MicroRNA-155 Controls Exosome Synthesis and Promotes Gemcitabine Resistance in Pancreatic Ductal Adenocarcinoma

Calix[6]arene dismantles extracellular vesicle biogenesis and metalloproteinases that support pancreatic cancer hallmarks

Many challenges are faced in pancreatic cancer treatment due to late diagnosis and poor prognosis because of high recurrence and metastasis. Extracellular vesicles (EVs) and matrix metalloproteinases (MMPs), besides acting in intercellular communication, are key players in the cancer cell plasticity responsible for initiating metastasis. Therefore, these entities provide valuable targets for the development of better treatments. In this context, this study aimed to evaluate the potential of calix[6]arene to disturb the release of EVs and the activity of MMPs in pancreatic cancer cells. We found a correlation between the endocytic-associated mediators and the prognosis of pancreatic cancer patients. We observed a more active EV machinery in the pancreatic cancer cell line PANC-1, which was reduced three-fold by treatment with calix[6]arene at subtoxic concentration (5 μM; p 〈0,001). We observed the modulation of 186 microRNAs (164 miRNAs upregulated and 22 miRNAs downregulated) upon calix[6]arene treatment. Interestingly, some of them as miR-4443 and miR-3909, regulates genes HIF1A e KIF13A that are well known to play a role in transport of vesicles. Furthermore, Calix[6]arene downmodulated matrix metalloproteinases (MMPs) -2 and - 9 and disturbed the viability of pancreatic organoids which recapitulate the cellular heterogeneity, structure, and functions of primary tissues. Our findings shed new insights on calix[6]arene's antitumor mechanism, including its intracellular effects on vesicle production and trafficking, as well as MMP activity, which may harm the tumor microenvironment and contribute to a reduction in cancer cell dissemination, which is one of the challenges associated with high mortality in pancreatic cancer.

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.

KLK10 derived from tumor endothelial cells accelerates colon cancer cell proliferation and hematogenous liver metastasis formation

Tumor endothelial cells (TECs), which are thought to be structurally and functionally different from normal endothelial cells (NECs), are increasingly attracting attention as a therapeutic target in hypervascular malignancies. Although colorectal liver metastasis (CRLM) tumors are hypovascular, inhibitors of angiogenesis are a key drug in multidisciplinary therapy, and TECs might be involved in the development and progression of cancer. Here, we analyzed the function of TEC in the CRLM tumor microenvironment. We used a murine colon cancer cell line (CT26) and isolated TECs from CRLM tumors. TECs showed higher proliferation and migration than NECs. Coinjection of CT26 and TECs yielded rapid tumor formation in vivo. Immunofluorescence analysis showed that coinjection of CT26 and TECs increased vessel formation and Ki-67+ cells. Transcriptome analysis identified kallikrein-related peptide 10 (KLK10) as a candidate target. Coinjection of CT26 and TECs after KLK10 downregulation with siRNA suppressed tumor formation in vivo. TEC secretion of KLK10 decreased after KLK10 downregulation, and conditioned medium after KLK10 knockdown in TECs suppressed CT26 proliferative activity. Double immunofluorescence staining of KLK10 and CD31 in CRLM tissues revealed a significant correlation between poor prognosis and positive KLK10 expression in TECs and tumor cells. On multivariate analysis, KLK10 expression was an independent prognostic factor in disease-free survival. In conclusion, KLK10 derived from TECs accelerates colon cancer cell proliferation and hematogenous liver metastasis formation. KLK10 in TECs might offer a promising therapeutic target in CRLM.

Extracellular vesicles associated microRNAs: Their biology and clinical significance as biomarkers in gastrointestinal cancers

Gastrointestinal (GI) cancers, including colorectal, gastric, esophageal, pancreatic, and liver, are associated with high mortality and morbidity rates worldwide. One of the underlying reasons for the poor survival outcomes in patients with these malignancies is late disease detection, typically when the tumor has already advanced and potentially spread to distant organs. Increasing evidence indicates that earlier detection of these cancers is associated with improved survival outcomes and, in some cases, allows curative treatments. Consequently, there is a growing interest in the development of molecular biomarkers that offer promise for screening, diagnosis, treatment selection, response assessment, and predicting the prognosis of these cancers. Extracellular vesicles (EVs) are membranous vesicles released from cells containing a repertoire of biological molecules, including nucleic acids, proteins, lipids, and carbohydrates. MicroRNAs (miRNAs) are the most extensively studied non-coding RNAs, and the deregulation of miRNA levels is a feature of cancer cells. EVs miRNAs can serve as messengers for facilitating interactions between tumor cells and the cellular milieu, including immune cells, endothelial cells, and other tumor cells. Furthermore, recent years have witnessed considerable technological advances that have permitted in-depth sequence profiling of these small non-coding RNAs within EVs for their development as promising cancer biomarkers -particularly non-invasive, liquid biopsy markers in various cancers, including GI cancers. Herein, we summarize and discuss the roles of EV-associated miRNAs as they play a seminal role in GI cancer progression, as well as their promising translational and clinical potential as cancer biomarkers as we usher into the area of precision oncology.

Optimizing Exosome Preparation Based on Size and Morphology: Insights From Electron Microscopy

Extracellular vesicles (EVs), including exosomes, are crucial in intercellular communication, but differentiating between exosomes and microvesicles is challenging due to their similar morphology and size. This study focuses on multivesicular bodies (MVBs), where exosomes mature, and optimizes exosome isolation using transmission electron microscopy (TEM) for size information. Considering that EVs are nanocolloidal particles, a salt-free Bis-Tris buffer is found to maintain EV integrity better than phosphate-buffered saline (PBS). Dynamic light scattering (DLS) and TEM analysis confirm that intact exosome fractions under the salt-free Bis-Tris buffer condition exhibit polydispersity, including a unique population of <50 nm vesicles resembling intraluminal membrane vesicles (ILVs) in MVBs, alongside larger populations. This <50 nm population disappears in PBS or Bis-Tris buffer with 140 mM NaCl, transforming into a monodisperse population >100 nm. Immunoelectron microscopy also validates the presence of CD63, an exosome biomarker, on approximately 50 nm EVs. These findings provide valuable insights into exosome characterization and isolation, essential for future biomedical applications in diagnostics and drug delivery.

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.

Thinking small to win big? A critical review on the potential application of extracellular vesicles for biomarker discovery and new therapeutic approaches in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is an extremely deadly form of cancer, with limited progress in 5-year survival rates despite significant research efforts. The main challenges in treating PDAC include difficulties in early detection, and resistance to current therapeutic approaches due to aggressive molecular and microenvironment features. These challenges emphasize the importance of identifying clinically validated biomarkers for early detection and clinical management. Extracellular vesicles (EVs), particularly exosomes, have emerged as crucial mediators of intercellular communication by transporting molecular cargo. Recent research has unveiled their role in initiation, metastasis, and chemoresistance of PDAC. Consequently, utilizing EVs in liquid biopsies holds promise for the identification of biomarkers for early detection, prognosis, and monitoring of drug efficacy. However, numerous limitations, including challenges in isolation and characterization of homogeneous EVs populations, as well as the absence of standardized protocols, can affect the reliability of studies involving EVs as biomarkers, underscoring the necessity for a prudent approach. EVs have also garnered considerable attention as a promising drug delivery system and novel therapy for tumors. The loading of biomolecules or chemical drugs into exosomes and their subsequent delivery to target cells can effectively impede tumor progression. Nevertheless, there are obstacles that must be overcome to ensure the accuracy and efficacy of therapies relying on EVs for the treatment of tumors. In this review, we examine both recent advancements and remaining obstacles, exploring the potential of utilizing EVs in biomarker discovery as well as for the development of drug delivery vehicles.

