Upregulated exosomic miR‑23b‑3p plays regulatory roles in the progression of pancreatic cancer

White adipocyte-derived exosomal miR-23b inhibits thermogenesis by targeting Elf4 to regulate GLP-1R transcription

Promoting non-trembling thermogenesis of brown adipose tissue (BAT) and browning of white adipose tissue (WAT) helps prevent obesity. MiR-23b is highly expressed in adipose tissue-derived exosomes obtained from obese people, but the role of exosomal miR-23b in regulating thermogenesis and obesity progression remains to be further explored. Here, a mouse obesity model was established through high-fat diet (HFD), and inguinal WAT (iWAT)-derived exosomes and miR-23b antagomir were administered by intraperitoneal injection. The results showed that WAT-derived exosomal miR-23b upregulated body weight and adipocyte hypertrophy and enhanced insulin resistance. Moreover, exosomal miR-23b restrained mtDNA copy number and the expression of genes related to thermogenesis and mitochondrial biogenesis in BAT, and suppressed the expression of WAT browning-related genes under cold stimulation, indicating that exosomal miR-23b hindered non-trembling thermogenesis of BAT and WAT browning. Mechanism studies found that miR-23b targeted Elf4 to inhibit its expression. And Elf4 bound to the GLP-1R promoter region to promote GLP-1R transcription. In addition, silencing miR-23b effectively abolished the inhibitory effect of WAT-derived exosomes on thermogenic gene expression and mitochondrial respiration in adipocytes isolated from BAT and iWAT, which was reversed by GLP-1R knockdown. In conclusion, WAT-derived exosomal miR-23b suppressed thermogenesis by targeting Elf4 to regulate GLP-1R transcription, which contributed to the progression of obesity.

Exosomes: Emerging Insights into the Progression of Pancreatic Cancer

Pancreatic cancer is a very aggressive and fatal malignancy with few therapeutic choices and a poor prognosis. Understanding the molecular pathways that drive its growth is critical for developing effective therapeutic strategies. Exosomes, small extracellular vesicles secreted by numerous cell types, have recently emerged as essential intercellular communication mediators, with implications for tumor growth and metastasis. In this article, we present a review of current knowledge about exosomes and their role in pancreatic cancer progression We discuss the biogenesis and characteristics of exosomes, as well as their cargo and functional significance in tumor growth, immune evasion, angiogenesis, invasion, and metastasis. We further emphasize the potential of exosomes as diagnostic biomarkers and therapeutic targets for pancreatic cancer. Finally, we discuss the challenges and future perspectives in using exosomes to improve patient outcomes in pancreatic cancer.

Extracellular Vesicular miRNA in Pancreatic Cancer: From Lab to Therapy

Pancreatic cancer is a prevalent lethal gastrointestinal cancer that generally does not show any symptoms until it reaches advanced stages, resulting in a high mortality rate. People at high risk, such as those with a family history or chronic pancreatitis, do not have a universally accepted screening protocol. Chemotherapy and radiotherapy demonstrate limited effectiveness in the management of pancreatic cancer, emphasizing the urgent need for innovative therapeutic strategies. Recent studies indicated that the complex interaction among pancreatic cancer cells within the dynamic microenvironment, comprising the extracellular matrix, cancer-associated cells, and diverse immune cells, intricately regulates the biological characteristics of the disease. Additionally, mounting evidence suggests that EVs play a crucial role as mediators in intercellular communication by the transportation of different biomolecules, such as miRNA, proteins, DNA, mRNA, and lipids, between heterogeneous cell subpopulations. This communication mediated by EVs significantly impacts multiple aspects of pancreatic cancer pathogenesis, including proliferation, angiogenesis, metastasis, and resistance to therapy. In this review, we delve into the pivotal role of EV-associated miRNAs in the progression, metastasis, and development of drug resistance in pancreatic cancer as well as their therapeutic potential as biomarkers and drug-delivery mechanisms for the management of pancreatic cancer.

Dysregulation of a Subset of Circulating and Vesicle-Associated miRNA in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive neoplasia, characterized by early metastasis, low diagnostic rates at early stages, resistance to drugs, and poor prognosis. There is an urgent need to better characterize this disease in order to identify efficient diagnostic/prognostic biomarkers. Since microRNAs (miRNAs) contribute to oncogenesis and metastasis formation in PDAC, they are considered potential candidates for fulfilling this task. In this work, the levels of two miRNA subsets (involved in chemoresistance or with oncogenic/tumor suppressing functions) were investigated in a panel of PDAC cell lines and liquid biopsies of a small cohort of patients. We used RT-qPCR and droplet digital PCR (ddPCR) to measure the amounts of cellular- and vesicle-associated, and circulating miRNAs. We found that both PDAC cell lines, also after gemcitabine treatment, and patients showed low amounts of cellular-and vesicle-associated miR-155-5p, compared to controls. Interestingly, we did not find any differences when we analyzed circulating miR-155-5p. Furthermore, vesicle-related miR-27a-3p increased in cancer patients compared to the controls, while circulating let-7a-5p, miR-221-3p, miR-23b-3p and miR-193a-3p presented as dysregulated in patients compared to healthy individuals. Our results highlight the potential clinical significance of these analyzed miRNAs as non-invasive diagnostic molecular tools to characterize PDAC.

MicroRNAs in Pancreatic Cancer: Advances in Biomarker Discovery and Therapeutic Implications

Pancreatic cancer remains a formidable malignancy characterized by high mortality rates, primarily attributable to late-stage diagnosis and a dearth of effective therapeutic interventions. The identification of reliable biomarkers holds paramount importance in enhancing early detection, prognostic evaluation, and targeted treatment modalities. Small non-coding RNAs, particularly microRNAs, have emerged as promising candidates for pancreatic cancer biomarkers in recent years. In this review, we delve into the evolving role of cellular and circulating miRNAs, including exosomal miRNAs, in the diagnosis, prognosis, and therapeutic targeting of pancreatic cancer. Drawing upon the latest research advancements in omics data-driven biomarker discovery, we also perform a case study using public datasets and address commonly identified research discrepancies, challenges, and limitations. Lastly, we discuss analytical approaches that integrate multimodal analyses incorporating clinical and molecular features, presenting new insights into identifying robust miRNA-centric biomarkers.

