Research of the mechanism on miRNA193 in exosomes promotes cisplatin resistance in esophageal cancer cells

Exosomal miR-130a-3p confers cisplatin resistance in esophageal cancer by regulating ferroptosis via the suppression of METTL14-mediated m6A RNA methylation of FSP1

Exosomal microRNA (miRNA)s have been proven to affect recipient cell chemoresistance in several cancers. This research attempted to uncover the role of exosomal miRNA and the regulatory mechanism in cisplatin resistance of esophageal cancer (EC). Cisplatin-resistant EC cells (KYSE-150-CisR and TE-1-CisR) were established by the parental cells (KYSE-150 and TE-1) treated with a gradual increase of cisplatin concentration. Exosomes from both cisplatin-resistant EC cells and the parental one were obtained with ultracentrifugation (CisR-exo and CisS-exo), and identified by transmission electron microscopy and nanoparticle tracking analysis. The effect of CisR-exo on the cisplatin resistance of EC was assessed by in vitro (and in vivo functional experiments.Intracellular reactive oxygen species and iron were determined by the corresponding kits. The m6A dot blot assay and methylated RIP-qPCR was conducted to analyze the m6A modification level. Dual-luciferase reporter assay was performed to confirm the intermolecular interaction. Increased levels of miR-130a-3p were observed in both KYSE-150CisR and TE-1CisR cells, as well as their derived CisR-exos when compared with the parental cells and CisS-exos. Exosomal miR-130a-3p from cisplatin-resistant EC cells conferred cisplatin resistance to EC in vitro and in vivo, which might be mediated by the suppression of ferroptosis. Mechanically, KYSE-150CisR derived exosomal miR-130a-3p interacted with METTL14 to inhibit FSP1 (a ferroptosis suppressor) m6A modification of recipient cells. Overexpressing METTL14 restrained the cisplatin resistance disseminated by CisR-exos in KYSE-150 cells. Cisplatin-resistant EC cell-isolated exosomal miR-130a-3p suppressed the m6A modification of FSP1 to modulate ferroptosis, enhancing cisplatin resistance.

Extracellular Vesicles as Mediators and Potential Targets in Combating Cancer Drug Resistance

Extracellular vesicles (EVs) are key mediators in the communication between cancer cells and their microenvironment, significantly influencing drug resistance. This review provides a comprehensive analysis of the roles of EVs in promoting drug resistance through mechanisms such as drug efflux, apoptosis resistance, autophagy imbalance, and tumor microenvironment modulation. Despite extensive research, details of EVs biogenesis, cargo selection, and specific pathways in EVs-mediated drug resistance are not fully understood. This review critically examines recent advancements, highlighting key studies that elucidate the molecular mechanisms of EVs functions. Additionally, innovative therapeutic strategies targeting EVs are explored, including inhibiting EVs biogenesis, engineering EVs for drug delivery, and identifying resistance-inhibiting molecules within EVs. By integrating insights from primary research and proposing new directions for future studies, this review aims to advance the understanding of EVs in cancer biology and foster effective interventions to mitigate drug resistance in cancer therapy.

Exosomes in esophageal cancer: function and therapeutic prospects

Esophageal cancer (EC) is one of the most common malignant tumors worldwide. Exosomes are a type of extracellular vesicles produced by eukaryotic cells and present in all body fluids. Recent studies have revealed that exosomes can be used as a tool for cell signaling and have great potential in cancer diagnosis and treatment strategies. This article reviews the research progress of exosomes in EC in recent years, mainly including the mechanism of action, diagnostic markers, therapeutic targets, and drug carriers. The challenges faced are discussed to provide guidelines for further research in future.