Investigating the regulatory role of miRNAs as silent conductors in the management of pathogenesis and therapeutic resistance of pancreatic cancer

Pancreatic cancer (PC) has the greatest mortality rate of all the main malignancies. Its advanced stage and poor prognosis place it at the bottom of all cancer sites. Hence, emerging biomarkers can enable precision medicine where PC therapy is tailored to each patient. This highlights the need for new, highly sensitive and specific biomarkers for early PC diagnosis. Prognostic indicators are also required to stratify PC patients. To avoid ineffective treatment, adverse events, and expenses, biomarkers are also required for patient monitoring and identifying responders to treatment. There is substantial evidence that microRNAs (miRs, miRNAs) play a critical role in regulating mRNA and, as a consequence, protein expression in normal and malignant tissues. Deregulated miRNA profiling in PC can help with diagnosis, treatment planning, and prognosis. Furthermore, knowledge of the primary effector genes and downstream pathways in PC can help pinpoint potential miRNAs for use in treatment. Different miRNA expression profiles may serve as diagnostic, prognostic markers, and therapeutic targets across the spectrum of malignant pancreatic illness. Dysregulation of miRNAs has been linked to the malignant pathophysiology of PC through affecting many cellular functions such as increasing invasive and proliferative prospect, supporting angiogenesis, cell cycle aberrance, apoptosis elusion, metastasis promotion, and low sensitivity to particular treatments. Accordingly, in the current review, we summarize the recent advances in the roles of oncogenic and tumor suppressor (TS) miRNAs in PC and discuss their potential as worthy diagnostic and prognostic biomarkers for PC, as well as their significance in PC pathogenesis and anticancer drug resistance.

Exosomes in Cancer Progression and Therapy Resistance: Molecular Insights and Therapeutic Opportunities

The development of therapy resistance still represents a major hurdle in treating cancers, leading to impaired treatment success and increased patient morbidity. The establishment of minimally invasive liquid biopsies is a promising approach to improving the early diagnosis, as well as therapy monitoring, of solid tumors. Because of their manifold functions in the tumor microenvironment, tumor-associated small extracellular vesicles, referred to as exosomes, have become a subject of intense research. Besides their important roles in cancer progression, metastasis, and the immune response, it has been proposed that exosomes also contribute to the acquisition and transfer of therapy resistance, mainly by delivering functional proteins and RNAs, as well as facilitating the export of active drugs or functioning as extracellular decoys. Extensive research has focused on understanding the molecular mechanisms underlying the occurrence of resistance and translating these into strategies for early detection. With this review, we want to provide an overview of the current knowledge about the (patho-)biology of exosomes, as well as state-of-the-art methods of isolation and analysis. Furthermore, we highlight the role of exosomes in tumorigenesis and cancer treatment, where they can function as therapeutic agents, biomarkers, and/or targets. By focusing on their roles in therapy resistance, we will reveal new paths of exploiting exosomes for cancer diagnosis and treatment.

Liquid biopsy techniques and pancreatic cancer: diagnosis, monitoring, and evaluation

Pancreatic cancer (PC) is one of the most common malignancies. Surgical resection is a potential curative approach for PC, but most patients are unsuitable for operations when at the time of diagnosis. Even with surgery, some patients may still experience tumour metastasis during the operation or shortly after surgery, as precise prognosis evaluation is not always possible. If patients miss the opportunity for surgery and resort to chemotherapy, they may face the challenging issue of chemotherapy resistance. In recent years, liquid biopsy has shown promising prospects in disease diagnosis, treatment monitoring, and prognosis assessment. As a noninvasive detection method, liquid biopsy offers advantages over traditional diagnostic procedures, such as tissue biopsy, in terms of both cost-effectiveness and convenience. The information provided by liquid biopsy helps clinical practitioners understand the molecular mechanisms underlying tumour occurrence and development, enabling the formulation of more precise and personalized treatment decisions for each patient. This review introduces molecular biomarkers and detection methods in liquid biopsy for PC, including circulating tumour cells (CTCs), circulating tumour DNA (ctDNA), noncoding RNAs (ncRNAs), and extracellular vesicles (EVs) or exosomes. Additionally, we summarize the applications of liquid biopsy in the early diagnosis, treatment response, resistance assessment, and prognostic evaluation of PC.

Role of exosomes in transferring chemoresistance through modulation of cancer glycolytic cell metabolism

Chemoresistance constitute a major obstacle in cancer treatment, leading to limited options and decreased patient survival. Recent studies have revealed a novel mechanism of chemoresistance acquisition: the transfer of information via exosomes, small vesicles secreted by various cells. Exosomes play a crucial role in intercellular communication by carrying proteins, nucleic acids, and metabolites, influencing cancer cell behavior and response to treatment. One crucial mechanism of resistance is cancer metabolic reprogramming, which involves alterations in the cellular metabolic pathways to support the survival and proliferation of drug-resistant cancer cells. This metabolic reprogramming often includes increased glycolysis, providing cancer cells with the necessary energy and building blocks to evade the effects of chemotherapy. Notably, exosomes have been found to transport glycolytic enzymes, as identified in proteomic profiling, leading to the reprogramming of metabolic pathways, facilitating altered glucose metabolism and increased lactate production. As a result, they profoundly impact the tumor microenvironment, promoting tumor progression, survival, immune evasion, and drug resistance.Understanding the complexities of such exosome-mediated cell-to-cell communication might open new therapeutic avenues and facilitate biomarker development in managing cancers characterized by aggressive glycolytic features. Moreover, given the intricate nature of metabolic abnormalities combining future exosome-based-targeted therapies with existing treatments like chemotherapy, immunotherapy, and targeted therapies holds promise for achieving synergistic effects to overcome resistance and improve cancer treatment outcomes.

Differential Effects of Pancreatic Cancer-Derived Extracellular Vesicles Driving a Suppressive Environment

Pancreatic ductal adenocarcinoma (PDAC) cells display extensive crosstalk with their surrounding environment to regulate tumor growth, immune evasion, and metastasis. Recent advances have attributed many of these interactions to intercellular communication mediated by small extracellular vesicles (sEVs), involving cancer-associated fibroblasts (CAF). To explore the impact of sEVs on monocyte lineage transition as well as the expression of checkpoint receptors and activation markers, peripheral blood monocytes from healthy subjects were exposed to PDAC-derived sEVs. Additionally, to analyze the role of sEV-associated HA in immune regulation and tissue-resident fibroblasts, monocytes and pancreatic stellate cells were cultured in the presence of PDAC sEVs with or depleted of HA. Exposure of monocytes to sEVs resulted in unique phenotypic changes in HLA-DR, PD-L1, CD86 and CD64 expression, and cytokine secretion that was HA-independent except for IL-1β and MIP1β. In contrast, monocyte suppression of autologous T cell proliferation was reduced following exposure to HA-low sEVs. In addition, exposure of stellate cells to sEVs upregulated the secretion of various cytokines, including MMP-9, while removal of HA from PDAC-derived sEVs attenuated the secretion of MMP-9, demonstrating the role of sEV-associated HA in regulating expression of this pro-tumorigenic cytokine from stellate cells. This observation lends credence to the findings from the TCGA database that PDAC patients with high levels of enzymes in the HA synthesis pathway had worse survival rates compared with patients having low expression of these enzymes. PDAC-derived sEVs have an immune modulatory role affecting the activation state of monocyte subtypes. However, sEV-associated HA does not affect monocyte phenotype but alters cytokine secretion and suppression of autologous T cell proliferation and induces secretion of pro-tumorigenic factors by pancreatic stellate cells (PSC), as has been seen following the conversion of PSCs to cancer-associated fibroblasts (CAFs). Interruption of the hexosamine biosynthetic pathway, activated in PDAC producing the key substrate (UDP-GlcNAc) for HA synthesis, thus, represents a potential clinical interception strategy for PDAC patients. Findings warrant further investigations of underlying mechanisms involving larger sample cohorts.