Applications of Exosome Vesicles in Different Cancer Types as Biomarkers

One of the biggest challenges in the fight against cancer is early detection. Early diagnosis is vital, but there are some barriers such as economic, cultural, and personal factors. Considering the disadvantages of radiological imaging techniques or serological analysis methods used in cancer diagnosis, such as being expensive, requiring expertise, and being time-consuming, there is a need to develop faster, more reliable, and cost-effective diagnostic methods for use in cancer diagnosis. Exosomes, which are responsible for intercellular communication with sizes ranging from 30-120 nm, are naturally produced biological nanoparticles. Thanks to the cargo contents they carry, they are a potential biomarker to be used in the diagnosis of cancer. Exosomes, defined as extracellular vesicles of endosomal origin, are effective in cancer growth, progression, metastasis, and drug resistance, and changes in microenvironmental conditions during tumor development change exosome secretion. Due to their high cellular activity, tumor cells produce much higher exosomes than healthy cells. Therefore, it is known that the number of exosomes in body fluids is significantly rich compared to other cells and can act as a stand-alone diagnostic biomarker. Cancer- derived exosomes have received great attention in recent years for the early detection of cancer and the evaluation of therapeutic response. In this article, the content, properties, and differences of exosomes detected in common types of cancer (lung, liver, pancreas, ovaries, breast, colorectal), which are the leading causes of cancer-related deaths, are reviewed. We also discuss the potential utility of exosome contents as a biomarker for early detection, which is known to be important in targeted cancer therapy.

Exosomes: a potential diagnostic and treatment modality in the quest for counteracting cancer

BACKGROUND

Exosomes are nanosized bio vesicles formed when multivesicular bodies and the plasma membrane merge and discharge into bodily fluids. They are well recognized for facilitating intercellular communication by transporting numerous biomolecules, including DNA, RNAs, proteins, and lipids, and have been implicated in varied diseases including cancer. Exosomes may be altered to transport a variety of therapeutic payloads, including as short interfering RNAs, antisense oligonucleotides, chemotherapeutic drugs, and immunological modulators, and can be directed to a specific target. Exosomes also possess the potential to act as a diagnostic biomarker in cancer, in addition to their therapeutic potential.

CONCLUSION

In this review, the physiological roles played by exosomes were summarized along with their biogenesis process. Different isolation techniques of exosomes including centrifugation-based, size-based, and polymer precipitation-based techniques have also been described in detail with a special focus on cancer therapeutic applications. The review also shed light on techniques of incubation of drugs with exosomes and their characterization methods covering the most advanced techniques. Myriad applications of exosomes in cancer as diagnostic biomarkers, drug delivery carriers, and chemoresistance-related issues have been discussed at length. Furthermore, a brief overview of exosome-based anti-cancer vaccines and a few prominent challenges concerning exosomal delivery have been concluded at the end.

Exosomes from adipose-derived stem cells inhibits skin cancer progression via miR-199a-5p/SOX4

Although miR-199a-5p is linked to the development of numerous cancers, its regulatory role in skin cancer is unclear. In this work, the impact of miR-199a-5p produced by adipose-derived stem cells on malignant melanoma skin cancer was investigated.30 pair tumor tissues and adjacent tissues were obtained from skin cancer patients. Adipose-derived stem cell (ADSCs) were isolated from adipose tissues harvested from healthy subjects. The mRNA relative expression was evaluated via qRT-PCR. Cell proliferation ability was measured via CCK-8 assay. Apoptosis was evaluated via flow cytometry. The connection between miR-199a-5p and SOX4 was confirmed via luciferase reporter assay. Western blot was conducted to evaluate protein expression. MiR-199a-5p was higher expressed in ADSCs exosomes and was lower expressed in skin cancer tissues and cells. ADSCs-derived exosomes inhibited cell invasion of skin cancer. MiR-199a-5p inhibitor enhanced cell viability and invasion. In addition, miR-199a-5p inhibitor suppressed cell apoptosis. MiR-199a-5p NC transfected ADSCs inhibited cell viability and invasion while miR-199a-5p mimic transfected ADSCs further inhibited cell viability and invasion. In addition, miR-199a-5p NC transfected ADSCs enhanced cell apoptosis while miR-199a-5p mimic transfected ADSCs further enhanced cell apoptosis. Luciferase supported the targetscan prediction that miR-199a-5p might control SOX4 expression. SOX4 expression was noticeably lower in the miR-199a-5p mimic group.Exosomes from adipose-derived stem cells inhibited skin cancer progression via miR-199a-5p/SOX4.

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.

Extracellular Vesicles as Delivery Shippers for Noncoding RNA-Based Modulation of Angiogenesis: Insights from Ischemic Stroke and Cancer

Ischemic stroke and systemic cancer are two of the leading causes of mortality. Hypoxia is a central pathophysiological component in ischemic stroke and cancer, representing a joint medical function. This function includes angiogenesis regulation. Vascular remodeling coupled with axonal outgrowth following cerebral ischemia is critical in improving poststroke neurological functional recovery. Antiangiogenic strategies can inhibit cancer vascularization and play a vital role in impeding cancer growth, invasion, and metastasis. Although there are significant differences in the cause of angiogenesis across both pathophysiological conditions, emerging evidence states that common signaling structures, such as extracellular vesicles (EVs) and noncoding RNAs (ncRNAs), are involved in this context. EVs, heterogeneous membrane vesicles encapsulating proteomic genetic information from parental cells, act as multifunctional regulators of intercellular communication. Among the multifaceted roles in modulating biological responses, exhaustive evidence shows that ncRNAs are selectively sorted into EVs, modulating common specific aspects of cancer development and stroke prognosis, namely, angiogenesis. This review will discuss recent advancements in the EV-facilitated/inhibited progression of specific elements of angiogenesis with a particular concern about ncRNAs within these vesicles. The review is concluded by underlining the clinical opportunities of EV-derived ncRNAs as diagnostic, prognostic, and therapeutic agents.

Modulating Effects of Cancer-Derived Exosomal miRNAs and Exosomal Processing by Natural Products

Cancer-derived exosomes exhibit sophisticated functions, such as proliferation, apoptosis, migration, resistance, and tumor microenvironment changes. Several clinical drugs modulate these exosome functions, but the impacts of natural products are not well understood. Exosome functions are regulated by exosome processing, such as secretion and assembly. The modulation of these exosome-processing genes can exert the anticancer and precancer effects of cancer-derived exosomes. This review focuses on the cancer-derived exosomal miRNAs that regulate exosome processing, acting on the natural-product-modulating cell functions of cancer cells. However, the role of exosomal processing has been overlooked in several studies of exosomal miRNAs and natural products. In this study, utilizing the bioinformatics database (miRDB), the exosome-processing genes of natural-product-modulated exosomal miRNAs were predicted. Consequently, several natural drugs that modulate exosome processing and exosomal miRNAs and regulate cancer cell functions are described here. This review sheds light on and improves our understanding of the modulating effects of exosomal miRNAs and their potential exosomal processing targets on anticancer treatments based on the use of natural products.

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.

