Exosomes carrying ALDOA and ALDH3A1 from irradiated lung cancer cells enhance migration and invasion of recipients by accelerating glycolysis

Enigmatic exosomal connection in lung cancer drug resistance

Lung cancer remains a significant global health concern with limited treatment options and poor prognosis, particularly in advanced stages. Small extracellular vesicles such as exosomes, secreted by cancer cells, play a pivotal role in mediating drug resistance in lung cancer. Exosomes have been found to facilitate intercellular communication by transferring various biomolecules between cancer cells and their microenvironment. Additionally, exosomes can transport signaling molecules promoting cancer cell survival and proliferation conferring resistance to chemotherapy. Moreover, exosomes can modulate the tumor microenvironment by inducing phenotypic changes hindering drug response. Understanding the role of exosomes in mediating drug resistance in lung cancer is crucial for developing novel therapeutic strategies and biomarkers to overcome treatment limitations. In this review, we summarize the current knowledge on conventional and emerging drug resistance mechanisms and the involvement of exosomes as well as exosome-mediated factors mediating drug resistance in lung cancer.

Prognosis significance and potential association between ALDOA and AKT expression in colorectal cancer

Colorectal cancer (CRC) is one of the most common malignant tumors of the digestive tract and a leading cause of cancer-related death worldwide. Since many CRC patients are diagnosed already in the advanced stage, and traditional chemoradiotherapy is prone to drug resistance, it is important to find new therapeutic targets. In this study, the expression levels of ALDOA and p-AKT were detected in cancer tissues and paired normal tissues, and it was found that they were significantly increased in CRC tissues, and their high expression indicated poor prognosis. Moreover, a positive correlation between the expression of ALDOA and p-AKT was found in CRC tissues and paired normal tissues. In addition, the Kaplan-Meier analysis revealed that the group with both negative of ALDOA/p-AKT expression had longer five-year survival rates compared with the other group. Besides, the group with both high expression of ALDOA/p-AKT had a worse prognosis compared with the other group. Based on the expression of ALDOA and p-AKT in tumor tissues, we can effectively distinguish tumor tissues from normal tissues through cluster analysis. Furthermore, we constructed nomograms to predict 3-year and 5-year overall survival, showing that the expression of ALDOA/p-AKT plays a crucial role in predicting the prognosis of CRC patients. Therefore, ALDOA/p-AKT may act as a crucial role in CRC, which may provide new horizons for targeted therapies for CRC.

Small extracellular vesicles-mediated cellular interactions between tumor cells and tumor-associated macrophages: Implication for immunotherapy

The tumor microenvironment consists of cancer cells and various stromal cells, including macrophages, which exhibit diverse phenotypes with either pro-inflammatory (M1) or anti-inflammatory (M2) effects. The interaction between cancer cells and macrophages plays a crucial role in tumor progression. Small extracellular vesicles (sEVs), which facilitate intercellular communication, are known to play a vital role in this process. This review provides a comprehensive summary of how sEVs derived from cancer cells, containing miRNAs, lncRNAs, proteins, and lipids, can influence macrophage polarization. Additionally, we discuss the impact of macrophage-secreted sEVs on tumor malignant transformation, including effects on proliferation, metastasis, angiogenesis, chemoresistance, and immune escape. Furthermore, we address the therapeutic advancements and current challenges associated with macrophage-associated sEVs, along with potential solutions.

The multifaceted role of extracellular ATP in sperm function: From spermatogenesis to fertilization

Extracellular adenosine 5'-triphosphate (ATP) is a vital signaling molecule involved in various physiological processes within the body. In recent years, studies have revealed its significant role in male reproduction, particularly in sperm function. This review explores the multifaceted role of extracellular ATP in sperm function, from spermatogenesis to fertilization. We discuss the impact of extracellular ATP on spermatogenesis, sperm maturation and sperm-egg fusion, highlighting the complex regulatory mechanisms and potential clinical applications in the context of male infertility. By examining the latest research, we emphasize the crucial role of extracellular ATP in sperm function and propose future research directions to further.

Exploring salivary exosomes as early predictors of oral cancer in susceptible tobacco consumers: noninvasive diagnostic and prognostic applications

BACKGROUND

Salivary exosome analysis provides a noninvasive and comprehensive approach with potential applications in oral cancer diagnosis and prognosis. The early detection of oral cancer has remained a critical concern in enhancing the quality of life, especially for individuals who consume tobacco and are at greater risk of developing the disease. The current study investigates the potential of salivary exosomes in screening smokers for early signs and transformations of oral cancer.

