Tumor metastasis is a major obstacle for the effective treatment of breast cancer. Some studies showed that exosomes could promote tumor distant metastasis by establishing pre-metastasis niches (PMN). MicroRNAs (miRNAs) in exosomes play a critical role in tumor development and invasion. We aimed to investigate the effects of exosomal miRNAs derived from breast cancer cells on metastasis. MiRNA sequencing and RT-PCR approach were used to screen potential exosomal miRNAs. We compared the levels of serum exosomal miRNAs from breast cancer patients and those from MCF10A/MCF7/MDA-MB-231 cells. We found that differential exosomal miRNAs screened from patients with metastasis have higher expression levels in exosomes secreted by MDA-MB-231 cells. Using miRNA mimics or inhibitors, exosomal miR-122-5p was found to enhance the secretion levels of chemokine MCP-1 and SDF-1 from WI-38 lung fibroblast cells. In vitro luciferase assay and western blot confirmed the targeting of 3'-untranslated region of MKP-2 and suppression of MKP-2 expression by miR-122-5p in WI-38 cells. Treatment of xenograft mice with exosomal miR-122-5p increased the levels of MCP-1 and SDF-1 in serum, and promoted lung metastasis of breast cancer. In conclusion, we identified exosomal miR-122-5p from breast cancer cells that could promote the chemokine secretion of lung fibroblasts, which might facilitate the chemotaxis and colonization of breast cancer cells in lung tissue.

Hindered by the challenges of blood-brain barrier (BBB) hindrance, tumor heterogeneity and immunosuppressive microenvironment, patients with breast cancer brain metastasis have yet to benefit from current clinical treatments, experiencing instead a decline in quality of life due to radiochemotherapy. While virus-mimicking nanosystems (VMN) mimicking viral infection processes show promise in treating peripheral tumors, the inability to modulate the immunosuppressive microenvironment limits the efficacy against brain metastasis. Accordingly, a VMN-based triple immunomodulatory strategy is initially proposed, aiming to activate innate and adaptive immune responses and reverse the immunosuppressive microenvironment. Here, manganese-based virus-mimicking nanomedicine (Vir-HD@HM) with intratumoral drug enrichment is engineered. Vir-HD@HM can induce the immune response through the activation of cGAS-STING by mimicking the in vivo infection process of herpesviruses. Meanwhile, DNAzyme mimicking the genome can rescue the epigenetic silencing of PTEN with the assistance of Mn2+, thus ameliorating the immunosuppressive metastatic microenvironment and achieving synergistic sensitizing therapeutic efficacy. In vivo experiments substantiate the efficacy of Vir-HD@HM in recruiting NK cells and CD8+ T cells to metastatic foci, inhibiting Treg cells infiltration, and prolonging murine survival without adjunctive radiochemotherapy. This study demonstrates that Vir-HD@HM with triple immunomodulation offers an encouraging therapeutic option for patients with brain metastasis.

Breast cancer brain metastases (BrM) are a common and fatal complication in advanced breast cancer patients, with the intricate brain microenvironment significantly limiting the efficacy of current therapeutic strategies. Recently, the neuro-astrocytic network, as a core component of the brain metastasis microenvironment, has garnered extensive attention for its pivotal role in supporting tumor adaptive growth. This review systematically outlines the adaptive mechanisms of the neuro-astrocytic network in BrM, including bidirectional interactions between tumor cells, neurons, and astrocytes, and their profound effects on synapse-like signaling, metabolic pathways, and regulatory networks. Furthermore, we integrate recent advancements in exploring therapeutic targets and discuss potential intervention strategies against tumor-microenvironment interactions and associated challenges. Future research focusing on the multi-target collaborative mechanisms within this network and its clinical translational potential may provide new avenues for precise treatment of BrM.

Lung cancer (LC) signifies the primary cause of cancer-related mortality, representing 24 % of all cancer fatalities. LC is intricate and necessitates innovative approaches for early detection, precise diagnosis, and tailored treatment. Exosomes (EXOs), a subclass of extracellular vesicles (EVs), are integral to LC advancement, intercellular communication, tumor spread, and resistance to anticancer therapies. EXOs represent a viable drug delivery strategy owing to their distinctive biological characteristics, such as natural origin, biocompatibility, stability in blood circulation, minimal immunogenicity, and potential for modification. They can function as vehicles for targeted pharmaceuticals and facilitate the advancement of targeted therapeutics. EXOs are pivotal in the metastatic cascade, facilitating communication between cancer cells and augmenting their invasive capacity. Nonetheless, obstacles such as enhancing cargo loading efficiency, addressing homogeneity concerns during preparation, and facilitating large-scale clinical translation persist. Interdisciplinary collaboration in research is crucial for enhancing the efficacy of EXOs drug delivery systems. This review explores the role of EXOs in LC, their potential as therapeutic agents, and challenges in their development, aiming to advance targeted treatments. Future research should concentrate on engineering optimization and developing innovative EXOs to improve flexibility and effectiveness in clinical applications.

Ductal carcinoma in situ (DCIS) is a precancerous condition that increases the risk of invasive breast cancer (IBC), but not all DCIS cases progress to IBC. The molecular factors driving this transition remain unclear. Small extracellular vesicles (sEVs), or exosomes, play a role in advanced cancer progression, though their function in DCIS is poorly understood. This study explores the role of sEVs and their RNA content in DCIS progression. We found that Rab27A, a key regulator of exosome release, is upregulated in DCIS and IBC tissues compared to normal breast tissue. Inhibiting sEV release by knocking down Rab27A disrupted pro-invasive signaling and reduced invasion in a DCIS mouse model. Using the MCF10 breast cancer progression series, we observed increased microRNA (miRNA) content in sEVs as cells transitioned from normal to malignant, with the most significant differential miRNA expression seen in IBC-derived sEVs. In vivo, DCIS progression raised circulating sEV miRNA levels, which were reduced by Rab27A knockdown. Reintroducing miR-205, enriched in IBC-derived sEVs, suppressed DCIS cell proliferation, invasion, and epithelial-mesenchymal transition (EMT) markers. Co-expression of miR-205 with Rab27A knockdown also suppressed TGF-β signaling, activated MAPK p38, and induced cell cycle arrest and apoptosis. These findings show that the RNA cargo of sEVs changes during malignancy, with specific miRNAs driving DCIS progression. Re-expression of miR-205 offers a promising therapeutic approach to prevent DCIS from becoming invasive.