Pioneer Role of Extracellular Vesicles as Modulators of Cancer Initiation in Progression, Drug Therapy, and Vaccine Prospects

Cancer is one of the leading diseases, causing deaths worldwide. Nearly 10 million deaths were reported in 2020 due to cancer alone. Several factors are involved in cancer progressions, such as lifestyle and genetic characteristics. According to a recent report, extracellular vesicles (EVs) are involved in cancer initiation, progression, and therapy failure. EVs can play a major role in intracellular communication, the maintenance of tissue homeostasis, and pathogenesis in several types of diseases. In a healthy person, EVs carry different cargoes, such as miRNA, lncRNA etc., to help other body functions. On the other hand, the same EV in a tumor microenvironment carries cargoes such as miRNA, lncRNA, etc., to initiate or help cancer progression at various stages. These stages may include the proliferation of cells and escape from apoptosis, angiogenesis, cell invasion, and metastasis, reprogramming energy metabolism, evasion of the immune response, and transfer of mutations. Tumor-derived EVs manipulate by altering normal functions of the body and affect the epigenetics of normal cells by limiting the genetic makeup through transferring mutations, histone modifications, etc. Tumor-derived EVs also pose therapy resistance through transferring drug efflux pumps and posing multiple drug resistances. Such EVs can also help as biomarkers for different cancer types and stages, which ultimately help with cancer diagnosis at early stages. In this review, we will shed light on EVs' role in performing normal functions of the body and their position in different hallmarks of cancer, in altering the genetics of a normal cell in a tumor microenvironment, and their role in therapy resistance, as well as the importance of EVs as diagnostic tools.

miR-23b-3p Inhibits the Oncogenicity of Colon Adenocarcinoma by Directly Targeting NFE2L3

Background and Aims

MicroR-23b-3p (miR-23b-3p) has been found to be abnormally expressed in a variety of malignant tumors and to play a role in tumor inhibition or promotion. However, the regulatory mechanism of miR-23b-3p in COAD remains unclear. The purpose of this study was to investigate the clinical significance of miR-23b-3p expression in COAD cells and to explore its role and regulatory mechanism in the growth of COAD.

Materials and Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure miR-23b-3p expression in COAD tissues and cell lines. After transfecting miR-23b-3p mimics into two human COAD cell lines (SW620 and LoVo), the cell counting kit-8 (CCK-8), colony formation, and 5-ethynyl-2′-deoxyuridine (EdU) assays were used to detect cell proliferation, the Transwell assay was used to measure cell migration and invasion capacity, and flow cytometry was used to evaluate cell apoptosis in vitro. In addition, a luciferase reporter assay was used to determine whether miR-23b-3p targets NFE2L3. The downstream regulatory mechanisms of miR-23b-3p action in COAD cells were also investigated. For in vivo tumorigenesis assay, COAD cells stably overexpressing miR-23b-3p were injected subcutaneously into the flank of nude mice to obtain tumors.

Results

Significantly decreased expression of miR-23b-3p was detected in COAD tissues and cell lines. Exogenous miR-23b-3p expression inhibited cell proliferation, migration, and invasion and promoted cell apoptosis of COAD cells in vitro. Nuclear factor erythroid 2 like 3 (NFE2L3) was identified as a direct target gene of miR-23b-3p. In addition, reintroduction of NFE2L3 partially abolished the anticancer effects of miR-23b-3p on COAD cells. Furthermore, miR-23b-3p overexpression hindered the growth of COAD cells in vivo.

Conclusion

miR-23b-3p inhibited the oncogenicity of COAD cells in vitro and in vivo by directly targeting NFE2L3, suggesting the importance of the miR-23b-3p/NFE2L3 pathway in the development of COAD.

Advances in the Detection of Pancreatic Cancer Through Liquid Biopsy

Pancreatic cancer refers to the development of malignant tumors in the pancreas: it is associated with high mortality rates and mostly goes undetected in its early stages for lack of symptoms. Currently, surgical treatment is the only effective way to improve the survival of pancreatic cancer patients. Therefore, it is crucial to diagnose the disease as early as possible in order to improve the survival rate of patients with pancreatic cancer. Liquid biopsy is a unique in vitro diagnostic technique offering the advantage of earlier detection of tumors. Although liquid biopsies have shown promise for screening for certain cancers, whether they are effective for early diagnosis of pancreatic cancer is unclear. Therefore, we reviewed relevant literature indexed in PubMed and collated updates and information on advances in the field of liquid biopsy with respect to the early diagnosis of pancreatic cancer.

Emerging role of exosomes as biomarkers in cancer treatment and diagnosis

Cancer is a leading cause of death worldwide and cancer incidence and mortality are rapidly growing. These massive amounts of cancer patients require rapid diagnosis and efficient treatment strategies. However, the currently utilized methods are invasive and cost-effective. Recently, the effective roles of exosomes as promising diagnostic, prognostic, and predictive biomarkers have been revealed. Exosomes are membrane-bound extracellular vesicles containing RNAs, DNAs, and proteins, and are present in a wide array of body fluids. Exosomal cargos have shown the potential to detect various types of cancers at early stages with high sensitivity and specificity. They can also delivery therapeutic agents efficiently. In this article, an overview of recent advances in the research of exosomal biomarkers and their applications in cancer diagnosis and treatment has been provided. Furthermore, the advantages and challenges of exosomes as liquid biopsy targets are discussed and the clinical implications of using exosomal miRNAs have been revealed.

MicroRNA-23b-3p targets non-SMC condensing I complex subunit G to promote proliferation and inhibit apoptosis of colorectal cancer cells via regulation of the PI3K/AKT signaling pathway

Colorectal cancer (CRC) is one of the most common types of malignancy worldwide and has a poor prognosis. Non-SMC condensing I complex subunit G (NCAPG) has been reported to be upregulated in numerous types of malignant tumor. However, to the best of our knowledge, its clinicopathological and biological significance in CRC remain to be elucidated. The results of the present study revealed that NCAPG expression levels were upregulated in human CRC tissues and cell lines. The upregulated expression of NCAPG was positively associated with patient clinicopathological characteristics, such as differentiation and tumor size, and independently associated with poor survival. Consistent with the clinical observations, NCAPG was discovered to promote the proliferation and inhibit the apoptosis of CRC cells. Moreover, NCAPG-knockdown inhibited CRC cell proliferation by regulating the PI3K/AKT signaling pathway. Furthermore, NCAPG was identified as a potential target of microRNA (miR)-23b-3p, which was subsequently demonstrated to negatively regulate NCAPG expression. In conclusion, the findings of the current study indicated that the miR-23b-3p/NCAPG/PI3K/AKT signaling axis may play an important role in CRC carcinogenesis, and the status of the molecule may represent a promising prognostic marker for the disease.

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 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

Simple Summary

Pancreatic cancer is the fourth leading cause of cancer death in the United States and over 90% of the patients suffer from pancreatic ductal adenocarcinoma (PDAC). PDAC is the most lethal gastrointestinal malignancies and only 10% of the people survive more than 5 years, therefore, novel diagnostic, prognostic, and therapeutic strategies are an immediate necessity. Studies have demonstrated microRNAs in bodily fluids that are bound with membranes (exosomes) can act as stable biomarkers both for disease development and metastasis. The diagnostic, prognostic, as well as therapeutic roles of exosomal microRNAs in pancreatic cancer have been discussed in this review.

Abstract

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.