METHODS

Morphological characterization of salivary exosomes among three study groups (non-smokers as control, smokers as high-risk tobacco consumers, and Oral cancer) (n = 120) was carried out through dynamic light scattering, and nanoparticle tracking analysis. For molecular characterization, EXOCET and Fourier transform infrared spectroscopy methods were utilized. The expression of the exosomal surface protein CD63 was evaluated using Western blotting.

RESULTS

Salivary exosomes exhibit noticeable differences in size between control group and tobacco consumers. The differentiation extended beyond exosome size and included variations in concentration and bio-molecular composition, as determined by FTIR screening. Tobacco consumers and oral cancer groups showed significantly larger and more concentrated exosomes compared to the healthy group.

CONCLUSION

Our study provides strong evidence that the properties of salivary exosomes can serve as reliable noninvasive biomarkers for distinguishing tobacco consumers from non-smokers and oral cancer patients. Our results underscore the potential of exosome-based diagnostics in early oral cancer detection for high-risk individuals. The larger size and higher concentration of exosomes in tobacco consumers indicate early changes in cell secretions associated with the transformation from healthy to abnormal cells.

The role of Extracellular Vesicles in glycolytic and lipid metabolic reprogramming of cancer cells: Consequences for drug resistance

In order to adapt to a higher proliferative rate and an increased demand for energy sources, cancer cells rewire their metabolic pathways, a process currently recognized as a hallmark of cancer. Even though the metabolism of glucose is perhaps the most discussed metabolic shift in cancer, lipid metabolic alterations have been recently recognized as relevant players in the growth and proliferation of cancer cells. Importantly, some of these metabolic alterations are reported to induce a drug resistant phenotype in cancer cells. The acquisition of drug resistance traits severely hinders cancer treatment, being currently considered one of the major challenges of the oncological field. Evidence suggests that Extracellular Vesicles (EVs), which play a crucial role in intercellular communication, may act as facilitators of tumour progression, survival and drug resistance by modulating several aspects involved in the metabolism of cancer cells. This review aims to gather and discuss relevant data regarding metabolic reprograming in cancer, particularly involving the glycolytic and lipid alterations, focusing on its influence on drug resistance and highlighting the relevance of EVs as intercellular mediators of this process.

The therapeutic potential of exosomes in lung cancer

BACKGROUND

Lung cancer (LC) is one of the most common malignancies globally. Besides early detection and surgical resection, there is currently no effective curative treatment for metastatic advanced LC. Exosomes are endogenous nano-extracellular vesicles produced by somatic cells that play an important role in the development and maintenance of normal physiology. Exosomes can carry proteins, peptides, lipids, nucleic acids, and various small molecules for intra- and intercellular material transport or signal transduction. LC cells can maintain their survival, proliferation, migration, invasion, and metastasis, by producing or interacting with exosomes. Basic and clinical data also show that exosomes can be used to suppress LC cell proliferation and viability, induce apoptosis, and enhance treatment sensitivity. Due to the high stability and target specificity, good biocompatibility, and low immunogenicity of exosomes, they show promise as vehicles of LC therapy.

CONCLUSION

We have written this comprehensive review to communicate the LC treatment potential of exosomes and their underlying molecular mechanisms. We found that overall, LC cells can exchange substances or crosstalk with themselves or various other cells in the surrounding TME or distant organs through exosomes. Through this, they can modulate their survival, proliferation, stemness, migration, and invasion, EMT, metastasis, and apoptotic resistance.

