Snail1-dependent cancer-associated fibroblasts induce epithelial-mesenchymal transition in lung cancer cells via exosomes

Circulating Extracellular Vesicles as Promising Biomarkers for Precession Diagnostics: A Perspective on Lung Cancer

Extracellular vesicles (EVs) have emerged as promising biomarkers in liquid biopsy, owing to their ubiquitous presence in bodily fluids and their ability to carry disease-related cargo. Recognizing their significance in disease diagnosis and treatment, substantial efforts have been dedicated to developing efficient methods for EV isolation, detection, and analysis. EVs, heterogeneous membrane-encapsulated vesicles secreted by all cells, contain bioactive substances capable of modulating recipient cell biology upon internalization, including proteins, lipids, DNA, and various RNAs. Their prevalence across bodily fluids has positioned them as pivotal mediators in physiological and pathological processes, notably in cancer, where they hold potential as straightforward tumor biomarkers. This review offers a comprehensive examination of advanced nanotechnology-based techniques for detecting lung cancer through EV analysis. It begins by providing a brief overview of exosomes and their role in lung cancer progression. Furthermore, this review explores the evolving landscape of EV isolation and cargo analysis, highlighting the importance of characterizing specific biomolecular signatures within EVs for improved diagnostic accuracy in lung cancer patients. Innovative strategies for enhancing the sensitivity and specificity of EV isolation and detection, including the integration of microfluidic platforms and multiplexed biosensing technologies are summarized. The discussion then extends to key challenges associated with EV-based liquid biopsies, such as the standardization of isolation and detection protocols and the establishment of robust analytical platforms for clinical translation. This review highlights the transformative impact of EV-based liquid biopsy in lung cancer diagnosis, heralding a new era of personalized medicine and improved patient care.

Harnessing the tumor microenvironment: targeted cancer therapies through modulation of epithelial-mesenchymal transition

The tumor microenvironment (TME) is integral to cancer progression, impacting metastasis and treatment response. It consists of diverse cell types, extracellular matrix components, and signaling molecules that interact to promote tumor growth and therapeutic resistance. Elucidating the intricate interactions between cancer cells and the TME is crucial in understanding cancer progression and therapeutic challenges. A critical process induced by TME signaling is the epithelial-mesenchymal transition (EMT), wherein epithelial cells acquire mesenchymal traits, which enhance their motility and invasiveness and promote metastasis and cancer progression. By targeting various components of the TME, novel investigational strategies aim to disrupt the TME's contribution to the EMT, thereby improving treatment efficacy, addressing therapeutic resistance, and offering a nuanced approach to cancer therapy. This review scrutinizes the key players in the TME and the TME's contribution to the EMT, emphasizing avenues to therapeutically disrupt the interactions between the various TME components. Moreover, the article discusses the TME's implications for resistance mechanisms and highlights the current therapeutic strategies toward TME modulation along with potential caveats.

Facilitation of Tumor Stroma-Targeted Therapy: Model Difficulty and Co-Culture Organoid Method

Background: Tumors, as intricate ecosystems, comprise oncocytes and the highly dynamic tumor stroma. Tumor stroma, representing the non-cancerous and non-cellular composition of the tumor microenvironment (TME), plays a crucial role in oncogenesis and progression, through its interactions with biological, chemical, and mechanical signals. This review aims to analyze the challenges of stroma mimicry models, and highlight advanced personalized co-culture approaches for recapitulating tumor stroma using patient-derived tumor organoids (PDTOs). Methods: This review synthesizes findings from recent studies on tumor stroma composition, stromal remodeling, and the spatiotemporal heterogeneities of the TME. It explores popular stroma-related models, co-culture systems integrating PDTOs with stromal elements, and advanced techniques to improve stroma mimicry. Results: Stroma remodeling, driven by stromal cells, highlights the dynamism and heterogeneity of the TME. PDTOs, derived from tumor tissues or cancer-specific stem cells, accurately mimic the tissue-specific and genetic features of primary tumors, making them valuable for drug screening. Co-culture models combining PDTOs with stromal elements effectively recreate the dynamic TME, showing promise in personalized anti-cancer therapy. Advanced co-culture techniques and flexible combinations enhance the precision of tumor-stroma recapitulation. Conclusions: PDTO-based co-culture systems offer a promising platform for stroma mimicry and personalized anti-cancer therapy development. This review underscores the importance of refining these models to advance precision medicine and improve therapeutic outcomes.

Cancer-Associated Fibroblast-Secreted Exosomes Regulate Macrophage Polarization in Pancreatic Cancer via the NOD1 Pathway

Metastasis is a major cause of poor prognosis of pancreatic cancer. Exosomes (Exos) regulate cancer progression by modulating macrophage polarization. This study aimed to investigate the effects of cancer-associated fibroblast (CAF)-released Exos on macrophage polarization in pancreatic cancer and the molecular mechanisms. THP-1 cells or xenografted tumor mice were treated with Exos from CAFs, and macrophage polarization was analyzed using quantitative real-time PCR (qPCR) and flow cytometry. THP-1 cells were cocultured with BXPC-3 cells, and metastasis was analyzed using Transwell assay and scratch test. Exosomal PTGS2 was detected using qPCR, and the NOD1 pathway was evaluated using western blot analysis. The results showed that Exos promoted M2-type polarization and inhibited M1-type polarization, and then facilitated pancreatic cancer cell migration, invasion, and epithelial-mesenchymal transition. PTGS2 expression was increased in Exo-treated macrophages, and its knockdown in CAFs facilitated M2 to M1 macrophage polarization. Moreover, Exos promoted the NOD1 pathway via PTGS2, and inhibition of NOD1 reversed the polarization caused by Exos. Additionally, NOD1 was required in M1/M2 polarization in vivo mediated by Exos. In conclusion, CAF-secreted Exos facilitated M2 macrophage polarization by carrying PTGS2 to activate the NOD1 pathway, thereby promoting pancreatic cancer metastasis, providing evidence that CAF-Exos accelerating pancreatic cancer progression.

Tumor necrosis factor receptor-associated factor 5 enhances perianal fistulizing Crohn's disease through epithelial-mesenchymal transition

Objective

Crohn's disease (CD) is a chronic inflammatory condition of the bowel that remarkably impairs a patient's quality of life and often has a poor prognosis. Perianal fistulizing CD (PFCD) is one of the most common parenteral symptoms of CD and a huge challenge for the management of this illness. This study aimed to elucidate the molecular mechanisms underlying PFCD and identify potential biomarkers to advance our understanding and management of this condition.

Material and Methods

Transcriptome sequencing was performed using the control and PFCD groups to investigate the mechanisms of PFCD development. The expression of tumor necrosis factor receptor-associated factor 5 (TRAF5), nuclear factor-kappa B (NF-κB), and interleukin 13 (IL-13) messenger ribonucleic acid (mRNAs) was detected by quantitative polymerase chain reaction (qPCR). Pathological morphology was observed using hematoxylin and eosin staining. The expression of TRAF5, Epithelial Cadherin (E-cadherin), Snail family transcriptional repressor 1 (SNAIL1), and vimentin protein was detected by immunohistochemistry. Following the knockdown of TRAF5 in human tumor-29 (HT-29) cells, the effects on cell proliferation and migration were assessed using the cell counting kit-8 and Transwell assays. The expression levels of crucial markers were analyzed by qPCR, Western blot, and immunohistochemistry.

Results

Transcriptomic sequencing revealed a significant upregulation of TRAF5 in the PFCD group, accompanied by elevated mRNA levels of NF-κB and IL-13 compared with those in the control group. In addition, the PFCD group exhibited increased expression of TRAF5, SNAIL, and vimentin and marked reduction in E-cadherin levels, indicating that PFCD may facilitate epithelial-mesenchymal transition (EMT). Knocking down TRAF5 in HT-29 cells reduced cell proliferation and migration; inhibited NF-κB and IL-13 mRNAs, SNAIL1, and vimentin levels; and promoted E-cadherin levels.

Conclusions

The development of PFCD was associated with EMT, and TRAF5 was a key gene of PFCD. Knocking down TRAF5 alleviated the EMT promotion of PFCD, indicating that TRAF5 drove the development of PFCD through EMT.