The roles of exosomes in esophageal cancer

The incidence and mortality rate of esophageal cancer (EC) are higher worldwide. Exosomes are nanoscale vesicles derived from various types of cells, exhibiting a stable presence in bodily fluids, and contain a plethora of bioactive components including proteins, DNA, and RNA. Exosomes can mediate cell-to-cell communication and signaling. Numerous studies conducted both domestically and internationally have indicated the significant involvement of exosomes in tumor development and their potential as novel diagnostic and prognostic biomarkers for liquid biopsy. This review seeks to consolidate the role of exosomes and bioactive substances in the progression of EC and elaborate on the opportunities and challenges associated with the clinical application of exosomes in EC.

HMGA1 drives chemoresistance in esophageal squamous cell carcinoma by suppressing ferroptosis

Chemotherapy is a primary treatment for esophageal squamous cell carcinoma (ESCC). Resistance to chemotherapeutic drugs is an important hurdle to effective treatment. Understanding the mechanisms underlying chemotherapy resistance in ESCC is an unmet medical need to improve the survival of ESCC. Herein, we demonstrate that ferroptosis triggered by inhibiting high mobility group AT-hook 1 (HMGA1) may provide a novel opportunity to gain an effective therapeutic strategy against chemoresistance in ESCC. HMGA1 is upregulated in ESCC and works as a key driver for cisplatin (DDP) resistance in ESCC by repressing ferroptosis. Inhibition of HMGA1 enhances the sensitivity of ESCC to ferroptosis. With a transcriptome analysis and following-up assays, we demonstrated that HMGA1 upregulates the expression of solute carrier family 7 member 11 (SLC7A11), a key transporter maintaining intracellular glutathione homeostasis and inhibiting the accumulation of malondialdehyde (MDA), thereby suppressing cell ferroptosis. HMGA1 acts as a chromatin remodeling factor promoting the binding of activating transcription factor 4 (ATF4) to the promoter of SLC7A11, and hence enhancing the transcription of SLC7A11 and maintaining the redox balance. We characterized that the enhanced chemosensitivity of ESCC is primarily attributed to the increased susceptibility of ferroptosis resulting from the depletion of HMGA1. Moreover, we utilized syngeneic allograft tumor models and genetically engineered mice of HMGA1 to induce ESCC and validated that depletion of HMGA1 promotes ferroptosis and restores the sensitivity of ESCC to DDP, and hence enhances the therapeutic efficacy. Our finding uncovers a critical role of HMGA1 in the repression of ferroptosis and thus in the establishment of DDP resistance in ESCC, highlighting HMGA1-based rewiring strategies as potential approaches to overcome ESCC chemotherapy resistance. Schematic depicting that HMGA1 maintains intracellular redox homeostasis against ferroptosis by assisting ATF4 to activate SLC7A11 transcription, resulting in ESCC resistance to chemotherapy.

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.

Role of exosomes in metastasis and therapeutic resistance in esophageal cancer

Esophageal cancer (EC) has a high incidence and mortality rate and is emerging as one of the most common health problems globally. Owing to the lack of sensitive detection methods, uncontrollable rapid metastasis, and pervasive treatment resistance, EC is often diagnosed in advanced stages and is susceptible to local recurrence. Exosomes are important components of intercellular communication and the exosome-mediated crosstalk between the cancer and surrounding cells within the tumor microenvironment plays a crucial role in the metastasis, progression, and therapeutic resistance of EC. Considering the critical role of exosomes in tumor pathogenesis, this review focused on elucidating the impact of exosomes on EC metastasis and therapeutic resistance. Here, we summarized the relevant signaling pathways involved in these processes. In addition, we discussed the potential clinical applications of exosomes for the early diagnosis, prognosis, and treatment of EC.