Hypoxia-induced ALDH3A1 promotes the proliferation of non-small-cell lung cancer by regulating energy metabolism reprogramming

Aldehyde dehydrogenase 3A1 (ALDH3A1) is an NAD+-dependent enzyme that is closely related to tumor development. However, its role in non-small-cell lung cancer (NSCLC) has not been elucidated. This study aimed to clarify the mechanism of ALDH3A1 and identify potential therapeutic targets for NSCLC. Here, for the first time, we found that ALDH3A1 expression could be induced by a hypoxic environment in NSCLC. ALDH3A1 was highly expressed in NSCLC tissue, especially in some late-stage patients, and was associated with a poor prognosis. In mechanistic terms, ALDH3A1 enhances glycolysis and suppresses oxidative phosphorylation (OXPHOS) to promote cell proliferation by activating the HIF-1α/LDHA pathway in NSCLC. In addition, the results showed that ALDH3A1 was a target of β-elemene. ALDH3A1 can be downregulated by β-elemene to inhibit glycolysis and enhance OXPHOS, thus suppressing NSCLC proliferation in vitro and in vivo. In conclusion, hypoxia-induced ALDH3A1 is related to the energy metabolic status of tumors and the efficacy of β-elemene, providing a new theoretical basis for better clinical applications in NSCLC.

Emerging diversity in extracellular vesicles and their roles in cancer

Extracellular vesicles have undergone a paradigm shift from being considered as 'waste bags' to being central mediators of cell-to-cell signaling in homeostasis and several pathologies including cancer. Their ubiquitous nature, ability to cross biological barriers, and dynamic regulation during changes in pathophysiological state of an individual not only makes them excellent biomarkers but also critical mediators of cancer progression. This review highlights the heterogeneity in extracellular vesicles by discussing emerging subtypes, such as migrasomes, mitovesicles, and exophers, as well as evolving components of extracellular vesicles such as the surface protein corona. The review provides a comprehensive overview of our current understanding of the role of extracellular vesicles during different stages of cancer including cancer initiation, metabolic reprogramming, extracellular matrix remodeling, angiogenesis, immune modulation, therapy resistance, and metastasis, and highlights gaps in our current knowledge of extracellular vesicle biology in cancer. We further provide a perspective on extracellular vesicle-based cancer therapeutics and challenges associated with bringing them to the clinic.

Small extracellular vesicle-mediated metabolic reprogramming: from tumors to pre-metastatic niche formation

Metastasis, the spread of a tumor or cancer from the primary site of the body to a secondary site, is a multi-step process in cancer progression, accounting for various obstacles in cancer treatment and most cancer-related deaths. Metabolic reprogramming refers to adaptive metabolic changes that occur in cancer cells in the tumor microenvironment (TME) to enhance their survival ability and metastatic potential. Stromal cell metabolism also changes to stimulate tumor proliferation and metastasis. Metabolic adaptations of tumor and non-tumor cells exist not only in the TME but also in the pre-metastatic niche (PMN), a remote TME conducive for tumor metastasis. As a novel mediator in cell-to-cell communication, small extracellular vesicles (sEVs), which have a diameter of 30-150 nm, reprogram metabolism in stromal and cancer cells within the TME by transferring bioactive substances including proteins, mRNAs and miRNAs (microRNAs). sEVs can be delivered from the primary TME to PMN, affecting PMN formation in stroma rewriting, angiogenesis, immunological suppression and matrix cell metabolism by mediating metabolic reprogramming. Herein, we review the functions of sEVs in cancer cells and the TME, how sEVs facilitate PMN establishment to trigger metastasis via metabolic reprogramming, and the prospective applications of sEVs in tumor diagnosis and treatment. Video Abstract.

Adipose Tissue-Derived Extracellular Vesicles Contribute to Phenotypic Plasticity of Prostate Cancer Cells

Metastatic prostate cancer is one of the leading causes of male cancer deaths in the western world. Obesity significantly increases the risk of metastatic disease and is associated with a higher mortality rate. Systemic chronic inflammation can result from a variety of conditions, including obesity, where adipose tissue inflammation is a major contributor. Adipose tissue endothelial cells (EC) exposed to inflammation become dysfunctional and produce a secretome, including extracellular vesicles (EV), that can impact function of cells in distant tissues, including malignant cells. The aim of this study was to explore the potential role of EVs produced by obese adipose tissue and the ECs exposed to pro-inflammatory cytokines on prostate cancer phenotypic plasticity in vitro. We demonstrate that PC3ML metastatic prostate cancer cells exposed to EVs from adipose tissue ECs and to EVs from human adipose tissue total explants display reduced invasion and increased proliferation. The latter functional changes could be attributed to the EV miRNA cargo. We also show that the functional shift is TWIST1-dependent and is consistent with mesenchymal-to-epithelial transition, which is key to establishment of secondary tumor growth. Understanding the complex effects of EVs on prostate cancer cells of different phenotypes is key before their intended use as therapeutics.