Heterogeneity and therapeutic implications of cancer-associated fibroblasts in lung cancer: Recent advances and future perspectives

Lung cancer is a leading cause of cancer-related mortality. The tumor microenvironment is a complex and heterogeneous cellular environment surrounding tumor cells, including cancer-associated fibroblasts (CAFs), blood vessels, immune cells, the extracellular matrix, and various cytokines secreted by cells. CAFs are highly heterogeneous and play crucial roles in lung cancer. This review highlights recent advances in the understanding of CAFs in lung cancer, focusing on their heterogeneity and functions in tumorigenesis, progression, angiogenesis, invasion, metastasis, therapy resistance, tumor immune suppression, and targeted therapy responses. Additionally, we explore the underlying mechanisms and the potential of CAFs as a target in the development of innovative therapies for lung cancer.

Comparative proteomic analysis between tumor tissues and intratumoral exosomes from lung adenocarcinoma patients identifies PAFAH1B3 as an exosomal protein key for initiating metastasis in lung adenocarcinoma

Mounting evidence strongly indicates that exosomes are pivotal in the advancement of cancer, yet the overarching profile of exosomal proteins and their contribution to lung adenocarcinoma (LUAD) progression remain underexplored. In our investigation, we isolated exosomes from treatment-naive LUAD (n = 20) and paired normal adjacent tissues (NATs), and conducted integrated proteomic on the acquired exosomes and source tissues to ascertain origin characteristics and potential therapeutic targets of the exosomal proteins in LUAD. The omics data revealed the overall landscape of exosomal proteins from tissues in LUAD, underscoring the profound linkage between exosomal proteins and tumor metastasis. Integrated analysis indicated a significant overlap in protein species, demonstrating high concordance between exosomal proteins and those in their originating tissues. However, only a small subset showed significant positive correlation in protein abundance between exosomes and their source tissues. Notably, we pinpointed five proteins (DDX18, DNAJA3, PAFAH1B3, BAG6, and CAD). Significantly, platelet activating factor acetylhydrolase 1b catalytic subunit 3 (PAFAH1B3), an essential serine hydrolase within cellular metabolic processes, stood out as the singular protein closely associated with disease-free survival (DFS) of patients. Cell invasion and migration assays further substantiated that PAFAH1B3 promoted metastasis of LUAD via the exosomal release pathway. Furthermore, analysis of public databases validated elevated PAFAH1B3 expression in LUAD and linked it to poor patient survival outcomes. Overall, our research positioned PAFAH1B3 as a promising candidate for prognostic marker and potential therapeutic target in lung cancer treatment.

Cell components of tumor microenvironment in lung adenocarcinoma: Promising targets for small-molecule compounds

ABSTRACT

Lung cancer is one of the most lethal tumors in the world with a 5-year overall survival rate of less than 20%, mainly including lung adenocarcinoma (LUAD). Tumor microenvironment (TME) has become a new research focus in the treatment of lung cancer. The TME is heterogeneous in composition and consists of cellular components, growth factors, proteases, and extracellular matrix. The various cellular components exert a different role in apoptosis, metastasis, or proliferation of lung cancer cells through different pathways, thus contributing to the treatment of adenocarcinoma and potentially facilitating novel therapeutic methods. This review summarizes the research progress on different cellular components with cell-cell interactions in the TME of LUAD, along with their corresponding drug candidates, suggesting that targeting cellular components in the TME of LUAD holds great promise for future theraputic development.

Pan-Cancer Screening and Validation of CALU's Role in EMT Regulation and Tumor Microenvironment in Triple-Negative Breast Cancer

Purpose

Cancer-associated fibroblasts (CAFs) significantly contribute to tumor progression and the development of resistance to therapies across a range of malignancies, notably breast cancer. This study aims to elucidate the specific role and prognostic relevance of CALU across multiple cancer types.

Patients and Methods

The association between CALU expression and prognosis, along with clinical characteristics in BRCA, HNSC, KIRP, LGG, and LIHC, was analyzed using data from the TCGA, GTEx, and GEO databases. Transcriptomic analysis of TCGA BRCA project data provided insights into the interaction between CALU and epithelial-mesenchymal transition (EMT) marker genes. Using TIMER and TISCH databases, the correlation between CALU expression and tumor microenvironment infiltration was assessed, alongside an evaluation of CALU expression across various cell types. Furthermore, CALU's influence on TNBC BRCA cell lines was explored, and its expression in tumor tissues was confirmed through immunohistochemical analysis of clinical samples.

Results

This study revealed a consistent upregulation of CALU across several tumor types, including BRCA, KIRP, LIHC, HNSC, and LGG, with elevated CALU expression being associated with unfavorable prognoses. CALU expression was particularly enhanced in clinical contexts linked to poor outcomes. Genomic analysis identified copy number alterations as the principal factor driving CALU overexpression. Additionally, a positive correlation between CALU expression and CAF infiltration was observed, along with its involvement in the EMT process in both CAFs and malignant cells. In vitro experiments demonstrated that CALU is highly expressed in TNBC-BRCA cell lines, and knockdown of CALU effectively reversed EMT progression and inhibited cellular migration. Immunohistochemical analysis of clinical samples corroborated the elevated expression of CALU in tumors, along with alterations in EMT markers.

Conclusion

This comprehensive pan-cancer analysis underscores CALU's critical role in modulating the tumor microenvironment and facilitating cell migration via the EMT pathway, identifying it as a potential therapeutic target.

3D cell culture models in research: applications to lung cancer pharmacology

Lung cancer remains one of the leading causes of cancer-related mortality worldwide, necessitating innovative research methodologies to improve treatment outcomes and develop novel strategies. The advent of three-dimensional (3D) cell cultures has marked a significant advancement in lung cancer research, offering a more physiologically relevant model compared to traditional two-dimensional (2D) cultures. This review elucidates the various types of 3D cell culture models currently used in lung cancer pharmacology, including spheroids, organoids and engineered tissue models, having pivotal roles in enhancing our understanding of lung cancer biology, facilitating drug development, and advancing precision medicine. 3D cell culture systems mimic the complex spatial architecture and microenvironment of lung tumours, providing critical insights into the cellular and molecular mechanisms of tumour progression, metastasis and drug responses. Spheroids, derived from commercialized cell lines, effectively model the tumour microenvironment (TME), including the formation of hypoxic and nutrient gradients, crucial for evaluating the penetration and efficacy of anti-cancer therapeutics. Organoids and tumouroids, derived from primary tissues, recapitulate the heterogeneity of lung cancers and are instrumental in personalized medicine approaches, supporting the simulation of in vivo pharmacological responses in a patient-specific context. Moreover, these models have been co-cultured with various cell types and biomimicry extracellular matrix (ECM) components to further recapitulate the heterotypic cell-cell and cell-ECM interactions present within the lung TME. 3D cultures have been significantly contributing to the identification of novel therapeutic targets and the understanding of resistance mechanisms against conventional therapies. Therefore, this review summarizes the latest findings in drug research involving lung cancer 3D models, together with the common laboratory-based assays used to study drug effects. Additionally, the integration of 3D cell cultures into lung cancer drug development workflows and precision medicine is discussed. This integration is pivotal in accelerating the translation of laboratory findings into clinical applications, thereby advancing the landscape of lung cancer treatment. By closely mirroring human lung tumours, these models not only enhance our understanding of the disease but also pave the way for the development of more effective and personalized therapeutic strategies.

Tumor-associated exosomes in cancer progression and therapeutic targets

Exosomes are small membrane vesicles that are released by cells into the extracellular environment. Tumor-associated exosomes (TAEs) are extracellular vesicles that play a significant role in cancer progression by mediating intercellular communication and contributing to various hallmarks of cancer. These vesicles carry a cargo of proteins, lipids, nucleic acids, and other biomolecules that can be transferred to recipient cells, modifying their behavior and promoting tumor growth, angiogenesis, immune modulation, and drug resistance. Several potential therapeutic targets within the TAEs cargo have been identified, including oncogenic proteins, miRNAs, tumor-associated antigens, immune checkpoint proteins, drug resistance proteins, and tissue factor. In this review, we will systematically summarize the biogenesis, composition, and function of TAEs in cancer progression and highlight potential therapeutic targets. Considering the complexity of exosome-mediated signaling and the pleiotropic effects of exosome cargoes has challenge in developing effective therapeutic strategies. Further research is needed to fully understand the role of TAEs in cancer and to develop effective therapies that target them. In particular, the development of strategies to block TAEs release, target TAEs cargo, inhibit TAEs uptake, and modulate TAEs content could provide novel approaches to cancer treatment.

