Breast cancer cell-derived extracellular vesicles transfer miR-182-5p and promote breast carcinogenesis via the CMTM7/EGFR/AKT axis

Emerging biologic and clinical implications of miR-182-5p in gynecologic cancers

MicroRNAs (miRNAs) have emerged as important regulators of gene expression in various biological processes, including cancer. miR-182-5p has gained attention for its potential implications in gynecologic cancers, including breast, ovarian, endometrial, and cervical cancers. miR-182-5p dysregulation has been associated with multiple facets of tumor biology in gynecologic cancers, including tumor initiation, progression, metastasis, and therapeutic response. Studies have highlighted its involvement in key signaling pathways and cellular processes that contribute to cancer development and progression. In addition, miR-182-5p has shown potential as a diagnostic and prognostic biomarker, with studies demonstrating its correlation with clinicopathological features and patient outcomes. Furthermore, the therapeutic potential of miR-182-5p is being explored in gynecologic cancers. Strategies such as miRNA mimics or inhibitors targeting miR-182-5p have shown promise in preclinical and early clinical studies. These approaches aim to modulate miR-182-5p expression, restoring normal cellular functions and potentially enhancing treatment responses. Understanding the biologic and clinical implications of miR-182-5p in gynecologic cancers is crucial for the development of targeted therapeutic strategies and personalized medicine approaches. Further investigations are needed to unravel the specific target genes and pathways regulated by miR-182-5p. It is important to consider the emerging biologic and clinical implications of miR-182-5p in gynecologic cancers.

Therapeutic efficacy of TMTP1-modified EVs in overcoming bone metastasis and immune resistance in PIK3CA mutant NSCLC

Non-small cell lung cancer (NSCLC) with PIK3CA mutations demonstrates significant challenges in treatment due to enhanced bone metastasis and immune checkpoint resistance. This study investigates the efficacy of tumor-targeting peptide 1-modified cancer stem cell-derived extracellular vesicles (TMTP1-TSRP-EVs) in reshaping the tumor microenvironment and reversing immune checkpoint resistance in NSCLC. By integrating TMTP1-TSRP into EVs, we aim to specifically deliver therapeutic agents to NSCLC cells, focusing on inhibiting the PI3K/Akt/mTOR pathway, a crucial driver of oncogenic activity and immune evasion in PIK3CA-mutated cells. Our comprehensive in vitro and in vivo analyses show that TMTP1-TSRP-EVs significantly inhibit tumor growth, reduce PD-L1 expression, and enhance CD8+ T cell infiltration, effectively reversing the immune-suppressive microenvironment. Moreover, the in vivo models confirm that our approach not only suppresses bone metastases but also overcomes primary resistance to immune checkpoint inhibitors by modulating the expression of key immunological markers. These findings suggest that targeted delivery of TMTP1-TSRP-EVs could provide a novel therapeutic strategy for treating PIK3CA-mutant NSCLC, offering significant improvements over traditional therapies by directly targeting the molecular pathogenesis of tumor resistance and metastasis. Molecular Mechanisms Reshaping the TME to Halt PI3K-Mutant Bone Metastasis of NSCLC and Overcoming Primary ICI Resistance. (Created by BioRender).

LncRNA PGM5-AS1 inhibits the progression of breast cancer by inhibiting miR-182-5p

LncRNAs serve as crucial regulators in the survival and proliferation of tumors. This study is dedicated to exploring the functional significance of lncRNA PGM5-AS1 in breast cancer (BRCA). First, the expression level of PGM5-AS1 in BRCA patients and its diagnostic ability for BRCA were analyzed by RT-qPCR and Receiver Operating Characteristic curve. Subsequently, LnCAR database was used to preliminarily explore the relationship between PGM5-AS1 and prognosis. Moreover, we investigated the effects PGM5-AS1 on proliferation, apoptosis, and migration of BRCA cells by MTT assay, flow cytometry, and Transwell assay. More importantly, the regulation effect of PGM5-AS1 on the downstream target miR-182-5p was verified by dual luciferase reporting experiment, and the role of miR-182-5p was further explored in vitro experiments. PGM5-AS1 is significantly decreased in both BRCA patients and BRCA cell lines. In the diagnosis of BRCA, the sensitivity and specificity of PGM5-AS1 were 81.5% and 78.5%. Furthermore, lower levels of PGM5-AS1 are associated with a poor prognosis for affected patients. In vitro studies demonstrate that the upregulation of PGM5-AS1 confers a protective effect against BRCA, markedly inhibiting the viability and migratory capacity of tumor cells. More importantly, overexpression of PGM5-AS1 inhibited the high expression of miR-182-5p in tumor cells. In fact, inhibition of miR-182-5p is detrimental to the proliferation and migration of BRCA cells in vitro. lncRNA PGM5-AS1 has potential as a diagnostic marker for BRCA and acts as an inhibitor in BRCA. It inhibits tumor proliferation and metastasis by targeting miR-182-5p.

NGR-Modified CAF-Derived exos Targeting Tumor Vasculature to Induce Ferroptosis and Overcome Chemoresistance in Osteosarcoma

Osteosarcoma (OS) chemoresistance presents a significant clinical challenge. This study aims to investigate the potential of using tumor vascular-targeting peptide NGR-modified cancer-associated fibroblasts (CAFs)-derived exosomes (exos) to deliver circ_0004872-encoded small peptides promoting autophagy-dependent ferroptosis to reverse chemoresistance in OS. Through combined single-cell transcriptome analysis and high-throughput sequencing, it identified circ_0004872 associated with chemoresistance. Subsequent experiments demonstrated that the small peptide encoded by this Circular RNA (circRNA) can effectively reverse chemoresistance by enhancing OS cell sensitivity to chemotherapy via the mechanism of promoting autophagy-dependent ferroptosis. Moreover, in vitro and in vivo results confirmed the efficient delivery of NGR-modified CAFs-derived exo-packaged circ_0004872-109aa to tumor cells, thereby improving targeted therapy efficacy. This study not only offers a novel strategy to overcome chemoresistance in OS but also highlights the potential application value of utilizing exos for drug delivery.

Role of Triple-Negative Breast Cancer-Derived Extracellular Vesicles in Metastasis: Implications for Therapeutics and Biomarker Development

Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer with a poor prognosis and high mortality. The chemotherapeutic regimen remains the predominant treatment modality for TNBC in current clinical practice. However, chemotherapy resistance significantly complicates the development of an effective treatment regimen. Furthermore, the immunosuppressive microenvironment of TNBC contributes to enhanced tumour aggressiveness. Consequently, understanding its mechanisms of progression and finding effective therapeutic interventions is crucial. Recent evidence has identified extracellular vesicles (EVs) as key mediators of cell-to-cell communication in TNBC progression and immune regulation. In view of the remarkable ability of EVs to transfer active molecules, such as proteins and nucleic acids, from parental to recipient cells, they are regarded as a promising biomarker and novel drug delivery system. In this review, we provide an overview of how EVs derived from TNBC cells and tumour microenvironment cells play a role in regulating tumour progression. We also discuss the potential of EVs for immune regulation and their application as novel therapeutic strategies and tumour markers in TNBC. The knowledge gained from studying EV-mediated communication in TNBC could lead to the development of targeted therapies and improve patient outcomes.