A prognostic signature model for unveiling tumor progression in lung adenocarcinoma

A more accurate prognosis is important for clinical treatment of lung adenocarcinoma. However, due to the limitation of sample and technical bias, most prognostic signatures lacked reproducibility, and few were applied to clinical practice. In addition, understanding the molecular driving mechanism is indispensable for developing more promising therapies for lung adenocarcinoma. Here, we built an unbiased prognostic significance model to perform an integrative analysis, including differentially expressed genes and clinical data with lung adenocarcinoma patients from TCGA. Multivariable Cox proportional hazards model with the Lasso penalty and 10-fold cross-validate were used to identify the best gene signature. We generated a 17-gene signature for prognostic risk prediction based on the overall survival time of lung adenocarcinoma patients. To further test the model's predictive ability, we have applied an independent GEO database to verify the predictive ability of prognostic signature. The model can more objectively describe several biological processes related to tumors and reveal important molecular mechanisms in tumor development by GO and KEGG analysis. Furthermore, differential expression analysis by GSEA revealed that tumor microenvironments such as ER stress, exosome, and immune microenvironment were enriched. Using single-cell RNA sequence technology, we found that risk score was positively correlated with lung adenocarcinoma marker genes and copy number variation but negatively correlated with lung epithelial marker genes. High-risk cell populations with the model had stronger cancer stemness and tumor-related pathway activation. As we expected, the risk score was in accordance with the malignancy of each cluster from tumor progression. In conclusion, the risking model established in this study is more reliable than others in evaluating the prognosis of LUAD patients.

Extracellular vesicles and particles impact the systemic landscape of cancer

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

Bioinformatics analysis of the role of aldolase A in tumor prognosis and immunity

Aldolase A (ALDOA) is an enzyme that plays an important role in glycolysis and gluconeogenesis, which is closely related to tumor metabolism. In this study, the overall roles of ALDOA in pan-cancer have been investigated from several aspects using databases and online analysis tools. Using the ONCOMINE database, the expression of ALDOA in various cancers was analyzed. The prognostic role of ALDOA was explored by PrognoScan, GEPIA, and Kaplan–Meier Plotter. The immune-related role of ALDOA and its downstream substrates was decided by TIMER, cBioPortal and String. Our data indicate that ALDOA expression level in lung adenocarcinoma, liver hepatocellular carcinoma, head and neck squamous cell carcinoma is higher than that in normal tissues. Increased expression of ALDOA often indicates a poor prognosis for patients. The correlation between ALDOA and immune infiltration among different tumors is very different. We also investigate the relationship between ALDOA and its upstream/downstream proteins. Our results showed that ALDOA could be used as a biomarker for the tumor prognosis, and could be correlated with the infiltrating levels of macrophages, CD4+ T cells and CD8+ T cells.

Role of the Pro-Inflammatory Tumor Microenvironment in Extracellular Vesicle-Mediated Transfer of Therapy Resistance

Advances in our understanding of cancer biology have contributed to generating different treatments to improve the survival of cancer patients. However, although initially most of the therapies are effective, relapse and recurrence occur in a large percentage of these cases after the treatment, and patients then die subsequently due to the development of therapy resistance in residual cancer cells. A large spectrum of molecular and cellular mechanisms have been identified as important contributors to therapy resistance, and more recently the inflammatory tumor microenvironment (TME) has been ascribed an important function as a source of signals generated by the TME that modulate cellular processes in the tumor cells, such as to favor the acquisition of therapy resistance. Currently, extracellular vesicles (EVs) are considered one of the main means of communication between cells of the TME and have emerged as crucial modulators of cancer drug resistance. Important in this context is, also, the inflammatory TME that can be caused by several conditions, including hypoxia and following chemotherapy, among others. These inflammatory conditions modulate the release and composition of EVs within the TME, which in turn alters the responses of the tumor cells to cancer therapies. The TME has been ascribed an important function as a source of signals that modulate cellular processes in the tumor cells, such as to favor the acquisition of therapy resistance. Although generally the main cellular components considered to participate in generating a pro-inflammatory TME are from the immune system (for instance, macrophages), more recently other types of cells of the TME have also been shown to participate in this process, including adipocytes, cancer-associated fibroblasts, endothelial cells, cancer stem cells, as well as the tumor cells. In this review, we focus on summarizing available information relating to the impact of a pro-inflammatory tumor microenvironment on the release of EVs derived from both cancer cells and cells of the TME, and how these EVs contribute to resistance to cancer therapies.

