery vehicles for ncRNA-based cancer therapy.

The Study of Ginger-Derived Extracellular Vesicles as a Natural Nanoscale Drug Carrier and Their Intestinal Absorption in Rats

Extracellular vesicles have been widely used in drug delivery systems and clinical studies as a new natural nanoscale drug carrier. Most of these studies focused on the extracellular vesicles from animals, but few involved in the extracellular vesicles from edible plants. This study was the first to explore the potential and value of ginger-derived extracellular vesicles (GDEVs) as drug carrier by using the content ratio method and to further study their intestinal absorption in rats. In this experiment, GDEVs were extracted and purified by ultrahigh-speed centrifugation. GDEVs were saucer-like with a particle size of 70.09±19.24 nm and a zeta potential of -27.70±12.20 mV. In this experiment, high-performance liquid chromatography was used to explore the difference in gingerol content between GDEVs and ginger slices. Under the same mass, the contents of 6-gingerol (6G), 8-gingerol (8G), and 10-gingerol (10G) in GDEVs were 10.21-fold, 22.69-fold, and 32.36-fold of those in ginger slices, respectively. In this experiment, the absorption kinetics and absorption site of GDEVs were investigated using in situ single-pass intestinal perfusion method in rats. GDEVs could be absorbed by the small intestine in the concentration range of 15-60 mg/mL, and the absorption trend of different intestinal segments was duodenum > jejunum > ileum. These results indicated that GDEVs had good loading capacity and significant prospects as a carrier of the drug delivery system. At the same time, combining the oil-water partition coefficient (6G < 8G < 10G) of three gingerol compounds, we speculated that the loading capacity of GDEVs increased with the increase of the lipid solubility of the compounds. This study fully demonstrated the potential and value of ginger-derived extracellular vesicles as natural nanocarrier and provided an important reference for the further application of plant-derived extracellular vesicles in the drug delivery system.

Extracellular Vesicles in Organ Fibrosis: Mechanisms, Therapies, and Diagnostics

Fibrosis is the unrelenting deposition of excessively large amounts of insoluble interstitial collagen due to profound matrigenic activities of wound-associated myofibroblasts during chronic injury in diverse tissues and organs. It is a highly debilitating pathology that affects millions of people globally and leads to decreased function of vital organs and increased risk of cancer and end-stage organ disease. Extracellular vesicles (EVs) produced within the chronic wound environment have emerged as important vehicles for conveying pro-fibrotic signals between many of the cell types involved in driving the fibrotic response. On the other hand, EVs from sources such as stem cells, uninjured parenchymal cells, and circulation have in vitro and in vivo anti-fibrotic activities that have provided novel and much-needed therapeutic options. Finally, EVs in body fluids of fibrotic individuals contain cargo components that may have utility as fibrosis biomarkers, which could circumvent current obstacles to fibrosis measurement in the clinic, allowing fibrosis stage, progression, or regression to be determined in a manner that is accurate, safe, minimally-invasive, and conducive to repetitive testing. This review highlights the rapid and recent progress in our understanding of EV-mediated fibrotic pathogenesis, anti-fibrotic therapy, and fibrosis staging in the lung, kidney, heart, liver, pancreas, and skin.

The Cellular and Biological Impact of Extracellular Vesicles in Pancreatic Cancer

Simple Summary

The increased incidence and global failure of ongoing therapies project pancreatic cancer as the second deadliest cancer worldwide. While our knowledge of pancreatic cancer cells’ abilities and specificities has drastically improved based on multi-scaled omics, one must consider that much more remains to be uncovered on the role and impact of stromal cells and the established network of communication with tumor cells. This review article discusses how tumor cells communicate with the various cells composing the stroma and its implication in tumor cells’ abilities, PDA (pancreatic ductal adenocarcinoma) carcinogenesis and therapeutic response. We will focus on extracellular vesicles-mediated crosstalk and how this multifaceted dialogue impacts both cellular compartments and its subsequent impact on PDA biology.