Extracellular Vesicles and Pancreatic Cancer: Insights on the Roles of miRNA, lncRNA, and Protein Cargos in Cancer Progression

Pancreatic cancer (PC) is among the most devastating digestive tract cancers worldwide. This cancer is characterized by poor diagnostic detection, lack of therapy, and difficulty in predicting tumorigenesis progression. Although mutations of key oncogenes and oncosuppressor involved in tumor growth and in immunosurveillance escape are known, the underlying mechanisms that orchestrate PC initiation and progression are poorly understood or still under debate. In recent years, the attention of many researchers has been concentrated on the role of extracellular vesicles and of a particular subset of extracellular vesicles, known as exosomes. Literature data report that these nanovesicles are able to deliver their cargos to recipient cells playing key roles in the pathogenesis and progression of many pancreatic precancerous conditions. In this review, we have summarized and discussed principal cargos of extracellular vesicles characterized in PC, such as miRNAs, lncRNAs, and several proteins, to offer a systematic overview of their function in PC progression. The study of extracellular vesicles is allowing to understand that investigation of their secretion and analysis of their content might represent a new and potential diagnostic and prognostic tools for PC.

Knockdown of plasmacytoma variant translocation 1 (PVT1) inhibits high glucose-induced proliferation and renal fibrosis in HRMCs by regulating miR-23b-3p/early growth response factor 1 (EGR1)

Long noncoding RNAs (lncRNAs) have been reported to play critical role in the development of diabetic nephropathy (DN). However, the effects and mechanism of plasmacytoma variant translocation 1 (PVT1) remain poorly understood. The expression of PVT1, miR-23b-3p, early growth response factor 1 (EGR1), Fibronectin (FN), Collagen IV (Col IV), alpha smooth muscle actin (α-SMA), E-cadherin, and vimentin, transforming growth factor (TGF)-β1 was examined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was assessed by Cell Counting-8 (CCK-8) assay. Western blot assay was conducted to measure the protein levels of FN, Col IV, E-cadherin, α-SMA, vimentin, TGF-β1, and EGR1. The interaction between miR-23b-3p and PVT1 or EGR1 was predicted by starBase or TargetScan and confirmed by the dual luciferase reporter assay. The oxidative stress factors were analyzed by corresponding kits. We found that the expression of PVT1 and EGR1 was increased and miR-23b-3p was decreased in serum samples of DN patients and HG-induced HRMCs. Knockdown of PVT1 significantly inhibited HG-induced proliferation, extracellular matrix (ECM) accumulation, epithelial-mesenchymal transition (EMT), and oxidative stress in HRMCs, while these effects were abated by inhibiting miR-23b-3p. In addition, EGR1 was confirmed as downstream target of miR-23b-3p and miR-23b-3p could specially bind to PVT1. Besides, downregulation of PVT1 inhibited the progression of DN partially via upregulating miR-23b-3p and downregulating EGR1. In conclusion, our results suggested that PVT1 knockdown suppressed DN progression though functioning as ceRNA of miR-23b-3p to regulate EGR1 expression in vitro, providing potential value for the treatment of DN.

Integrative Analysis of miRNA and mRNA Expression Profiles in Mammary Glands of Holstein Cows Artificially Infected with Staphylococcus aureus

Staphylococcus aureus- induced mastitis is one of the most intractable problems for the dairy industry, which causes loss of milk yield and early slaughter of cows worldwide. Few studies have used a comprehensive approach based on the integrative analysis of miRNA and mRNA expression profiles to explore molecular mechanism in bovine mastitis caused by S. aureus. In this study, S. aureus (A1, B1 and C1) and sterile phosphate buffered saline (PBS) (A2, B2 and C2) were introduced to different udder quarters of three individual cows, and transcriptome sequencing and microarrays were utilized to detected miRNA and gene expression in mammary glands from the challenged and control groups. A total of 77 differentially expressed microRNAs (DE miRNAs) and 1625 differentially expressed genes (DEGs) were identified. Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that multiple DEGs were enriched in significant terms and pathways associated with immunity and inflammation. Integrative analysis between DE miRNAs and DEGs proved that miR-664b, miR-23b-3p, miR-331-5p, miR-19b and miR-2431-3p were potential factors regulating the expression levels of CD14 Molecule (CD14), G protein subunit gamma 2 (GNG2), interleukin 17A (IL17A), collagen type IV alpha 1 chain (COL4A1), microtubule associated protein RP/EB family member 2 (MAPRE2), member of RAS oncogene family (RAP1B), LDOC1 regulator of NFKB signaling (LDOC1), low-density lipoprotein receptor (LDLR) and S100 calcium binding protein A9 (S100A9) in bovine mastitis caused by S. aureus. These findings could enhance the understanding of the underlying immune response in bovine mammary glands against S. aureus infection and provide a useful foundation for future application of the miRNA–mRNA-based genetic regulatory network in the breeding cows resistant to S. aureus.

Serum Exosomal miRNA-1226 as Potential Biomarker of Pancreatic Ductal Adenocarcinoma

Background

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related mortality and it is urgent to find biomarkers for early detection of PDAC. Exosomal miRNAs are useful biomarkers for cancer detection. The aims of this study were to investigate the potential role of serum exosomal miRNA in detection of PDAC and to analyze the correlation between the levels of exosome miRNA and the tumor biological behaviors.

Materials and Methods

Thirteen serum samples were collected from five patients with PDACs, three healthy individuals (HIs) and five benign pancreatic lesions (BP) for a high throughput profiling analysis to identify an altered miRNA expression patterns in PDAC. Candidate exosomal miRNAs were filtered based on a second independent cohort that included 17 PDACs and 12 benign pancreatic lesions by quantitative real-time polymerase chain reaction (qRT-PCR). Four miRNAs were selected for miRNA validation as PDAC biomarkers in a subsequent set of samples. The association between candidate exosomal miRNA and tumor behavior (tumor invasion or metastases) was evaluated in 17 PDACs. In vitro studies were performed to evaluate the role of candidate exosomal miRNA on cell viability, apoptosis and cell migration in two PDAC cell lines.

Results

The expression of 11 miRNAs showed same trend between PDAC and BP, and between PDAC and HIs. Six of them were upregulated (miR-203b-5p, miR-342-5p, miR-337-5p, miR-149-5p, miR-877-5p, miR-203a-3p), and five were downregulated (miR-1226-3p, miR-3182, miR-625-3p, miR-624-5p, miR-664a-5p). miR-1226-3p was selected as the candidate exosomal biomarker for the PDAC detection. The expression of serum exosomal miRNA-1226-3p was downregulated in PDACs compared to the BPs (p = 0.025). miR-1226-3p had acceptable performance in predicting [area under the curve (AUC) = 0.74] PDAC. Exosomal miRNA-1226-3p level in PDAC with invasion or metastases was lower than that without invasion or metastases (p = 0.028). Transfection of miRNA-1226-3p significantly inhibited the proliferation of PANC-1 and BXP-3 cells, stimulated cell apoptosis and inhibited cell migration.

Conclusion

Serum exosomal miRNA-1226-3p is a potential biomarker in diagnosing and predicting the tumor invasion or metastases of PDAC.