Cancer-Associated-Fibroblast-Mediated Paracrine and Autocrine SDF-1/CXCR4 Signaling Promotes Stemness and Aggressiveness of Colorectal Cancers

Colorectal cancer (CRC) is a leading cause of cancer mortality worldwide, and cancer-associated fibroblasts (CAFs) play a major role in the tumor microenvironment (TME), which facilitates the progression of CRC. It is critical to understand how CAFs promote the progression of CRC for the development of novel therapeutic approaches. The purpose of this study was to understand how CAF-derived stromal-derived factor-1 (SDF-1) and its interactions with the corresponding C-X-C motif chemokine receptor 4 (CXCR4) promote CRC progression. Our study focused on their roles in promoting tumor cell migration and invasion and their effects on the characteristics of cancer stem cells (CSCs), which ultimately impact patient outcomes. Here, using in vivo approaches and clinical histological samples, we analyzed the influence of secreted SDF-1 on CRC progression, especially in terms of tumor cell behavior and stemness. We demonstrated that CAF-secreted SDF-1 significantly enhanced CRC cell migration and invasion through paracrine signaling. In addition, the overexpression of SDF-1 in CRC cell lines HT29 and HCT-116 triggered these cells to generate autocrine SDF-1 signaling, which further enhanced their CSC characteristics, including those of migration, invasion, and spheroid formation. An immunohistochemical study showed a close relationship between SDF-1 and CXCR4 expression in CRC tissue, and this significantly affected patient outcomes. The administration of AMD3100, an inhibitor of CXCR4, reversed the entire phenomenon. Our results strongly suggest that targeting this signaling axis in CRC is a feasible approach to attenuating tumor progression, and it may, therefore, serve as an alternative treatment method to improve the prognosis of patients with CRC, especially those with advanced, recurrent, or metastatic CRC following standard therapy.

Advances in targeting cancer-associated fibroblasts through single-cell spatial transcriptomic sequencing

Cancer-associated fibroblasts (CAFs) are the major components of the tumor microenvironment and are related to tumor proliferation, metastasis, relapse, and drug resistance. With the development of sequencing technologies, single-cell RNA sequencing has become a popular method for identifying CAFs in the tumor microenvironment. Whereas the drawbacks of CAFs, such as the lack of a spatial landscape, still exist, recent research has utilized spatial transcriptomics combined with single-cell RNA sequencing to address this issue. These multiomics analyses can resolve the single-cell resolution problem in spatial transcriptomics. In this review, we summarized the recent literature regarding the targeting of CAFs to address drug resistance, angiogenesis, metabolic reprogramming and metastasis in tumor tissue.

A comprehensive review of engineered exosomes from the preparation strategy to therapeutic applications

Exosomes exhibit high bioavailability, biological stability, targeted specificity, low toxicity, and low immunogenicity in shuttling various bioactive molecules such as proteins, lipids, RNA, and DNA. Natural exosomes, however, have limited production, targeting abilities, and therapeutic efficacy in clinical trials. On the other hand, engineered exosomes have demonstrated long-term circulation, high stability, targeted delivery, and efficient intracellular drug release, garnering significant attention. The engineered exosomes bring new insights into developing next-generation drug delivery systems and show enormous potential in therapeutic applications, such as tumor therapies, diabetes management, cardiovascular disease, and tissue regeneration and repair. In this review, we provide an overview of recent advancements associated with engineered exosomes by focusing on the state-of-the-art strategies for cell engineering and exosome engineering. Exosome isolation methods, including traditional and emerging approaches, are systematically compared along with advancements in characterization methods. Current challenges and future opportunities are further discussed in terms of the preparation and application of engineered exosomes.

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.

Identification of CAF-related lncRNAs at the pan-cancer level represents a potential carcinogenic risk

Cancer-associated fibroblasts (CAFs) are increasingly recognized as playing a crucial role in regulating cancer progression and metastasis. These cells can be activated by long non-coding RNAs (lncRNAs), promoting the malignant biological processes of tumor cells. Therefore, it is essential to understand the regulatory relationship between CAFs and lncRNAs in cancers. Here, we identified CAF-related lncRNAs at the pan-cancer level to systematically predict their potential regulatory functions. The identified lncRNAs were also validated using various external data at both tissue and cellular levels. This study has revealed that these CAF-related lncRNAs exhibit expression perturbations in cancers and are highly correlated with the infiltration of stromal cells, particularly fibroblasts and endothelial cells. By prioritizing a list of CAF-related lncRNAs, we can further distinguish patient subtypes that show survival and molecular differences. In addition, we have developed a web server, CAFLnc (https://46906u5t63.zicp.fun/CAFLnc/), to visualize our results. In conclusion, CAF-related lncRNAs hold great potential as a valuable resource for comprehending lncRNA functions and advancing the identification of biomarkers for cancer progression and therapeutic targets in cancer treatment.

Advancements and trends in exosome research in lung cancer from a bibliometric analysis (2004-2023)

Background

Lung cancer, characterized by its high morbidity and lethality, necessitates thorough research to enhance our understanding of its pathogenesis and discover novel therapeutic approaches. Recent studies increasingly demonstrate that lung cancer cells can modulate the tumor microenvironment, promoting tumor growth, and metastasis through the release of exosomes. Exosomes are small vesicles secreted by cells and contain a variety of bioactive molecules such as proteins, nucleic acids, and metabolites. This paper presents a comprehensive review of exosome research in lung cancer and its progress through bibliometric analysis.

Methods

Publications related to exosomes in lung cancer patients were systematically searched on the Web of Science Core Collection (WoSCC) database. Bibliometric analysis was performed using VOSviwers, CiteSpace, and the R package "Bibliometrics". Publications were quantitatively analyzed using Microsoft Office Excel 2019. The language of publication was restricted to "English" and the search strategy employed TS=(exosomes or exosomes or exosomes) and TS=(lung cancer). The search period commenced on January 1, 2004, and concluded on November 12, 2023, at noon. The selected literature types included Articles and Reviews.

Results

The study encompassed 1699 papers from 521 journals across 71 countries and 2105 institutions. Analysis revealed a consistent upward trend in lung cancer exosome research over the years, with a notable surge in recent times. This surge indicates a growing interest and depth of inquiry into lung cancer exosomes. Major research institutions in China and the United States, including Nanjing Medical University, Shanghai Jiao Tong University, Chinese Academy Of Sciences, and Utmd Anderson Cancer Center, emerged as crucial research hubs. The annual publication count in this field witnessed a continuous rise, particularly in recent years. Key terms such as lung cancer, non-small cell lung cancer (NSCLC), microvesicles, intercellular communication, exosomal miRNAs, and oncology dominated the research landscape. Fields like cell biology, biochemistry, biotechnology, and oncology exhibited close relation with this research. Clotilde Théry emerged as the most cited author in the field, underlining her significant contributions. These results demonstrate the broad impact of exosome research in lung cancer, with key terms covering not only disease-specific aspects such as lung cancer and NSCLC but also basic biological concepts like microvesicles and intercellular communication. Explorations into exosomal microRNAs and oncology have opened new avenues for lung cancer exosome research. In summary, lung cancer exosome research is poised to continue receiving attention, potentially leading to breakthroughs in treatment and prevention.

Conclusion

Publications on lung cancer exosomes show a rising trend year by year, with China and the United States ranking first and second in terms of the number of publications. However, there is insufficient academic learning cooperation and exchanges between the two sides, and Chinese universities account for a large proportion of research institutions in this field. Jing Li is the most productive author, Clotilde Théry is the most co-cited author, and Cancers is the journal with the highest number of publications. The current focus in the field of lung cancer exosomes is on biomarkers, liquid biopsies, immunotherapy, and tumor microenvironment.

Clinical impact of epithelial–mesenchymal transition for cancer therapy

The epithelial–mesenchymal transition (EMT) represents a pivotal frontier in oncology, playing a central role in the metastatic cascade of cancer—a leading global health challenge. This comprehensive review delves into the complexities of EMT, a process where cancer cells gain exceptional mobility, facilitating their invasion into distant organs and the establishment of secondary malignancies. We thoroughly examine the myriad of factors influencing EMT, encompassing transcription factors, signalling pathways, metabolic alterations, microRNAs, long non‐coding RNAs, epigenetic changes, exosomal interactions and the intricate dynamics of the tumour microenvironment. Particularly, the review emphasises the advanced stages of EMT, crucial for the development of highly aggressive cancer phenotypes. During this phase, cancer cells penetrate the vascular barrier and exploit the bloodstream to propagate life‐threatening metastases through the mesenchymal–epithelial transition. We also explore EMT's significant role in fostering tumour dormancy, senescence, the emergence of cancer stem cells and the formidable challenge of therapeutic resistance. Our review transcends a mere inventory of EMT‐inducing elements; it critically assesses the current state of EMT‐focused clinical trials, revealing both the hurdles and significant breakthroughs. Highlighting the potential of EMT research, we project its transformative impact on the future of cancer therapy. This exploration is aimed at paving the way towards an era of effectively managing this relentless disease, positioning EMT at the forefront of innovative cancer research strategies.