The Role of Extracellular Vesicles in Metabolic Reprogramming of the Tumor Microenvironment

The tumor microenvironment (TME) includes a network of cancerous and non-cancerous cells, together with associated blood vessels, the extracellular matrix, and signaling molecules. The TME contributes to cancer progression during various phases of tumorigenesis, and interactions that take place within the TME have become targets of focus in cancer therapy development. Extracellular vesicles (EVs) are known to be conveyors of genetic material, proteins, and lipids within the TME. One of the hallmarks of cancer is its ability to reprogram metabolism to sustain cell growth and proliferation in a stringent environment. In this review, we provide an overview of TME EV involvement in the metabolic reprogramming of cancer and stromal cells, which favors cancer progression by enhancing angiogenesis, proliferation, metastasis, treatment resistance, and immunoevasion. Targeting the communication mechanisms and systems utilized by TME-EVs is opening a new frontier in cancer therapy.

Energy Sources for Exosome Communication in a Cancer Microenvironment

Simple Summary

Exosomal communication in the tumor microenvironment plays a crucial role in cancer development, progression, and metastasis, and is achieved by either short-distance communication with neighboring cells or long-distance communication with distant organs. Nevertheless, how exosomes gain energy to establish such communication and the different sources of energy are unclear. Recently, a handful of studies have demonstrated the presence of mitochondria, adenosine triphosphate, and glycolytic enzymes, which may serve as potential energy sources for exosomes. This review clarifies how exosomes maintain their structural integrity and stability during their intracellular communication, and reviews evidence of their energy source.

Abstract

Exosomes are crucial extracellular vesicles (EVs) with a diameter of approximately 30–200 nm. They are released by most cell types in their extracellular milieu and carry various biomolecules, including proteins and nucleic acids. Exosomes are increasingly studied in various diseases, including cancer, due to their role in local and distant cell–cell communication in which they can promote tumor growth, cancer progression, and metastasis. Interestingly, a tremendous number of exosomes is released by malignant cancer cells, and these are then taken up by autologous and heterologous recipient stromal cells such as immune cells, cancer stem cells, and endothelial cells. All these events demand an enormous amount of energy and require that exosomes remain stable while having the capacity to reach distant sites and cross physical barriers. Nevertheless, there is a dearth of research pertaining to the energy sources of exosomes, and questions remain about how they maintain their motility in the tumor microenvironment (TME) and beyond. Moreover, exosomes can produce adenosine triphosphate (ATP), an important energy molecule required by all cells, and mitochondria have been identified as one of the exosomal cargoes. These findings strengthen the prospect of exosomal communication via transfer of mitochondria and the bioenergetics of target recipient cells. In the TME, the accumulation of ATP and lactate may facilitate the entry of exosomes into cancer cells to promote metastasis, as well as help to target cancer cells at the tumor site. This review highlights how exosomes obtain sufficient energy to thrive in the TME and communicate with distant physiological destinations.

Tumor-derived exosomes: Key players in non-small cell lung cancer metastasis and their implication for targeted therapy

Exosomes represent extracellular vesicles of endocytic origin ranging from 30 to 100 nm that are released by most of eukaryotic cells and can be found in body fluids. These vesicles in carrying DNA, RNA, microRNA (miRNA), Long noncoding RNA, proteins, and lipids serve as intercellular communicators. Due to their role in crosstalk between tumor cells and mesenchymal stroma cells, they are vital for tumor growth, progression, and anticancer drug resistance. Lung cancer is a global leading cause of cancer-related deaths with 5-year survival rates of about 7% in patients with distant metastasis. Although the implementation of targeted therapy has improved the clinical outcome of nonsmall cell lung cancer, drug resistance remains a major obstacle. Lung tumor-derived exosomes (TDEs) conveying molecular information from tumor cells to their neighbor cells or cells at distant sites of the body activate the tumor microenvironment (TME) and facilitate tumor metastasis. Exosomal miRNAs are also considered as noninvasive biomarkers for early diagnosis of lung cancer. This review summarizes the influence of lung TDEs on the TME and metastasis. Their involvement in targeted therapy resistance and potential clinical applications are discussed. Additionally, challenges encountered in the development of exosome-based therapeutic strategies are addressed.