Extracellular vesicles (EVs) are small particles released by various cells, including cancer cells. They play a significant role in the development of different cancers, including brain metastasis. These EVs transport biomolecular materials such as RNA, DNA, and proteins from tumour cells to other cells, facilitating the spread of primary tumours to the brain tissue. EVs interact with the endothelial cells of the blood-brain barrier (BBB), compromising its integrity and allowing metastatic cells to pass through easily. Additionally, EVs interact with various cells in the brain's microenvironment, creating a conducive environment for incoming metastatic cells. They also influence the immune system within this premetastatic environment, promoting the growth of metastatic cells. This review paper focuses on the research regarding the role of EVs in the development of brain metastasis, including their impact on disrupting the BBB, preparing the premetastatic environment, and modulating the immune system. Furthermore, the paper discusses the potential of EVs as diagnostic and prognostic biomarkers for brain metastasis.

Guanylate binding protein 5 (GBP5) and exosomal miRNAs are involved in tumor progression. While several studies reveal the connection between GBP5 and exosomes for immune response and infection, this relationship in cancer, particularly in oral squamous cell carcinoma (OSCC), remains unexplored.

The exosomal miRNA extracted from the cells was analyzed using next-generation sequencing. Bioinformatic tools were used to predict exosomal miRNA target genes. OSCC cell growth was verified by colony formation, cell viability, and cell cycle analysis. The Cancer Genome Atlas database was used to inspect the prognosis of OSCC patients.

Our results showed that OSCC cells treated with exosomes from GBP5-silenced OSCC cells reduced colony formation. Also, 56 differentially expressed exosomal miRNAs were found in GBP5-silenced OSCC cells compared to scrambled OSCC cells. Among them, exosomal miR-320d exhibited the highest negative correlation with GBP5 in OSCC patients. High GBP5/low miR-320d co-expression was linked to reduced disease-free survival (DFS) in patients with OSCC. Interestingly, the inhibitory effect of GBP5-silenced exosomes on OSCC cell growth was reversed by miR-320d inhibitors. Moreover, five miR-320d target genes were predicted, and only Family with Sequence Similarity 49, Member B (FAM49B) showed a negative correlation with miR-320d. A decreased level of FAM49B was found in OSCC cells treated with exosomes derived from GBP5-silenced OSCC cells, while the decreased level of FAM49B was reversed by miR-320d inhibitors. Silencing FAM49B and GBP5-silenced exosomes enhanced the cytotoxicity of paclitaxel. FAM49B was abundantly expressed in tumor tissues, and high FAM49B/low miR-320d and high GBP5/high FAM49B co-expression were linked to reduced DFS of OSCC patients.

Our study suggests that GBP5 downregulated exosomal miR-320d may trigger FAM49B expression and facilitate OSCC tumor growth and progression.

Glioblastoma is the most common and aggressive brain tumor with a low survival rate. Due to its heterogeneous composition, high invasiveness, and frequent recurrence after surgery, treatment success has been limited. In addition, due to the brain's unique immune status and the suppressor tumor microenvironment (TME), glioblastoma treatment has faced more challenges. Exosomes play a critical role in cancer metastasis by regulating cell-cell interactions that promote tumor growth, angiogenesis, metastasis, treatment resistance, and immunological regulation in the tumor microenvironment. This review explores the pivotal role of exosomes in the development of glioblastoma, with a focus on their potential as non-invasive biomarkers for prognosis, early detection and real-time monitoring of disease progression. Notably, exosome-based drug delivery methods hold promise for overcoming the blood-brain barrier (BBB) and developing targeted therapies for glioblastoma. Despite challenges in clinical translation, the potential for personalized exosome = -054321`therapies and the capacity to enhance therapeutic responses in glioblastoma, present intriguing opportunities for improving patient outcomes. It seems that getting a good and current grasp of the role of exosomes in the fight against glioblastoma would properly serve the scientific community to further their understanding of the related potentials of these biological moieties.

The metastatic cascade is a complicated process where cancer cells travel across multiple organs distant from their primary site of onset. Despite the wide acceptance of the 'seed and soil' theory, mechanisms driving metastasis organotropism remain mystery. Using breast cancer of different subtypes as the disease model, we characterized the 'metastatic profile of cancer cells' and the 'redox status of the organ microenvironment' as the primary determinants of cancer metastasis organotropism. Mechanically, we identified a positive correlation between cancer metabolic plasticity and stemness, and proposed oxidative stress as the selection power of cancer cells succeeding the metastasis cascade. Therapeutically, we proposed the use of pro-oxidative therapeutics in ablating cancer cells taking advantages of this fragile moment during metastasis. We comprehensively reviewed current pro-oxidative strategies for treating cancers that cover the first line chemo- and radio-therapies, approaches relying on naturally existing power including magnetic field, electric field, light and sound, nanoparticle-based anti-cancer composites obtained through artificial design, as well as cold atmospheric plasma as an innovative pro-oxidative multi-modal modality. We discussed possible combinations of pro-oxidative approaches with existing therapeutics in oncology prior to the forecast of future research directions. This paper identified the fundamental mechanics driving metastasis organotropism and proposed intervention strategies accordingly. Insights provided here may offer clues for the design of innovative solutions that may open a new paradigm for cancer treatment.