Immune-related gene SOX10 affects ferroptosis in pancreatic cancer and facilitates tumor progression by targeting CMTM7-mediated Wnt/β-catenin signaling pathway

OBJECTIVES

SOX10 is crucially implicated in various cancer, yet the regulatory role in pancreatic cancer (PC) remains enigmatic. Underlying molecular mechanisms of SOX10 in PC were explored in our study.

METHODS

Relationships between SOX10 and immune landscape were estimated using bioinformatic approaches. The expression of SOX10 and CMTM7 was analyzed using quantitative real-time polymerase chain reaction and western blot. To assess cell functions, cell counting kit-8, flow cytometry, scratch test, and Transwell assays were performed. Dual-luciferase assay was performed to confirm the target-binding relationship of SOX10 and CMTM7. After knocking down SOX10 using lentiviral transfection, SOX10 action on Wnt/β-catenin pathway and ferroptosis, as well as its anti-tumor activity in tumor-bearing mice were explored.

RESULTS

SOX10 was significantly correlated with immune infiltrations, checkpoints, and characteristics in PC. Mechanically, SOX10 level was increased and CMTM7 was down-regulated in both PANC-1 cells and PC tissues. When SOX10 was downregulated or CMTM7 was overexpressed, it notably hindered the cells' activity, while also promoting cell apoptosis in vitro. Meanwhile, CMTM7 is regulated by SOX10 in the downstream, and its silencing significantly reversed the inhibition of sh-SOX10 on PANC-1 cells growth and Wnt/β-catenin pathway. Furthermore, overexpression of CMTM7 induced ferroptosis in PC by inhibiting the Wnt/β-catenin pathway. More interestingly, by targeting CMTM7-mediated Wnt/β-catenin signaling pathway, the knockdown of SOX10 was confirmed to induce ferroptosis in PC and suppress tumor progression in vivo.

CONCLUSIONS

SOX10 is deemed as an immune-related gene. Its knockdown induces ferroptosis in PC and suppresses tumor progression via CMTM7-mediated Wnt/β-catenin pathway.

CMTM7 shapes the chronic inflammatory and immunosuppressive tumor microenvironment in hepatocellular carcinoma as an M2 macrophage biomarker

Transmembrane domain-containing 7 (CMTM7) is a protein located at the plasma membrane. It plays a role in regulating the development and immune microenvironment of tumor cells. However, the impact of CMTM7 on hepatocellular carcinoma (HCC) is not well understood. To better understand the role of CMTM7 in HCC, the correlations of CMTM7 with clinical characteristics, patient prognosis, chronic inflammation, and immune cell infiltration were analyzed using tissue microarray slides, sequencing datasets and various analysis tools (Web). The bulk sequencing analysis indicated that elevated expression of CMTM7 appears to promote chronic inflammation, immunosuppression, M2 macrophage infiltration, a diminished response to cancer immunotherapy, and an unfavorable clinical prognosis in patients with hepatocellular carcinoma (HCC). Further investigation through single-cell RNA sequencing and multiple fluorescence staining demonstrated that CMTM7 serves as a molecular marker for M2 macrophages and is associated with T cell exhaustion as well as highly plastic stem-like characteristics. We propose that CMTM7 may represent a novel immune checkpoint for HCC patients experiencing suboptimal therapeutic outcomes. Utilizing the Connectivity Map and AutoDock Vina, we predicted two potential compounds targeting CMTM7-fasudil and arachidonyltrifluoromethane-as promising therapeutic candidates. Collectively, these findings suggest that CMTM7-positive macrophages play significant roles in establishing an immunosuppressive tumor microenvironment while promoting highly plastic and stem-like traits in HCC cells, ultimately contributing to poor prognostic outcomes.

Extracellular vesicle-mediated delivery of miR-766-3p from bone marrow stromal cells as a therapeutic strategy against colorectal cancer

OBJECTIVE

As colorectal cancer (CRC) remains one of the leading causes of cancer-related deaths, understanding novel therapeutic mechanisms is crucial. This research focuses on the role of extracellular vesicles (EVs) from bone marrow stromal cells (BMSCs) in delivering miR-766-3p to CRC cells, targeting the MYC/CDK2 signaling axis.

METHODS

Differentially expressed genes between BMSCs-EVs and CRC were identified using the Gene Expression Omnibus database. miR-766-3p target genes were predicted via TargetScan and RNAInter, with protein interactions analyzed using the STRING database. The analysis included RT-qPCR and Western blot on samples from 52 CRC patients. Characterization of BMSCs-EVs was followed by their functional assessment on CRC cell lines and the normal colon cell line CCD-18CO, evaluating cellular uptake, proliferation, migration, invasion, and apoptosis.

RESULTS

miR-766-3p was confirmed in BMSCs-EVs and found underexpressed in CRC. BMSCs-EVs transported miR-766-3p to CRC cells, inhibiting their proliferation, migration, and invasion while promoting apoptosis. miR-766-3p targeted MYC, leading to decreased CDK2 transcription. Overexpression of MYC in HCT-116 cells counteracted these effects. In vivo studies showed that BMSCs-EVs carrying miR-766-3p hindered tumor growth.

CONCLUSION

The study demonstrates the efficacy of BMSCs-EVs in delivering miR-766-3p to CRC cells, leading to the suppression of the MYC/CDK2 signaling pathway and hindering cancer progression.

BMSC derived EVs inhibit colorectal Cancer progression by transporting MAGI2-AS3 or something similar

In this study, we investigated the molecular mechanisms underlying the impact of extracellular vesicles (EVs) derived from bone marrow stromal cells (BMSCs) on colorectal cancer (CRC) development. The focus was on the role of MAGI2-AS3, delivered by BMSC-EVs, in regulating USP6NL DNA methylation-mediated MYC protein translation modification to promote CDK2 downregulation. Utilizing bioinformatics analysis, we identified significant enrichment of MAGI2-AS3 related to copper-induced cell death in CRC. In vitro experiments demonstrated the downregulation of MAGI2-AS3 in CRC cells, and BMSC-EVs were found to deliver MAGI2-AS3 to inhibit CRC cell proliferation, migration, and invasion. Further exploration revealed that MAGI2-AS3 suppressed MYC protein translation modification by regulating USP6NL DNA methylation, leading to CDK2 downregulation and prevention of colorectal cancer. Overexpression of MYC reversed the functional effects of BMSC-EVs-MAGI2-AS3. In vivo experiments validated the inhibitory impact of BMSC-EVs-MAGI2-AS3 on CRC tumorigenicity by promoting CDK2 downregulation through USP6NL DNA methylation-mediated MYC protein translation modification. Overall, BMSC-EVs-MAGI2-AS3 may serve as a potential intervention to prevent CRC occurrence by modulating key molecular pathways.