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.

Targeting miRNA and using miRNA as potential therapeutic options to bypass resistance in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease with poor prognosis due to early metastasis, low diagnostic rates at early stages, and resistance to current therapeutic regimens. Despite numerous studies and clinical trials, the mortality rate for PDAC has shown limited improvement. Therefore, there is a pressing need to attain. a more comprehensive molecular characterization to identify biomarkers enabling early detection and evaluation of treatment response. MicroRNA (miRNAs) are critical regulators of gene expression on the post-transcriptional level, and seem particularly interesting as biomarkers due to their relative stability, and the ability to detect them in fixed tissue specimens and biofluids. Deregulation of miRNAs is common and affects several hallmarks of cancer and contribute to the oncogenesis and metastasis of PDAC. Unique combinations of upregulated oncogenic miRNAs (oncomiRs) and downregulated tumor suppressor miRNAs (TsmiRs), promote metastasis, characterize the tumor and interfere with chemosensitivity of PDAC cells. Here, we review several oncomiRs and TsmiRs involved in chemoresistance to gemcitabine and FOLFIRINOX in PDAC and highlighted successful/effective miRNA-based therapy approaches in vivo. Integrating miRNAs in PDAC treatment represents a promising therapeutic avenue that can be used as guidance for personalized medicine for PDAC patients.

Circulating microRNAs as Potential Biomarkers in Pancreatic Cancer-Advances and Challenges

There is an urgent unmet need for robust and reliable biomarkers for early diagnosis, prognosis, and prediction of response to specific treatments of many aggressive and deadly cancers, such as pancreatic cancer, and liquid biopsy-based miRNA profiling has the potential for this. MiRNAs are a subset of non-coding RNAs that regulate the expression of a multitude of genes post-transcriptionally and thus are potential diagnostic, prognostic, and predictive biomarkers and have also emerged as potential therapeutics. Because miRNAs are involved in the post-transcriptional regulation of their target mRNAs via repressing gene expression, defects in miRNA biogenesis pathway and miRNA expression perturb the expression of a multitude of oncogenic or tumor-suppressive genes that are involved in the pathogenesis of various cancers. As such, numerous miRNAs have been identified to be downregulated or upregulated in many cancers, functioning as either oncomes or oncosuppressor miRs. Moreover, dysregulation of miRNA biogenesis pathways can also change miRNA expression and function in cancer. Profiling of dysregulated miRNAs in pancreatic cancer has been shown to correlate with disease diagnosis, indicate optimal treatment options and predict response to a specific therapy. Specific miRNA signatures can track the stages of pancreatic cancer and hold potential as diagnostic, prognostic, and predictive markers, as well as therapeutics such as miRNA mimics and miRNA inhibitors (antagomirs). Furthermore, identified specific miRNAs and genes they regulate in pancreatic cancer along with downstream pathways can be used as potential therapeutic targets. However, a limited understanding and validation of the specific roles of miRNAs, lack of tissue specificity, methodological, technical, or analytical reproducibility, harmonization of miRNA isolation and quantification methods, the use of standard operating procedures, and the availability of automated and standardized assays to improve reproducibility between independent studies limit bench-to-bedside translation of the miRNA biomarkers for clinical applications. Here I review recent findings on miRNAs in pancreatic cancer pathogenesis and their potential as diagnostic, prognostic, and predictive markers.

Diabetes mellitus promotes susceptibility to periodontitis-novel insight into the molecular mechanisms

Diabetes mellitus is a main risk factor for periodontitis, but until now, the underlying molecular mechanisms remain unclear. Diabetes can increase the pathogenicity of the periodontal microbiota and the inflammatory/host immune response of the periodontium. Hyperglycemia induces reactive oxygen species (ROS) production and enhances oxidative stress (OS), exacerbating periodontal tissue destruction. Furthermore, the alveolar bone resorption damage and the epigenetic changes in periodontal tissue induced by diabetes may also contribute to periodontitis. We will review the latest clinical data on the evidence of diabetes promoting the susceptibility of periodontitis from epidemiological, molecular mechanistic, and potential therapeutic targets and discuss the possible molecular mechanistic targets, focusing in particular on novel data on inflammatory/host immune response and OS. Understanding the intertwined pathogenesis of diabetes mellitus and periodontitis can explain the cross-interference between endocrine metabolic and inflammatory diseases better, provide a theoretical basis for new systemic holistic treatment, and promote interprofessional collaboration between endocrine physicians and dentists.

Efficacy of Autologous Skeletal Myoblast Cell Sheet Transplantation for Liver Regeneration in Liver Failure

BACKGROUND

No effective therapies have yet been established for liver regeneration in liver failure. Autologous skeletal myoblast cell sheet transplantation has been proven to improve cardiac function in patients with heart failure, and one of the mechanisms has been reported to be a paracrine effect by various growth factors associated with liver regeneration. Therefore, the present study focused on the effect of myoblast cells on liver regeneration in vitro and in vivo.

METHODS

We assessed the effect of myoblast cells on the cells comprising the liver in vitro in association with liver regeneration. In addition, we examined in vivo effect of skeletal myoblast cell sheet transplantation in C57/BL/6 mouse models of liver failure, such as liver fibrosis induced by thioacetamide and hepatectomy.

RESULTS

In vitro, the myoblast cells exhibited a capacity to promote the proliferation of hepatic epithelial cells and the angiogenesis of liver sinusoidal endothelial cells, and suppress the activation of hepatic stellate cells. In vivo, sheet transplantation significantly suppressed liver fibrosis in the induced liver fibrosis model and accelerated liver regeneration in the hepatectomy model.

CONCLUSIONS

Autologous skeletal myoblast cell sheet transplantation significantly improved the liver failure in the in vitro and in vivo models. Sheet transplantation is expected to have the potential to be a clinically therapeutic option for liver regeneration in liver failure.

Noncoding RNAs: an emerging modulator of drug resistance in pancreatic cancer

Pancreatic cancer is the eighth leading cause of cancer-related deaths worldwide. Chemotherapy including gemcitabine, 5-fluorouracil, adriamycin and cisplatin, immunotherapy with immune checkpoint inhibitors and targeted therapy have been demonstrated to significantly improve prognosis of pancreatic cancer patients with advanced diseases. However, most patients developed drug resistance to these therapeutic agents, which leading to shortened patient survival. The detailed molecular mechanisms contributing to pancreatic cancer drug resistance remain largely unclear. The growing evidences have shown that noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), are involved in pancreatic cancer pathogenesis and development of drug resistance. In the present review, we systematically summarized the new insight on of various miRNAs, lncRNAs and circRNAs on drug resistance of pancreatic cancer. These results demonstrated that targeting the tumor-specific ncRNA may provide novel options for pancreatic cancer treatments.

Evolving utility of exosomes in pancreatic cancer management

Despite the development of newer oncological treatment, the survival of patients with pancreatic cancer (PC) remains poor. Recent studies have identified exosomes as essential mediators of intercellular communications and play a vital role in tumor initiation, metastasis and chemoresistance. Thus, the utility of liquid biopsies using exosomes in PC management can be used for early detection, diagnosis, monitoring as well as drug delivery vehicles for cancer therapy. This review summarizes the function, and clinical applications of exosomes in cancers as minimally invasive liquid biomarker in diagnostic, prognostic and therapeutic roles.