Metastasis is the leading cause of mortality for colorectal cancer (CRC). Cancer-derived exosomes are widely recognized as the primary catalysts behind the development of pre-metastasis niche (PMN) in distal sites. However, the exact mechanism behind this process in CRC remains elusive. This study aimed to investigate the function and mechanisms underlying the role of exosomal miR-188-3p in activating hepatic stellate cells (HSCs) to develop the PMN and promote liver metastasis.

We extracted exosomes from CRC cells using ultracentrifugation. Exosomes were identified using transmission electron microscopy, nanoparticle tracking analysis, and Western blot. Exosome uptake was assessed using fluorescence tracing, exosome PKH67 staining, and real-time quantitative PCR. The effects of CRC cell-derived exosomes on HSCs migration were evaluated using Transwell migration and wound healing assays. Key differentially expressed miRNAs were screened from the GEO database, and bioinformatics prediction along with dual-luciferase reporter assays were used to identify downstream target genes of miR-188-3p. Downstream related proteins of the target genes were detected by Western blot. In vivo, the distribution of exosomes and activation of HSCs in the liver were explored by tail vein injection of exosomes into nude mice. Further, the impact of exosomal miR-188-3p on liver metastasis was investigated using a spleen injection liver metastasis model. Finally, the expression levels of miR-188-3p in exosomes from CRC patient plasma were determined by real-time quantitative PCR, and the relationship between the expression of miR-188-3p in plasma exosomes and CRC prognosis was analyzed.

The expression level of miR-188-3p within plasma exosomes demonstrated a statistically significant increase in CRC with liver metastasis compared to those without liver metastases. We also demonstrated the transferability of miR-188-3p from CRC cells to HSCs cells via the exosomes. Exosomal miR-188-3p plays a pivotal role in orchestrating the establishment of PMN through targeting PHLPP2 to activate HSCs before tumor metastasis. Exosomal miR-188-3p was found to actively foster in vivo metastasis of CRC. Additionally, plasma exosomal miR-188-3p potentially serves as a viable blood-based biomarker for CRLM.

Exosomal miR-188-3p derived from CRC cells can promote liver metastasis by activating HSCs to form a PMN through targeting PHLPP2 to activate the AKT/mTOR pathway. These results offer a new perspective on the mechanisms driving CRLM.

Exosomes are tiny extracellular vesicles that are essential for intercellular communication and have shown great promise in the detection and treatment of disease. They are especially useful in the treatment of cancer, cardiovascular conditions, and neurological diseases because of their capacity to transport bioactive substances including proteins, lipids, and nucleic acids. Because of their low immunogenicity, ability to traverse biological barriers, and biocompatibility, exosome-based medicines have benefits over conventional treatments. Large-scale production, standardization of separation methods, possible immunological reactions, and worries about unforeseen biological effects are some of the obstacles that still need to be overcome. Furthermore, there are major barriers to the clinical use of exosomes due to their complex cargo sorting mechanisms and heterogeneity. Future studies should concentrate on enhancing separation and purification procedures, optimizing exosome engineering techniques, and creating plans to reduce immune system modifications. This review examines the most recent developments in exosome-based diagnostics and treatments, identifies current issues, and suggests ways to improve their clinical translation in the future.

Extracellular vesicles (EVs) are critical mediators of intercellular communication, carrying bioactive cargo and displaying diverse surface components that reflect their cellular origins and functions. The EV surface, composed of proteins, lipids, and glycocalyx elements, plays a pivotal role in targeting recipient cells, mediating biological interactions, and enabling selective cargo delivery. This review comprehensively examined the molecular architecture of EV surfaces, linking their biogenesis to functional diversity, and highlights their therapeutic and diagnostic potential in diseases such as cancer and cardiovascular disorders. Additionally, we explore emerging applications of EVs, including machine-learning-assisted analysis, chemical integration, and cross-system combinations. The review also discusses some key challenges in the clinical translation of EV-related technologies.

Brain metastases are the most commonly diagnosed type of central nervous system tumor, yet the mechanisms of their occurrence are still widely unknown. Lung cancer, breast cancer, and melanoma are the most common etiologies, but renal and colorectal cancers have also been described as metastasizing to the brain. Regardless of their origin, there are common mechanisms for progression to all types of brain metastases, such as the creation of a suitable tumor microenvironment in the brain, priming of tumor cells, adaptations to survive spreading in lymphatic and blood vessels, and development of mechanisms to penetrate the blood-brain barrier. However, there are complex genetic and molecular interactions that are specific to every type of primary tumor, making the understanding of the metastatic progression of tumors to the brain a challenging field of study. In this review, we aim to summarize current knowledge on the pathophysiology of brain metastases, from specific genetic characteristics of commonly metastatic tumors to the molecular and cellular mechanisms involved in progression to the central nervous system. We also briefly discuss current challenges in targeted therapies for brain metastases and how there is still a gap in knowledge that needs to be overcome to improve patient outcomes.

The increasing prevalence and poor prognosis of central nervous system (CNS) metastases pose a significant challenge in oncology, necessitating improved therapeutic strategies. Recent research has shed light on the complex genomic landscape of brain metastases, identifying unique and potentially actionable genetic alterations. These insights offer new avenues for targeted therapy, highlighting the potential of precision medicine approaches in treating CNS metastases. However, translating these discoveries into clinical practice requires overcoming challenges such as availability of tissue for characterization, access to molecular testing, drug delivery across the blood-brain barrier (BBB) and addressing intra- and intertumoral genetic heterogeneity. This review explores novel insights into the evolution of CNS metastases, the molecular mechanisms underlying their development, and implications for therapeutic interventions.