Abstract

Deciphering the interactions between tumor and stromal cells is a growing field of research to improve pancreatic cancer-associated therapies and patients’ care. Indeed, while accounting for 50 to 90% of the tumor mass, many pieces of evidence reported that beyond their structural role, the non-tumoral cells composing the intra-tumoral microenvironment influence tumor cells’ proliferation, metabolism, cell death and resistance to therapies, among others. Simultaneously, tumor cells can influence non-tumoral neighboring or distant cells in order to shape a tumor-supportive and immunosuppressive environment as well as influencing the formation of metastatic niches. Among intercellular modes of communication, extracellular vesicles can simultaneously transfer the largest variety of signals and were recently reported as key effectors of cell–cell communication in pancreatic cancer, from its development to its evolution as well as its ability to resist available treatments. This review focuses on extracellular vesicles-mediated communication between different cellular components of pancreatic tumors, from the modulation of cellular activities and abilities to their biological and physiological relevance. Taking into consideration the intra-tumoral microenvironment and its extracellular-mediated crosstalk as main drivers of pancreatic cancer development should open up new therapeutic windows.

Exosomal microRNA in Pancreatic Cancer Diagnosis, Prognosis, and Treatment: From Bench to Bedside

Pancreatic cancer is the fourth leading cause of cancer death among men and women in the United States, and pancreatic ductal adenocarcinoma (PDAC) accounts for more than 90% of pancreatic cancer cases. PDAC is one of the most lethal gastrointestinal malignancies with an overall five-year survival rate of ~10%. Developing effective therapeutic strategies against pancreatic cancer is a great challenge. Novel diagnostic, prognostic, and therapeutic strategies are an immediate necessity to increase the survival of pancreatic cancer patients. So far, studies have demonstrated microRNAs (miRNAs) as sensitive biomarkers because of their significant correlation with disease development and metastasis. The miRNAs have been shown to be more stable inside membrane-bound vesicles in the extracellular environment called exosomes. Varieties of miRNAs are released into the body fluids via exosomes depending on the normal physiological or pathological conditions of the body. In this review, we discuss the recent findings on the diagnostic, prognostic, and therapeutic roles of exosomal miRNAs in pancreatic cancer.

Cancer spheroids derived exosomes reveal more molecular features relevant to progressed cancer

Cancer cell spheroids have been shown to be more physiologically relevant to native tumor tissue than monolayer 2D culture cells. Due to enhanced intercellular communications among cells in spheroids, spheroid secreted exosomes which account for transcellular transportation should exceed those from 2D cell culture and may display a different expression pattern of miRNA or protein. To test this, we employed a widely used pancreatic cancer cell line, PANC-1, to create 3D spheroids and compared exosomes generated by both 2D cell culture and 3D PANC-1 spheroids. We further measured and compared exosomal miRNA and GPC-1 protein expression with qRT-PCR and enzyme-linked immunosorbent assay, respectively. It showed that PANC-1 cells cultured in 3D spheroids can produce significantly more exosomes than PANC-1 2D cells and exosomal miRNA and GPC-1 expression derived from spheroids show more features relevant to the progression of pancreatic cancer. These findings point to the potential importance of using spheroids as in vitro model to study cancer development and progression.

Liquid Biopsy for Colorectal Adenoma: Is the Exosomal miRNA Derived From Organoid a Potential Diagnostic Biomarker?

INTRODUCTION

MicroRNAs (miRNAs) can serve as tumor biomarkers; however, their role in evaluating colorectal adenoma (CRA) is unclear. Recently, the organoid culture system enabled long-term expansion of human colon epithelium. This study aimed to examine the potential of exosomal miRNAs extracted from CRA organoids as biomarkers in the clinical liquid biopsy CRA test.

METHODS

We established organoid cultures from normal colon and CRA using resected specimens. Exosomes were isolated from the conditioned medium organoids. MiRNAs were isolated from the exosomes, and their expression profiles were compared using microarray analysis. To identify miRNA candidates for liquid biopsy, we prospectively compared changes in their expression in serum and exosomes before and after endoscopic resection in 26 patients with CRA.

RESULTS

Seven exosomal miRNAs were overexpressed in CRA organoids: miR-4323, miR-4284, miR-1268a, miR-1290, miR-6766-3p, miR-21-5p, and miR-1246. The expression levels of 4 exosomal miRNAs (miR-4323, miR-4284, miR-1290, and miR-1246) and 2 serum miRNAs (miR-1290 and miR-1246) were significantly lower in posttreatment sera. The combined expression of 4 exosomal miRNAs could identify both CRA and large-size (>12.6 cm2) CRA with respective areas under the curve of 0.698 (95% confidence interval [CI] = 0.536-0.823) and 0.834 (95% CI = 0.660-0.929). Combinations of 2-serum miRNA expression values could identify both CRA and large-size CRA with respective area under the curves of 0.691 (95% CI = 0.528-0.817) and 0.834 (95% CI = 0.628-0.938).