Emerging role of exosome-shuttled noncoding RNAs in gastrointestinal cancers: From intercellular crosstalk to clinical utility

Gastrointestinal cancer remains a significant global health burden. The pursuit of advancing the comprehension of tumorigenesis, along with the identification of reliable biomarkers and the development of precise therapeutic strategies, represents imperative objectives in this field. Exosomes, small membranous vesicles released by most cells, commonly carry functional biomolecules, including noncoding RNAs (ncRNAs), which are specifically sorted and encapsulated by exosomes. Exosome-mediated communication involves the release of exosomes from tumor or stromal cells and the uptake by nearby or remote recipient cells. The bioactive cargoes contained within these exosomes exert profound effects on the recipient cells, resulting in significant modifications in the tumor microenvironment (TME) and distinct alterations in gastrointestinal tumor behaviors. Due to the feasibility of isolating exosomes from various bodily fluids, exosomal ncRNAs have shown great potential as liquid biopsy-based indicators for different gastrointestinal cancers, using blood, ascites, saliva, or bile samples. Moreover, exosomes are increasingly recognized as natural delivery vehicles for ncRNA-based therapeutic interventions. In this review, we elucidate the processes of ncRNA-enriched exosome biogenesis and uptake, examine the regulatory and functional roles of exosomal ncRNA-mediated intercellular crosstalk in gastrointestinal TME and tumor behaviors, and explore their potential clinical utility in diagnostics, prognostics, and therapeutics.

The interplay of signaling pathways and miRNAs in the pathogenesis and targeted therapy of esophageal cancer

Globally, esophageal cancer (EC) is the 6th leading cause of cancer-related deaths and the second deadliest gastrointestinal cancer. Multiple genetic and epigenetic factors, such as microRNAs (miRNAs), influence its onset and progression. miRNAs are short nucleic acid molecules that can regulate multiple cellular processes by regulating gene expression. Therefore, EC initiation, progression, apoptosis evasions, invasion capacity, promotion, angiogenesis, and epithelial-mesenchymal transition (EMT) enhancement are associated with miRNA expression dysregulation. Wnt/-catenin signaling, Mammalian target of rapamycin (mTOR)/P-gp, phosphoinositide-3-kinase (PI3K)/AKT/c-Myc, epidermal growth factor receptor (EGFR), and transforming growth factor (TGF)-β signaling are crucial pathways in EC that are controlled by miRNAs. This review was conducted to provide an up-to-date assessment of the role of microRNAs in EC pathogenesis and their modulatory effects on responses to various EC treatment modalities.

Role of exosomal noncoding RNA in esophageal carcinoma

Esophageal cancer is a common malignant tumor with a high degree of malignancy. Understanding its pathogenesis and identifying early diagnostic biomarkers can significantly improve the prognosis of esophageal cancer patients. Exosomes are small double-membrane vesicles found in various body fluids containing various components (DNA, RNA, and proteins) that mediate intercellular signal communication. Non-coding RNAs are a class of gene transcription products that encode polypeptide functions and are widely detected in exosomes. There is growing evidence that exosomal non-coding RNAs are involved in cancer growth, metastasis and angiogenesis, and can also be used as diagnostic and prognostic markers. This article reviews the recent progress in exosomal non-coding RNAs in esophageal cancer, including research progress, diagnostic value, proliferation, migration, invasion, and drug resistance, provide new ideas for the precise treatment of esophageal cancer.

Roles of oncogenes in esophageal squamous cell carcinoma and their therapeutic potentials

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer (EC) in Asia. It is a malignant digestive tract tumor with abundant gene mutations. Due to the lack of specific diagnostic markers and early cancer screening markers, most patients are diagnosed at an advanced stage. Genetic and epigenetic changes are closely related to the occurrence and development of ESCC. Here, We review the activation of proto-oncogenes into oncogenes through gene mutation and gene amplification in ESCC from a genetic and epigenetic genome perspective, We also discuss the specific regulatory mechanisms through which these oncogenes mainly affect the biological function and occurrence and development of ESCC through specific regulatory mechanisms. In addition, we summarize the clinical application value of these oncogenes is summarized, and it provides a feasible direction for clinical use as potential therapeutic and diagnostic markers.