Role of exosomes in pancreatic cancer

Pancreatic cancer (PC) is a malignant tumour of the human digestive system that has a poor prognosis. Exosomes contain proteins and nucleic acids, and constitute a class of extracellular vesicles defined as membrane-bound nanovesicles of endocytic origin, with a diameter of 40-150 nm. Exosomes are potential diagnostic markers of PC; however, their roles in cancer initiation and progression remain unclear. Previous studies have focused on the molecular mechanisms and functions of exosomes that allow them to accelerate PC cell proliferation, migration and invasion. The present review discusses the interactions between exosomes and the pathophysiology of PC. The potential clinical applications of exosomes are also discussed.

Comparative evaluation of methods for isolating small extracellular vesicles derived from pancreatic cancer cells

BACKGROUND

Small extracellular vesicles (sEVs) are nanosized vesicles involved in cell-to-cell communication. sEVs have been widely studied for clinical applications such as early detection of diseases and as therapeutics. Various methods for sEVs isolation are been using, but different methods may result in different qualities of sEVs and impact downstream analysis and applications. Here, we compared current isolation methods and performed a comparative analysis of sEVs from supernatant of cultured pancreatic cancer cells.

METHODS

Ultracentrifugation, ultrafiltration and co-precipitation as concentration methods were firstly evaluated for yield, size, morphology and protein level of pellets. Then, isolate sEVs obtained by four different purification methods: size exclusion chromatography, density gradient ultracentrifugation, ultracentrifugation, and immunoaffinity capturing, were analysed and compared.

RESULTS

For the concentration process, ultracentrifugation method obtained high quality and high concentration of pellets. For the purification process, immunoaffinity capturing method obtained the purest sEVs with less contaminants, while density gradient ultracentrifugation-based method obtained sEVs with the smallest size. Proteomic analysis revealed distinct protein contents of purified sEVs from different methods.

CONCLUSIONS

For isolating sEVs derived from supernatant of cultured pancreatic cancer cell line, ultracentrifugation-based method is recommended for concentration of sEVs, density gradient ultracentrifugation-based method may be applied for obtaining purified sEVs with controlled size, immunoaffinity capturing may be suitable for studies requiring sEVs with high purity but may loss subtypes of sEVs without specific protein marker.

Extracellular vesicles and pancreatitis: mechanisms, status and perspectives

Comprehensive reviews and large population-based cohort studies have played an important role in the diagnosis and treatment of pancreatitis and its sequelae. The incidence and mortality of pancreatitis have been reduced significantly due to substantial advancements in the pathophysiological mechanisms and clinically effective treatments. The study of extracellular vesicles (EVs) has the potential to identify cell-to-cell communication in diseases such as pancreatitis. Exosomes are a subset of EVs with an average diameter of 50~150 nm. Their diverse and unique constituents include nucleic acids, proteins, and lipids, which can be transferred to trigger phenotypic changes of recipient cells. In recent years, many reports have indicated the role of EVs in pancreatitis, including acute pancreatitis, chronic pancreatitis and autoimmune pancreatitis, suggesting their potential influence on the development and progression of pancreatitis. Plasma exosomes of acute pancreatitis can effectively reach the alveolar cavity and activate alveolar macrophages to cause acute lung injury. Furthermore, upregulated exosomal miRNAs can be used as biomarkers for acute pancreatitis. Here, we summarized the current understanding of EVs in pancreatitis with an emphasis on their biological roles and their potential use as diagnostic biomarkers and therapeutic agents for this disease.

"Open Sesame?": Biomarker Status of the Human Equilibrative Nucleoside Transporter-1 and Molecular Mechanisms Influencing its Expression and Activity in the Uptake and Cytotoxicity of Gemcitabine in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive tumor characterized by early invasiveness, rapid progression and resistance to treatment. For more than twenty years, gemcitabine has been the main therapy for PDAC both in the palliative and adjuvant setting. After the introduction of FOLFIRINOX as an upfront treatment for metastatic disease, gemcitabine is still commonly used in combination with nab-paclitaxel as an alternative first-line regimen, as well as a monotherapy in elderly patients unfit for combination chemotherapy. As a hydrophilic nucleoside analogue, gemcitabine requires nucleoside transporters to permeate the plasma membrane, and a major role in the uptake of this drug is played by human equilibrative nucleoside transporter 1 (hENT-1). Several studies have proposed hENT-1 as a biomarker for gemcitabine efficacy in PDAC. A recent comprehensive multimodal analysis of hENT-1 status evaluated its predictive role by both immunohistochemistry (with five different antibodies), and quantitative-PCR, supporting the use of the 10D7G2 antibody. High hENT-1 levels observed with this antibody were associated with prolonged disease-free status and overall-survival in patients receiving gemcitabine adjuvant chemotherapy. This commentary aims to critically discuss this analysis and lists molecular factors influencing hENT-1 expression. Improved knowledge on these factors should help the identification of subgroups of patients who may benefit from specific therapies and overcome the limitations of traditional biomarker studies.

Anticancer effects of miR-124 delivered by BM-MSC derived exosomes on cell proliferation, epithelial mesenchymal transition, and chemotherapy sensitivity of pancreatic cancer cells

OBJECTIVE

This study aims to explore the roles of miR-124 in pancreatic tumor and potential vehicles.

RESULTS

The miR-124 expression levels decreased in pancreatic adenocarcinoma tissues and cancer cell lines AsPC-1, PANC1, BxPC-3 and SW1990. Furthermore, the elevated expression of miR-124 in AsPC-1 and PANC1 via miR-124 mimic transfection-induced apoptosis, metastasis and epithelial mesenchymal transition was suppressed, and the EZH2 overexpression partly reversed the protective effects of miR-124 against pancreatic tumors. In addition, the expression of miR-124 was detected in exosomes extracted from miR-124-transfected BM-MSCs, and these exosomes delivered miR-124 into pancreatic cancer cells, and presented the anti-tumor effects in vitro and in vivo.

CONCLUSION

MiR-124-carried BM-MSC-derived exosomes have potential applications for the treatment of pancreatic tumors.

METHODS

The expression of miR-124 and EZH2 was determined in both pancreatic cancer tissues and cell lines. miR-124 or EZH2 was overexpressed in AsPC-1 and PANC1 cells. Then, the effects on cell viability. apoptosis, invasion, migration and epithelial mesenchymal transition were evaluated. Afterwards, the roles of miR-124 on the expression and function of EZH2 in pancreatic tumors were determined by dual luciferase reporter assay. Subsequently, miR-124 was transfected to bone marrow mesenchymal stromal cells (BM-MSCs), and the BM-MSCs derived exosomes were isolated and co-cultured with AsPC-1 and PANC1 cells, or injected into pancreatic cancer tumor-bearing mice.