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.

Extracellular vesicles: General features and usefulness in diagnosis and therapeutic management of colorectal cancer

In the world, among all type of cancers, colorectal cancer (CRC) is the third most commonly diagnosed in males and the second in females. In most of cases, (RP1) patients’ prognosis limitation with malignant tumors can be attributed to delayed diagnosis of the disease. Identification of patients with early-stage disease leads to more effective therapeutic interventions. Therefore, new screening methods and further innovative treatment approaches are mandatory as they may lead to an increase in progression-free and overall survival rates. For the last decade, the interest in extracellular vesicles (EVs) research has exponentially increased as EVs generation appears to be a universal feature of every cell that is strongly involved in many mechanisms of cell-cell communication either in physiological or pathological situations. EVs can cargo biomolecules, such as lipids, proteins, nucleic acids and generate transmission signal through the intercellular transfer of their content. By this mechanism, tumor cells can recruit and modify the adjacent and systemic microenvironment to support further invasion and dissemination. This review intends to cover the most recent literature on the role of EVs production in colorectal normal and cancer tissues. Specific attention is paid to the use of EVs for early CRC diagnosis, follow-up, and prognosis as EVs have come into the spotlight of research as a high potential source of ‘liquid biopsies’. The use of EVs as new targets or nanovectors as drug delivery systems for CRC therapy is also summarized.

Emerging role of tumor-derived extracellular vesicles in T cell suppression and dysfunction in the tumor microenvironment

Immunotherapeutic drugs including immune checkpoint blockade antibodies have been approved to treat patients in many types of cancers. However, some patients have little or no reaction to the immunotherapy drugs. The mechanisms underlying resistance to tumor immunotherapy are complicated and involve multiple aspects, including tumor-intrinsic factors, formation of immunosuppressive microenvironment, and alteration of tumor and stromal cell metabolism in the tumor microenvironment. T cell is critical and participates in every aspect of antitumor response, and T cell dysfunction is a severe barrier for effective immunotherapy for cancer. Emerging evidence indicates that extracellular vesicles (EVs) secreted by tumor is one of the major factors that can induce T cell dysfunction. Tumor-derived EVs are widely distributed in serum, tissues, and the tumor microenvironment of patients with cancer, which serve as important communication vehicles for cancer cells. In addition, tumor-derived EVs can carry a variety of immune suppressive signals driving T cell dysfunction for tumor immunity. In this review, we explore the potential mechanisms employed by tumor-derived EVs to control T cell development and effector function within the tumor microenvironment. Especially, we focus on current understanding of how tumor-derived EVs molecularly and metabolically reprogram T cell fates and functions for tumor immunity. In addition, we discuss potential translations of targeting tumor-derived EVs to reconstitute suppressive tumor microenvironment or to develop antigen-based vaccines and drug delivery systems for cancer immunotherapy.

Tumor-associated exosomes promote lung cancer metastasis through multiple mechanisms

As an important medium of intercellular communication, exosomes play an important role in information transmission between tumor cells and their microenvironment. Tumor metastasis is a serious influencing factor for poor treatment effect and shortened survival. Lung cancer is a major malignant tumor that seriously threatens human health. The study of the underlying mechanisms of exosomes in tumor genesis and development may provide new ideas for early and effective diagnosis and treatment of lung cancer metastasis. Many studies have shown that tumor-derived exosomes promote lung cancer development through a number of processes. By promoting epithelial-mesenchymal transition of tumor cells, they induce angiogenesis, establishment of the pretransfer microenvironment, and immune escape. This understanding enables researchers to better understand the mechanism of lung cancer metastasis and explore new treatments for clinical application. In this article, we systematically review current research progress of tumor-derived exosomes in metastasis of lung cancer. Although positive progress has been made toward understanding the mechanism of exosomes in lung cancer metastasis, systematic basic research and clinical translational research remains lacking and are needed to translate our scientific understanding toward applications in the clinical diagnosis and treatment of lung cancer metastasis in the near future.