DISCUSSION

We found that exosomal miRNAs derived from the CRA organoid culture could be potential diagnostic biomarkers for CRA.

Tumor-derived extracellular vesicles containing microRNA-1290 promote immune escape of cancer cells through the Grhl2/ZEB1/PD-L1 axis in gastric cancer

Gastric cancer (GC) is a highly prevalent malignancy featured by dismal oncological outcomes. Accumulating pieces of evidence have consensus over the therapeutic significance of extracellular vesicles (EVs) and its role in carcinogenesis. Here, we planned to uncover EVs' role in GC by shuttling microRNA-1290 (miR-1290) and to identify the possible molecular mechanism associated with Grhl2, PD-L1, and ZEB1. Grhl2 was under-expressed in GC tissues, exhibiting a negative correlation with PD-L1 expression. In addition, Grhl2 promoted T cell proliferation by down-regulating PD-L1 via inhibiting ZEB1, while miR-1290 was found to negatively regulate Grhl2. EVs were also isolated from GC cells or normal gastric epithelial cells and identified with the presence of EV markers. miR-1290 expression was determined to be enriched in the EVs derived from GC cells and observed to promote the suppressive action of GC cells on T cell activation by up-regulating PD-L1 via the Grhl2/ZEB1 pathway in the co-culture system of GC cells with or without treatment of EVs with T cells. Moreover, we also developed a mouse model of GC and injected the EVs derived from miR-1290-inhibitor-treated GC cells into the tumor-bearing mice for further validation of mechanism in vivo. Intriguingly, the pivotal role of EVs-shuttled miR-1290 as an oncomiR was demonstrated in vivo. Collectively, we found that miR-1290 in EVs secreted from GC cells contributed to immune escape through the Grhl2/ZEB1/PD-L1 axis.

Centrosome amplification mediates small extracellular vesicle secretion via lysosome disruption

Bidirectional communication between cells and their surrounding environment is critical in both normal and pathological settings. Extracellular vesicles (EVs), which facilitate the horizontal transfer of molecules between cells, are recognized as an important constituent of cell-cell communication. In cancer, alterations in EV secretion contribute to the growth and metastasis of tumor cells. However, the mechanisms underlying these changes remain largely unknown. Here, we show that centrosome amplification is associated with and sufficient to promote small extracellular vesicle (SEV) secretion in pancreatic cancer cells. This is a direct result of lysosomal dysfunction, caused by increased reactive oxygen species (ROS) downstream of extra centrosomes. We propose that defects in lysosome function could promote multivesicular body fusion with the plasma membrane, thereby enhancing SEV secretion. Furthermore, we find that SEVs secreted in response to amplified centrosomes are functionally distinct and activate pancreatic stellate cells (PSCs). These activated PSCs promote the invasion of pancreatic cancer cells in heterotypic 3D cultures. We propose that SEVs secreted by cancer cells with amplified centrosomes influence the bidirectional communication between the tumor cells and the surrounding stroma to promote malignancy.

Exosomes as Pleiotropic Players in Pancreatic Cancer

Pancreatic cancer (PC) incidence is rising and due to late diagnosis, combined with unsatisfactory response to current therapeutic approaches, this tumor has an extremely high mortality rate. A better understanding of the mechanisms underlying pancreatic carcinogenesis is of paramount importance for rational diagnostic and therapeutic approaches. Multiple lines of evidence have showed that exosomes are actively involved in intercellular communication by transferring their cargos of bioactive molecules to recipient cells within the tumor microenvironment and systemically. Intriguingly, exosomes may exert both protumor and antitumor effects, supporting or hampering processes that play a role in the pathogenesis and progression of PC, including shifts in tumor metabolism, proliferation, invasion, metastasis, and chemoresistance. They also have a dual role in PC immunomodulation, exerting immunosuppressive or immune enhancement effects through several mechanisms. PC-derived exosomes also induce systemic metabolic alterations, leading to the onset of diabetes and weight loss. Moreover, exosomes have been described as promising diagnostic and prognostic biomarkers for PC. Their potential application in PC therapy as drug carriers and therapeutic targets is under investigation. In this review, we provide an overview of the multiple roles played by exosomes in PC biology through their specific cargo biomolecules and of their potential exploitation in early diagnosis and treatment of PC.