Noncoding RNAs in esophageal cancer: A glimpse into implications for therapy resistance

Esophageal cancer (EC) is one of the most common malignancies of the digestive system and has a high morbidity and mortality worldwide. Chemotherapy in combination with radiotherapy is one of the most important treatment modalities for EC. Chemoradiotherapy is currently acknowledged worldwide as being the standard treatment for locally advanced or unresectable disease. Unfortunately, due to the existence of therapy resistance, a number of EC patients fail to benefit from drug or irradiation treatment, which ultimately leads to poor outcomes. Considerable efforts have been made to explore the mechanisms underlying the therapy resistance of EC. Notably, noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), are current research areas for the modulation of therapy responses and may serve as new targets to overcome treatment resistance in EC. Herein, we summarized the mechanisms by which ncRNAs are involved in drug and radiation resistance in EC and highlighted their role in promoting or repressing treatment resistance. Additionally, we discussed the clinical relevance of ncRNAs, which may serve as potential therapeutic targets and predictive biomarkers for EC.

Focus on the molecular mechanisms of cisplatin resistance based on multi-omics approaches

Cisplatin is commonly used in combination with other cytotoxic agents as a standard treatment regimen for a variety of solid tumors, such as lung, ovarian, testicular, and head and neck cancers. However, the effectiveness of cisplatin is accompanied by toxic side effects, for instance, nephrotoxicity and neurotoxicity. The response of tumors to cisplatin treatment involves multiple physiological processes, and the efficacy of chemotherapy is limited by the intrinsic and acquired resistance of tumor cells. Although enormous efforts have been made toward molecular mechanisms of cisplatin resistance, the development of omics provides new insights into the understanding of cisplatin resistance at genome, transcriptome, proteome, metabolome and epigenome levels. Mechanism studies using different omics approaches revealed the necessity of multi-omics applications, which provide information at different cellular function levels and expand our recognition of the peculiar genetic and phenotypic heterogeneity of cancer. The present work systematically describes the underlying mechanisms of cisplatin resistance in different tumor types using multi-omics approaches. In addition to the classical mechanisms such as enhanced drug efflux, increased DNA damage repair and changes in the cell cycle and apoptotic pathways, other changes like increased protein damage clearance, increased protein glycosylation, enhanced glycolytic process, dysregulation of the oxidative phosphorylation pathway, ferroptosis suppression and mRNA m6A methylation modification can also induce cisplatin resistance. Therefore, utilizing the integrated omics to identify key signaling pathways, target genes and biomarkers that regulate chemoresistance are essential for the development of new drugs or strategies to restore tumor sensitivity to cisplatin.

Mechanisms of function and clinical potential of exosomes in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) remains one of the most lethal and widespread malignancies in China. Exosomes, a subset of tiny extracellular vesicles manufactured by all cells and present in all body fluids, contribute to intercellular communication and have become a focus of the search for new therapeutic strategies for cancer. A number of global analyses of exosome-mediated functions and regulatory mechanism in malignant diseases have recently been reported. There is extensive evidence that exosomes can be used as diagnostic and prognostic markers for cancer. However, our understanding of their clinical value and mechanisms of action in ESCC is still limited and has not been systematically reviewed. Here, we review current research specifically focused on the functions and mechanisms of action of ESCC tumor-derived exosomes and non-ESCC-derived exosomes in ESCC progression and describe opportunities and challenges in the clinical translation of exosomes.

Epigenetic modifications in esophageal cancer: An evolving biomarker

Esophageal cancer is a widespread cancer of the digestive system that has two main subtypes: esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EA). In the diverse range of cancer therapy schemes, the side effects of conventional treatments remain an urgent challenge to be addressed. Therefore, the pursuit of novel drugs with multiple targets, good efficacy, low side effects, and low cost has become a hot research topic in anticancer therapy. Based on this, epigenetics offers an attractive target for the treatment of esophageal cancer, where major mechanisms such as DNA methylation, histone modifications, non-coding RNA regulation, chromatin remodelling and nucleosome localization offer new opportunities for the prevention and treatment of esophageal cancer. Recently, research on epigenetics has remained at a high level of enthusiasm, focusing mainly on translating the basic research into the clinical setting and transforming epigenetic alterations into targets for cancer screening and detection in the clinic. With the increasing emergence of tumour epigenetic markers and antitumor epigenetic drugs, there are also more possibilities for anti-esophageal cancer treatment. This paper focuses on esophageal cancer and epigenetic modifications, with the aim of unravelling the close link between them to facilitate precise and personalized treatment of esophageal cancer.