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.

Re-Shaping the Pancreatic Cancer Tumor Microenvironment: A New Role for the Metastasis Suppressor NDRG1

Pancreatic cancer (PaC) is a highly aggressive disease, with poor response to current treatments and 5-year survival rates of 10-15%. PaC progression is facilitated by its interaction with the complex and multifaceted tumor microenvironment (TME). In the TME, cancer cells and surrounding stromal cells constantly communicate with each other via the secretion and uptake of factors including cytokines, chemokines, growth factors, metabolites, and extracellular vesicles (EVs), reshaping the landscape of PaC. Recent studies demonstrated that the metastasis suppressor N-myc downstream regulated 1 (NDRG1) not only inhibits oncogenic signaling pathways in PaC cells but also alters the communication between PaC cells and the surrounding stroma. In fact, NDRG1 was found to influence the secretome of PaC cells, alter cancer cell metabolism, and interfere with intracellular trafficking and intercellular communication between PaC cells and surrounding fibroblasts. This review will present recent advancements in understanding the role of NDRG1 in PaC progression, with a focus on how this molecule influences PaC-stroma communication and its potential for re-shaping the PaC TME.

Exosomal miRNAs in the microenvironment of pancreatic cancer

Pancreatic cancer (PC) is highly aggressive having an extremely poor prognosis. The tumor microenvironment (TME) of PC is complex and heterogeneous. Various cellular components in the microenvironment are capable of secreting different active substances that are involved in promoting tumor development. Their release may occur via exosomes, the most abundant extracellular vesicles (EVs), that can carry numerous factors as well as act as a mean of intercellular communication. Emerging evidence suggests that miRNAs are involved in the regulation and control of many pathological and physiological processes. They can also be transported by exosomes from donor cells to recipient cells, thereby regulating the TME. Exosomal miRNAs show promise for use as future targets for PC diagnosis and prognosis, which may reveal new treatment strategies for PC. In this paper, we review the important role of exosomal miRNAs in mediating cellular communication in the TME of PC as well as their potential use in clinical applications.

A comprehensive survey into the role of exosomes in pancreatic cancer; from the origin of cancer to the progress and possibility of diagnosis and treatment

Pancreatic cancer is the fourth most common malignant tumor in the world, which has a high mortality rate due to high invasiveness, early metastases, lack of specific symptoms, and high invasiveness. Recent studies have shown that exosomes can be essential sources of biomarkers in pancreatic cancer. Over the past ten years, exosomes have been implicated in multiple trials to prevent the growth and metastasis of many cancers, including pancreatic cancer. Exosomes also play essential roles in immune evasion, invasion, metastasis, proliferation, apoptosis, drug resistance, and cancer stemness. Exosomes help cells communicate by carrying proteins and genetic material, such as non-coding RNAs, including mRNAs and microRNAs. This review examines the biological significance of exosomes in pancreatic cancer and their functions in tumor invasion, metastasis, treatment resistance, proliferation, stemness, and immune evasion. We also emphasize recent advances in our understanding of the main functions of exosomes in diagnosing and treating pancreatic cancer.

The Role of Exosomes in Pancreatic Ductal Adenocarcinoma Progression and Their Potential as Biomarkers

Pancreatic ductal adenocarcinoma (PDAC), the most common pancreatic malignancy, is an aggressive and lethal cancer with a dismal five-year survival rate. Despite remarkable improvements in cancer therapeutics, the clinical outcome of PDAC patients remains poor due to late diagnosis of the disease. This highlights the importance of early detection, wherein biomarker evaluation including exosomes would be helpful. Exosomes, small extracellular vesicles (sEVs), are cell-secreted entities with diameters ranging from 50 to 150 nm that deliver cellular contents (e.g., proteins, lipids, and nucleic acids) from parent cells to regulate the cellular processes of targeted cells. Recently, an increasing number of studies have reported that exosomes serve as messengers to facilitate stromal-immune crosstalk within the PDAC tumor microenvironment (TME), and their contents are indicative of disease progression. Moreover, evidence suggests that exosomes with specific surface markers are capable of distinguishing patients with PDAC from healthy individuals. Detectable exosomes in bodily fluids (e.g., blood, urine, saliva, and pancreatic juice) are omnipresent and may serve as promising biomarkers for improving early detection and evaluating patient prognosis. In this review, we shed light on the involvement of exosomes and their cargos in processes related to disease progression, including chemoresistance, angiogenesis, invasion, metastasis, and immunomodulation, and their potential as prognostic markers. Furthermore, we highlight feasible clinical applications and the limitations of exosomes in liquid biopsies as tools for early diagnosis as well as disease monitoring. Taking advantage of exosomes to improve diagnostic capacity may provide hope for PDAC patients, although further investigation is urgently needed.

Rubicon can predict prognosis in patients with pancreatic ductal adenocarcinoma after neoadjuvant chemoradiotherapy

BACKGROUND

Despite previous therapeutic studies on autophagy in cancer, its role in the treatment of pancreatic ductal adenocarcinoma remains controversial, especially regarding its effect on chemotherapy, radiotherapy, and both combined. We focused on RUN domain Beclin-1 interacting and cysteine-rich-containing protein (Rubicon) to reveal its contribution to pancreatic ductal adenocarcinoma after chemoradiotherapy.

METHODS

To evaluate the clinical significance of Rubicon, immunohistochemistry was performed, and Rubicon expression was analyzed across 81 specimens resected from patients with pancreatic ductal adenocarcinoma after neoadjuvant chemoradiotherapy. A gemcitabine-resistant pancreatic ductal adenocarcinoma cell line was established followed by Rubicon expression and autophagy flux estimation. Finally, gemcitabine sensitivity, invasion ability, and cell viability were evaluated using Rubicon-targeting small interfering RNA.

RESULTS

Rubicon expression in resected pancreatic ductal adenocarcinoma samples after chemoradiotherapy revealed significantly worse overall survival and recurrence-free survival in the Rubicon-high expression group than in the Rubicon-low expression group (overall survival: median [years] 2.02 vs. 3.21, p = 0.0359; recurrence-free survival: median [years] 0.90 vs. 1.90, p = 0.0146). In vitro, gemcitabine-resistant pancreatic ductal adenocarcinoma cell lines exhibited higher Rubicon expression and lower autophagy flux than the parental cell line (p < 0.01). Transduction with small interfering RNA downregulated the expression without affecting gemcitabine sensitivity, but it reduced invasion ability and cell viability (p < 0.01) in the gemcitabine-resistant pancreatic ductal adenocarcinoma cell line.

CONCLUSIONS

High Rubicon expression is a significant, unfavorable prognostic factor in pancreatic ductal adenocarcinoma after neoadjuvant chemoradiotherapy. Downregulation of Rubicon expression improves invasion ability and cell viability in gemcitabine-resistant pancreatic ductal adenocarcinoma.