Current Update of Research on Exosomes in Cancer

Exosomes are vesicles secreted by the plasma membrane of the cells delimited by a lipid bilayer membrane into the extracellular space of the cell. Their release is associated with the disposal mechanism to remove unwanted materials from the cells. Exosomes released from primary tumour sites migrate to other parts of the body to create a metastatic environment for spreading the tumour cells. We have reviewed that exosomes interfere with the tumour progression by (i) promoting angiogenesis, (ii) initiating metastasis, (iii) regulating tumour microenvironment (TME) and inflammation, (iv) modifying energy metabolism, and (v) transferring mutations. We have found that EVs play an important role in inducing tumour drug resistance against anticancer drugs. This review discusses the potential of exosomes to generate a significant therapeutic effect along with improved diagnosis, prognosis, insights on the various research conducted and their significant findings of our interest.

The Role of Cancer Stem Cell Markers in Ovarian Cancer

Ovarian cancer is the most lethal gynaecological cancer and the eighth most common female cancer. The early diagnosis of ovarian cancer remains a clinical problem despite the significant development of technology. Nearly 70% of patients with ovarian cancer are diagnosed with stages III-IV metastatic disease. Reliable diagnostic and prognostic biomarkers are currently lacking. Ovarian cancer recurrence and resistance to chemotherapy pose vital problems and translate into poor outcomes. Cancer stem cells appear to be responsible for tumour recurrence resulting from chemotherapeutic resistance. These cells are also crucial for tumour initiation due to the ability to self-renew, differentiate, avoid immune destruction, and promote inflammation and angiogenesis. Studies have confirmed an association between CSC occurrence and resistance to chemotherapy, subsequent metastases, and cancer relapses. Therefore, the elimination of CSCs appears important for overcoming drug resistance and improving prognoses. This review focuses on the expression of selected ovarian CSC markers, including CD133, CD44, CD24, CD117, and aldehyde dehydrogenase 1, which show potential prognostic significance. Some markers expressed on the surface of CSCs correlate with clinical features and can be used for the diagnosis and prognosis of ovarian cancer. However, due to the heterogeneity and plasticity of CSCs, the determination of specific CSC phenotypes is difficult.

The Nexus of Inflammation-Induced Epithelial-Mesenchymal Transition and Lung Cancer Progression: A Roadmap to Pentacyclic Triterpenoid-Based Therapies

Lung cancer is the leading cause of cancer-related death worldwide. Its high mortality is partly due to chronic inflammation that accompanies the disease and stimulates cancer progression. In this review, we analyzed recent studies and highlighted the role of the epithelial-mesenchymal transition (EMT) as a link between inflammation and lung cancer. In the inflammatory tumor microenvironment (iTME), fibroblasts, macrophages, granulocytes, and lymphocytes produce inflammatory mediators, some of which can induce EMT. This leads to increased invasiveness of tumor cells and self-renewal of cancer stem cells (CSCs), which are associated with metastasis and tumor recurrence, respectively. Based on published data, we propose that inflammation-induced EMT may be a potential therapeutic target for the treatment of lung cancer. This prospect is partially realized in the development of EMT inhibitors based on pentacyclic triterpenoids (PTs), described in the second part of our study. PTs reduce the metastatic potential and stemness of tumor cells, making PTs promising candidates for lung cancer therapy. We emphasize that the high diversity of molecular mechanisms underlying inflammation-induced EMT far exceeds those that have been implicated in drug development. Therefore, analysis of information on the relationship between the iTME and EMT is of great interest and may provide ideas for novel treatment approaches for lung cancer.

Extracellular vesicles targeting tumor microenvironment in ovarian cancer

Ovarian cancer (OC) is a prevalent neoplastic condition affecting women. Extracellular vesicles (EVs), nano-sized membrane vesicles, are secreted by various cells in both physiological and pathological states. The profound interplay between EVs and the tumor microenvironment (TME) in ovarian cancer is crucial. In this review, we explores the pivotal role of EVs in facilitating intercellular communication between cancer cells and the TME, emphasizing the potential of EVs as promising diagnostic markers and innovative therapeutic targets for ovarian cancer. The comprehensive analysis outlines the specific mechanisms by which EVs engage in communication with the constituents of the TME, including the modulation of tumor growth through EVs carrying matrix metalloproteinases (MMPs) and EV-mediated inhibition of angiogenesis, among other factors. Additionally, the we discuss the potential clinical applications of EVs that target the TME in ovarian cancer, encompassing the establishment of novel treatment strategies and the identification of novel biomarkers for early detection and prognosis. Finally, this review identifies novel strategies for therapeutic interventions, such as utilizing EVs as carriers for drug delivery and targeting specific EV-mediated signaling pathways. In summary, this manuscript offers valuable insights into the role of EVs in ovarian cancer and highlights the significance of comprehending intercellular communication in the realm of cancer biology.

GW4869 Can Inhibit Epithelial-Mesenchymal Transition and Extracellular HSP90α in Gefitinib-Sensitive NSCLC Cells

Objective

GW4869 is an exosomal inhibitor. It is necessary to delay the occurrence of gefitinib resistance during non-small-cell lung cancer (NSCLC) treatment. This study aimed to investigate the anti-tumor effects of GW4869 on epithelial-mesenchymal transition (EMT) and expression of extracellular heat shock protein 90α (eHSP90α) that contributes to acquired resisitance. Our study provides a new sight into the treatment of EGFR-mutated NSCLC.

Materials and Methods

We performed western blotting to detect levels of EMT and eHSP90α. Wound healing and transwell assays were performed to evaluate the behavioral dynamics of EMT. A nude mouse model of HCC827 was established in vivo.

Results

GW4869 inhibited the expression of eHSP90α, EMT, invasion and migration abilities of HCC827 and PC9. GW4869 enhanced sensitivity to gefitinib in BALB/c nude mice bearing tumors of HCC827.

Conclusion

These studies suggest that GW4869 can inhibit EMT and extracellular HSP90α, providing new strategies for enhancing gefitinib sensitivity in NSCLC.

Engineered exosomes-based theranostic strategy for tumor metastasis and recurrence

Metastasis-associated processes are the predominant instigator of fatalities linked to cancer, wherein the pivotal role of circulating tumor cells lies in the resurgence of malignant growth. In recent epochs, exosomes, constituents of the extracellular vesicle cohort, have garnered attention within the field of tumor theranostics owing to their inherent attributes encompassing biocompatibility, modifiability, payload capacity, stability, and therapeutic suitability. Nonetheless, the rudimentary functionalities and limited efficacy of unmodified exosomes curtail their prospective utility. In an effort to surmount these shortcomings, intricate methodologies amalgamating nanotechnology with genetic manipulation, chemotherapy, immunotherapy, and optical intervention present themselves as enhanced avenues to surveil and intercede in tumor metastasis and relapse. This review delves into the manifold techniques currently employed to engineer exosomes, with a specific focus on elucidating the interplay between exosomes and the metastatic cascade, alongside the implementation of tailored exosomes in abating tumor metastasis and recurrence. This review not only advances comprehension of the evolving landscape within this domain but also steers the trajectory of forthcoming investigations.

Non-immune cell components in tumor microenvironment influencing lung cancer Immunotherapy

Lung cancer (LC) is one of the leading causes of cancer-related deaths worldwide, with a significant morbidity and mortality rate, endangering human life and health. The introduction of immunotherapies has significantly altered existing cancer treatment strategies and is expected to improve immune responses, objective response rates, and survival rates. However, a better understanding of the complex immunological networks of LC is required to improve immunotherapy efficacy further. Tumor-associated antigens (TAAs) and tumor-specific antigens (TSAs) are significantly expressed by LC cells, which activate dendritic cells, initiate antigen presentation, and activate lymphocytes to exert antitumor activity. However, as tumor cells combat the immune system, an immunosuppressive microenvironment forms, enabling the enactment of a series of immunological escape mechanisms, including the recruitment of immunosuppressive cells and induction of T cell exhaustion to decrease the antitumor immune response. In addition to the direct effect of LC cells on immune cell function, the secreting various cytokines, chemokines, and exosomes, changes in the intratumoral microbiome and the function of cancer-associated fibroblasts and endothelial cells contribute to LC cell immune escape. Accordingly, combining various immunotherapies with other therapies can elicit synergistic effects based on the complex immune network, improving immunotherapy efficacy through multi-target action on the tumor microenvironment (TME). Hence, this review provides guidance for understanding the complex immune network in the TME and designing novel and effective immunotherapy strategies for LC.