Regulation of Pancreatic Fibrosis by Acinar Cell-Derived Exosomal miR-130a-3p via Targeting of Stellate Cell PPAR-γ

Introduction

As endogenous miRNA carriers, exosomes play a role in the pathophysiological processes of various diseases. However, their functions and regulation mechanisms in pancreatic fibrosis remain unclear.

Methods

In this study, an RNA microarray was used to detect differentially expressed exosomal miR-130a-3p in AR42J cells before and after taurolithocholate (TLC) treatment. mRNA-seq was used to screen differentially expressed genes before and after pancreatic stellate cell (PSC) activation. We used the STRING database to construct a protein-protein interaction (PPI) network for differentially expressed genes, used CytoNCA to analyze the centrality of the PPI network, and identified 10 essential proteins in the biological network. Then, the TargetScan and miRanda databases were used to predict the target genes of miR-130a-3p. The intersections of the target genes and the mRNAs encoding the 10 essential proteins were identified to construct miR-130a-3p/peroxisome proliferator-activated receptor gamma (PPAR-γ) pairs. Fluorescence labeling of exosomes and dynamic tracing showed that exosomes can fuse with the cell membranes of PSCs and transport miR-130a-3p into PSCs. A luciferase reporter gene assay was used to confirm that miR-130a-3p can bind to PPAR-γ to inhibit PPAR-γ expression. In vitro and in vivo functional experiments were performed for gain-of-function studies and loss-of-function studies, respectively.

Results

The studies showed that acinar cell-derived exosomal miR-130a-3p promotes PSC activation and collagen formation through targeting of stellate cellular PPAR-γ. Knockdown of miR-130a-3p significantly improved pancreatic fibrosis. Notably, miR-130a-3p knockdown reduced serum levels of hyaluronic acid (HA) and β-amylase and increased the C-peptide level to protect endocrine and exocrine pancreatic functions and the function of endothelial cells.

Conclusion

This study revealed that the exosomal miR-130a-3p/PPAR-γ axis participates in PSC activation and the mechanism of chronic pancreatitis (CP) with fibrosis, thus providing a potential new target for the treatment of chronic pancreatic fibrosis.

Preliminary study on SPECT/CT imaging of pancreatic cancer xenografts by targeting integrin α5 in pancreatic stellate cells

Background: Integrin α5 (ITGA5) is overexpressed specifically in pancreatic cancer stroma, specially, in the activated pancreatic stellate cells (PSCs). Molecular imaging of pancreatic cancer via targeting PSCs has its advantages.

Purpose: This study aims to investigate the feasibility of ITGA5-targeted SPECT/CT imaging of pancreatic cancer by targeting PSCs.

Methods: ITGA5 expression in PSCs treated without or with pancreatic cancer SW1990 cells conditioned medium (SW1990-CM) was assessed by western blotting and immunofluorescence staining. ITGA5 specific inhibitor AV3 peptide was radiolabeled with ¹²⁵I to synthesize ¹²⁵I-AV3, and the labeling rate, in vitro stability and cellular uptake were further investigated. SW1990 cells alone or with PSCs were injected subcutaneously on the left and right lower limbs of nude mice respectively to establish pancreatic cancer xenograft model, and then ¹²⁵I-AV3 SPECT/CT imaging of pancreatic cancer-bearing nude mice was performed. The expression of ITGA5 in tumors was detected by immunohistochemical (IHC) staining.

Results:¹²⁵I-AV3 has an excellent labeling rate and good in vitro stability. After treated with SW1990-CM, PSCs had an increased expression of ITGA5 and higher ¹²⁵I-AV3 uptake. SPECT/CT imaging study showed that ¹²⁵I-AV3 was mainly accumulated in the right xenografts (co-injection of cancer cells and PSCs), while the left xenografts tumors have a poor imaging. Moreover, the uptake of radiotracer in both side tumors was inhibited significantly after the non-radiolabeled AV3 pretreatment. IHC staining showed that SW1990 + PSCs tumor has a higher positive rate of ITGA5 than SW1990 tumor.