In recent years, liquid biopsy has gained prominence as an emerging biomarker in cancer research, providing critical insights into tumor biology and metastasis. Technological advancements have enabled its integration into clinical practice, with ongoing trials demonstrating encouraging outcomes. Key applications of liquid biopsy include early cancer detection, cancer staging, prognosis evaluation, and real-time monitoring of tumor progression to optimize treatment decisions. In this review, we present a comprehensive conceptual framework for liquid biopsy, discuss the challenges in its research and clinical application, and highlight its significant potential in identifying therapeutic targets and resistance mechanisms across various cancer types. Furthermore, we explore the emerging role of liquid biopsy-based multicancer screening, which has shown promising advancements. Looking ahead, standardization, multi-omics coanalysis, and the advancement of precision medicine and personalized treatments are expected to drive the future development and integration of liquid biopsy into routine clinical workflows, enhancing cancer diagnosis and treatment management.

Small extracellular vesicles (sEVs) facilitate intercellular communication and play a pivotal role in tumor progression. Accumulated evidence has indicated the diversity of sEVs but with limited results revealing the landscape of heterogeneity of sEVs. The heterogeneity of cargo RNA in sEVs presents the different cell origins and indicates different functions. Here, we analyzed the heterogeneity of sEVs at droplet levels from single-cell RNA sequencing results of head and neck squamous cell carcinoma (HNSCC) with the previously reported algorithm SEVtras. With the sEVs secretion activity calculated by SEVtras, we also found that the T cells held the major role of sEVs secretion. In addition, we found these sEVs secreted by T cells increased the cytotoxic ability of natural killer cells (NK cells), which illustrated an indirect manner for the anti-tumor function of T cells. These results revealed the heterogeneity of cargo RNA of sEVs in HNSCC and underlined a sEVs-dependent manner in which T cells act on NK cells and anti-tumor immunity.

Brain metastasis represents a significant challenge in oncology, driven by complex molecular and epigenetic mechanisms that distinguish it from primary tumors. While recent research has focused on identifying genomic mutation drivers with potential clinical utility, these strategies have not pinpointed specific genetic mutations responsible for site-specific metastasis to the brain. It is now clear that successful brain colonization by metastatic cancer cells requires intricate interactions with the brain tumor ecosystem and the acquisition of specialized molecular traits that facilitate their adaptation to this highly selective environment. This is best exemplified by widespread transcriptional adaptation during brain metastasis, resulting in aberrant gene programs that promote extravasation, seeding, and colonization of the brain. Increasing evidence suggests that epigenetic mechanisms play a significant role in shaping these pro-brain metastasis traits. This review explores dysregulated chromatin patterns driven by chromatin remodeling, histone modifications, DNA/RNA methylation, and other epigenetic regulators that underpin brain metastatic seeding, initiation, and outgrowth. We provide novel insights into how these epigenetic modifications arise within both the brain metastatic tumor and the surrounding brain metastatic tumor ecosystem. Finally, we discuss how the inherent plasticity and reversibility of the epigenomic landscape in brain metastases may offer new therapeutic opportunities.

The triple-negative subtype of breast cancer is particularly challenging to treat due to its aggressiveness with a high risk of brain metastasis, and the lack of effective targeted therapies. Tubulin beta 2B class IIb (TUBB2B), a β-tubulin isoform regulating axon guidance during embryonic development, was found to be overexpressed in various types of cancers including triple-negative breast cancer (TNBC). However, its functional roles in breast cancer or metastasis remain unclear.

To identify TUBB2B as a novel molecular target in TNBC, we performed bioinformatics analysis to assess the association of TUBB2B expression and survival of patients. RNAscope in situ hybridization was used to examine TUBB2B expression in clinical breast tumor samples. The effect of TUBB2B knockdown on TNBC growth and brain metastasis colonization was evaluated by in vitro and in vivo assays. Mass spectrometry (MS) and biochemical experiments were performed to explore the underlying mechanisms. Preclinical efficacy of targeting TUBB2B was determined in xenograft studies using the siRNA-gold nanoparticle (siRNA-AuNP) approach.

TUBB2B, but not other β-tubulin isoforms, is frequently overexpressed in TNBC primary tumors as well as brain metastases. We also find that upregulation of TUBB2B is associated with poor prognosis in breast cancer patients. Silencing TUBB2B induces tumor cell death and inhibits the outgrowth of brain metastasis. Mechanistically, we identify eukaryotic translation elongation factor 1 alpha 1 (eEF1A1) as a novel interacting partner of TUBB2B, revealing a previously unexplored role of TUBB2B in translational regulation. In line with its neural-related functions, TUBB2B overexpression in TNBC cells activates astrocytes, which in turn upregulate TUBB2B in tumor cells. These findings suggest a feed-forward interaction between TUBB2B in TNBC cells and astrocytes that promotes brain metastatic colonization. Furthermore, we demonstrate the potent inhibition of TNBC xenograft growth as well as brain metastatic colonization using TUBB2B siRNA-AuNP treatment, indicating potential clinical applications of targeting TUBB2B for TNBC.

TUBB2B is a novel TNBC gene that plays a key role in promoting tumor cell survival and brain metastatic colonization, and can be targeted by siRNA-AuNPs as a treatment strategy.

Despite the efforts to identify fluid biomarkers to improve diagnosis of Frontotemporal dementia (FTD), only a few candidates have been described in recent years. In a previous study, we identified three circulating miRNAs (miR-92a-3p, miR-320a and miR-320b) differentially expressed in FTD patients with respect to healthy controls and/or Alzheimer's disease (AD) patients. Now, we investigated whether those changes could be due to miRNAs contained in neuron-derived extracellular vesicles (NDEVs). We also evaluated miRNAs content in total plasma EVs and in CSF samples. The analysis of plasma NDEVs carried out on 40 subjects including controls (n = 13), FTD (n = 13) and AD (n = 14) patients, showed that both miR-92a-3p and miR-320a levels were triplicated in the FTD group if compared with CT and AD patients. Increased levels of the same miRNAs were found also in CSF derived from FTD group compared to CTs. No differences were observed in expression levels of miR-320b among the three groups. Worthy of note, all miRNAs analysed were increased in an FTD cell model, MAPT IVS10 + 16 neurons. Our results suggest that miR-92a and miR-320a in NDEVs could be proposed as FTD biomarkers.