Nrf2 Depletion Sensitizes Pancreatic Cancer Cells to Gemcitabine via Aldehyde Dehydrogenase 3a1 Repression

As the central regulator of the oxidative stress response, nuclear factor erythroid 2-related factor 2 (Nrf2) is attracting great interest as a therapeutic target for various cancers, and the possible clinical applications of novel Nrf2 inhibitors have been explored in Nrf2-activated cancers. In the present study, we specifically investigated halofuginone, which is derived from a natural plant alkaloid. We found that halofuginone administration decreased the number of pancreatic intraepithelial neoplasias in pancreas-specific Kras and p53 mutant (KPC) mice. In Nrf2-activated pancreatic cancer cell lines established from KPC mice, halofuginone rapidly depleted Nrf2 in Nrf2-activated cancer cells. Both in vitro and in vivo, it sensitized Nrf2-activated pancreatic cancer cells to gemcitabine, which is the first-line chemotherapy in clinical practice. In our mechanistic study, we found that halofuginone downregulated ALDH3A1 in mouse pancreatic cancer cells. The Nrf2 inducer diethyl maleate upregulated ALDH3A1, and knockdown of Aldh3a1 sensitized Nrf2-activated cancer cells to gemcitabine, strongly suggesting that ALDH3A1 is regulated by Nrf2 and that it contributes to gemcitabine resistance. The current study demonstrated the therapeutic benefits of halofuginone in Nrf2-activated pancreatic cancers. Significance Statement We identified Nrf2 and its downstream target ALDH3A1 as novel therapeutic targets in pancreatic cancer. They negatively impact the conventional chemotherapeutic agent, gemcitabine efficacy. We confirmed that Nrf2 plays a pivotal role in the induction of ALDH3A1.

PRPS2 Enhances Resistance to Cisplatin via Facilitating Exosomes-mediated Macrophage M2 Polarization in Non-small Cell Lung Cancer

Background: Phosphoribosyl pyrophosphate synthetases 2 (PRPS2) is reported as an oncogene in various cancers. However, the role of PRPS2 in cisplatin (DDP) resistance of non-small cell lung cancer (NSCLC) remains unclear. The present study aimed to explore the effect of PRPS2 in DDP resistance of NSCLC.Methods: mRNA expression levels of genes were detected by RT-PCR. Enzyme-linked immunosorbent assay (ELISA) and Western blot were used to detect protein expression levels. Cell viability was determined by the MTT assay and colony formation assay. Cell apoptosis was detected using nucleosome ELISA assay and caspase-3 activity assay. PRPS2 silencing was achieved using siRNA transfection. Exosomes of cultured cells were isolated through ultracentrifugation.Results: Elevated PRPS2 was correlated with DDP resistance and poor prognosis in NSCLC patients. PRPS2 silencing enhanced sensitivity of DDP-resistant cells to DDP treatment. NSCLC cell-derived exosome induced M2 macrophage polarization. PRPS2 was enriched in the exosomes of NSCLC cells. Exosomal PRPS2 mediated M2 macrophage polarization to promote DDP resistance of NSCLC cells.Conclusions: In conclusion, PRPS2 potentiates resistance to DDP by promoting exosome-mediated macrophage M2 polarization in NSCLC.

ALDH3A1 driving tumor metastasis is mediated by p53/BAG1 in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a lethal malignancy with metastasis, a major tumor feature that predominantly correlated with progression, but the molecules that mediated tumor metastasis remain elusive. To declare the critical regulatory genes, RNA sequencing data in LUAD patients was acquired from The Cancer Genome Atlas (TCGA) and found that ALDH3A1 was distinctly highly expressed in LUAD patients with metastasis (M1) compared with those without metastasis (M0), linked to the property of cancer stem cell and epithelial-mesenchymal transition (EMT). Besides, high ALDH3A1 expression predicted a poor prognosis. Knockdown of ALDH3A1 showed decreased proliferation, migration, and invasion in A549 cell line. Furthermore, BAG1 was regulated by ALDH3A1 through p53, enhanced cell proliferation, and predicted clinical prognosis. Our findings collectively uncovered a novel mechanism that orchestrates tumor cells' metastasis, and decreasing ALDH3A1 represented a potential therapeutic target for reprogramming metastasis.