Angelica sinensis polysaccharide suppresses the Wnt/β-catenin-mediated malignant biological behaviors of breast cancer cells via the miR-3187-3p/PCDH10 axis

Breast cancer (BC) is one of the most common malignant tumors in women. Angelica sinensis polysaccharide (ASP) is one of the main components extracted from the traditional Chinese medicine Angelica sinensis. Research has shown that ASP affects the progression of various cancers by regulating miRNA expression. This study aimed to explore the specific molecular mechanism by which ASP regulates BC progression through miR-3187-3p. After the overexpression or knockdown of miR-3187-3p and PDCH10 in BC cells, the proliferation, migration, invasion, and phenotype of BC cells were evaluated after ASP treatment. Bioinformatics software was used to predict the target genes of miR-3187-3p, and luciferase gene reporter experiments reconfirmed the targeted binding relationship. Subcutaneous tumor formation experiments were conducted in nude mice after the injection of BC cells. Western blot and Ki-67 immunostaining were performed on the tumor tissues. The results indicate that ASP can significantly inhibit the proliferation, migration, and invasion of BC cells. ASP can inhibit the expression of miR-3187-3p in BC cells and upregulate the expression of PDCH10 by inhibiting miR-3187-3p. A regulatory relationship exists between miR-3187-3p and PDCH10. ASP can inhibit the expression of β-catenin and phosphorylated glycogen synthase kinase-3β (p-GSK-3β) proteins through miR-3187-3p/PDCH10 and prevent the occurrence of malignant biological behavior in BC. Overall, this study revealed the potential mechanism by which ASP inhibits the BC process. ASP mediates the Wnt/β-catenin signaling pathway by affecting the miR-3187-3p/PDCH10 molecular axis, thereby inhibiting the proliferation, migration, invasion, and other malignant biological behaviors of BC cells.

Extracellular vesicles in neuroblastoma: role in progression, resistance to therapy and diagnostics

Neuroblastoma (NB) is the most common extracranial solid pediatric cancer, and is one of the leading causes of cancer-related deaths in children. Despite the current multi-modal treatment regimens, majority of patients with advanced-stage NBs develop therapeutic resistance and relapse, leading to poor disease outcomes. There is a large body of knowledge on pathophysiological role of small extracellular vesicles (EVs) in progression and metastasis of multiple cancer types, however, the importance of EVs in NB was until recently not well understood. Studies emerging in the last few years have demonstrated the involvement of EVs in various aspects of NB pathogenesis. In this review we summarize these recent findings and advances on the role EVs play in NB progression, such as tumor growth, metastasis and therapeutic resistance, that could be helpful for future investigations in NB EV research. We also discuss different strategies for therapeutic targeting of NB-EVs as well as utilization of NB-EVs as potential biomarkers.

Research insights into the chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing family (CMTM): their roles in various tumors

The chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing (CMTM) family includes CMTM1-8 and CKLF, and they play key roles in the hematopoietic, immune, cardiovascular, and male reproductive systems, participating in the physiological functions, cancer, and other diseases associated with these systems. CMTM family members activate and chemoattract immune cells to affect the proliferation and invasion of tumor cells through a similar mechanism, the structural characteristics typical of chemokines and transmembrane 4 superfamily (TM4SF). In this review, we discuss each CMTM family member's chromosomal location, involved signaling pathways, expression patterns, and potential roles, and mechanisms of action in pancreatic, breast, gastric and liver cancers. Furthermore, we discuss several clinically applied tumor therapies targeted at the CMTM family, indicating that CMTM family members could be novel immune checkpoints and potential targets effective in tumor treatment.

Extracellular vesicles-associated miRNAs in triple-negative breast cancer: from tumor biology to clinical relevance

Breast cancer (BC), a heterogeneous group of diseases, is the most frequent type and the leading cause of cancer-related death among women worldwide. Tumor heterogeneity directly impacts cancer progression and treatment, as evidenced by the patients´ diverse prognosis and treatment responses across the distinct molecular subtypes. Triple-negative breast cancer (TNBC), which accounts for 10-20% of all diagnosed BC cases, is an aggressive BC subtype with a challenging prognosis. Current treatment options include systemic chemotherapy and/or target therapies based on PARP and PD-L1 inhibitors for eligible patients. MicroRNAs (miRNAs) are important regulatory non-coding RNAs (ncRNAs) in TNBC tumorigenesis. These molecules are present both intracellularly and released into biofluids, packaged into extracellular vesicles (EVs). Emerging evidence indicates that EVs-associated miRNAs (EVs-miRNAs), transferred from parental to recipient cells, are key mediators of cell-to-cell communication. Considering their stability and abundance in several biofluids, these molecules may reflect the epigenomic composition of their tumors of origin and contribute to mediate tumorigenesis, similar to their intracellular counterparts. This review provides the current knowledge on EVs-miRNAs in the TNBC subtype, focusing on their role in regulating mRNA targets involved in tumor phenotypes and their clinical relevance as promising biomarkers in liquid biopsies.

The role of non-coding RNAs in extracellular vesicles in breast cancer and their diagnostic implications

Breast Cancer (BC) is the most common form of cancer worldwide, responsible for 25% of cancers in women. Whilst treatment is effective and often curative in early BC, metastatic disease is incurable, highlighting the need for early detection. Currently, early detection relies on invasive procedures, however recent studies have shown extracellular vesicles (EVs) obtained from liquid biopsies may have clinical utility. EVs transport diverse bioactive cargos throughout the body, play major roles in intercellular communication and, importantly, mirror their cell of origin. In cancer cells, EVs alter the behaviour of the tumour microenvironment (TME), forming a bridge of communication between cancerous and non-cancerous cells to alter all aspects of cancer progression, including the formation of a pre-metastatic niche. Through gene regulatory frameworks, non-coding RNAs (ncRNAs) modulate vital molecular and cellular processes and can act as both tumour suppressors and oncogenic drivers in various cancer types. EVs transport and protect ncRNAs, facilitating their use clinically as liquid biopsies for early BC detection. This review summarises current research surrounding ncRNAs and EVs within BC, focusing on their roles in cancer progression through bi-directional communication with the microenvironment and their diagnostic implications. The role of EV ncRNAs in breast cancer. A representation of the different EV ncRNAs involved in tumourigenic processes in breast cancer. Pro-tumourigenic ncRNAs displayed in green and ncRNAs which inhibit oncogenic processes are shown in red.

Current Opinions on the Relationship Between CMTM Family and Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a typically malignant tumor in the digestive system. The mortality of HCC ranks third place in the world, second only to lung cancer and colorectal cancer. For the characteristics of high invasiveness, high metastasis, high recurrence rate as well as short survival time, HCC treatment has always been difficult in clinical practice. Many causes have contributed to the appearance of these features, including insidious onset, high degree of malignancy, lack of effective early molecular diagnostic markers, and disease prediction models. The human chemokine-like factor superfamily (CMTMs) is a new gene family consisting of CKLF and CMTM1-CMTM8. CMTMs have a marvel domain which can activate and chemotaxis immune cells. Many studies have reported that CMTMs are involved in the regulation of cell growth and development, and play an important role in the malignant progression of the immune system and reproductive system, especially in the development of tumors. In this review, we summarized the structure and function of the human CMTMs, the relationship between its family members and HCC, the prognostic value, potential functions, and mechanisms in HCC. CMTMs could provide a new diagnostic and therapeutic target in clinical practice for patients with HCC.