Over the past decade, a scientific field has been developed demonstrating microRNAs (miRNAs) to be actively sorted into extracellular vesicles via specific nucleotide motifs that interact with discrete RNA-binding proteins. These miRNAs are proposed to be transported into recipient cells in which they can regulate specific cellular pathways. This mechanism could have enormous potential in explaining how cells signal and regulate other cells nearby or at a distance. Tens of studies have built this theme of a regulated transport of miRNAs. However, some concerns exist about this field. Taken together, there are concerns of a lack of a consistent motif, RNA-binding protein, or preferential miRNA involved in this process. In this study, we provide an expert and extensive analysis of the field that makes the cases for and against an active sorting mechanism. We provide potential explanations on why there is a lack of agreement. Most importantly, we provide ideas on how to move this field forward with more rigor and reproducibility. It is hoped that by engaging in a scientific debate of the pros and cons of this field, more rigorous experiments can be performed to conclusively demonstrate this biological activity.

Brain metastasis in nasopharyngeal carcinoma is a rare but poor prognosis clinical problem. This study aims to investigate the clinical characteristics and identify the genomic profiling of nasopharyngeal carcinoma brain metastasis. Patients with a diagnosis of nasopharyngeal carcinoma who visited at the Fifth Affiliated Hospital of Sun Yat-sen University since January 2013 to December 2023 were retrospectively collected. Clinical data of patients diagnosed with nasopharyngeal carcinoma brain metastasis were extracted. Paraffin blocks of NPC brain metastases were acquired for immunohistochemistry and genetic testing. High-throughput second generation sequencing was performed for genomic analysis. The mutation landscape was further analyzed. Of the 2378 NPC patients from our database, only six were clinically diagnosed with nasopharyngeal carcinoma brain metastasis. Three were pathologically diagnosed with nasopharyngeal carcinoma brain metastasis. The time interval from the first diagnosis of nasopharyngeal carcinoma to brain metastasis was 15-56 months. The common sites of brain metastasis were frontal lobe and cerebellum, and could be single or multiple, cystic or solid lesions. The OS ranged from 7 to 48 months. Single nucleotide variants were found in 32 genes, such as PTEN, TP53, NFKBIA, KMT2C, and NOTCH1. Copy number variation occurred in five genes, including PTEN, CCDN1, FGF19, FGF3 and FGF4. PTEN and fibroblast growth factors might be involved in the molecular regulation of brain metastasis in nasopharyngeal carcinoma.

Advances in molecular biology, genetics, and epigenetics have refined our understanding of metastatic brain cancer and underscored the need for better classification and targeted approaches. The heterogeneity of brain metastases highlights the differences from their primary source of origin and contributes to therapeutic resistance. Before colonising the brain, tumour cells acquire specialised proficiencies that enable them to capitalise on the unique microenvironment of the brain. The tumour cells further orchestrate key adaptations to adjust to the brain microenvironment by manipulating the blood-brain barrier, evading immune surveillance, rewiring metabolic profiles, and reprogramming astrocytes. These adaptations facilitate tumour survival, growth, and treatment resistance. Recognising metastatic brain cancer as a distinctive CNS disease, rather than an extension of the primary cancer, would support the development of rational approaches that target its molecular and genetic features and improve research funding in this area. Here, we delve into the distinct genetic and phenotypic characteristics of metastatic brain cancer, and reflect on how a change in the perception of this disease could accelerate the development of more effective therapies and drive continued progress in the field of neuro-oncology.

High-grade infiltrating gliomas are highly aggressive and fatal brain tumors that present significant challenges for research and treatment due to their complex microenvironment and tissue structure. Recent discovery of tumor microtubes (TMs) has provided new insights into how high-grade gliomas develop in the brain and resist treatment. TMs are unique, ultra-long, and highly functional membrane protrusions that form multicellular networks and play crucial roles in glioma invasiveness, drug resistance, recurrence, and heterogeneity. This review focuses on the different roles that TMs play in glioma cell communication, material transport, and tumor cell behavior. Specifically, non-connecting TMs primarily promote glioma invasiveness, likely related to their role in enhancing cell motility. On the other hand, interconnecting TMs form functional and communication networks by connecting with surrounding astrocytes and neurons, thereby promoting glioma malignancy. We summarize the factors that influence the formation of TMs in gliomas and current strategies targeting TMs. As the understanding of TMs advances, we are closer to uncovering whether they might be the long-sought Achilles' heel of treatment-resistant gliomas. By delving deeper into TMs research, we hope to develop more effective therapeutic strategies for patients with malignant gliomas.

The blood-brain barrier and the distinct brain immunology provide challenges in translating commonly used chemotherapeutics to treat intracranial tumors. Previous reports suggest anti-tumoral effects of antipsychotics, encouraging investigations into potential treatment effects of neuroleptics on brain metastases. For the first time, the therapeutic potential of the antipsychotic drug clozapine in treating melanoma brain metastases (MBM) was investigated using three human MBM cell lines. Through in vitro cell culture and viability experiments, clozapine displayed potent anti-tumoral effects on MBM cells with an exploitable therapeutic window when compared to normal human astrocytes or rat brain organoids. Further, it was shown that clozapine inhibited migration, proliferation, and colony formation in a dose-dependent manner. Through flow cytometry and proteome screening, we found that clozapine induced apoptosis in MBM cells and potentially altered the tumor immunological environment by upregulating proteins such as macrophage inflammatory protein-1 alpha (MIP-1α) and interleukin-8 (IL-8). In conclusion, clozapine shows significant and selective anti-tumoral effects on MBM cell lines in vitro. Further in vivo experiments are warranted to translate these results into clinical use.