Nannocystin Ax, a natural elongation factor 1α inhibitor from Nannocystis sp., suppresses epithelial-mesenchymal transition, adhesion and migration in lung cancer cells

Epithelial-mesenchymal transition (EMT), the epithelial cells transdifferentiation into the mesenchymal cells, has been involved in cancer metastasis. Nannocystin ax (NAN) is a cyclodepsipeptide initially isolated from Myxobacterial genus, Nannocystis sp. with anticancer activities. This study was designed to explore the effect of NAN on TGF-β1-induced EMT in lung cancer cells. The morphological alteration was observed with a microscope. Western blotting and immunofluorescence assays were used to detect the protein expression and the localization. The adhesion and migration were evaluated by adhesion assay and wound healing assay. The mRNA expression of TGF-β receptor type I (TβRI) was determined by real-time PCR. NAN significantly restrained TGF-β1-induced EMT morphological changes, the protein expression of E-cadherin, N-cadherin, and Vimentin, etc. TGF-β1 activated phosphorylation and nuclear translocation of Smad2/3 were inhibited by NAN. Furthermore, NAN suppressed adhesion and migration triggered by TGF-β1. In addition, NAN significantly down-regulated TβRI on the transcriptional level directly. In summary, these results showed that NAN restrained TGF-β1-induced epithelial-mesenchymal transition, migration, and adhesion in human lung cancer cells. The underlying mechanism involved the inhibition of Smad2/3 and the TβRI signaling pathway. This study reveals the new anticancer effect and mechanism of NAN.

Exosome-mediated communication between tumor cells and tumor-associated macrophages: implications for tumor microenvironment

Exosomes are extracellular vesicles released from numerous types of cells that are involved in multiple tumors development. Exosomes contribute to the modulation of tumor microenvironment (TME) through intercellular communication. As essential immune stromal cells in the TME, tumor-associated macrophages (TAMs) participate in tumor development by mediating angiogenesis, metastasis, chemoresistance, and immune escape. Due to communication with multiple cells in the TME, they exhibit plasticity and heterogeneity during the progress of polarization from monocytes to macrophages. Previous studies suggest that targeting TAMs is a promising therapeutic strategy; however, the detailed mechanism by which TAMs regulate tumor development still remains unclear. In this review, we provide an overview of the roles of exosomes as messengers in the communication between tumor cells and polarization of TAMs; we also describe the effects of their interaction on tumor development. Finally, we comprehensively discussed the potential application of exosomes as the promising tumor immunotherapy strategy.

Exosome-mediated metabolic reprogramming: the emerging role in tumor microenvironment remodeling and its influence on cancer progression

Metabolic reprogramming is reported to be one of the hallmarks of cancer, which is an adaptive mechanism by which fast-growing cancer cells adapt to their increasing energy demands. Recently, extracellular vesicles (EVs) known as exosomes have been recognized as crucial signaling mediators in regulating the tumor microenvironment (TME). Meanwhile, the TME is a highly heterogeneous ecosystem incorporating cancer cells, fibroblasts, adipocytes, endothelial cells, mesenchymal stem cells, and extracellular matrix. Accumulated evidence indicates that exosomes may transfer biologically functional molecules to the recipient cells, which facilitate cancer progression, angiogenesis, metastasis, drug resistance, and immunosuppression by reprogramming the metabolism of cancer cells and their surrounding stromal cells. In this review, we present the role of exosomes in the TME and the underlying mechanism of how exosomes exacerbate tumor development through metabolic reprogramming. In addition, we will also discuss the potential role of exosomes targeting metabolic process as biomarkers for tumor diagnosis and prognosis, and exosomes-mediated metabolic reprogramming as potential targets for cancer therapy. Furthermore, a better understanding of the link between exosomes and metabolic reprogramming, and their impact on cancer progression, would provide novel insights for cancer prevention and treatment in the future.

Advances of exosome isolation techniques in lung cancer

Lung cancer (LC) is among the leading causes of death all over the world and it is often diagnosed at advanced or metastatic stages. Exosomes, derived from circulating vesicles that are released from the multivesicular body, can be utilized for diagnosis and also the prognosis of LC at early stages. Exosomal proteins, RNAs, and DNAs can help to better discern the prognostic and diagnostic features of LC. To our knowledge, there are various reviews on LC and the contribution of exosomes, but none of them are about the exome techniques and also their efficiency in LC. To fill this gap, in this review, we summarize the recent investigations regarding isolation and also the characterization of exosomes of LC cells. Furthermore, we discuss the noncoding RNAs as biomarkers and their applications in the diagnosis and prognosis of LC. Finally, we compare the efficacy of exosome isolation methods to better fi + 6 + guring out feasible techniques.