Conclusion: The preliminary study suggests that ¹²⁵I-AV3 can be used for SPECT/CT imaging of pancreatic cancer via targeting ITGA5 in PSCs, which is independent of the state of cancer cells and may have a special meaning.

Defined serum-free three-dimensional culture of umbilical cord-derived mesenchymal stem cells yields exosomes that promote fibroblast proliferation and migration in vitro

Stem cell-derived exosomes are emerging as novel and clinically relevant cell-free therapeutics for regenerative therapy. This work focused on investigating the stimulation of fibroblasts by exosomes derived from umbilical cord-derived mesenchymal stem cells (ucMSC) in a defined serum-free three-dimensional (3D) culture. 3D culture of ucMSC was carried out in medium supplemented with KnockOut serum replacement (KO-medium) using the Aggrewell system. ucMSC in KO-medium formed spheroids with maintained size and integrity throughout culture. This enabled the isolation of vesicles from ucMSC spheroids in KO-medium with sizes that fall within the exosomal size range and were positive for the expression of canonical exosomal markers CD63, CD9, CD81, Alix, and TSG101. The ucMSC-derived exosomes (ExoucMSC ) were shown to significantly increase the migration and proliferation of murine fibroblasts in vitro. To conclude, 3D culture of ucMSC in defined serum-free KO-medium formed viable spheroids which enabled the isolation of ExoucMSC with the potential of accelerating wound healing.

The emerging roles of exosomes in anti-cancer drug resistance and tumor progression: An insight towards tumor-microenvironment interaction

The tumor microenvironment (TME) is a complex network of cellular organization consisting of fibroblasts, adipocytes, pericytes, immune cells endothelial cells, and extracellular matrix proteins. Besides communicating with each other, tumor cells are also involved in the tumor stroma interaction. Presently, most of the studies have focused on the contribution of TME in supporting tumor growth through intercellular communication by physical contact between the cells or through paracrine signaling cascades of growth factors and cytokines. The crosstalk between the tumor and TME has a pivotal role in the development of anti-cancer drug resistance. Drug resistance, be it against targeted or non-targeted drugs, has emerged as a major hurdle in the successful therapeutic intervention of cancer. Among the several mechanisms involved in the development of the resistance to anti-cancer therapies, exosomes have recently come into the limelight. Exosomes are the nano-sized vesicles, originated from the endolysosomal compartments and have the inherent potential to shuttle diverse biomolecules like proteins, lipids, and nucleic acids to the recipient cells. There are also instances where the pharmacological compounds are transferred between the cells via exosomes. For instance, the transfer of the cargoes from the drug-resistant tumor cells immensely affects the recipient drug-sensitive cells in terms of their proliferation, survival, migration, and drug resistance. In this review, we have discussed multiple aspects of the exosome-mediated bidirectional interplay between tumor and TME. Furthermore, we have also emphasized the contribution of exosomes promoting drug resistance and therapeutic strategies to mitigate the exosome induced drug resistance as well.

Pancreatic stellate cells derived exosomal miR-5703 promotes pancreatic cancer by downregulating CMTM4 and activating PI3K/Akt pathway

Exosomes play important role in tumor microenvironment, and mediate the crosstalk between pancreatic cancer (PC) cells and matrix components including pancreatic stellate cells (PSCs) to regulate pancreatic cancer progression. Here we isolated primary PSCs from PC patients, and demonstrated that PSC-derived exosomes could be internalized by PC cells to promote cell proliferation. Furthermore, we identified that miR-5703 in the exosomes acted as a driver of cell proliferation and its inhibitor suppressed the function of exosomes to promote PC cell proliferation. miR-5703 directly bound to the 3'UTR of CMTM4 and downregulated its expression. CMTM4 knockdown promoted PC cell proliferation, while overexpression of CMTM4 suppressed PC cell proliferation both in vivo and in vitro. Mechanistically, we revealed that CMTM4 suppressed PI3K/Akt pathway via downregulating PAK4. In conclusion, our results suggest that PSC-derived exosomal miR-5703 could target CMTM4 in PC cells and promote cell proliferation due to PAK4 activated PI3K/Akt pathway.