Potential roles of exosomes in the initiation and metastatic progression of lung cancer

Lung cancer (LC) incidence and mortality continue to increase annually worldwide. LC is insidious and readily metastasizes and relapses. Except for its early diagnosis and surgical resection, there is no effective cure for advanced metastatic LC, and the prognosis remains dismal. Exosomes, a class of nano-sized extracellular vesicles produced by healthy or diseased cells, are coated with a bilayer lipid membrane and contain various functional molecules such as proteins, lipids, and nucleic acids. They can be used for intracellular or intercellular signaling or the transportation of biological substances. A growing body of evidence supports that exosomes play multiple crucial roles in the occurrence and metastatic progression of many malignancies, including LC. The elucidation of the potential roles of exosomes in the initiation, invasion, and metastasis of LC and their underlying molecular mechanisms may contribute to improved early diagnosis and treatment.

Potential targets of natural medicines: preventing lung cancer pre-metastatic niche formation by regulating exosomes

Lung cancer is one of the most devastating diseases worldwide with high incidence and mortality, and the incidence continues to rise. Metastasis is the leading cause of death in lung cancer patients, yet the molecular effectors underlying tumor dissemination remain poorly defined. Research findings in recent years confirmed primed microenvironment of future metastatic sites, called the pre-metastatic niche, is a prerequisite for overt metastasis. Exosomes have recently emerged as important players in pre-metastatic niche formation. Natural medicines have traditionally been rich sources of drug discovery. Some of them exhibit favorable anti-lung cancer activity. The review focused on the latest advances in the regulation of the pre-metastatic niche formation in lung cancer by the contents of exosomes of representative natural medicines. Additionally, the mechanism of natural medicines was summarized in detail, which would provide new insights for anti-cancer new drug development.

Morphological Characterization of Human Lung Cancer Organoids Cultured in Type I Collagen Hydrogels: A Histological Approach

The malignity of lung cancer is conditioned by the tumor microenvironment (TME), in which cancer-associated fibroblasts (CAFs) are relevant. In this work, we generated organoids by combining A549 cells with CAFs and normal fibroblasts (NF) isolated from adenocarcinoma tumors. We optimized the conditions for their manufacture in a short time. We evaluated the morphology of organoids using confocal microscopy analysis of F-actin, vimentin and pankeratin. We determined the ultrastructure of the cells in the organoids via transmission electron microscopy and the expression of CDH1, CDH2 and VIM via RT-PCR. The addition of stromal cells induces the self-organization of the organoids, which acquired a bowl morphology, as well as their growth and the generation of cell processes. They also influenced the expression of genes related to epithelial mesenchymal transition (EMT). CAFs potentiated these changes. All cells acquired a characteristic secretory phenotype, with cohesive cells appearing inside the organoids. In the periphery, many cells acquired a migratory phenotype, especially in organoids that incorporated CAFs. The deposit of abundant extracellular matrix could also be observed. The results presented here reinforce the role of CAFs in the progression of lung tumors and could lay the foundation for a useful in vitro pharmacological model.

The effectiveness of blood-activating and stasis-transforming traditional Chinese medicines (BAST) in lung cancer progression-a comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Blood-activating and stasis-transforming traditional Chinese medicines (BAST) are a class of herbs that have the effect of dilating blood vessels and dispersing stagnation. Modern pharmaceutical research has demonstrated that they are capable of improving hemodynamics and micro-flow, resist thrombosis and promote blood flow. BAST contain numerous active ingredients, which can theoretically regulate multiple targets at the same time and have a wide range of pharmacological effects in the treatment of diseases including human cancers. Clinically, BAST have minimal side effects and can be used in combination with Western medicine to improve patients' quality of life, lessen adverse effects and minimize the risk of recurrence and metastasis of cancers.

AIM OF THE REVIEW

We aimed to summarize the research progression of BAST on lung cancer in the past five years and present a prospect for the future. Particularly, this review further analyzes the effects and molecular mechanisms that BAST inhibit the invasion and metastasis of lung cancer.

MATERIALS AND METHODS

Relevant studies about BSAT were collected from PubMed and Web of science.

RESULTS

Lung cancer is one of the malignant tumors with the highest mortality rate. Most patients with lung cancer are diagnosed at an advanced stage and are highly susceptible to metastasis. Recent studies have shown that BAST, a class of traditional Chinese medicine (TCM) with the function of opening veins and dispersing blood stasis, significantly improve hemodynamics and microcirculation, prevent thrombosis and promote blood flow, and thereby inhibiting the invasion and metastasis of lung cancer. In the current review, we analyzed 51 active ingredients extracted from BAST. It was found that BAST and their active ingredients contribute to the prevention of invasion and metastasis of lung cancer through multiple mechanisms, such as regulation of EMT process, specific signaling pathway and metastasis-related genes, tumor blood vessel formation, immune microenvironment and inflammatory response of tumors.

CONCLUSIONS

BSAT and its active ingredients have showed promising anticancer activity and significantly inhibit the invasion and metastasis of lung cancer. A growing number of studies have realized their potential clinical significance in the therapy of lung cancer, which will provide substantial evidences for the development of new TCM for lung cancer therapy.

Cancer-associated fibroblasts are the main contributors to epithelial-to-mesenchymal signatures in the tumor microenvironment

Epithelial-to-mesenchymal transition (EMT) is associated with tumor initiation, metastasis, and drug resistance. However, the mechanisms underlying these associations are largely unknown. We studied several tumor types to identify the source of EMT gene expression signals and a potential mechanism of resistance to immuno-oncology treatment. Across tumor types, EMT-related gene expression was strongly associated with expression of stroma-related genes. Based on RNA sequencing of multiple patient-derived xenograft models, EMT-related gene expression was enriched in the stroma versus parenchyma. EMT-related markers were predominantly expressed by cancer-associated fibroblasts (CAFs), cells of mesenchymal origin which produce a variety of matrix proteins and growth factors. Scores derived from a 3-gene CAF transcriptional signature (COL1A1, COL1A2, COL3A1) were sufficient to reproduce association between EMT-related markers and disease prognosis. Our results suggest that CAFs are the primary source of EMT signaling and have potential roles as biomarkers and targets for immuno-oncology therapies.

Extracellular Vesicles: New Classification and Tumor Immunosuppression

Extracellular vesicles (EVs) are cell-derived membrane-surrounded vesicles carrying various types of molecules. These EV cargoes are often used as pathophysiological biomarkers and delivered to recipient cells whose fates are often altered in local and distant tissues. Classical EVs are exosomes, microvesicles, and apoptotic bodies, while recent studies discovered autophagic EVs, stressed EVs, and matrix vesicles. Here, we classify classical and new EVs and non-EV nanoparticles. We also review EVs-mediated intercellular communication between cancer cells and various types of tumor-associated cells, such as cancer-associated fibroblasts, adipocytes, blood vessels, lymphatic vessels, and immune cells. Of note, cancer EVs play crucial roles in immunosuppression, immune evasion, and immunotherapy resistance. Thus, cancer EVs change hot tumors into cold ones. Moreover, cancer EVs affect nonimmune cells to promote cellular transformation, including epithelial-to-mesenchymal transition (EMT), chemoresistance, tumor matrix production, destruction of biological barriers, angiogenesis, lymphangiogenesis, and metastatic niche formation.