EV-miRNA-Mediated Intercellular Communication in the Breast Tumor Microenvironment

Cancer research has prioritized the study of the tumor microenvironment (TME) as a crucial area of investigation. Understanding the communication between tumor cells and the various cell types within the TME has become a focal point. Bidirectional communication processes between these cells support cellular transformation, as well as the survival, invasion, and metastatic dissemination of tumor cells. Extracellular vesicles are lipid bilayer structures secreted by cells that emerge as important mediators of this cell-to-cell communication. EVs transfer their molecular cargo, including proteins and nucleic acids, and particularly microRNAs, which play critical roles in intercellular communication. Tumor-derived EVs, for example, can promote angiogenesis and enhance endothelial permeability by delivering specific miRNAs. Moreover, adipocytes, a significant component of the breast stroma, exhibit high EV secretory activity, which can then modulate metabolic processes, promoting the growth, proliferation, and migration of tumor cells. Comprehensive studies investigating the involvement of EVs and their miRNA cargo in the TME, as well as their underlying mechanisms driving tumoral capacities, are necessary for a deeper understanding of these complex interactions. Such knowledge holds promise for the development of novel diagnostic and therapeutic strategies in cancer treatment.

Deregulated miRNA Expression in Triple-Negative Breast Cancer of Ancestral Genomic-Characterized Latina Patients

Among patients with triple-negative breast cancer (TNBC), several studies have suggested that deregulated microRNA (miRNA) expression may be associated with a more aggressive phenotype. Although tumor molecular signatures may be race- and/or ethnicity-specific, there is limited information on the molecular profiles in women with TNBC of Hispanic and Latin American ancestry. We simultaneously profiled TNBC biopsies for the genome-wide copy number and miRNA global expression from 28 Latina women and identified a panel of 28 miRNAs associated with copy number alterations (CNAs). Four selected miRNAs (miR-141-3p, miR-150-5p, miR-182-5p, and miR-661) were validated in a subset of tumor and adjacent non-tumor tissue samples, with miR-182-5p being the most discriminatory among tissue groups (AUC value > 0.8). MiR-141-3p up-regulation was associated with increased cancer recurrence; miR-661 down-regulation with larger tumor size; and down-regulation of miR-150-5p with larger tumor size, high p53 expression, increased cancer recurrence, presence of distant metastasis, and deceased status. This study reinforces the importance of integration analysis of CNAs and miRNAs in TNBC, allowing for the identification of interactions among molecular mechanisms. Additionally, this study emphasizes the significance of considering the patients ancestral background when examining TNBC, as it can influence the relationship between intrinsic tumor molecular characteristics and clinical manifestations of the disease.

Deciphering the Functional Status of Breast Cancers through the Analysis of Their Extracellular Vesicles

Breast cancer (BC) accounts for the highest incidence of tumor-related mortality among women worldwide, justifying the growing search for molecular tools for the early diagnosis and follow-up of BC patients under treatment. Circulating extracellular vesicles (EVs) are membranous nanocompartments produced by all human cells, including tumor cells. Since minimally invasive methods collect EVs, which represent reservoirs of signals for cell communication, these particles have attracted the interest of many researchers aiming to improve BC screening and treatment. Here, we analyzed the cargoes of BC-derived EVs, both proteins and nucleic acids, which yielded a comprehensive list of potential markers divided into four distinct categories, namely, (i) modulation of aggressiveness and growth; (ii) preparation of the pre-metastatic niche; (iii) epithelial-to-mesenchymal transition; and (iv) drug resistance phenotype, further classified according to their specificity and sensitivity as vesicular BC biomarkers. We discuss the therapeutic potential of and barriers to the clinical implementation of EV-based tests, including the heterogeneity of EVs and the available technologies for analyzing their content, to present a consistent, reproducible, and affordable set of markers for further evaluation.

Tumor Cell-Derived Extracellular Vesicles Promote the Growth, Metastasis and Chemoresistance in Cholangiocarcinoma by Delivering microRNA-210 to Downregulate RECK

The development of cholangiocarcinoma (CCA) can be regulated by extracellular vesicles (EVs). In this study, we intend to investigate whether tumor cell-derived EVs delivering microRNA (miR)-210 affect CCA development, involved with reversion-inducing-cysteine-rich protein with kazal motifs (RECK). In silico analysis was performed for identifying differentially expressed miRs and the downstream target genes. The CCA related microarray GSE77984 was used to verify the expression of the target genes in CCA tissue samples. Targeting relationship between miR-210 and RECK was assayed. EVs were extracted from CCA cells, followed by co-culture with CCA cells. The in vitro and in vivo roles of tumor cell-derived EVs on the growth and metastasis of CCA cells were assayed. Upregulated miR-210 and downregulated RECK were found in CCA. CCA cells could uptake tumor cell-derived EVs, and the EVs could promote their migration, invasion, and chemoresistance. RECK expression could be target and inhibited by miR-210. It was further confirmed in vivo that miR-210 shuttled by tumor cell-derived EVs could specifically inhibit RECK expression, which promotes growth, metastasis and chemoresistance of CCA cells. Our current study highlighted that tumor cell-derived EVs could deliver miR-210 to CCA cells, where miR-210 specifically decreases RECK expression, which facilitates growth, metastasis and chemoresistance in CCA.

MicroRNAs in Tumor Endothelial Cells: Regulation, Function and Therapeutic Applications

Tumor endothelial cells (TECs) are key stromal components of the tumor microenvironment, and are essential for tumor angiogenesis, growth and metastasis. Accumulating evidence has shown that small single-stranded non-coding microRNAs (miRNAs) act as powerful endogenous regulators of TEC function and blood vessel formation. This systematic review provides an up-to-date overview of these endothelial miRNAs. Their expression is mainly regulated by hypoxia, pro-angiogenic factors, gap junctions and extracellular vesicles, as well as long non-coding RNAs and circular RNAs. In preclinical studies, they have been shown to modulate diverse fundamental angiogenesis-related signaling pathways and proteins, including the vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) pathway; the rat sarcoma virus (Ras)/rapidly accelerated fibrosarcoma (Raf)/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway; the phosphoinositide 3-kinase (PI3K)/AKT pathway; and the transforming growth factor (TGF)-β/TGF-β receptor (TGFBR) pathway, as well as krüppel-like factors (KLFs), suppressor of cytokine signaling (SOCS) and metalloproteinases (MMPs). Accordingly, endothelial miRNAs represent promising targets for future anti-angiogenic cancer therapy. To achieve this, it will be necessary to further unravel the regulatory and functional networks of endothelial miRNAs and to develop safe and efficient TEC-specific miRNA delivery technologies.