Exosomal Long Non-coding RNAs: Emerging Players in the Tumor Microenvironment

Recent advances in exosome biology have uncovered a significant role of exosomes in cancer and make them a determining factor in intercellular communication. Exosomes are types of extracellular vesicles that are involved in the communication between cells by exchanging various signaling molecules between the surrounding cells. Among various signaling molecules, long non-coding RNAs (lncRNAs), a type of non-coding RNA having a size of more than 200 nt in length and lacking protein-coding potential, have emerged as crucial regulators of intercellular communication. Tumor-derived exosomes containing various lncRNAs, known as exosomal lncRNAs, reprogram the microenvironment by regulating numerous cellular functions, including the regulation of gene transcription that favors cancer growth and progression, thus significantly determining the biological effects of exosomes. In addition, deregulated expression of lncRNAs is found in various human cancers and serves as a diagnostic biomarker to predict cancer type. The present review discusses the role of exosomal lncRNAs in the crosstalk between tumor cells and the surrounding cells of the microenvironment. Furthermore, we also discuss the involvement of exosomal lncRNAs within the tumor microenvironment in favoring tumor growth, metabolic reprogramming of tumor cells, and tumor-supportive autophagy. Therefore, lncRNAs can be used as a therapeutic target in the treatment of various human cancers.

MicroRNA-23b-3p promotes pancreatic cancer cell tumorigenesis and metastasis via the JAK/PI3K and Akt/NF-κB signaling pathways

MicroRNA (miR)-23b-3p plays an important role in tumor growth, proliferation, invasion and migration in pancreatic cancer (PC). However, the function and mechanistic role of miR-23b-3p in the development of PC remains largely unknown. In the present study, the miR-23b-3p levels in the serum of patients with PC were found to be elevated, and the phosphorylation levels of Janus kinase (JAK)2, PI3K, Akt and NF-κВ were found to be upregulated. In addition, miR-23b-3p was induced in response to interleukin-6 (IL-6), which is known to be involved in the progression of PC. Overexpression of miR-23b-3p, on the other hand, activated the JAK/PI3K and Akt/NF-κB signaling pathways in PC cells, as evidenced by miR-23b-3p-induced upregulation of phosphorylated (p-)JAK2, p-PI3K, p-Akt and p-NF-κВ, as well as the downregulation of PTEN; and these effects were found to be reversible by miR-23b-3p inhibition. Furthermore, miR-23b-3p was found to downregulate PTEN by directly targeting the 3′-untranslated region of PTEN mRNA. Notably, in an in vivo xenograft mouse model, overexpression of miR-23b-3p accelerated PC cell-derived tumor growth, activated the JAK/Akt/NF-κВ signaling pathway and promoted liver metastasis. In contrast, knockdown of miR-23b-3p suppressed tumor growth and metastasis as well as JAK/Akt/NF-κВ signaling activity. In vivo imaging of the mice further confirmed the metastasis promoting role of miR-23b-3p in PC. These results suggested that miR-23b-3p enhances PC cell tumorigenesis and metastasis, at least, partially via the JAK/PI3K and Akt/NF-κB signaling pathways. Therefore, targeting miR-23b-3p or the JAK/PI3K and Akt/NF-κB signalings may be potential therapeutic strategy against PC.

Extracellular Vesicles (EVs) and Pancreatic Cancer: From the Role of EVs to the Interference with EV-Mediated Reciprocal Communication

Pancreatic cancer is malignant and the seventh leading cause of cancer-related deaths worldwide. However, chemotherapy and radiotherapy are—at most—moderately effective, indicating the need for new and different kinds of therapies to manage this disease. It has been proposed that the biologic properties of pancreatic cancer cells are finely tuned by the dynamic microenvironment, which includes extracellular matrix, cancer-associated cells, and diverse immune cells. Accumulating evidence has demonstrated that extracellular vesicles (EVs) play an essential role in communication between heterogeneous subpopulations of cells by transmitting multiplex biomolecules. EV-mediated cell–cell communication ultimately contributes to several aspects of pancreatic cancer, such as growth, angiogenesis, metastasis and therapeutic resistance. In this review, we discuss the role of extracellular vesicles and their cargo molecules in pancreatic cancer. We also present the feasibility of the inhibition of extracellular biosynthesis and their itinerary (release and uptake) for a new attractive therapeutic strategy against pancreatic cancer.

Expression of serum exosomal miR-23b-3p in non-small cell lung cancer and its diagnostic efficacy

The present study aimed to investigate the expression of serum exosomal miR-23b-3p in non-small cell lung cancer (NSCLC) and to determine its diagnostic efficacy for NSCLC. From October, 2017 to October, 2019, 80 patients with NSCLC, 60 patients with pneumonia and 30 healthy subjects undergoing physical examination were enrolled at the People's Hospital of Yangzhong City. Serum samples were collected from the 3 groups of patients. The expression of miR-23b-3p in exosomes was detected by RT-qPCR. The Chi-squared test was used to analyze the expression level of miR-23b-3p in exosomes, and the patients with NSCLC were divided into 2 groups according to the expression level. The association between the patient clinicopathological parameters and receiver operating characteristic (ROC) curves was used to evaluate the diagnostic efficacy of serum exosomal miR-23b-3p in NSCLC. The expression level of serum exosomal miR-23b-3p in the patients with NSCLC was significantly higher than that in patients with pneumonia (t=10.332, P<0.001) and healthy subjects (t=12.810, P<0.001); serum exosomal miR-23b-3p was significantly associated with tumor size, depth of invasion, liver metastasis and TNM stage (P<0.05). The area under the curve (AUC) for miR-23b-3p was 0.915 (95% CI, 0.84-0.92), the optimal relative expression of miR-23b-3p was 3.46, the sensitivity of diagnosis was 87.4%, and the specificity was 93.8%, all higher than that of carcinoembryonic antigen (CEA). The ROC^AUC of NSCLC was 0.645 (95% CI, 0.641-0.772) and for Cyfra21-1 it was 0.745 (95% CI, 0.701-0.812). Compared with the patients with pneumonia and the healthy subjects, the patients with NSCLC exhibited a higher level of serum exosomal miR-23b-3p. On the whole, these findings indicate that miR-23b-3p has a higher clinical diagnostic efficacy and may thus be a potential biomarker for the early diagnosis of NSCLC.

Immuno-Surgical Management of Pancreatic Cancer with Analysis of Cancer Exosomes

Exosomes (EXs), a type of extracellular vesicles secreted from various cells and especially cancer cells, mesenchymal cells, macrophages and other cells in the tumor microenvironment (TME), are involved in biologically malignant behaviors of cancers. Recent studies have revealed that EXs contain microRNAs on their inside and express proteins and glycolipids on their outsides, every component of which plays a role in the transmission of genetic and/or epigenetic information in cell-to-cell communications. It is also known that miRNAs are involved in the signal transduction. Thus, EXs may be useful for monitoring the TME of tumor tissues and the invasion and metastasis, processes that are associated with patient survival. Because several solid tumors secrete immune checkpoint proteins, including programmed cell death-ligand 1, the EX-mediated mechanisms are suggested to be potent targets for monitoring patients. Therefore, a companion therapeutic approach against cancer metastasis to distant organs is proposed when surgical removal of the primary tumor is performed. However, EXs and immune checkpoint mechanisms in pancreatic cancer are not fully understood, we provide an update on the recent advances in this field and evidence that EXs will be useful for maximizing patient benefit in precision medicine.