Exosomal microRNA-342-5p from human umbilical cord mesenchymal stem cells inhibits preeclampsia in rats

We aimed to investigate the inhibitory effect of human umbilical cord mesenchymal stem cell (hucMSC)-derived exosomes (hucMSC-Exos) transmitting microRNA-342-5p (miR-342-5p) on the development of preeclampsia (PE) by targeting programmed cell death 4 (PDCD4). The primary hucMSCs were cultured and transfected with miR-342-5p, and the exosomes (Exo) were extracted from the hucMSCs. PE rats were performed with an intraperitoneal injection of L-NAME from days 11 to 19 of gestation, and injection of Exo, Exo-negative control (NC), Exo-miR-342-5p agomir, Exo-miR-342-5p antagomir, and overexpressing PDCD4 (oe-PDCD4) vector into the placenta on the 16th day of pregnancy. HE staining was utilized to observe the pathological changes in placental tissues. TUNEL staining was implemented to evaluate cell apoptosis in placental tissues. Blood pressure and 24-h urinary protein in pregnant rats were measured by a non-invasive rat tail artery blood pressure measurement and protein auto-analyzer. Expressions of miR-342-5p, PDCD4, proinflammatory cytokines (TNF-α and IL-1β), and anti-inflammatory cytokines (IL-10 and TGF-β) were detected by RT-qPCR, and PDCD4 protein expression was determined by Western blot. The interaction between miR-342-5p and PDCD4 was analyzed by luciferase activity assay. MiR-342-5p was downregulated while PDCD4 was upregulated in the placental tissues of PE rats. HucMSC-Exo relieved pathology and suppressed inflammatory response, and apoptosis in the placental tissues, as well as reducing blood pressure and 24-h urinary protein of PE rats. Elevated miR-342-5p enhanced the promoting influence of hucMSC-Exo on PE rats, while inhibited miR-342-5p reversed the functions of hucMSC-Exo on PE rats. miR-342-5p targeted PDCD4. Overexpression of PDCD4 worsened the development of PE in rats. HucMSC-Exo conveying elevated miR-342-5p inhibits the development of PE in a rat model through downregulating PDCD4.

Role of exosomes in non-small cell lung cancer and EGFR-mutated lung cancer

As an important mediator of information transfer between cells, exosomes play a unique role in regulating tumor growth, supporting vascular proliferation, tumor invasion, and metastasis. Exosomes are widely present in various body fluids, and therefore they can be used as a potential tool for non-invasive liquid biopsy. The present study reviews the role of exosomes in liquid biopsy, tumor microenvironment formation, and epithelial-mesenchymal transition in non-small cell lung cancer (NSCLC). By targeting epidermal growth factor receptor (EGFR) therapy as a first-line treatment for patients with NSCLC, this study also briefly describes the occurrence of EGRF+ exosomes and the role of exosomes and their contents in non-invasive detection and potential therapeutic targets in EGFR-mutated lung cancer.

Cancer-associated fibroblasts in gynecological malignancies: are they really allies of the enemy?

Molecular and cellular components of the tumor microenvironment are essential for cancer progression. The cellular element comprises cancer cells and heterogeneous populations of non-cancer cells that satisfy tumor needs. Immune, vascular, and mesenchymal cells provide the necessary factors to feed the tumor mass, promote its development, and favor the spread of cancer cells from the primary site to adjacent and distant anatomical sites. Cancer-associated fibroblasts (CAFs) are mesenchymal cells that promote carcinogenesis and progression of various malignant neoplasms. CAFs act through the secretion of metalloproteinases, growth factors, cytokines, mitochondrial DNA, and non-coding RNAs, among other molecules. Over the last few years, the evidence on the leading role of CAFs in gynecological cancers has notably increased, placing them as the cornerstone of neoplastic processes. In this review, the recently reported findings regarding the promoting role that CAFs play in gynecological cancers, their potential use as therapeutic targets, and the new evidence suggesting that they could act as tumor suppressors are analyzed and discussed.

The role and underlying mechanisms of tumour-derived exosomes in lung cancer metastasis

PURPOSE OF REVIEW

Lung cancer is one of the most common malignant tumours worldwide. Metastasis is a serious influencing factor for poor treatment effect and shortened survival in lung cancer. But the complicated underlying molecular mechanisms of tumour metastasis remain unclear. In this review, we aim to further summarize and explore the underlying mechanisms of tumour-derived exosomes (TDEs) in lung cancer metastasis.

RECENT FINDINGS

TDEs are actively produced and released by tumour cells and carry messages from tumour cells to normal or abnormal cells residing at close or distant sites. Many studies have shown that TDEs promote lung cancer metastasis and development through multiple mechanisms, including epithelial-mesenchymal transition, immunosuppression and the formation of a premetastatic niche. TDEs regulate these mechanisms to promote metastasis by carrying DNA, proteins, miRNA, mRNA, lncRNA and ceRNA. Further exploring TDEs related to metastasis may be a promising treatment strategy and deserve further investigation.

SUMMARY

Overall, TDEs play a critical role in metastatic of lung cancer. Further studies are needed to explore the underlying mechanisms of TDEs in lung cancer metastasis.

Knockdown of lncRNA-ASLNC12002 alleviates epithelial-mesenchymal transition of type II alveolar epithelial cells in sepsis-induced acute respiratory distress syndrome

Patients with sepsis-induced acute respiratory distress syndrome (ARDS) have higher mortality and poor prognosis than pneumonia-induced ARDS. Pulmonary fibrosis is an irreversible accumulation of connective tissue in the interstitium of the lung and closely associated with the epithelial-mesenchymal transition (EMT) of type II alveolar epithelial cells (AECIIs). Therefore, it is undoubtedly worth studying whether the EMT of AECIIs in sepsis-induced ARDS patients is different from that in patients with pneumonia-induced ARDS in the regulatory mechanism. Here, we will report for the first time that an lncRNA-ASLNC12002 is highly expressed in AECIIs of patients with sepsis-induced pneumonia and promotes EMT in AECIIs. The research results showed that the expression of ASLNC12002 in AECIIs derived from patients with sepsis-induced ARDS is significantly higher than that in normal people and pneumonia-induced ARDS patients. Mechanism research showed that ASLNC12002 can cause the inactivation of the anti-EMT pathway NR2F2/miR128-3p/Snail1 by acting as the sponge of miR128-3p. Functional experiments showed that targeted silencing of ASLNC12002 could effectively inhibit EMT progression in AECIIs of patients with sepsis-induced pneumonia by restoring NR2F2/miR128-3p/Snail1 pathway. In a word, our study shows for the first time that the inactivation of NR2F2/miR128-3p/Snail1 pathway caused by the enhanced expression of ASLNC12002 is the direct reason why AECIIs in sepsis-induced ARDS patients are prone to get EMT progress. ASLNC12002 has the potential to become a biological target for the prevention and treatment of pulmonary fibrosis in patients with sepsis-induced ARDS. At the same time, the expectation that ASLNC12002 and its related products may be used as clinical markers for the evaluation of early pulmonary fibrosis in ARDS patients should not be ignored.

Exosomal epidermal growth factor receptor is involved in HPV-16 E7-induced epithelial-mesenchymal transition of non-small cell lung cancer cells: A driver of signaling in vivo?

Our previous studies have demonstrated that human papillomavirus (HPV)-16 E7 oncoprotein promoted epithelial-mesenchymal transition (EMT) in non-small cell lung cancer (NSCLC) cells. Moreover, recent studies have found that exosomes can mediate EMT of NSCLC cells and epidermal growth factor receptor (EGFR) is related to the progression of NSCLC. Here, we further investigated the role of exosomal EGFR in HPV-16 E7-induced EMT of NSCLC cells. Our results showed that the exosomes derived from the stable HPV-16 E7-overexpressing A549 and NCI-H460 NSCLC cells (E7 Exo) significantly increased migration, invasion, and proliferation abilities of NSCLC cells as compared with the exosomes derived from empty vector-infected NSCLC cells (ev Exo). Moreover, both in vitro and in vivo results demonstrated that E7 Exo dramatically enhanced EMT of NSCLC cells and promoted the growth of subcutaneous NSCLC xenografts. Additionally, HPV-16 E7 enhanced the expression of EGFR and p-EGFR in both NSCLC cells and exosomes. Furthermore, the inhibition of EGFR activation or exosome secretion suppressed E7 Exo-induced migration, invasion, and EMT of NSCLC. Moreover, 12 kinds of differentially expressed miRNAs between E7 Exo and ev Exo (fold change≥2, P ≤ .05) were screened out, of which 7 miRNAs were up-regulated while 5 miRNAs were down-regulated in A549 E7 Exo. Taken together, our findings suggest that exosomal EGFR is involved in HPV-16 E7-induced EMT of NSCLC cells, which may play a key role in the progression of HPV-related NSCLC.