Identifying miRNA biomarkers for breast cancer and ovarian cancer: a text mining perspective

BACKGROUND

microRNA (miRNAs) are small, non-coding RNAs that mediate post-transcriptional gene silencing. Numerous studies have demonstrated the critical role of miRNAs in the development of breast cancer and ovarian cancer. To reduce potential bias from individual studies, a more comprehensive approach of exploring miRNAs in cancer research is essential. This study aims to explore the role of miRNAs in the development of breast cancer and ovarian cancer.

METHODS

Abstracts of the publications were tokenized and the biomedical terms (miRNA, gene, disease, species) were identified and extracted for vectorization. Predictive analyses were conducted with four machine learning models: K-Nearest Neighbors (KNN), Support Vector Machines (SVM), Random Forest (RF), and Naïve Bayes. Both holdout validation and cross-validation were utilized. Feature importance will be identified for miRNA-cancer networks construction.

RESULTS

We found that miR-182 is highly specific to female cancers. miR-182 targets different genes in regulating breast cancer and ovarian cancer. Naïve Bayes provided a promising prediction model for breast cancer and ovarian cancer with miRNAs and genes combination, with an accuracy score greater than 60%. Feature importance identified miR-155 and miR-199 are critical for breast cancer and ovarian cancer prediction, with miR-155 being highly related to breast cancer, whereas miR-199 being more associated with ovarian cancer.

CONCLUSION

Our approach effectively identified potential miRNA biomarkers associated with breast cancer and ovarian cancer, providing a solid foundation for generating novel research hypotheses and guiding future experimental studies.

Breast cancer stem cell-derived extracellular vesicles transfer ARRDC1-AS1 to promote breast carcinogenesis via a miR-4731-5p/AKT1 axis-dependent mechanism

OBJECTIVES

Deregulation of long non-coding RNAs (lncRNAs) has been frequently reported in breast cancer (BC). This goes to show the importance of understanding its significant contribution towards breast carcinogenesis. In the present study, we clarified a carcinogenic mechanism based on the ARRDC1-AS1 delivered by breast cancer stem cells-derived extracellular vesicles (BCSCs-EVs) in BC.

METHODS

The isolated and well characterized BCSCs-EVs were co-cultured with BC cells. The expression of ARRDC1-AS1, miR-4731-5p, and AKT1 was determined in BC cell lines. BC cells were assayed for their viability, invasion, migration and apoptosis in vitro by CCK-8, Transwell and flow cytometry, as well as tumor growth in vivo after loss- and gain-of function assays. Dual-luciferase reporter gene, RIP and RNA pull-down assays were performed to determine the interactions among ARRDC1-AS1, miR-4731-5p, and AKT1.

RESULTS

Elevation of ARRDC1-AS1 and AKT1 as well as miR-4731-5p downregulation were observed in BC cells. ARRDC1-AS1 was enriched in BCSCs-EVs. Furthermore, EVs containing ARRDC1-AS1 enhanced the BC cell viability, invasion and migration and glutamate concentration. Mechanistically, ARRDC1-AS1 elevated the expression of AKT1 by competitively binding to miR-4731-5p. ARRDC1-AS1-containing EVs were also found to enhance tumor growth in vivo.

CONCLUSION

Collectively, BCSCs-EVs-mediated delivery of ARRDC1-AS1 may promote the malignant phenotypes of BC cells via the miR-4731-5p/AKT1 axis.

Terminal fucosylation of haptoglobin in cancer-derived exosomes during cholangiocarcinoma progression

BACKGROUND

Cholangiocarcinoma (CCA) is a silent tumor with a high mortality rate due to the difficulty of early diagnosis and prediction of recurrence even after timely surgery. Serologic cancer biomarkers have been used in clinical practice, but their low specificity and sensitivity have been problematic. In this study, we aimed to identify CCA-specific glycan epitopes that can be used for diagnosis and to elucidate the mechanisms by which glycosylation is altered with tumor progression.

METHODS

The serum of patients with various cancers was fractioned into membrane-bound and soluble components using serial ultracentrifugation. Lectin blotting was conducted to evaluate glycosylation. Proteins having altered glycosylation were identified using proteomic analysis and further confirmed using immunoblotting analysis. We performed HPLC, gene analysis, real-time cargo tracking, and immunohistochemistry to determine the origin of CCA glycosylation and its underlying mechanisms. Extracellular vesicles (EV) were isolated from the sera of 62 patients with CCA at different clinical stages and inflammatory conditions and used for glycan analysis to assess their clinical significance.

RESULTS

The results reveal that glycosylation patterns between soluble and membrane-bound fractions differ significantly even when obtained from the same donor. Notably, glycans with α1-3/4 fucose and β1-6GlcNAc branched structures increase specifically in membrane-bound fractions of CCA. Mechanically, it is primarily due to β-haptoglobin (β-Hp) originating from CCA expressing fucosyltransferase-3/4 (FUT 3/4) and N-acetylglucosaminyltransferase-V (MGAT5). Newly synthesized β-Hp is loaded into EVs in early endosomes via a KFERQ-like motif and then secreted from CCA cells to induce tumor progression. In contrast, β-Hp expressed by hepatocytes is secreted in a soluble form that does not affect CCA progression. Moreover, evaluation of EV glycosylation in CCA patients shows that fucosylation level of EV-Hp gradually increases with tumor progression and decreases markedly when the tumors are eliminated by surgery.

CONCLUSION

This study suggests that terminal fucosylation of Hp in cancer-derived exosomes can be a novel glycan marker for diagnosis and prognosis of CCA. These findings highlight the potential of glycan analysis in different fractions of serum for biomarker discover for other diseases. Further research is needed to understand the role of fucosylated EVs on CCA progression.

Two oncomiRs, miR-182-5p and miR-103a-3p, Involved in Intravenous Leiomyomatosis

Leiomyomas, also referred to as fibroids, belong to the most common type of benign tumors developing in the myometrium of the uterus. Intravenous leiomyomatosis (IVL) tends to be regarded as a rare type of uterine leiomyoma. IVL tumors are characterized by muscle cell masses developing within the uterine and extrauterine venous system. The underlying mechanism responsible for the proliferation of these lesions is still unknown. The aim of the study was to investigate the expression of the two epigenetic factors, oncomiRs miR-182-5p and miR-103a-3p, in intravenous leiomyomatosis. This study was divided into two stages: initially, miR-182-5p and miR-103a-3p expression was assessed in samples coming from intravenous leiomyomatosis localized in myometrium (group I, n = 6), intravenous leiomyomatosis beyond the uterus (group II; n = 5), and the control group, i.e., intramural leiomyomas (group III; n = 9). The expression level of miR-182-5p was significantly higher in samples coming from intravenous leiomyomatosis (group I and group II) as compared to the control group (p = 0.029 and p = 0.024, respectively). In the second part of the study, the expression levels of the studied oncomiRs were compared between seven samples delivered from one woman during a four-year observation. The long-term follow-up of one patient demonstrated significantly elevated levels of both studied oncomiRs in intravenous leiomyomatosis in comparison to intramural leiomyoma samples.