Glioblastoma (GBM) is an aggressive brain tumor characterized by extensive metabolic reprogramming that drives tumor growth and therapeutic resistance. Key metabolic pathways, including glycolysis, lactate production, and lipid metabolism, are upregulated to sustain tumor survival in the hypoxic and nutrient-deprived tumor microenvironment (TME), while glutamine and tryptophan metabolism further contribute to the aggressive phenotype of GBM. These metabolic alterations impair immune cell function, leading to exhaustion and stress in CD8+ and CD4+ T cells while favoring immunosuppressive populations such as regulatory T cells (Tregs) and M2-like macrophages. Recent studies emphasize the role of slow-cycling GBM cells (SCCs), lipid-laden macrophages, and tumor-associated astrocytes (TAAs) in reshaping GBM's metabolic landscape and reinforcing immune evasion. Genetic mutations, including Isocitrate Dehydrogenase (IDH) mutations, Epidermal Growth Factor Receptor (EGFR) amplification, and Phosphotase and Tensin Homolog (PTEN) loss, further drive metabolic reprogramming and offer potential targets for therapy. Understanding the relationship between GBM metabolism and immune suppression is critical for overcoming therapeutic resistance. This review focuses on the role of metabolic rewiring in GBM, its impact on the immune microenvironment, and the potential of combining metabolic targeting with immunotherapy to improve clinical outcomes for GBM patients.

The prognosis for patients with brain metastasis remains dismal despite intensive therapy including surgical resection, radiotherapy, chemo-, targeted, and immunotherapy. Thus, there is a high medical need for new therapeutic options. Recent advances employing high-throughput and spatially resolved single-cell analyses have provided unprecedented insights into the composition and phenotypes of the diverse immune cells in the metastatic brain, revealing a unique immune landscape starkly different from that of primary brain tumors or other metastatic sites. This review summarizes the current evidence on the composition and phenotypes of the most prominent immune cells in the brain metastatic niche, along with their dynamic interactions with metastatic tumor cells and each other. As the most abundant immune cell types in this niche, we explore in detail the phenotypic heterogeneity and functional plasticity of tumor-associated macrophages, including both resident microglia and monocyte-derived macrophages, as well as the T-cell compartment. We also review preclinical and clinical trials evaluating the therapeutic potential of targeting the immune microenvironment in brain metastasis. Given the substantial evidence highlighting a significant role of the immune microenvironmental niche in brain metastasis pathogenesis, a comprehensive understanding of the key molecular and cellular factors within this niche holds great promise for developing novel therapeutic approaches as well as innovative combinatory treatment strategies for brain metastasis.

Previous studies revealed that tumor-associated macrophages/microglia (TAMs) promoted glioma invasiveness during tumor progression and after radiotherapy. However, the communication of TAMs with tumor cells remains unclear. This study aimed to examine the role of small extracellular vesicles (sEVs) derived from TAMs in TAMs-mediated brain tumor invasion. This study utilized BV2 and RAW264.7 cell lines representing resident and infiltrating macrophages, respectively, to unveil their effect on tumor cells. Purified sEVs from BV2 and RAW264.7 were validated by nanoparticle track analysis (NTA), transmission electron microscopy (TEM), and western blotting for sEV markers. The effect of sEVs on the murine astrocytoma tumor cell line ALTS1C1 was examined on cell proliferation, migration, and gene expression. The results showed that ALTS1C1 cells effectively engulfed sEVs purified from BV2 and RAW264.7. Only BV2-derived sEVs promoted cell proliferation and were dose-dependent. Further, morphological changes in ALTS1C1 cells were observed after incubation with BV2-derived sEVs, which was associated with enhancing cell migration. BV2-mediated glioma proliferation and mobility were related to the upregulation of vascular endothelial growth factor (VEGF) and downregulation of death effector domain-containing protein (DEDD) gene expression. This study demonstrates the distinct function of sEVs of resident macrophages on glioma cell invasion and reveals the mechanism underlying microglia-mediated tumor progression. These findings suggested resident microglia is the potential therapeutic target for TAMs-induced brain tumor invasiveness.

Brain metastases (BrM) arising from solid tumors is an ever-increasing and often devastating clinical challenge impacting hundreds of thousands of patients annually worldwide. As systemic anticancer therapies, and thus survival, improve, the risk for central nervous system (CNS) recurrence has increased. Historically, patients with BrM were excluded from clinical trials; however, there has been a shift toward increasing inclusion over the past decade. To most effectively design the next generation of clinical trials for patients with BrM, a multidisciplinary team spanning local and systemic therapies is imperative. CIMARa (Consortium for Intracranial Metastasis Academic Research), formalized in June 2021, is an inclusive group of multidisciplinary clinical investigators, research scientists, and advocates who share the collective goal of improving outcomes for patients with BrM. CIMARa aims to improve outcomes through the development, coordination, and awareness of multi-institutional clinical trials testing novel therapeutic agents for this unique patient population alongside the translation of preclinical research to the clinical setting.

Exosomal microRNAs (exomiRs) play a critical role in intercellular communication, especially in cancer, where they regulate key cellular processes like proliferation, angiogenesis, and metastasis, highlighting their significance as potential diagnostic and therapeutic targets. Here, we aimed to characterize the role of exomiRs, derived from seven cancer types (four cell lines and three tumors), in influencing the pre-metastatic niche (PMN). In each cancer type we extracted high confidence exomiRs (LogFC >= 2 in exosomes relative to control), their experimentally validated targets, and the enriched pathways among those targets. We then selected the top100 high-confidence targets based on their frequency of appearance in the enriched pathways. We observed significantly higher GC content in exomiRs relative to genomic background. Gene Ontology analysis revealed both general cancer processes, such as wound healing and epithelial cell proliferation, as well as cancer-specific processes, such as "angiogenesis" in the kidney and "ossification" in the lung. ExomiR targets were enriched for cancer-specific tumor suppressor genes and downregulated in PMN formed in lungs compared to normal. Motif analysis showed high inter-cancer similarity among motifs enriched in exomiRs. Our analysis recapitulated exomiRs associated with M2 macrophage differentiation and chemoresistance, such as miR-21 and miR-222-3p, regulating signaling pathways like PTEN/PI3/Akt, NF-kB, etc. Additionally, Cox regression analysis in TCGA indicated that exomiR targets are significantly associated with better overall survival of patients. Lastly, support vector machine model using exomiR targets gene expression classified responders and non-responders to therapy with an AUROC ranging from 0.72 to 0.96, higher than previously reported gene signatures.