Exosomal microRNAs: A Diagnostic and Therapeutic Small Bio-molecule in Esophageal Cancer

Esophageal cancer (EC) is one of the major causes of cancer-related death worldwide. EC is usually diagnosed at a late stage, and despite aggressive therapy, the five-year survival rate of patients remains poor. Exosomes play important roles in cancer biology. Indeed, exosomes are implicated in tumor proliferation, angiogenesis, and invasion. They contain bioactive molecules such as lipids, proteins, and non-coding RNAs. Exosome research has recently concentrated on microRNAs, which are tiny noncoding endogenous RNAs that can alter gene expression and are linked to nearly all physiological and pathological processes, including cancer. It is suggested that deregulation of miRNAs results in cancer progression and directly induces tumor initiation. In esophageal cancer, miRNA dysregulation plays an important role in cancer prognosis and patients' responsiveness to therapy, indicating that miRNAs are important in tumorigenesis. In this review, we summarize the impact of exosomal miRNAs on esophageal cancer pathogenesis and their potential applications for EC diagnosis and therapy.

Exosomes in the tumor microenvironment: Promoting cancer progression

Exosomes, which are extracellular vesicles produced by endosomes, are important performers of intercellular communication functions. For more than three decades, there has been a growing awareness of exosomes as the contents of the tumor microenvironment and their intimate connection to the development of cancer. The composition, generation, and uptake of exosomes as well as their roles in tumor metastasis, angiogenesis, and immunosuppression are discussed in this paper. In order to stop the progression of cancer, it is crucial to find new diagnostic biomarkers and therapeutic targets for the disease. Knowing the biological characteristics of exosomes and their functions in tumor development helps in this endeavor.

Small Extracellular Vesicles and Their Involvement in Cancer Resistance: An Up-to-Date Review

In recent years, tremendous progress has been made in understanding the roles of extracellular vesicles (EVs) in cancer. Thanks to advancements in molecular biology, it has been found that the fraction of EVs called exosomes or small EVs (sEVs) modulates the sensitivity of cancer cells to chemotherapeutic agents by delivering molecularly active non-coding RNAs (ncRNAs). An in-depth analysis shows that two main molecular mechanisms are involved in exosomal modified chemoresistance: (1) translational repression of anti-oncogenes by exosomal microRNAs (miRs) and (2) lack of translational repression of oncogenes by sponging of miRs through long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). At the cellular level, these processes increase the proliferation and survival of cancer cells and improve their ability to metastasize and resist apoptosis. In addition, studies in animal models have shown enhancing tumor size under the influence of exosomal ncRNAs. Ultimately, exosomal ncRNAs are responsible for clinically significant chemotherapy failures in patients with different types of cancer. Preliminary data have also revealed that exosomal ncRNAs can overcome chemotherapeutic agent resistance, but the results are thoroughly fragmented. This review presents how exosomes modulate the response of cancer cells to chemotherapeutic agents. Understanding how exosomes interfere with chemoresistance may become a milestone in developing new therapeutic options, but more data are still required.

Extracellular Vesicles and Circulating Tumour Cells - complementary liquid biopsies or standalone concepts?