Advances in Liquid Biopsy Technology and Implications for Pancreatic Cancer

Pancreatic cancer is a highly aggressive malignancy with a climbing incidence. The majority of cases are detected late, with incurable locally advanced or metastatic disease. Even in individuals who undergo resection, recurrence is unfortunately very common. There is no universally accepted screening modality for the general population and diagnosis, evaluation of treatment response, and detection of recurrence relies primarily on the use of imaging. Identification of minimally invasive techniques to help diagnose, prognosticate, predict response or resistance to therapy, and detect recurrence are desperately needed. Liquid biopsies represent an emerging group of technologies which allow for non-invasive serial sampling of tumor material. Although not yet approved for routine use in pancreatic cancer, the increasing sensitivity and specificity of contemporary liquid biopsy platforms will likely change clinical practice in the near future. In this review, we discuss the recent technological advances in liquid biopsy, focusing on circulating tumor DNA, exosomes, microRNAs, and circulating tumor cells.

microRNAs Associated with Gemcitabine Resistance via EMT, TME, and Drug Metabolism in Pancreatic Cancer

Despite extensive research, pancreatic cancer remains a lethal disease with an extremely poor prognosis. The difficulty in early detection and chemoresistance to therapeutic agents are major clinical concerns. To improve prognosis, novel biomarkers, and therapeutic strategies for chemoresistance are urgently needed. microRNAs (miRNAs) play important roles in the development, progression, and metastasis of several cancers. During the last few decades, the association between pancreatic cancer and miRNAs has been extensively elucidated, with several miRNAs found to be correlated with patient prognosis. Moreover, recent evidence has revealed that miRNAs are intimately involved in gemcitabine sensitivity and resistance through epithelial-to-mesenchymal transition, the tumor microenvironment, and drug metabolism. Gemcitabine is the gold standard drug for pancreatic cancer treatment, but gemcitabine resistance develops easily after chemotherapy initiation. Therefore, in this review, we summarize the gemcitabine resistance mechanisms associated with aberrantly expressed miRNAs in pancreatic cancer, especially focusing on the mechanisms associated with epithelial-to-mesenchymal transition, the tumor microenvironment, and metabolism. This novel evidence of gemcitabine resistance will drive further research to elucidate the mechanisms of chemoresistance and improve patient outcomes.

Diagnostic and Prognostic Role of Extracellular Vesicles in Pancreatic Cancer: Current Evidence and Future Perspectives

Pancreatic cancer is one of the most aggressive tumors, with a dismal prognosis due to poor detection rates at early stages, rapid progression, post-surgical complications, and limited effectiveness of conventional oncologic therapies. There are no consistently reliable biomarkers or imaging modalities to accurately diagnose, classify, and predict the biological behavior of this tumor. Therefore, it is imperative to develop new and improved strategies to detect pancreatic lesions in the early stages of cancerization with greater sensitivity and specificity. Extracellular vesicles, including exosome and microvesicles, are membrane-coated cellular products that are released in the outer environment. All cells produce extracellular vesicles; however, this process is enhanced by inflammation and tumorigenesis. Based on accumulating evidence, extracellular vesicles play a crucial role in pancreatic cancer progression and chemoresistance. Moreover, they may represent potential biomarkers and promising therapy targets. The aim of the present review is to review the current evidence on the role of extracellular vesicles in pancreatic cancer.

Exosomal microRNAs in cancer: Potential biomarkers and immunotherapeutic targets for immune checkpoint molecules

Exosomes are small extracellular vesicles with a lipid bilayer structure secreted from different cell types which can be found in various body fluids including blood, pleural fluid, saliva and urine. They carry different biomolecules including proteins, metabolites, and amino acids such as microRNAs which are small non-coding RNAs that regulate gene expression and promote cell-to-cell communication. One main function of the exosomal miRNAs (exomiRs) is their role in cancer pathogenesis. Alternation in exomiRs expression could indicate disease progression and can regulate cancer growth and facilitate drug response/resistance. It can also influence the tumour microenvironment by controlling important signaling that regulating immune checkpoint molecules leading to activation of T cell anti-tumour immunity. Therefore, they can be used as potential novel cancer biomarkers and innovative immunotherapeutic agents. This review highlights the use of exomiRs as potential reliable biomarkers for cancer diagnosis, treatment response and metastasis. Finally, discuses their potential as immunotherapeutic agents to regulate immune checkpoint molecules and promote T cell anti-tumour immunity.

Cancer Therapy Empowered by Extracellular Vesicle-Mediated Targeted Delivery

Extracellular vesicles (EVs) are a class of nanoparticles that mediate signaling molecules delivery between donor and recipient cells. Heterogeneity in the content of EVs and their membrane surface proteins determines their unique targetability. Their low immunogenicity, capability to cross various biological barriers, and superior biocompatibility enable engineering-modified EVs to be ideal drug delivery carriers. In addition, the engineered EVs that emerge in recent years have become a powerful tool for cancer treatment through the selective delivery of bioactive molecules to therapeutic targets, such as tumor cells and stroma. Our review focuses on the various types of EV modifications and their promoting therapeutic capabilities, which provide an innovative means for cancer precision therapy.

Porphyromonas gingivalis association with inflammatory markers and exosomal miRNA-155 in saliva of periodontitis patients with and without diabetes diagnosed with COVID-19

Background

/Purposes: Studies have indicated that salivary molecules from patients with periodontitis and diabetes are confounded with pathological conditions associated with SARS-CoV-2 infection. The study aimed to address whether the abundance of Porphyromonas gingivalis which causes periodontitis, differed compared with that of Aggregatibacter actinomycetemcomitans (used as control) and to analyze the correlation of periodontitis with the expression levels of severe acute respiratory syndrome coronavirus 2 receptor (ACE2) and periodontitis inflammatory markers (TLR-2/TLR-4, TNFα, and miR-155).

Materials and Methods

A saliva sample (5 mL) was obtained from 23 hospitalized patients with COVID-19, categorized into two groups: diabetic (G1, n = 10) and non-diabetic (G2, n = 13). Saliva from patients with periodontitis without diabetes and coronavirus disease 2019 (COVID-19; n = 6) were included as control. The quantitative real-time polymerase chain reaction measured the levels of P. gingivalis and A. actinomycetemcomitans, as well as periodontitis markers in saliva. The obtained data were analyzed using one-way ANOVA and the Spearman correlation test.

Results

The abundance of P. gingivalis was observed to be higher (p < 0.05) in saliva of patients with diabetes (G1) than in those without diabetes (G2). A contradictory trend was observed for A. actinomycetemcomitans. The transcription level of ACE2 was comparable in all groups tested, while the expression of periodontitis markers varied. The relationships and sensitivity/specificity among P. gingivalis infection ACE2 expression, and inflammatory markers were also evaluated.

Conclusions

This study showed that the association between P. gingivalis infection and ACE2 expression might reflect the characteristics of saliva in COVID-19 patients with and without diabetes. However, the relationships between TLR-4 and miR-155 are more specific in discriminating against COVID-19 patients with and without diabetes.

Tumor Cell Derived Exosomal GOT1 Suppresses Tumor Cell Ferroptosis to Accelerate Pancreatic Cancer Progression by Activating Nrf2/HO-1 Axis via Upregulating CCR2 Expression

Recently, evidence has shown that GOT1 expression is upregulated in pancreatic cancer tissues and promotes cancer development, but the specific mechanism remains unclear. We found that GOT1 expression was upregulated in pancreatic cancer cell-derived exosomes. When PANC-1 cells were incubated with exosomes alone or transfected together with si-GOT1, we found that exosomes enhanced cell proliferation, invasion and migration, promoted ferroptosis, and si-GOT1 reversed the effects of exosomes. The results of online bioinformatics database analysis indicated that CCR2 was a potential binding protein of GOT1 and is highly expressed in pancreatic cancer tissues. PANC-1 cells were transfected with pcDNA-CCR2 or si-CCR2, and it was found that pcDNA-CCR2 enhanced cell proliferation, invasion and migration, promoted ferroptosis, and si-CCR2 had an opposite effect. Next, exosome-treated cells were transfected with si-GOT1 alone or together with pcDNA-CCR2, and we found that exosomes promoted CCR2 expression, promoted cell proliferation and invasion, and inhibited ferroptosis, the transfection of si-GOT1 abolished the effect of exosomes, and the transfection of pcDNA-CCR2 again reversed the effect of si-GOT1. Furthermore, when exosome-treated cells were transfected with si-GOT1 alone or co-incubated with Nrf2 activator NK-252, we found that si-GOT1 reversed the promoting effect of exosomes on Nrf2 and HO-1 expression, as well as its inhibitory effect on ferroptosis, but this effect was abrogated by NK-252. In vivo studies showed that knockdown of GOT1 expression inhibited tumor formation compared with tumor tissues formed upon exosome induction, which was mediated by promoting ferroptosis via suppressing the protein expression of GOT1, CCR2, Nrf2 and HO-1 in tumor tissues.