Epidermal growth factor receptor 2-positive breast cancer (HER2+ BC) is a highly invasive and malignant type of tumor. Due to its resistance to HER2-targeted therapy, HER2+ BC has a poor prognosis and a tendency for metastasis. Understanding the mechanisms underlying this resistance and developing effective treatments for HER2+ BC are major research challenges. The phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) pathway, which is frequently altered in cancers, plays a critical role in cellular proliferation and drug resistance. This signaling pathway activates various downstream pathways and exhibits complex interactions with other signaling networks. Given the significance of the PI3K/AKT pathway in HER2+ BC, several targeted drugs are currently in development. Multiple drugs have entered clinical trials or gained market approval, bringing new hope for HER2+ BC therapy. However, new drugs and therapies raise concerns related to safety, regulation, and ethics. Populations of different races and disease statuses exhibit varying responses to treatments. Therefore, in this review, we summarize current knowledge on the alteration and biological roles of the PI3K/AKT pathway, as well as its clinical applications and perspectives, providing new insights for advancing targeted therapies in HER2+ BC.

The fibrotic stroma characterizing pancreatic ductal adenocarcinoma (PDAC) derives from a progressive tissue rigidification, which induces epithelial mesenchymal transition and metastatic dissemination. The aim of this study was to investigate the influence of matrix stiffness on PDAC progression by analyzing the proteome of PDAC-derived extracellular vesicles (EVs). PDAC cell lines (mPDAC and KPC) were grown on synthetic supports with a stiffness close to non-tumor (NT) or tumor tissue (T), and the protein expression levels in cell-derived EVs were analyzed by a quantitative MSE label-free mass spectrometry approach. Our analysis figured out 15 differentially expressed proteins (DEPs) in mPDAC-EVs and 20 DEPs in KPC-EVs in response to matrix rigidification. Up-regulated proteins participate to the processes of metabolism, matrix remodeling, and immune response, altogether hallmarks of PDAC progression. A multimodal network analysis revealed that the majority of DEPs are strongly related to pancreatic cancer. Interestingly, among DEPs, 11 related genes (ACTB/ANXA7/C3/IGSF8/LAMC1/LGALS3/PCD6IP/SFN/TPM3/VARS/YWHAZ) for mPDAC-EVs and 9 (ACTB/ALDH2/GAPDH/HNRNPA2B/ITGA2/NEXN/PKM/RPN1/S100A6) for KPC-EVs were significantly overexpressed in tumor tissues according to gene expression profiling interaction analysis (GEPIA). Concerning the potential clinical relevance of these data, the cluster of ACTB, ITGA2, GAPDH and PKM genes displayed an adverse effect (p < 0.05) on the overall survival of PDAC patients.

Gliomas are increasingly becoming a major disease affecting human health, and current treatments are not as effective as expected. Deeper insights into glioma heterogeneity and the search for new diagnostic and therapeutic strategies appear to be urgent. Gliomas adapt to their surroundings and form a supportive tumor microenvironment (TME). Glioma cells will communicate with the surrounding cells through extracellular vesicles (EVs) carrying bioactive substances such as nucleic acids, proteins and lipids which is related to the modification to various metabolic pathways and regulation of biological behaviors, and this regulation can be bidirectional, widely existing between cells in the TME, constituting a complex network of interactions. This complex regulation can affect glioma therapy, leading to different types of resistance. Because of the feasibility of EVs isolation in various body fluids, they have a promising usage in the diagnosis and monitoring of gliomas. At the same time, the nature of EVs to cross the blood-brain barrier (BBB) confers potential for their use as drug delivery systems. In this review, we will focus on the roles and functions of EVs derived from different cellular origins in the glioma microenvironment and the intercellular regulatory networks, and explore possible clinical applications in glioma diagnosis and precision therapy.

The pathogenesis of myelocytomatosis oncogene (MYC) and B-cell lymphoma 2 (BCL2) double-expressor diffuse large B-cell lymphoma (DE-DLBCL) remains unclear. To investigate how MYC and BCL2 contribute to tumor aggressiveness, we analyzed tumors from 14 patients each with DE-DLBCL and non-DE-DLBCL using whole transcriptome sequencing. Validation was performed using publicly available data sets, tumor tissues from 126 patients, DLBCL cell lines, and a syngeneic mouse lymphoma model. Our transcriptome analysis revealed significantly elevated messenger RNA levels of C-C motif chemokine ligand 2 (CCL2) and C-C chemokine receptor type 2 (CCR2) in DE-DLBCLs when compared with non-DE-DLBCLs (adjusted P value < .05). Transcriptomic analysis of public data sets and immunohistochemistry corroborated these findings, indicating increased levels of M2 macrophages but a reduction in T-cell infiltration in DE-DLBCLs when compared with non-DE-DLBCLs (all P < .05). CCR2 expression was observed mainly in tumor-infiltrating macrophages and not in DLBCL cells. Increased expression of CCL2 and CCR2 was significantly associated with a poor prognosis in patients with DLBCL. In the in vitro analyses, MYChigh/BCL2high DLBCL cells showed higher CCL2 expression and secretion than MYClow/BCL2low cells. MYC and BCL2 increased CCL2 expression and secretion by upregulation of nuclear factor κB p65 in DLBCL cells, and CCL2 promoted M2 polarization of macrophages. In a mouse lymphoma model, CCL2 contributed to the immunosuppressive microenvironment and tumor growth of MYChigh/BCL2high tumors. We demonstrated that the increased CCL2/CCR2 axis confers aggressiveness to DE-DLBCL by increasing M2 polarization and can be a potential therapeutic target.