Extracellular vesicles as a novel approach for breast cancer therapeutics

Breast cancer (BC) still lacks effective management approaches to control metastatic and therapy-resistant disease. Extracellular vesicles (EVs), with a diameter of 50-1000 nm, are secreted by all types of living cells, are protected by a lipid bilayer and encapsulate biological cargos including RNAs, proteins and lipids. They play an important role in intercellular communications and are significantly associated with pathological conditions. Accumulating evidence indicates that cancer cells secrete EVs and communicate with neighboring cells within the tumor microenvironment (TME), which plays an important role in BC metastasis, immune escape and chemoresistance, thus providing a new therapeutic window. EVs can stimulate angiogenesis and extracellular matrix remodeling, establish premetastatic niches, inhibit immune response and promote cancer metastasis. Recent advances have demonstrated that EVs are a potential therapeutic target or carrier and have emerged as promising strategies for BC treatment. In this review, we summarize the role of EVs in BC metastasis, chemoresistance and immune escape, which provides the foundation for developing novel therapeutic approaches. We also focus on current EV-based drug delivery strategies in BC and EV cargo-targeted BC therapy and discuss the limitations and future perspectives of EV-based drug delivery in BC.

CMTM7 inhibits breast cancer progression by regulating Wnt/β-catenin signaling

BACKGROUND

Breast cancer is the major cause of death in females globally. Chemokine-like factor like MARVEL transmembrane domain containing 7 (CMTM7) is reported as a tumor suppressor and is involved in epidermal growth factor receptor degradation and PI3K/AKT signaling in previous studies. However, other molecular mechanisms of CMTM7 remain unclear.

METHODS

The expression level of CMTM7 in breast cancer cells and tissues was detected by qRT-PCR and western blot, and the methylation of CMTM7 promoter was detected by BSP sequencing. The effect of CMTM7 was verified both in vitro and in vivo, including MTT, colony formation, EdU assay, transwell assay and wound healing assay. The interaction between CMTM7 and CTNNA1 was investigated by co-IP assay. The regulation of miR-182-5p on CMTM7 and TCF3 on miR-182-5p was detected by luciferase reporter assay and ChIP analysis.

RESULTS

This study detected the hypermethylation levels of the CMTM7 promoter region in breast cancer tissues and cell lines. CMTM7 was performed as a tumor suppressor both in vitro and in vivo. Furthermore, CMTM7 was a direct miR-182-5p target. Besides, we found that CMTM7 could interact with Catenin Alpha 1 (CTNNA1) and regulate Wnt/β-catenin signaling. Finally, transcription factor 3 (TCF3) can regulate miR-182-5p. We identified a feedback loop with the composition of miR-182-5p, CMTM7, CTNNA1, CTNNB1 (β-catenin), and TCF3, which play essential roles in breast cancer progression.

CONCLUSION

These findings reveal the emerging character of CMTM7 in Wnt/β-catenin signaling and bring new sights of gene interaction. CMTM7 and other elements in the feedback loop may serve as emerging targets for breast cancer therapy.

Endothelial progenitor cell derived exosomes mediated miR-182-5p delivery accelerate diabetic wound healing via down-regulating PPARG

Diabetic wound is one of the most common and serious complications of diabetes, which is characterized by abnormal number and quality of wound repair related cells. Previous studies have shown that human endothelial progenitor cells derived exosomes (EPCs-EXO) can promote diabetic wound healing through modulating vascular endothelial cell function. The purpose of this study was to investigate the biological effects and molecular mechanisms of EPCs-EXO on diabetic wound healing. The regulation of EPCs-EXO on human immortalized epidermal cell line HaCaT in high glucose (HG) environment was evaluated. Our data showed that EPCs-EXO promoted the proliferation, migration, while inhibited apoptosis of HaCaTs challenged by HG via elevating miR-182-5p expression level in vitro. Skin wound healing was significantly enhanced by EPCs-EXO in diabetic mice. Moreover, bioinformatics analyses and luciferase reporter assay indicated that exosomal miR-182-5p was bound to PPARG 3' UTR sequence and inhibited the expression of PPARG. Collectively, our findings provided a new role of EPCs-EXO in the clinical treatment of diabetic skin wounds. Diabetic wound is one of the most common and serious complications of diabetes, which is characterized by abnormal number and quality of wound repair related cells. Previous studies have shown that human endothelial progenitor cells derived exosomes (EPCs-EXO) can promote diabetic wound healing through modulating vascular endothelial cell function. The purpose of this study was to investigate the biological effects and molecular mechanisms of EPCs-EXO on diabetic wound healing. The regulation of EPCs-EXO on human immortalized epidermal cell line HaCaT in high glucose (HG) environment was evaluated. Our data showed that EPCs-EXO promoted the proliferation, migration, while inhibited apoptosis of HaCaTs challenged by HG via elevating miR-182-5p expression level in vitro. Skin wound healing was significantly enhanced by EPCs-EXO in diabetic mice. Moreover, bioinformatics analyses and luciferase reporter assay indicated that exosomal miR-182-5p was bound to PPARG 3' UTR sequence and inhibited the expression of PPARG. Collectively, our findings provided a new role of EPCs-EXO in the clinical treatment of diabetic skin wounds.

MiR-182 Is Upregulated in Prostate Cancer and Contributes to Tumor Progression by Targeting MITF

Altered expression of microRNA-182-5p (miR-182) has been consistently linked with many cancers, but its specific role in prostate cancer remains unclear. In particular, its contribution to epithelial-to-mesenchymal transition (EMT) in this setting has not been well studied. Therefore, this paper profiles the expression of miR-182 in prostate cancer and investigates how it may contribute to progression of this disease. In vitro experiments on prostate cancer cell lines and in silico analyses of The Cancer Genome Atlas (TCGA) prostate adenocarcinoma (PRAD) datasets were performed. PCR revealed miR-182 expression was significantly increased in prostate cancer cell lines compared to normal prostate cells. Bioinformatic analysis of TCGA PRAD data similarly showed upregulation of miR-182 was significantly associated with prostate cancer and clinical markers of disease progression. Functional enrichment analysis confirmed a significant association of miR-182 and its target genes with EMT. The EMT-linked gene MITF (melanocyte inducing transcription factor) was subsequently shown to be a novel target of miR-182 in prostate cancer cells. Further TCGA analysis suggested miR-182 expression can be an indicator of patient outcomes and disease progression following therapy. In summary, this is the first study to report that miR-182 over-expression in prostate cancer may contribute to EMT by targeting MITF expression. We propose miR-182 as a potentially useful diagnostic and prognostic biomarker for prostate cancer and other malignancies.