Machine Learning-Based Ensemble Recursive Feature Selection of Circulating miRNAs for Cancer Tumor Classification

Circulating microRNAs (miRNA) are small noncoding RNA molecules that can be detected in bodily fluids without the need for major invasive procedures on patients. miRNAs have shown great promise as biomarkers for tumors to both assess their presence and to predict their type and subtype. Recently, thanks to the availability of miRNAs datasets, machine learning techniques have been successfully applied to tumor classification. The results, however, are difficult to assess and interpret by medical experts because the algorithms exploit information from thousands of miRNAs. In this work, we propose a novel technique that aims at reducing the necessary information to the smallest possible set of circulating miRNAs. The dimensionality reduction achieved reflects a very important first step in a potential, clinically actionable, circulating miRNA-based precision medicine pipeline. While it is currently under discussion whether this first step can be taken, we demonstrate here that it is possible to perform classification tasks by exploiting a recursive feature elimination procedure that integrates a heterogeneous ensemble of high-quality, state-of-the-art classifiers on circulating miRNAs. Heterogeneous ensembles can compensate inherent biases of classifiers by using different classification algorithms. Selecting features then further eliminates biases emerging from using data from different studies or batches, yielding more robust and reliable outcomes. The proposed approach is first tested on a tumor classification problem in order to separate 10 different types of cancer, with samples collected over 10 different clinical trials, and later is assessed on a cancer subtype classification task, with the aim to distinguish triple negative breast cancer from other subtypes of breast cancer. Overall, the presented methodology proves to be effective and compares favorably to other state-of-the-art feature selection methods.

The Role of Extracellular Vesicles in the Hallmarks of Cancer and Drug Resistance

Extracellular vesicles (EVs) mediate intercellular signaling and communication, allowing the intercellular exchange of proteins, lipids, and genetic material. Their recognized role in the maintenance of the physiological balance and homeostasis seems to be severely disturbed throughout the carcinogenesis process. Indeed, the modus operandi of cancer implies the highjack of the EV signaling network to support tumor progression in many (if not all) human tumor malignancies. We have reviewed the current evidence for the role of EVs in affecting cancer hallmark traits by: (i) promoting cell proliferation and escape from apoptosis, (ii) sustaining angiogenesis, (iii) contributing to cancer cell invasion and metastasis, (iv) reprogramming energy metabolism, (v) transferring mutations, and (vi) modulating the tumor microenvironment (TME) by evading immune response and promoting inflammation. Special emphasis was given to the role of EVs in the transfer of drug resistant traits and to the EV cargo responsible for this transfer, both between cancer cells or between the microenvironment and tumor cells. Finally, we reviewed evidence for the increased release of EVs by drug resistant cells. A timely and comprehensive understanding of how tumor EVs facilitate tumor initiation, progression, metastasis and drug resistance is instrumental for the development of innovative EV-based therapeutic approaches for cancer.

From tumor microenvironment communicants to biomarker discovery: Selectively packaged extracellular vesicular cargoes in pancreatic cancer

Virtually all cells release various types of vesicles into the extracellular environment. These extracellular vesicles (EVs) transport molecular cargoes, performing as communicants for information exchange both within the tumor microenvironment (TME) and to distant organs. Thus, understanding the selective packaging of EV cargoes and the mechanistic impact of those cargoes - including metabolites, lipids, proteins, and/or nucleic acids - offers an opportunity to increase our knowledge of cancer biology and identify EV cargoes that might serve as cancer biomarkers in blood, saliva, or urine samples. In this review, we collect and organize recent advances in this field with an emphasis on pancreatic cancer (pancreatic adenocarcinoma, PDAC) and the concept that cells selectively package cargo into EVs. These studies demonstrate PDAC EV cargoes signal to reprogram and remodel the TME and impact distant organs. EV cargoes identified as potential PDAC diagnostic and prognostic biomarkers are summarized.

The Potential Therapeutic Role of Exosomal MicroRNA-520b Derived from Normal Fibroblasts in Pancreatic Cancer

Pancreatic cancer (PC) remains a major health concern, with conventional cancer treatments exerting little influence on the disease course. MicroRNA-520b (miR-520b) functions as a tumor suppressor in several types of human cancers, whereas its anti-tumor property in the context of PC is still fundamental. The aim of this study is to identify the potential therapeutic role of miR-520b, transferred by exosomes, derived from normal fibroblasts (NFs) in PC progression. A gain-of-function study was performed to examine the roles of miR-520b in PC cell line SW1990, which suggested that miR-520b served as a tumor suppressor in PC. In order to confirm the role of exosomal miR-520b, exosomes were isolated from NF culture medium and cocultured with SW1990 cells. During the coculture experiments, we disrupted exosome secretion and upregulated exosomal miR-520b. The in vitro coculture studies revealed that miR-520b was transferred from NF-derived exosomes to PC cells and thereby suppressed PC cell proliferation, invasion, migration, and stimulated apoptosis. Furthermore, inhibited tumor growth and live metastasis upon elevated miR-520b in exosomes were observed in vivo. Conjointly, our study demonstrates that NF-derived exosomal miR-520b impedes the progression of PC, which contributes to a novel, therapeutic role of exosomal miR-520b for treating PC.

Clinical value of circular RNAs and autophagy-related miRNAs in the diagnosis and treatment of pancreatic cancer

BACKGROUND

Circular RNAs (circRNAs) are a special group of long-chain and non-coding RNAs characterized by a closed-loop structure without 3' and 5' polarity. In recent years, studies have demonstrated that circRNAs act as microRNA (miRNA) sponges to regulate the function of miRNAs. Increasing evidence indicates that circRNAs and targeted miRNAs are involved in the development, progression and metastasis of various cancers and drug resistance. A number of miRNAs are known to be associated with the pathogenesis, development and treatment of pancreatic cancer by regulating the autophagic activity.

DATA SOURCES

A comprehensive literature search was executed in PubMed and EMBASE using the medical subject headings (MeSH) terms "Pancreatic Neoplasms", "autophagy", "RNA, circular" and "microRNA". We also used text terms such as "diagnosis", "prognosis" and "biomarker" to supplement the results.

RESULTS

Autophagy-related miRNAs is closely related to pancreatic cancer. On basis of the retrieval results, we summarized the synthesis, features and functions of circRNAs and analyzed the association between autophagy-related miRNAs and pancreatic cancer.

CONCLUSIONS

circRNAs act as the miRNA sponges and there is an association between miRNAs and autophagy, which provides a new concept to broaden the knowledge about the mechanisms underlying the development, progression and metastasis of pancreatic cancer. Additionally, clinical value of circRNAs and autophagy-related miRNAs in the diagnosis and treatment of pancreatic cancer would be further verified with in-depth researches.