Intercellular crosstalk between cancer cells and cancer-associated fibroblasts via extracellular vesicles

Intercellular communication plays an important role in cancer initiation and progression through direct contact and indirect interactions, such as via secretory molecules. Cancer-associated fibroblasts (CAFs) are one of the principal components of such communication with cancer cells, modulating cancer metastasis and tumour mechanics and influencing angiogenesis, the immune system, and therapeutic resistance. Over the past few years, there has been a significant increase in research on extracellular vesicles (EVs) as regulatory agents in intercellular communication. EVs enable the transfer of functional molecules, including proteins, mRNAs and microRNAs (miRNAs), to recipient cells. Cancer cells utilize EVs to dictate the specific characteristics of CAFs within the tumour microenvironment, thereby promoting cancer progression. In response to such "education" by cancer cells, CAFs contribute to cancer progression via EVs. In this review, we summarize experimental data indicating the pivotal roles of EVs in intercellular communication between cancer cells and CAFs.

Cancer-associated fibroblasts in nonsmall cell lung cancer: From molecular mechanisms to clinical implications

Lung cancer is the common and leading cause of cancer death worldwide. The tumor microenvironment has been recognized to be instrumental in tumorigenesis. To have a deep understanding of the molecular mechanism of nonsmall cell lung carcinoma (NSCLC), cancer-associated fibroblasts (CAFs) have gained increasing research interests. CAFs belong to the crucial and dominant cell population in the tumor microenvironment to support the cancer cells. The interplay and partnership between cancer cells and CAFs contribute to each stage of tumorigenesis. CAFs exhibit prominent heterogeneity and secrete different kinds of cytokines and chemokines, growth factors and extracellular matrix proteins involved in cancer cell proliferation, invasion, metastasis and chemoresistance. Many studies focused on the protumorigenic functions of CAFs, yet many challenges about the heterogeneity of CAFS remain unresolved. This review comprehensively summarized the tumor-promoting role and molecular mechanisms of CAFs in NSCLC, including their origin, phenotypic changes and heterogeneity and their functional roles in carcinogenesis. Meanwhile, we also highlighted the updated molecular classifications based on the molecular features and functional roles of CAFs. With the development of cutting-edge platforms and further investigations of CAFs, novel therapeutic strategies for accurately targeting CAFs in NSCLC may be developed based on the increased understanding of the relevant molecular mechanisms.

Cancer-associated fibroblasts: Origin, function, imaging, and therapeutic targeting

The tumor microenvironment (TME) is emerging as one of the primary barriers in cancer therapy. Cancer-associated fibroblasts (CAF) are a common inhabitant of the TME in several tumor types and play a critical role in tumor progression and drug resistance via different mechanisms such as desmoplasia, angiogenesis, immune modulation, and cancer metabolism. Due to their abundance and significance in pro-tumorigenic mechanisms, CAF are gaining attention as a diagnostic target as well as to improve the efficacy of cancer therapy by their modulation. In this review, we highlight existing imaging techniques that are used for the visualization of CAF and CAF-induced fibrosis and provide an overview of compounds that are known to modulate CAF activity. Subsequently, we also discuss CAF-targeted and CAF-modulating nanocarriers. Finally, our review addresses ongoing challenges and provides a glimpse into the prospects that can spearhead the transition of CAF-targeted therapies from opportunity to reality.

Comparison of methods of isolating extracellular vesicle microRNA from HepG2 cells for High-throughput sequencing

Background: Extracellular vesicles (EVs) were reported to participate in various cellular processes based on the biomolecules, particularly microRNAs. Numerous commercial EVs isolation reagents are available. However, whether these reagents are suitable for separating EVs from the culture medium supernatant supernatant of model cell lines, such as HepG2, and whether the isolated products are suitable for High-throughput sequencing remains unclear.

Methods: We examined three commonly used EVs isolation kits: the ExoQuick-TC exosome precipitation solution (EQ), Total Exosome Isolation from cell culture medium (EI), and exoEasy Maxi Kit (EM), to isolate EVs from HepG2 cell culture medium supernatants. EVs were identified based on marker proteins, particle size measurements, and electron microscopy analysis. The total amounts of microRNA and microRNA High-throughput sequencing data quality from EVs isolated by each kit were compared.

Results: The total amount of EVs’ microRNA isolated from the EI and EM groups were higher than that obtained from the EQ group (EQ/EI: p = 0.036, EI/EM: p = 0.024). High-throughput sequencing data quality evaluation showed that the EI group possessed higher quality than those in the EM group.

Conclusion: For the cell culture medium from HepG2, EVs’ microRNA isolated by EI reagents might be more suitable for High-throughput sequencing applications.

Recent Advances in Molecular Diagnosis of Pulmonary Fibrosis for Precision Medicine

Pulmonary fibrosis is a serious, progressive lung disease characterized by scarring and stiffening lung tissues, affecting the respiratory system and leading to organ failure. It is a complex disease consisting of alveolar damage, chronic inflammation, and a varying degree of lung fibrosis. Significant challenges with pulmonary fibrosis include the lack of effective means to diagnose the disease at early stages, identify patients at higher risks of progress, and assess disease progression and treatment response. Precision medicine powered by accurate molecular profiling and phenotyping could significantly improve our understanding of the disease's heterogeneity, potential biomarkers for diagnosis and prognosis, and molecular targets for treatment development. This Review discusses various translational model systems, including organoids and lung-on-a-chip systems, biomarkers in single cells and extracellular vesicles, and functional pharmacodynamic markers. We also highlight emerging sensing technologies for molecular characterization of pulmonary fibrosis and biomarker detection.

Tumor microenvironment in lung cancer-derived brain metastasis

ABSTRACT

Brain metastasis (BM) is the leading cause of mortality in lung cancer patients. The process of BM (from initial primary tumor development, migration and intravasation, dissemination and survival in the bloodstream, extravasation, to colonization and growth to metastases) is a complex process for which few tumor cells complete the entire process. Recent research on BM of lung cancer has recently stressed the essential role of tumor microenvironment (TME) in assisting tumor cells in the completion of each BM step. This review summarizes recent studies regarding the effects of TME on tumor cells in the entire process of BM derived from lung cancer. The identification of vulnerable targets in the TME and their prospects to provide novel therapeutic opportunities are also discussed.

FAPhigh α-SMAlow cancer-associated fibroblast-derived SLPI protein encapsulated in extracellular vesicles promotes ovarian cancer development via activation of PI3K/AKT and downstream signaling pathways

Ovarian cancer is the most lethal gynecological malignancy worldwide with high metastasis and poor prognosis rates. Cancer‐associated fibroblasts (CAFs), a heterogeneous population of cells that constitutes a major component of the tumor microenvironment, secrete extracellular vesicles (EVs) loading with proteins, lipids, and RNAs to promote tumorigenesis. However, the specific roles of CAF‐derived proteins contained in EVs in ovarian cancer remain poorly understood at present. Using the gene expression microarray analysis, we identified a list of dysregulated genes between the α‐SMA⁺CAF and FAP⁺CAF subpopulations, from which secretory leukocyte protease inhibitor (SLPI) was chosen for further validation. Quantitative PCR, western blot, immunohistochemistry, and enzyme‐linked immunosorbent assays were used to assess SLPI expression in ovarian cancer cells, tissues, CAFs, and EVs. Additionally, we evaluated the effects of exogenous SLPI on proliferation, migration, invasion, and adhesion of ovarian cancer cells in vitro. Our results showed SLPI protein was upregulated in CAFs, particularly in the FAP^highα‐SMA^lowCAF subpopulation, and associated with increased tumor grade and decreased overall survival (OS). Importantly, CAF‐derived SLPI protein could be encapsulated in EVs for delivery to ovarian cancer cells, thus facilitating cell proliferation, migration, invasion, and adhesion via activating the PI3K/AKT and downstream signaling pathways. Moreover, high plasma expression of SLPI encapsulated in EVs was closely correlated with tumor stage in ovarian cancer patients. Our collective results highlight an oncogenic role of plasma EV‐encapsulated SLPI secreted by CAFs in tumor progression for the first time, supporting its potential utility as a prognostic biomarker of ovarian cancer.