Exosomes and their roles in the chemoresistance of pancreatic cancer

Pancreatic cancer (PC) remains one of the most lethal human malignancies worldwide. Due to the insidious onset and the rapid progression, most patients with PC are diagnosed at an advanced stage rendering them inoperable. Despite the development of multiple promising chemotherapeutic agents as recommended first-line treatment for PC, the therapeutic efficacy is largely limited by unwanted drug resistance. Recent studies have identified exosomes as essential mediators of intercellular communications during the occurrence of drug resistance. Understanding the underlying molecular mechanisms and complex signaling pathways of exosome-mediated drug resistance will contribute to the improvement of the design of new oncologic therapy regimens. This review focuses on the intrinsic connections between the chemoresistance of PC cells and exosomes in the tumor microenvironment (TME).

Functions and clinical applications of exosomes in pancreatic cancer

Pancreatic cancer (PC) is one of the most malignant tumors and has an abysmal prognosis, with a 5-year survival rate of only 11%. At present, the main clinical dilemmas in PC are the lack of biomarkers and the unsatisfactory therapeutic effects. The treatments for and outcomes of PC have improved, but remain unsatisfactory. Exosomes are nanosized extracellular vesicles, and an increasing number of studies have found that exosomes play an essential role in tumor pathology. In this review, we describe the process of exosome biogenesis, as well as exosome extraction methods and identification strategies, and we then explain in detail the roles and mechanisms of exosomes in invasion, metastasis, chemoresistance and immunosuppression in PC. Finally, we summarize the clinical applications of exosomes. Our observations indicate that exosomes represent a novel direction in the clinical treatment of PC.

Cancer-derived small extracellular vesicles: emerging biomarkers and therapies for pancreatic ductal adenocarcinoma diagnosis/prognosis and treatment

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal cancers worldwide with high mortality, which is mainly due to the lack of reliable biomarkers for PDAC diagnosis/prognosis in the early stages and effective therapeutic strategies for the treatment. Cancer-derived small extracellular vesicles (sEVs), which carry various messages and signal biomolecules (e.g. RNAs, DNAs, proteins, lipids, and glycans) to constitute the key features (e.g. genetic and phenotypic status) of cancer cells, are regarded as highly competitive non-invasive biomarkers for PDAC diagnosis/prognosis. Additionally, new insights on the biogenesis and molecular functions of cancer-derived sEVs pave the way for novel therapeutic strategies based on cancer-derived sEVs for PDAC treatment such as inhibition of the formation or secretion of cancer-derived sEVs, using cancer-derived sEVs as drug carriers and for immunotherapy. This review provides a comprehensive overview of the most recent scientific and clinical research on the discovery and involvement of key molecules in cancer-derived sEVs for PDAC diagnosis/prognosis and strategies using cancer-derived sEVs for PDAC treatment. The current limitations and emerging trends toward clinical application of cancer-derived sEVs in PDAC diagnosis/prognosis and treatment have also been discussed.

Clinicopathological significance of MYL9 expression in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma is one of the most aggressive malignancies, and often involves invasion and distant metastasis from the early tumor stages. Myosin II reportedly plays a key role in regulating tumor progression and metastasis.

AIMS

We examined whether myosin regulatory light polypeptide 9 (MYL9) regulates cancer cell proliferation.

METHODS AND RESULTS

To investigate the expression pattern and clinical significance of MYL9 in pancreatic ductal adenocarcinoma, we performed immunohistochemical analysis of samples collected from 101 patients with pancreatic ductal adenocarcinoma. The expression of MYL9 was investigated to evaluate its functional role and contribution to proliferation and apoptosis in pancreatic ductal adenocarcinoma cells in vitro. The results showed that MYL9 was predominantly expressed in the cytoplasm and membrane of pancreatic ductal adenocarcinoma cells. Multivariate analysis indicated that MYL9 acted as an independent prognostic factor for overall survival and distant metastasis-free survival. MYL9 expression was strongly associated with malignancy in in vitro analyses, including proliferation and anti-apoptotic activities.

CONCLUSIONS

Our findings suggest that MYL9 is an independent prognostic factor of pancreatic ductal adenocarcinoma. MYL9 is a crucial biomarker and potential therapeutic target for pancreatic ductal adenocarcinoma.

Urine exosomes as biomarkers in bladder cancer diagnosis and prognosis: From functional roles to clinical significance

Bladder cancer is one of the top ten most common cancers and top ten causes of cancer death globally. 5-year survival rates have decreased in Australia from 66% to 55% in the past three decades. The current gold standard for diagnosis is cystoscopy. However, cystoscopies are an invasive and health-resource intensive procedure which has sub-optimal sensitivity for flat lesions such as CIS (carcinoma in situ) and low specificity for differentiating inflammation from cancer - hence requiring biopsies under anesthesia. Frequent and life-long surveillance cystoscopy is required for most patients since there are high rates of progression and local recurrence in high-risk non-muscle invasive cancer (NMIBC) as well as poor outcomes associated with delayed detection of muscle-invasive bladder cancer (MIBC). There is an unmet need for a non-invasive test to provide better discrimination and risk-stratification of bladder cancer which could aid clinicians by improving patient selection for cystoscopy; enhanced risk stratification methods may guide the frequency of surveillance cystoscopies and inform treatment choices. Exosomes, which are nano-sized extracellular vesicles containing genetic material and proteins, have been shown to have functional roles in the development and progression of bladder cancer. Exosomes have also been demonstrated to be a robust source of potential biomarkers for bladder cancer diagnosis and prognosis and may also have roles as therapeutic agents. In this review, we summarize the latest evidence of biological roles of exosomes in bladder cancer and highlight their clinical significance in bladder cancer diagnosis, surveillance and treatment.

Exosomes and cancer - Diagnostic and prognostic biomarkers and therapeutic vehicle

Exosomes belong to a subpopulation of extracellular vesicles secreted by the dynamic multistep endocytosis process and carry diverse functional molecular cargoes, including proteins, lipids, nucleic acids (DNA, messenger and noncoding RNA), and metabolites to promote intercellular communication. Proteins and noncoding RNA are among the most abundant contents in exosomes; they have biological functions and are selectively packaged into exosomes. Exosomes derived from tumor, stromal and immune cells contribute to the multiple stages of cancer progression as well as resistance to therapy. In this review, we will discuss the biogenesis of exosomes and their roles in cancer development. Since specific contents within exosomes originate from their cells of origin, this property allows exosomes to function as valuable biomarkers. We will also discuss the potential use of exosomes as diagnostic and prognostic biomarkers or predictors for different therapeutic strategies for multiple cancers. Furthermore, the applications of exosomes as direct therapeutic targets or engineered vehicles for drugs are an important field of exosome study. Better understanding of exosome biology may pave the way to promising exosome-based clinical applications.