Liquid biopsies do promise a lot, but are they keeping it? In the past decade, additional novel biomarkers qualified to be called like that, of which, some took necessary hurdles resulting in FDA approval and clinical use. Some others are since a while around, well known and were once regarded to be a game changer in cancer diagnosis or cancer screening. But, during their clinical use limitations were observed from statistical significance and questions raised regarding their robustness, that eventually led to be dropped from associated clinical guidelines for certain applications including cancer diagnosis. The purpose of this review isn't to give a broad overview of all current liquid biopsy as biomarkers, weight them and promise a brighter future in cancer prevention, but rather to take a deeper look on two of those who do qualify to be called liquid biopsies now or then. These two are probably of greatest interest conceptually and methodically, and likely have the highest chances to be in clinical use soon, with a portfolio extension over their original conceptual usage. We aim to dig deeper beyond cancer diagnosis or cancer screening. Actually, we aim to review in depth extracellular vesicles (EVs) and compare with circulating tumour cells (CTCs). The latter methodology is partially FDA approved and in clinical use. We will lay out similarities as taking advantage of surface antigens on EVs and CTCs in case of characterization and quantification. But drawing readers' attention to downstream application based on capture/isolation methodology and simply on their overall nature, here apparently being living material eventually recoverable as CTCs are vs. dead material with transient effects on recipient cell as in case of EVs. All this we try to bring in perspective, compare and conclude towards which future direction we are aiming for, or should aim for. Do we announce a winner between CTCs vs EVs? No, but we provide good reasons to intensify research on them.

Emerging role of exosomes in cancer progression and tumor microenvironment remodeling

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

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.

Novel Implications of MicroRNAs, Long Non-coding RNAs and Circular RNAs in Drug Resistance of Esophageal Cancer

Esophageal cancer is the eighth most common malignancy and the sixth leading cause of cancer-related deaths worldwide. Chemotherapy based on platinum drugs, 5-fluorouracil, adriamycin, paclitaxel, gemcitabine, and vinorelbine, as well as targeted treatment and immunotherapy with immune checkpoint inhibitors improved the prognosis in a portion of patients with advanced esophageal cancer. Unfortunately, a number of esophageal cancer patients develop drug resistance, resulting in poor outcomes. Multiple mechanisms contributing to drug resistance of esophageal cancer have been reported. Notably, non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), have been identified to play crucial roles in modulating esophageal cancer drug resistance. In the present review, we highlight the underlying mechanisms how miRNAs, lncRNAs, and circRNAs impact the drug resistance of esophageal cancer. Several miRNAs, lncRNAs, and circRNAs may have potential clinical implications as novel biomarkers and therapeutic targets for esophageal cancer.

Gastrointestinal cancer drug resistance: the role of exosomal miRNAs

Resistance of gastrointestinal (GI) cancer cells to therapeutic agents are one of the major problems in treating this type of cancer. Although the exact mechanism of drug resistance has not yet been fully elucidated, various factors have been identified as contributing factors involved in this process. Several studies have revealed the role of exosomes, especially exosomal microRNAs (miRNAs), in GI tumorigenesis, invasion, angiogenesis, and drug resistance. Exosomes, a type of small extracellular vesicles (EVs), are originated from endosomes and are released into the extracellular environment and body fluids by different cell types. Exosomes mediate cell-cell communication by transferring different cargos, including miRNAs, between parent and recipient cells. Therefore, identifying these exosomal miRNAs and their functions in GI cancers might provide new clues to further explore the secret of this process and thus help in drug-resistance management. This review article will discuss the roles of exosomal miRNAs and their mechanisms of action in drug resistance of different types of GI cancer cells (e.g., stomach, esophagus, liver, pancreas, and colon) to therapeutic agents.

Small Extracellular Vesicles in the Development, Diagnosis, and Possible Therapeutic Application of Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) persists among the most lethal and broad-spreading malignancies in China. The exosome is a kind of extracellular vesicle (EV) from about 30 to 200 nm in diameter, contributing to the transfer of specific functional molecules, such as metabolites, proteins, lipids, and nucleic acids. The paramount role of exosomes in the formation and development of ESCC, which relies on promoting intercellular communication in the tumor microenvironment (TME), is manifested with immense amounts. Tumor-derived exosomes (TDEs) participate in most hallmarks of ESCC, including tumorigenesis, invasion, angiogenesis, immunologic escape, metastasis, radioresistance, and chemoresistance. Published reports have delineated that exosome-encapsulated cargos like miRNAs may have utility in the diagnosis, as prognostic biomarkers, and in the treatment of ESCC. This review summarizes the function of exosomes in the neoplasia, progression, and metastasis of ESCC, which improves our understanding of the etiology and pathogenesis of ESCC, and presents a promising target for early diagnostics in ESCC. However, recent studies of exosomes in the treatment of ESCC are sparse. Thus, we introduce the advances in exosome-based methods and indicate the possible applications for ESCC therapy in the future.