Local exposure to ionizing radiation (IR) can induce changes in biological processes in distant tissues and organs. Exosomes are nanoscale vesicles that transport biomolecules, mediate communication between cells and tissues, and can affect the abscopal effects of radiotherapy.

Mice were treated with 8.0 Gy doses of chest and abdomen IR, after which serum samples were taken 24 h after exposure. Their serum exosomes were then isolated via ultracentrifugation and the small RNA portions were extracted for sequencing and bioinformatic analysis. Exosomes were injected intravenously into the mice to assess their ability to cross the blood-brain barrier (BBB). Glioma cells and glioma stem cells (GSCs) were examined for malignant biological behaviors, stemness, and tumorigenic capacity after co-culturing with different groups of exosomes.

We found that serum exosomes crossed the BBB in mice after local IR exposure-which induced decreases in the expression of BBB tight-junction proteins and increased brain endothelial cell apoptosis. Exosomes from the exposed groups promoted malignant biological behaviors, stemness, and tumorigenic capacity in glioma cells and GSCs by upregulating the expression of SOS1. Phospho-MEK1/2 and Phospho-ERK1/2, of the MAPK signaling pathway, were found to be up-regulated in cells that were co-cultured with the exposing groups of the exosomes. Further analyses demonstrated that differentially expressed levels of miR-93-5p in mouse serum exosomes regulated the cellular expression of SOS1.

Following local IR exposure, serum exosomes cross the BBB to promote the progression of distant gliomas. Exosomal microRNAs play an important role in this process.

Intracranial metastatic disease is a serious complication of cancer, treated through surgery, radiation, and targeted therapies. The central role of radiation therapy makes understanding the radioresistance of metastases a priori a key interest for prognostication and therapeutic development. Although historically defined clinic-radiographically according to tumour response, developments in new techniques for delivering radiation treatment and understanding of radioprotective mechanisms led to a need to revisit the definition of radioresistance in the modern era. Factors influencing radioresistance include tumour-related factors (hypoxia, cancer stem cells, tumour kinetics, tumour microenvironment, metabolic alterations, tumour heterogeneity DNA damage repair, non-coding RNA, exosomes, methylomes, and autophagy), host-related factors (volume effect & dose-limiting non-cancerous tissue, pathophysiology, and exosomes), technical factors, and probabilistic factors (cell cycle and random gravity of DNA damage). Influences on radioresistance are introduced and discussed in the context of brain metastases.

Aggressive clear cell renal cell carcinoma (ccRCC) has a bad prognosis. We seek new ccRCC biomarkers for diagnosis and treatment. We used exoRBase and The Cancer Genome Atlas Database to compare DEmRNAs, DEmiRNAs, DElncRNAs, and DEcircRNAs in ccRCC and normal renal tissues. CircRNAs and circRNAs targeting microRNAs (miRNAs) were anticipated and taken intersections, and several databases assessed the targeted link between common miRNAs and messenger RNAs (mRNAs). The Cancer Genome Atlas database was used to create a predictive mRNA signature that was validated in E-MTAB-1980. Finally, we examined competing endogenous RNA network miRNAs and long noncoding RNAs for ccRCC predictive biomarkers using overall survival analysis. We built the first competing endogenous RNA regulation network of circRNA-lncRNA-miRNA-mRNA and found that it substantially correlates with ccRCC prognosis. We unveiled ccRCC's posttranscriptional regulation mechanism in greater detail. Our findings identified novel biomarkers for ccRCC diagnosis, therapy, and prognosis.

Extracellular vehicles (EVs) are gaining increasing recognition as central contributors to the intricate landscape of the tumor microenvironment (TME). This manuscript provides an extensive examination of the multifaceted roles played by EVs in shaping the TME, with a particular emphasis on their involvement in metastasis, drug resistance, and immune evasion. Metastasis, the process by which cancer cells disseminate to distant sites, remains a formidable challenge in cancer management. EVs, encompassing exosomes and microvesicles, have emerged as critical participants in this cascade of events. They facilitate the epithelial-to-mesenchymal transition (EMT), foster pre-metastatic niche establishment, and enhance the invasive potential of cancer cells. This manuscript delves into the intricate molecular mechanisms underpinning these processes, underscoring the therapeutic potential of targeting EVs to impede metastasis. Drug resistance represents a persistent impediment to successful cancer treatment. EVs are instrumental in intrinsic and acquired drug resistance, acting as mediators of intercellular communication. They ferry molecules like miRNAs and proteins, which confer resistance to conventional chemotherapy and targeted therapies. This manuscript scrutinizes the diverse strategies employed by EVs in propagating drug resistance while also considering innovative approaches involving EV-based drug delivery systems to counteract this phenomenon. Immune evasion is a hallmark of cancer, and EVs are central in sculpting the immunosuppressive milieu of the TME. Tumor-derived EVs thwart immune responses through various mechanisms, including T cell dysfunction induction, the expansion of regulatory T cells (Tregs), and polarization of macrophages towards an immunosuppressive phenotype. In addition, the manuscript explores the diagnostic potential of EVs as biomarkers and their role as therapeutic agents in immune checkpoint blockade therapies. This manuscript provides a comprehensive overview of EV's pivotal role in mediating intricate interactions within the TME, ultimately influencing cancer progression and therapeutic outcomes. A profound understanding of EV-mediated processes in metastasis, drug resistance, and immune evasion opens up promising avenues for developing innovative therapeutic strategies and identifying valuable biomarkers in the ongoing battle against cancer.