MiRNAs Overexpression and Their Role in Breast Cancer: Implications for Cancer Therapeutics

MicroRNAs have a plethora of roles in various biological processes in the cells and most human cancers have been shown to be associated with dysregulation of the expression of miRNA genes. MiRNA biogenesis involves two alternative pathways, the canonical pathway which requires the successful cooperation of various proteins forming the miRNA-inducing silencing complex (miRISC), and the non-canonical pathway, such as the mirtrons, simtrons, or agotrons pathway, which bypasses and deviates from specific steps in the canonical pathway. Mature miRNAs are secreted from cells and circulated in the body bound to argonaute 2 (AGO2) and miRISC or transported in vesicles. These miRNAs may regulate their downstream target genes via positive or negative regulation through different molecular mechanisms. This review focuses on the role and mechanisms of miRNAs in different stages of breast cancer progression, including breast cancer stem cell formation, breast cancer initiation, invasion, and metastasis as well as angiogenesis. The design, chemical modifications, and therapeutic applications of synthetic anti-sense miRNA oligonucleotides and RNA mimics are also discussed in detail. The strategies for systemic delivery and local targeted delivery of the antisense miRNAs encompass the use of polymeric and liposomal nanoparticles, inorganic nanoparticles, extracellular vesicles, as well as viral vectors and viruslike particles (VLPs). Although several miRNAs have been identified as good candidates for the design of antisense and other synthetic modified oligonucleotides in targeting breast cancer, further efforts are still needed to study the most optimal delivery method in order to drive the research beyond preclinical studies.

CMTM7 recognizes an immune-hot tumor microenvironment and predicts therapeutic response of immunotherapy in breast cancer well

Breast cancer (BRCA) is a complex disease that leads to major mortalities and unsatisfactory clinical outcomes among women worldwide. CKLF-like MARVEL transmembrane domain-containing 7 (CMTM7) is a potential tumor suppressor and regulator of PD-L1, which has been found as a functional signature in considerable oncogenesis, progression, and therapeutic resistance via deletion and downregulation. In this research, triple-negative breast cancer (BRCA), a molecular subtype having a lower response to endocrinotherapy but a higher response to chemotherapy and immunotherapy, showed higher transcriptional levels of CMTM7. Moreover, CMTM7 positively correlated with immunomodulators, tumor-infiltrating immune cells (TIICs), and immune checkpoints in many independent datasets. Furthermore, in an immunotherapy cohort of BRCA, patients with high CMTM7 expression were more sensitive to immunotherapy, and the therapeutic predictive value of CMTM7 is higher than that of PD-1 and PD-L1. To sum up, CMTM7 correlated with an inflamed tumor microenvironment and identified immune-hot tumors, which can be a novel biomarker for the recognition of immunological characteristics and an immunotherapeutic response in BRCA.

Counter Regulation of Tumor Angiogenesis by Vascular Endothelial Growth Factor and Thrombospondin-1

Considerable progress has been made in our understanding of the process of angiogenesis in the context of normal and tumor tissue over the last fifty years. Angiogenesis, like most physiological processes, is carefully controlled by dynamic and opposing effects of positive factors, such as vascular endothelial growth factor (VEGF), and negative factors, such as thrombospondin-1. In most cases, the progression of a small mass of cancerous cells to a life-threatening tumor depends upon the initiation of angiogenesis and involves the dysregulation of the angiogenic balance. Whereas our newfound appreciation for the role of angiogenesis in cancer has opened up new avenues for treatment, the success of these treatments, which have focused almost exclusively on antagonizing the VEGF pathway, has been limited to date. It is anticipated that this situation will improve as more therapeutics that target other pathways are developed, more strategies for combination therapies are advanced, more detailed stratification of patient populations occurs, and a better understanding of resistance to anti-angiogenic therapy is gained.

Extracellular vesicles as central regulators of blood vessel function in cancer

Blood vessels deliver oxygen and nutrients that sustain tumor growth and enable the dissemination of cancer cells to distant sites and the recruitment of intratumoral immune cells. In addition, the structural and functional abnormalities of the tumor vasculature foster the development of an aggressive tumor microenvironment and impair the efficacy of existing cancer therapies. Extracellular vesicles (EVs) have emerged as major players of tumor progression, and a growing body of evidence has demonstrated that EVs derived from cancer cells trigger multiple responses in endothelial cells that alter blood vessel function in tumors. EV-mediated signaling in endothelial cells can occur through the transfer of functional cargos such as miRNAs, lncRNAs, cirRNAs, and proteins. Moreover, membrane-bound proteins in EVs can elicit receptor-mediated signaling in endothelial cells. Together, these mechanisms reprogram endothelial cells and contribute to the sustained exacerbated angiogenic signaling typical of tumors, which, in turn, influences cancer progression. Targeting these angiogenesis-promoting EV-dependent mechanisms may offer additional strategies to normalize tumor vasculature. Here, we discuss the current knowledge pertaining to the contribution of cancer cell-derived EVs in mechanisms regulating blood vessel functions in tumors. Moreover, we discuss the translational opportunities in targeting the dysfunctional tumor vasculature using EVs and highlight the open questions in the field of EV biology that can be addressed using mass spectrometry-based proteomics analysis.

Breast Cancer-Delivered Exosomal miRNA as Liquid Biopsy Biomarkers for Metastasis Prediction: A Focus on Translational Research with Clinical Applicability

Metastasis represents the most important cause of breast cancer-associated mortality. Even for early diagnosed stages, the risk of metastasis is significantly high and predicts a grim outcome for the patient. Nowadays, efforts are made for identifying blood-based biomarkers that could reliably distinguish patients with highly metastatic cancers in order to ensure a closer follow-up and a more personalized therapeutic method. Exosomes are nano vesicles secreted by cancer cells that can transport miRNAs, proteins, and other molecules and deliver them to recipient cells all over the body. Through this transfer, cancer cells modulate their microenvironment and facilitate the formation of the pre-metastatic niche, leading to sustained progression. Exosomal miRNAs have been extensively studied due to their promising potential as prognosis biomarkers for metastatic breast cancer. In this review, we tried to depict an overview of the existing literature regarding exosomal miRNAs that are already validated as potential biomarkers, and which could be immediately available for the clinic. Moreover, in the last section, we highlighted several miRNAs that have proven their function in preclinical studies and could be considered for clinical validation. Considering the lack of standard methods for evaluating exosomal miRNA, we also discussed the challenges and the technical aspects underlying this issue.

Comprehensive Analyses of miRNAs Revealed miR-92b-3p, miR-182-5p and miR-183-5p as Potential Novel Biomarkers in Melanoma-Derived Extracellular Vesicles

Extracellular vesicles (EVs) are important mediators in the intercellular communication, influencing the function and phenotype of different cell types within the tumor micro-milieu and thus promote tumor progression. Since EVs safely transport packages of proteins, lipids and also nucleic acids such as miRNAs, EVs and their cargo can serve as diagnostic and prognostic markers. Therefore, the aim of this study was to investigate EV embedded miRNAs specific for melanoma, which could serve as potential biomarkers. In contrast to previous studies, we not only analysed miRNAs from EVs, but also included the miRNA profiles from the EV-secreting cells to identify candidates as suitable biomarkers. While the characterization of EVs derived from normal melanocytes and melanoma cells showed largely comparable properties with regard to size distribution and expression of protein markers, the NGS analyses yielded marked differences for several miRNAs. While miRNA load of EVs derived from normal human epidermal melanocytes (NHEMs) and melanoma cells were very similar, they were highly different from their secreting cells. By comprehensive analyses, six miRNAs were identified to be enriched in both melanoma cells and melanoma cell-derived EVs. Of those, the accumulation of miR-92b-3p, miR-182-5p and miR-183-5p in EVs could be validated in vitro. By functional network generation and pathway enrichment analysis we revealed an association with different tumor entities and signaling pathways contributing melanoma progression. Furthermore, we found that miR-92b-3p, miR-182-5p and miR-183-5p were also enriched in EVs derived from serum of melanoma patients. Our results support the hypothesis that miRNAs derived from EVs can serve as prognostic or diagnostic liquid biopsy markers in melanoma. We identified EV-derived miRNAs and showed that those miRNAs, which were enriched in melanoma cells and EVs, are also found elevated in serum-derived EVs of patients with metastatic melanoma, but not in healthy subjects.