The Significance of Exosomes in Pathogenesis, Diagnosis, and Treatment of Esophageal Cancer

Esophageal cancer is one of the most common malignancy in China with high mortality. Understanding pathogenesis and identifying early diagnosis biomarkers can significantly improve the prognosis of patients with esophageal cancer. Exosomes are small vesicular structures containing a variety of components (including DNA, RNA, and proteins) mediating cell-to-cell material exchange and signal communication. Growing evidences have shown that exosomes and its components are involved in growth, metastasis and angiogenesis in cancer, and could also be used as diagnostic and prognostic markers. In this review, we summarized recent progress to elucidate the significance of exosomes in the esophageal cancer progression, microenvironment remodeling, therapeutic resistance, and immunosuppression. We also discuss the utility of exosomes as diagnostic and prognostic biomarkers and therapeutic tool in esophageal cancer.

miR-4486 enhances cisplatin sensitivity of gastric cancer cells by restraining the JAK3/STAT3 signalling pathway

Along with the occurrence of cisplatin resistance, treatment on gastric cancer (GC) becomes difficult. Therefore, researches on new therapeutic methods to revert cisplatin resistance are becoming increasingly urgent. qRT-PCR was used to quantify the expression of miR-4486, JAK3 in SGC-7901 or SGC-7901/DDP cell lines. WB was utilized to analyze the expression of JAK3, STAT3 and p-STAT3 in SGC-7901/DDP cell lines. CCK-8 assay was used to determine the IC₅₀ of cisplatin on both cell lines and cell viability of SGC-7901/DDP cell lines. The target relationship between miR-4486 and JAK3 was determined by luciferase assay. MiR-4486 expression on apoptosis of SGC-7901/DDP cell lines was determined by flow cytometry. qRT-PCR testified that miR-4486 decreased in SGC-7901/DDP cells, and the expression of miR-4486 mimic increased significantly compared with miR-4486 NC. By CCK-8 assay, the IC₅₀ of cisplatin on both cell lines were 9 μg/mL and 81.3 μg/mL, and overexpression of miR-4486 decreased the viability of SGC-7901/DDP cells. Compared with DDP group, the expression of miR-4486 accelerated SGC-7901/DDP cells apoptosis. Dual-luciferase assay suggested that JAK3 was the target gene of miR-4486. qRT-PCR and WB proved that miR-4486/JAK3 axis inhibit the activation of JAK3/STAT3 pathway, and JAK3 overexpression can partly reverse this. As shown by CCK-8 and flow cytometry, miR-4486 overexpression decreased viability and stimulated apoptosis of SGC-7901/DDP cells. However, JAK3 overexpression can also partly revert this. miR-4486 overexpression could decrease viability and improve apoptosis of SGC-7901/DDP cells to revert its cisplatin-resistance, and the mechanism may be related to JAK3/STAT3 signalling pathway.

The Role of Extracellular Vesicles in Mediating Resistance to Anticancer Therapies

Although advances in targeted therapies have driven great progress in cancer treatment and outcomes, drug resistance remains a major obstacle to improving patient survival. Several mechanisms are involved in developing resistance to both conventional chemotherapy and molecularly targeted therapies, including drug efflux, secondary mutations, compensatory genetic alterations occurring upstream or downstream of a drug target, oncogenic bypass, drug activation and inactivation, and DNA damage repair. Extracellular vesicles (EVs) are membrane-bound lipid bilayer vesicles that are involved in cell-cell communication and regulating biological processes. EVs derived from cancer cells play critical roles in tumor progression, metastasis, and drug resistance by delivering protein and genetic material to cells of the tumor microenvironment. Understanding the biochemical and genetic mechanisms underlying drug resistance will aid in the development of new therapeutic strategies. Herein, we review the role of EVs as mediators of drug resistance in the context of cancer.