In Vitro Effect of Δ9-Tetrahydrocannabinol and Cannabidiol on Cancer-Associated Fibroblasts Isolated from Lung Cancer

There is evidence that demonstrates the effect of cannabinoid agonists inhibiting relevant aspects in lung cancer, such as proliferation or epithelial-to-mesenchymal transition (EMT). Most of these studies are based on evidence observed in in vitro models developed on cancer cell lines. These studies do not consider the complexity of the tumor microenvironment (TME). One of the main components of the TME is cancer-associated fibroblasts (CAFs), cells that are relevant in the control of proliferation and metastasis in lung cancer. In this work, we evaluated the direct effects of two cannabinoid agonists, tetrahydrocannabinol (THC) and cannabidiol (CBD), used alone or in combination, on CAFs and non-tumor normal fibroblasts (NFs) isolated from adenocarcinoma or from healthy lung tissue from the same patients. We observed that these compounds decrease cell density in vitro and inhibit the increase in the relative expression of type 1 collagen (COL1A1) and fibroblast-specific protein 1 (FSP1) induced by transforming growth factor beta (TGFβ). On the other hand, we studied whether THC and CBD could modulate the interactions between CAFs or NFs and cancer cells. We conditioned the culture medium with stromal cells treated or not with THC and/or CBD and cultured A549 cells with them. We found that culture media conditioned with CAFs or NFs increased cell density, induced morphological changes consistent with EMT, inhibited cadherin-1 (CDH1) gene expression, and induced an increase in the relative expression of cadherin-2 (CDH2) and vimentin (VIM) genes in A549 cells. These changes were inhibited or decreased by THC and CBD administered alone or in combination. In another series of experiments, we conditioned culture media with A549 cells treated or not with THC and/or CBD, in the presence or absence of TGFβ. We observed that culture media conditioned with A549 in the presence of TGFβ induced an increase in the expression of COL1A1 and VIM, both in CAFs and in non-tumor NFs. Both THC and CBD ameliorated these effects. In summary, the results presented here reinforce the usefulness of cannabinoid agonists for the treatment of some relevant aspects of lung cancer pathology, and demonstrate in a novel way their possible effects on CAFs as a result of their relationship with cancer cells. Likewise, the results reinforce the usefulness of the combined use of THC and CBD, which has important advantages in relation to the possibility of using lower doses, thus minimizing the psychoactive effects of THC.

The role of human umbilical cord mesenchymal stem cells-derived exosomal microRNA-431-5p in survival and prognosis of colorectal cancer patients

We aim to discuss the role of miR-431-5p in colorectal cancer (CRC) progression via regulating peroxiredoxin 1 (PRDX1). miR-431-5p and PRDX1 expression were detected in CRC tissues and cells, and the relationship between miR-431-5p expression and prognosis of CRC patients was analyzed. Exosomes were extracted from human umbilical cord mesenchymal stem cells (hUCMSCs) and co-cultured with LoVo cells. MTT assay, flow cytometry and Transwell assay were implemented to test cell viability, apoptosis and invasion and migration ability, respectively. The tumor growth was determined as well, and the binding relation between miR-431-5p and PRDX1 was confirmed. miR-431-5p was downregulated and PRDX1 was upregulated in CRC, and miR-431-5p downregulation was associated with poor prognosis. hUCMSC-Exos suppressed the malignant behaviors of LoVo cells, and overexpression of miR-431-5p further aggravated the inhibitory effect of hUCMSC-Exos on LoVo cells. hUCMSC-Exos inhibited PRDX1 expression via miR-431-5p. PRDX1 was targeted by miR-431-5p. miR-431-5p serves as a prognostic biomarker in CRC, and hUCMSC-Exos transfer of miR-431-5p decelerates CRC cell growth by inhibiting PRDX1.

Exosomes Regulate the Epithelial-Mesenchymal Transition in Cancer

Exosomes are important mediators of intercellular communication and participate in complex biological processes by transferring a variety of bioactive molecules between cells. Epithelial–mesenchymal transition (EMT) is a process in which the cell phenotype changes from epithelioid to mesenchymal-like. EMT is also an important process for cancer cells by which they acquire invasive and metastatic capabilities, which aggravates the degree of tumor malignancy. Numerous studies have demonstrated that exosomes encapsulate various components, such as microRNAs and proteins, and transfer information between tumor cells or between tumor cells and the tumor microenvironment, thereby regulating the EMT process. Exosomes can also be used for cancer diagnosis and treatment or as a drug delivery platform. Thus, they can be used as a therapeutic tool to control the occurrence of EMT and affect cancer progression. In this review, we summarize the latest research advancements in the regulation of the EMT process in tumor cells by the contents of exosomes. Furthermore, we discuss the potential and challenges of using exosomes as a tool for cancer treatment.

The Interaction Between Long Non-Coding RNAs and Cancer-Associated Fibroblasts in Lung Cancer

Despite great advances in research and treatment, lung cancer is still one of the most leading causes of cancer-related deaths worldwide. Evidence is mounting that dynamic communication network in the tumor microenvironment (TME) play an integral role in tumor initiation and development. Cancer-associated fibroblasts (CAFs), which promote tumor growth and metastasis, are the most important stroma component in the tumor microenvironment. Consequently, in-depth identification of relevant molecular mechanisms and biomarkers related to CAFs will increase understanding of tumor development process, which is of great significance for precise treatment of lung cancer. With the development of sequencing technologies such as microarray and next-generation sequencing, lncRNAs without protein-coding ability have been found to act as communicators between tumor cells and CAFs. LncRNAs participate in the activation of normal fibroblasts (NFs) to CAFs. Moreover, activated CAFs can influence the gene expression and secretion characteristics of cells through lncRNAs, enhancing the malignant biological process in tumor cells. In addition, lncRNA-loaded exosomes are considered to be another important form of crosstalk between tumor cells and CAFs. In this review, we focus on the interaction between tumor cells and CAFs mediated by lncRNAs in the lung cancer microenvironment, and discuss the analysis of biological function and molecular mechanism. Furthermore, it contributes to paving a novel direction for the clinical treatment of lung cancer.

The Colorectal Cancer Tumor Microenvironment and Its Impact on Liver and Lung Metastasis

Simple Summary

Colorectal cancer (CRC) is the third most common cancer worldwide. Metastasis to secondary organs, such as the liver and lungs, is a key driver of CRC-related mortality. The tumor microenvironment, which consists of the primary cancer cells, as well as associated support and immune cells, significantly affects the behavior of CRC cells at the primary tumor site, as well as in metastatic lesions. In this paper, we review the role of the individual components of the tumor microenvironment on tumor progression, immune evasion, and metastasis, and we discuss the implications of these components on antitumor therapies.

Abstract

Colorectal cancer (CRC) is the third most common malignancy and the second most common cause of cancer-related mortality worldwide. A total of 20% of CRC patients present with distant metastases, most frequently to the liver and lung. In the primary tumor, as well as at each metastatic site, the cellular components of the tumor microenvironment (TME) contribute to tumor engraftment and metastasis. These include immune cells (macrophages, neutrophils, T lymphocytes, and dendritic cells) and stromal cells (cancer-associated fibroblasts and endothelial cells). In this review, we highlight how the TME influences tumor progression and invasion at the primary site and its function in fostering metastatic niches in the liver and lungs. We also discuss emerging clinical strategies to target the CRC TME.

Cancer associated-fibroblast-derived exosomes in cancer progression

To identify novel cancer therapies, the tumor microenvironment (TME) has received a lot of attention in recent years in particular with the advent of clinical successes achieved by targeting immune checkpoint inhibitors (ICIs). The TME consists of multiple cell types that are embedded in the extracellular matrix (ECM), including immune cells, endothelial cells and cancer associated fibroblasts (CAFs), which communicate with cancer cells and each other during tumor progression. CAFs are a dominant and heterogeneous cell type within the TME with a pivotal role in controlling cancer cell invasion and metastasis, immune evasion, angiogenesis and chemotherapy resistance. CAFs mediate their effects in part by remodeling the ECM and by secreting soluble factors and extracellular vesicles. Exosomes are a subtype of extracellular vesicles (EVs), which contain various biomolecules such as nucleic acids, lipids, and proteins. The biomolecules in exosomes can be transmitted from one to another cell, and thereby affect the behavior of the receiving cell. As exosomes are also present in circulation, their contents can also be explored as biomarkers for the diagnosis and prognosis of cancer patients. In this review, we concentrate on the role of CAFs-derived exosomes in the communication between CAFs and cancer cells and other cells of the TME. First, we introduce the multiple roles of CAFs in tumorigenesis. Thereafter, we discuss the ways CAFs communicate with cancer cells and interplay with other cells of the TME, and focus in particular on the role of exosomes. Then, we elaborate on the mechanisms by which CAFs-derived exosomes contribute to cancer progression, as well as and the clinical impact of exosomes. We conclude by discussing aspects of exosomes that deserve further investigation, including emerging insights into making treatment with immune checkpoint inhibitor blockade more efficient.