Extracellular vesicles and particles impact the systemic landscape of cancer

Intercellular cross talk between cancer cells and stromal and immune cells is essential for tumor progression and metastasis. Extracellular vesicles and particles (EVPs) are a heterogeneous class of secreted messengers that carry bioactive molecules and that have been shown to be crucial for this cell-cell communication. Here, we highlight the multifaceted roles of EVPs in cancer. Functionally, transfer of EVP cargo between cells influences tumor cell growth and invasion, alters immune cell composition and function, and contributes to stromal cell activation. These EVP-mediated changes impact local tumor progression, foster cultivation of pre-metastatic niches at distant organ-specific sites, and mediate systemic effects of cancer. Furthermore, we discuss how exploiting the highly selective enrichment of molecules within EVPs has profound implications for advancing diagnostic and prognostic biomarker development and for improving therapy delivery in cancer patients. Altogether, these investigations into the role of EVPs in cancer have led to discoveries that hold great promise for improving cancer patient care and outcome.

Association between microRNAs and chemoresistance in pancreatic cancer: Current knowledge, new insights, and forthcoming perspectives

Pancreatic duct adenocarcinoma, commonly known as pancreatic cancer (PC), is a cancer-related cause of death due to delayed diagnosis, metastasis, and drug resistance. Patients with PC suffer from incorrect responses to chemotherapy due to inherent and acquired chemical resistance. Numerous studies have shown the mechanism of the effect of chemoresistance on PC, such as genetic and epigenetic changes or the elucidation of signaling pathways. In this regard, microRNAs (miRNAs) have been identified as essential modulators of gene expression in various cellular functions, including chemoresistance. Thus, identifying the underlying link between microRNAs and PC chemoresistance helps determine the exact pathogenesis of PC. This study aims to classify miRNAs and signaling pathways related to PC chemoresistance, suggesting new therapeutic approaches to overcome PC chemoresistance.

Clinical Significance of Acylphosphatase 1 Expression in Combined HCC-iCCA, HCC, and iCCA

BACKGROUND

Combined hepatocellular and cholangiocarcinoma is a rare primary liver cancer with histological features of both hepatocellular carcinoma and intrahepatic cholangiocarcinoma. Little is known about the prognostic features and molecular mechanism of cHCC-iCCA. Acylphosphatase 1 is a cytosolic enzyme that produces acetic acid from acetyl phosphate and plays an important role in cancer progression.

AIMS

We evaluated the clinical significance of ACYP1 expression in cHCC-iCCA, HCC, and iCCA.

METHODS

ACYP1 immunohistochemistry was performed in 39 cases diagnosed with cHCC-iCCA. The prognosis was evaluated in three different cohorts (cHCC-iCCA, HCC, and iCCA). The relationships between ACYP1 expression and cell viability, migration, invasiveness, and apoptosis were examined using siRNA methods in vitro. In vivo subcutaneous tumor volumes and cell apoptosis were evaluated after downregulation of ACYP1 expression.

RESULTS

Almost half of the patients with cHCC-iCCA were diagnosed with high ACYP1 expression. In all three cohorts, the cases with high ACYP1 expression had significantly lower overall survival, and high ACYP1 expression was identified as an independent prognostic factor. Downregulation of ACYP1 reduced the proliferative capacity, migration, and invasiveness of both HCC and iCCA cells. Moreover, knockdown of ACYP1 increased the ratio of apoptotic cells and decreased the expression of anti-apoptosis proteins. In vivo tumor growth was significantly inhibited by the transfection of ACYP1 siRNA, and the number of apoptotic cells increased.

CONCLUSION

High ACYP1 expression could influence the prognosis of cHCC-iCCA, HCC, and iCCA patients. In vitro ACYP1 expression influences the tumor growth and cell viability in both HCC and iCCA by regulating anti-apoptosis proteins.

Engineering of MSC-Derived Exosomes: A Promising Cell-Free Therapy for Osteoarthritis

Osteoarthritis (OA) is characterized by progressive cartilage degeneration with increasing prevalence and unsatisfactory treatment efficacy. Exosomes derived from mesenchymal stem cells play an important role in alleviating OA by promoting cartilage regeneration, inhibiting synovial inflammation and mediating subchondral bone remodeling without the risk of immune rejection and tumorigenesis. However, low yield, weak activity, inefficient targeting ability and unpredictable side effects of natural exosomes have limited their clinical application. At present, various approaches have been applied in exosome engineering to regulate their production and function, such as pretreatment of parental cells, drug loading, genetic engineering and surface modification. Biomaterials have also been proved to facilitate efficient delivery of exosomes and enhance treatment effectiveness. Here, we summarize the current understanding of the biogenesis, isolation and characterization of natural exosomes, and focus on the large-scale production and preparation of engineered exosomes, as well as their therapeutic potential in OA, thus providing novel insights into exploring advanced MSC-derived exosome-based cell-free therapy for the treatment of OA.

Apigenin Targets MicroRNA-155, Enhances SHIP-1 Expression, and Augments Anti-Tumor Responses in Pancreatic Cancer

Pancreatic cancer (PC) is a deadly disease with a grim prognosis. Pancreatic tumor derived factors (TDF) contribute to the induction of an immunosuppressive tumor microenvironment (TME) that impedes the effectiveness of immunotherapy. PC-induced microRNA-155 (miRNA-155) represses expression of Src homology 2 (SH2) domain-containing Inositol 5'-phosphatase-1 (SHIP-1), a regulator of myeloid cell development and function, thus impacting anti-tumor immunity. We recently reported that the bioflavonoid apigenin (API) increased SHIP-1 expression which correlated with the expansion of tumoricidal macrophages (TAM) and improved anti-tumor immune responses in the TME of mice with PC. We now show that API transcriptionally regulates SHIP-1 expression via the suppression of miRNA-155, impacting anti-tumor immune responses in the bone marrow (BM) and TME of mice with PC. We discovered that API reduced miRNA-155 in the PC milieu, which induced SHIP-1 expression. This promoted the restoration of myelopoiesis and increased anti-tumor immune responses in the TME of heterotopic, orthotopic and transgenic SHIP-1 knockout preclinical mouse models of PC. Our results suggest that manipulating SHIP-1 through miR-155 may assist in augmenting anti-tumor immune responses and aid in the therapeutic intervention of PC.

Extracellular Vesicles Inhibit the Response of Pancreatic Ductal Adenocarcinoma Cells to Gemcitabine and TRAIL Treatment

Pancreatic ductal adenocarcinoma remains an aggressive cancer with a low 5-year survival rate. Although gemcitabine has been a standard treatment for advanced pancreatic cancer, patients often develop resistance to this therapeutic. We have previously shown that treating pancreatic cancer cells in vitro with a combination of gemcitabine and the cytokine TRAIL significantly reduced both cell viability and survival. The data presented here demonstrate that this response to treatment is inhibited when cells are incubated with a conditioned medium derived from untreated cells. We show that this inhibition is specifically mediated by extracellular vesicles present in the conditioned medium, as seen by a significant decrease in apoptosis. Additionally, we further demonstrate that this effect can be reversed in the presence of GW4869, an inhibitor of exosome biogenesis and release. These results show that pancreatic cancer cell-derived extracellular vesicles can confer resistance to treatment with gemcitabine and TRAIL. The implications of these findings suggest that removal of EVs during treatment can improve the response of cells to gemcitabine and TRAIL treatment in vitro.

EV-Mediated Chemoresistance in the Tumor Microenvironment: Is NF-κB a Player?