Advances in Drug Resistance of Esophageal Cancer: From the Perspective of Tumor Microenvironment

Drug resistance represents the major obstacle to get the maximum therapeutic benefit for patients with esophageal cancer since numerous patients are inherently or adaptively resistant to therapeutic agents. Notably, increasing evidence has demonstrated that drug resistance is closely related to the crosstalk between tumor cells and the tumor microenvironment (TME). TME is a dynamic and ever-changing complex biological network whose diverse cellular and non-cellular components influence hallmarks and fates of tumor cells from the outside, and this is responsible for the development of resistance to conventional therapeutic agents to some extent. Indeed, the formation of drug resistance in esophageal cancer should be considered as a multifactorial process involving not only cancer cells themselves but cancer stem cells, tumor-associated stromal cells, hypoxia, soluble factors, extracellular vesicles, etc. Accordingly, combination therapy targeting tumor cells and tumor-favorable microenvironment represents a promising strategy to address drug resistance and get better therapeutic responses for patients with esophageal cancer. In this review, we mainly focus our discussion on molecular mechanisms that underlie the role of TME in drug resistance in esophageal cancer. We also discuss the opportunities and challenges for therapeutically targeting tumor-favorable microenvironment, such as membrane proteins, pivotal signaling pathways, and cytokines, to attenuate drug resistance in esophageal cancer.

New Insights into Therapy-Induced Progression of Cancer

The malignant tumor is a complex heterogeneous set of cells functioning in a no less heterogeneous microenvironment. Like any dynamic system, cancerous tumors evolve and undergo changes in response to external influences, including therapy. Initially, most tumors are susceptible to treatment. However, remaining cancer cells may rapidly reestablish the tumor after a temporary remission. These new populations of malignant cells usually have increased resistance not only to the first-line agent, but also to the second- and third-line drugs, leading to a significant decrease in patient survival. Multiple studies describe the mechanism of acquired therapy resistance. In past decades, it became clear that, in addition to the simple selection of pre-existing resistant clones, therapy induces a highly complicated and tightly regulated molecular response that allows tumors to adapt to current and even subsequent therapeutic interventions. This review summarizes mechanisms of acquired resistance, such as secondary genetic alterations, impaired function of drug transporters, and autophagy. Moreover, we describe less obvious molecular aspects of therapy resistance in cancers, including epithelial-to-mesenchymal transition, cell cycle alterations, and the role of intercellular communication. Understanding these molecular mechanisms will be beneficial in finding novel therapeutic approaches for cancer therapy.

EVs as Potential New Therapeutic Tool/Target in Gastrointestinal Cancer and HCC

For more than a decade, extracellular vesicles (EVs) have been in focus of science. Once thought to be an efficient way to eliminate undesirable cell content, EVs are now well-accepted as being an important alternative to cytokines and chemokines in cell-to-cell communication route. With their cargos, mainly consisting of functional proteins, lipids and nucleic acids, they can activate signalling cascades and thus change the phenotype of recipient cells at local and systemic levels. Their substantial role as modulators of various physiological and pathological processes is acknowledged. Importantly, more and more evidence arises that EVs play a pivotal role in many stages of carcinogenesis. Via EV-mediated communication, tumour cells can manipulate cells from host immune system or from the tumour microenvironment, and, ultimately, they promote tumour progression and modulate host immunity towards tumour's favour. Additionally, the role of EVs in modulating resistance to pharmacological and radiological therapy of many cancer types has become evident lately. Our understanding of EV biology and their role in cancer promotion and drug resistance has evolved considerably in recent years. In this review, we specifically discuss the current knowledge on the association between EVs and gastrointestinal (GI) and liver cancers, including their potential for diagnosis and treatment.