IL-35 enhances angiogenic effects of small extracellular vesicles in breast cancer

As an indispensable process for breast cancer metastasis, tumour angiogenesis requires a tight interaction between cancer cells and endothelial cells in tumour microenvironment. Here, we explored the participation of small extracellular vesicles (sEVs) derived from breast cancer cells in modulating angiogenesis and investigated the effect of IL-35 in facilitating this process. Firstly, we characterized breast cancer cells-derived sEVs untreated or treated with IL-35 and visualized the internalization of these sEVs by human umbilical vein endothelial cells (HUVECs). Breast cancer cells-derived sEVs promoted endothelial cell proliferation through facilitating cell cycle progression and enhanced capillary-like structures formation and microvessel formation. Subsequent results proved that IL-35 further reinforced the angiogenic effect induced by breast cancer cells-derived sEVs. Moreover, sEVs from breast cancer cells significantly enhanced tumour growth and microvessel density in breast tumour-bearing mice model. Microarray analysis showed that IL-35 might alter the mRNA profiles of sEVs and activate the Ras/Raf/MEK/ERK signalling pathway. These findings demonstrated that IL-35 indirectly promoted angiogenesis in breast cancer through regulating the content of breast cancer cells-derived sEVs, which could be internalized by HUVECs.

Circulating miRNAs in Breast Cancer Diagnosis and Prognosis

Great improvement has been made in the diagnosis and therapy of breast cancer patients. However, the identification of biomarkers for early diagnosis, prognosis, therapy assessment and monitoring, including drug resistance and the early detection of micro-metastases, is still lacking. Recently, circulating microRNAs (miRNAs), circulating freely in the blood stream or entrapped in extracellular vesicles (EVs), have been shown to have a potential diagnostic, prognostic or predictive power. In this review, recent findings are summarized, both at a preclinical and clinical level, related to miRNA applicability in the context of breast cancer. Different aspects, including clinical and technical challenges, are discussed, describing the potentialities of miRNA use in breast cancer. Even though more methodological standardized studies conducted in larger and selected patient cohorts are needed to support the effective clinical utility of miRNA as biomarkers, they could represent novel and accessible tools to be transferred into clinical practice.

Targeting Angiogenesis in Breast Cancer: Current Evidence and Future Perspectives of Novel Anti-Angiogenic Approaches

Angiogenesis is a vital process for the growth and dissemination of solid cancers. Numerous molecular pathways are known to drive angiogenic switch in cancer cells promoting the growth of new blood vessels and increased incidence of distant metastasis. Several angiogenesis inhibitors are clinically available for the treatment of different types of advanced solid cancers. These inhibitors mostly belong to monoclonal antibodies or small-molecule tyrosine kinase inhibitors targeting the classical vascular endothelial growth factor (VEGF) and its receptors. Nevertheless, breast cancer is one example of solid tumors that had constantly failed to respond to angiogenesis inhibitors in terms of improved survival outcomes of patients. Accordingly, it is of paramount importance to assess the molecular mechanisms driving angiogenic signaling in breast cancer to explore suitable drug targets that can be further investigated in preclinical and clinical settings. This review summarizes the current evidence for the effect of clinically available anti-angiogenic drugs in breast cancer treatment. Further, major mechanisms associated with intrinsic or acquired resistance to anti-VEGF therapy are discussed. The review also describes evidence from preclinical and clinical studies on targeting novel non-VEGF angiogenic pathways in breast cancer and several approaches to the normalization of tumor vasculature by targeting pericytes, utilization of microRNAs and extracellular tumor-associate vesicles, using immunotherapeutic drugs, and nanotechnology.

Insights into the Steps of Breast Cancer-Brain Metastases Development: Tumor Cell Interactions with the Blood-Brain Barrier

Brain metastases (BM) represent a growing problem for breast cancer (BC) patients. Recent studies have demonstrated a strong impact of the BC molecular subtype on the incidence of BM development. This study explores the interaction between BC cells of different molecular subtypes and the blood–brain barrier (BBB). We compared the ability of BC cells of different molecular subtypes to overcome several steps (adhesion to the brain endothelium, disruption of the BBB, and invasion through the endothelial layer) during cerebral metastases formation, in vitro as well as in vivo. Further, the impact of these cells on the BBB was deciphered at the molecular level by transcriptome analysis of the triple-negative (TNBC) cells themselves as well as of hBMECs after cocultivation with BC cell secretomes. Compared to luminal BC cells, TNBC cells have a greater ability to influence the BBB in vitro and consequently develop BM in vivo. The brain-seeking subline and parental TNBC cells behaved similarly in terms of adhesion, whereas the first showed a stronger impact on the brain endothelium integrity and increased invasive ability. The comparative transcriptome revealed potential brain-metastatic-specific key regulators involved in the aforementioned processes, e.g., the angiogenesis-related factors TNXIP and CXCL1. In addition, the transcriptomes of the two TNBC cell lines strongly differed in certain angiogenesis-associated factors and in several genes related to cell migration and invasion. Based on the present study, we hypothesize that the tumor cell’s ability to disrupt the BBB via angiogenesis activation, together with increased cellular motility, is required for BC cells to overcome the BBB and develop brain metastases.

Anti-Cancer Role and Therapeutic Potential of Extracellular Vesicles

Cell-cell communication is an important mechanism in biological processes. Extracellular vesicles (EVs), also referred to as exosomes, microvesicles, and prostasomes, are microvesicles secreted by a variety of cells. EVs are nanometer-scale vesicles composed of a lipid bilayer and contain biological functional molecules, such as microRNAs (miRNAs), mRNAs, and proteins. In this review, "EVs" is used as a comprehensive term for vesicles that are secreted from cells. EV research has been developing over the last four decades. Many studies have suggested that EVs play a crucial role in cell-cell communication. Importantly, EVs contribute to cancer malignancy mechanisms such as carcinogenesis, proliferation, angiogenesis, metastasis, and escape from the immune system. EVs derived from cancer cells and their microenvironments are diverse, change in nature depending on the condition. As EVs are thought to be secreted into body fluids, they have the potential to serve as diagnostic markers for liquid biopsy. In addition, cells can encapsulate functional molecules in EVs. Hence, the characteristics of EVs make them suitable for use in drug delivery systems and novel cancer treatments. In this review, the potential of EVs as anti-cancer therapeutics is discussed.