Drug resistance is a major impediment to patient survival and remains the primary cause of unsuccessful cancer therapy. Drug resistance occurs in many tumors and is frequently induced by chemotherapy which triggers a defensive response both in cancerous and cancer-associated cells that constitute the tumor microenvironment (TME). Cell to cell communication within the TME is often mediated by extracellular vesicles (EVs) which carry specific tumor-promoting factors able to activate survival pathways and immune escape mechanisms, thus sustaining tumor progression and therapy resistance. NF-κB has been recognized as a crucial player in this context. NF-κB activation is involved in EVs release and EVs, in turn, can trigger NF-κB pathway activation in specific contexts, based on secreting cytotype and their specific delivered cargo. In this review, we discuss the role of NF-κB/EVs interplay that sustain chemoresistance in the TME by focusing on the molecular mechanisms that underlie inflammation, EVs release, and acquired drug resistance.

Cancer-Associated Fibroblasts Confer Gemcitabine Resistance to Pancreatic Cancer Cells through PTEN-Targeting miRNAs in Exosomes

Simple Summary

Previous studies have shown that cancer associated fibroblasts exposed to chemotherapy release exosomes which promote chemoresistance in recipient cells. However, the molecular mechanism responsible for this has not been fully elucidated. In this study, we found that gemcitabine treatment caused fibroblasts to release exosome which contain PTEN-targeting miRNAs. These findings shed light on how fibroblasts exposed to chemotherapy promote tumor growth and drug resistance.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is currently the third leading cause of cancer-related death in the United States. Even though the poor prognosis of PDAC is often attributed to late diagnosis, patients with an early diagnosis who undergo tumor resection and adjuvant chemotherapy still show tumor recurrence, highlighting a need to develop therapies which can overcome chemoresistance. Chemoresistance has been linked to the high expression of microRNAs (miRs), such as miR-21, within tumor cells. Tumor cells can collect miRs through the uptake of miR-containing lipid extracellular vesicles called exosomes. These exosomes are secreted in high numbers from cancer-associated fibroblasts (CAFs) within the tumor microenvironment during gemcitabine treatment and can contribute to cell proliferation and chemoresistance. Here, we show a novel mechanism in which CAF-derived exosomes may promote proliferation and chemoresistance, in part, through suppression of the tumor suppressor PTEN. We identified five microRNAs: miR-21, miR-181a, miR-221, miR-222, and miR-92a, that significantly increased in number within the CAF exosomes secreted during gemcitabine treatment which target PTEN. Furthermore, we found that CAF exosomes suppressed PTEN expression in vitro and that treatment with the exosome inhibitor GW4869 blocked PTEN suppression in vivo. Collectively, these findings highlight a mechanism through which the PTEN expression loss, often seen in PDAC, may be attained and lend support to investigations into the use of exosome inhibitors as potential therapeutics to improve the effectiveness of chemotherapy.

A Novel Exosome-Relevant Molecular Classification Uncovers Distinct Immune Escape Mechanisms and Genomic Alterations in Gastric Cancer

Objective: Gastric cancer (GC) is a highly heterogeneous malignant carcinoma. This study aimed to conduct an exosome-based classification for assisting personalized therapy for GC.

Methods: Based on the expression profiling of prognostic exosome-related genes, GC patients in The Cancer Genome Atlas (TCGA) cohort were classified using the unsupervised consensus clustering approach, and the reproducibility of this classification was confirmed in the GSE84437 cohort. An exosome-based gene signature was developed via Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis. Immunological features, responses to immune checkpoint inhibitors, and genetic alterations were evaluated via computational methods.

Results: Two exosome-relevant phenotypes (A and B) were clustered, and this classification was independent of immune subtypes and TCGA subtypes. Exosome-relevant phenotype B had a poorer prognosis and an inflamed tumor microenvironment (TME) relative to phenotype A. Patients with phenotype B presented higher responses to the anti-CTLA4 inhibitor. Moreover, phenotype B occurred at a higher frequency of genetic mutation than phenotype A. The exosome-based gene signature (GPX3, RGS2, MATN3, SLC7A2, and SNCG) could independently and accurately predict GC prognosis, which was linked to stromal activation and immunosuppression.

Conclusion: Our findings offer a conceptual frame to further comprehend the roles of exosomes in immune escape mechanisms and genomic alterations of GC. More work is required to evaluate the reference value of exosome-relevant phenotypes for designing immunotherapeutic regimens.

Pancreatic Cancer: Nucleic Acid Drug Discovery and Targeted Therapy

Pancreatic cancer (PC) is one of the most lethal cancers with an almost 10% 5-year survival rate. Because PC is implicated in high heterogeneity, desmoplastic tumor-microenvironment, and inefficient drug-penetration, the chemotherapeutic strategy currently recommended for the treatment of PC has limited clinical benefit. Nucleic acid-based targeting therapies have become strong competitors in the realm of drug discovery and targeted therapy. A vast evidence has demonstrated that antibody-based or alternatively aptamer-based strategy largely contributed to the elevated drug accumulation in tumors with reduced systematic cytotoxicity. This review describes the advanced progress of antisense oligonucleotides (ASOs), small interfering RNAs (siRNAs), microRNAs (miRNAs), messenger RNA (mRNAs), and aptamer-drug conjugates (ApDCs) in the treatment of PC, revealing the bright application and development direction in PC therapy.

Exosome-Mediated Response to Cancer Therapy: Modulation of Epigenetic Machinery

Exosomes, the extracellular vesicles produced in the endosomal compartments, facilitate the transportation of proteins as well as nucleic acids. Epigenetic modifications are now considered important for fine-tuning the response of cancer cells to various therapies, and the acquired resistance against targeted therapies often involves dysregulated epigenetic modifications. Depending on the constitution of their cargo, exosomes can affect several epigenetic events, thus impacting post-transcriptional regulations. Thus, a role of exosomes as facilitators of epigenetic modifications has come under increased scrutiny in recent years. Exosomes can deliver methyltransferases to recipient cells and, more importantly, non-coding RNAs, particularly microRNAs (miRNAs), represent an important exosome cargo that can affect the expression of several oncogenes and tumor suppressors, with a resulting impact on cancer therapy resistance. Exosomes often harbor other non-coding RNAs, such as long non-coding RNAs and circular RNAs that support resistance. The exosome-mediated transfer of all this cargo between cancer cells and their surrounding cells, especially tumor-associated macrophages and cancer-associated fibroblasts, has a profound effect on the sensitivity of cancer cells to several chemotherapeutics. This review focuses on the exosome-induced modulation of epigenetic events with resulting impact on sensitivity of cancer cells to various therapies, such as, tamoxifen, cisplatin, gemcitabine and tyrosine kinase inhibitors. A better understanding of the mechanisms by which exosomes can modulate response to therapy in cancer cells is critical for the development of novel therapeutic strategies to target cancer drug resistance.

The Role of Nonapoptotic Programmed Cell Death — Ferroptosis, Necroptosis, and Pyroptosis — in Pancreatic Ductal Adenocarcinoma Treatment

Pancreatic ductal adenocarcinoma (PDAC) is the most lethal cancer, with a dismal 5-year survival rate of less than 10%. It is estimated that approximately 80% of pancreatic ductal carcinoma (PDAC) patients are diagnosed at an advanced or metastatic stage. Hence, most patients are not appropriate candidates for surgical resection and therefore require systemic chemotherapy. However, it has been reported that most patients develop chemoresistance within several months, partly because of antiapoptotic mechanisms. Hence, inducing alternative programmed cell death (PCD), including ferroptosis, necroptosis or pyroptosis, seems to be a promising strategy to overcome antiapoptosis-mediated chemoresistance. In this review, we shed light on the molecular mechanisms of ferroptosis, necroptosis and pyroptosis and suggest several potential strategies (e.g., compounds and nanoparticles [NPs]) that are capable of triggering nonapoptotic PCD to suppress PDAC progression. In conclusion, these strategies might serve as adjuvants in combination with clinical first-line chemotherapies to improve patient survival rates.