Novel Epigenetic Biomarkers in Pregnancy-Related Disorders and Cancers

As the majority of cancers and gestational diseases are prognostically stage- and grade-dependent, the ultimate goal of ongoing studies in precision medicine is to provide early and timely diagnosis of such disorders. These studies have enabled the development of various new diagnostic biomarkers, such as free circulating nucleic acids, and detection of their epigenetic changes. Recently, extracellular vesicles including exosomes, microvesicles, oncosomes, and apoptotic bodies have been recognized as powerful diagnostic tools. Extracellular vesicles carry specific proteins, lipids, DNAs, mRNAs, and miRNAs of the cells that produced them, thus reflecting the function of these cells. It is believed that exosomes, in particular, may be the optimal biomarkers of pathological pregnancies and cancers, especially those that are frequently diagnosed at an advanced stage, such as ovarian cancer. In the present review, we survey and critically appraise novel epigenetic biomarkers related to free circulating nucleic acids and extracellular vesicles, focusing especially on their status in trophoblasts (pregnancy) and neoplastic cells (cancers).

Secondary Structural Model of Human MALAT1 Reveals Multiple Structure-Function Relationships

Human metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is an abundant nuclear-localized long noncoding RNA (lncRNA) that has significant roles in cancer. While the interacting partners and evolutionary sequence conservation of MALAT1 have been examined, much of the structure of MALAT1 is unknown. Here, we propose a hypothetical secondary structural model for 8425 nucleotides of human MALAT1 using three experimental datasets that probed RNA structures in vitro and in various human cell lines. Our model indicates that approximately half of human MALAT1 is structured, forming 194 helices, 13 pseudoknots, five structured tetraloops, nine structured internal loops, and 13 intramolecular long-range interactions that give rise to several multiway junctions. Evolutionary conservation and covariation analyses support 153 of 194 helices in 51 mammalian MALAT1 homologs and 42 of 194 helices in 53 vertebrate MALAT1 homologs, thereby identifying an evolutionarily conserved core that likely has important functional roles in mammals and vertebrates. Data mining revealed that RNA modifications, somatic cancer-associated mutations, and single-nucleotide polymorphisms may induce structural rearrangements that sequester or expose binding sites for several cancer-associated microRNAs. Our findings reveal new mechanistic leads into the roles of MALAT1 by identifying several intriguing structure–function relationships in which the dynamic structure of MALAT1 underlies its biological functions.

miRNA and Gene Expression in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains a challenging disease that is mostly diagnosed late in the course of the illness. Unlike other cancers in which measurable successes have been achieved with traditional chemotherapy, targeted therapy, and, recently, immunotherapy, PDAC has proved to be poorly responsive to these treatments, with only marginal to modest incremental benefits using conventional cytotoxic therapy. There is, therefore, a great unmet need to develop better therapies based on improved understanding of biology and identification of predictive and prognostic biomarkers that would guide therapy. miRNAs are small noncoding RNAs that regulate the expression of some key genes by targeting their 3'-untranslated mRNA region. Aberrant expression of miRNAs has been linked to the development of various malignancies, including PDAC. A series of miRNAs have been identified as potential tools for early diagnosis, prediction of treatment response, and prognosis of patients with PDAC. In this review, we present a summary of the miRNAs that have been studied in PDAC in the context of disease biology.

The State of the Art on Blood MicroRNAs in Pancreatic Ductal Adenocarcinoma

Despite enormous advances being made in diagnosis and therapeutic interventions, pancreatic ductal adenocarcinoma (PDAC) is still recognized as one of the most lethal malignancies. Early diagnosis and timely curative surgery can markedly improve the prognosis; hence, there is an unmet necessity to explore efficient biomarkers for patients' benefit. Recently, blood miRNAs (miRNAs) have been reported to be a novel biomarker in human cancers. Part of it is selectively packaged by plasma exosomes released from cells via exocytosis and is highly sensitive to changes in the tumor microenvironment. Furthermore, due to less invasiveness and technical availability, miRNA-based liquid biopsy holds promise for further wide usage. Therefore, this review is aimed at presenting an update on the association between blood miRNAs and the biology of PDAC, then discussing its clinical utilization further.

MicroRNA-23b-3p promotes the proliferation, migration, and epithelial-mesenchymal transition of lens epithelial cells by targeting Sprouty2

Cataract, opacification of the lens, is one of the most important reasons of visual impairment and blindness. Though microRNAs (miRNAs) have been demonstrated to play important roles in cataractogenesis, the underlying molecular mechanisms in this progress remain obscure. In the present study, microRNA-23b-3p (miR-23b) overexpression promoted the proliferation, migration and epithelial-mesenchymal transition (EMT), whereas miR-23b knockdown markedly inhibited the proliferation, migration and TGF-β-induced EMT of lens epithelial cells (LECs). In TGF-β-induced LECs, the expression of miR-23b was markedly upregulated and the expression of Sprouty2 (SPRY2) was markedly downregulated, furthermore the mRNA and protein levels of SPRY2 were markedly decreased in miR-23b inhibitor-transfected LECs. We then performed a Dual-luciferase reporter assay to confirm that miR-23b directly targeted SPRY2. The promoted migration and EMT of LECs by enforced expression of miR-23b were suppressed by SPRY2 overexpression. The findings present the first evidence indicating that miR-23b can promote the proliferation, migration, and EMT of LECs by targeting SPRY2 and the inhibition of miR-23b may possess the therapeutic potential for cataract.

Reprogramming of Amino Acid Transporters to Support Aspartate and Glutamate Dependency Sustains Endocrine Resistance in Breast Cancer

Endocrine therapy (ET) is the standard of care for estrogen receptor-positive (ER+) breast cancers. Despite its efficacy, ∼40% of women relapse with ET-resistant (ETR) disease. A global transcription analysis in ETR cells reveals a downregulation of the neutral and basic amino acid transporter SLC6A14 governed by enhanced miR-23b-3p expression, resulting in impaired amino acid metabolism. This altered amino acid metabolism in ETR cells is supported by the activation of autophagy and the enhanced import of acidic amino acids (aspartate and glutamate) mediated by the SLC1A2 transporter. The clinical significance of these findings is validated by multiple orthogonal approaches in a large cohort of ET-treated patients, in patient-derived xenografts, and in in vivo experiments. Targeting these amino acid metabolic dependencies resensitizes ETR cells to therapy and impairs the aggressive features of ETR cells, offering predictive biomarkers and potential targetable pathways to be exploited to combat or delay ETR in ER+ breast cancers.

The critical role of exosomes in tumor biology

Exosomes are a type of extracellular vesicles (diameter, 30-160 nm), which contain multiple proteins, nucleic acids, lipid molecules, and other substances. Most types of cells can secrete exosomes, although the biogenesis, composition, and function is specific to different cell types. Recently, many studies have demonstrated that exosomes play a critical role in tumor development. In this review, we briefly summarize the biogenesis, composition, and function of exosomes. We also discuss the recent advances in the critical role of exosomes in tumor biology with a special focus on their application in tumor diagnosis and treatment.