Exosome-mediated transfer of microRNAs within the tumor microenvironment and neuroblastoma resistance to chemotherapy

Exosome-based approaches in cancer along with unlocking new insights into regeneration of cancer-prone tissues

Most eukaryotic cells secrete extracellular vesicles called exosomes, which are involved in intercellular communication. Exosomes play a role in tumor development and metastasis by transporting bioactive chemicals from cancerous cells to other cells in local and distant microenvironments. However, the potential of exosomes can be used by engineering them and considering different therapeutic approaches to overcome tumors. Exosomes are a promising drug delivery approach that can help decrease side effects from traditional treatments like radiation and chemotherapy by acting as targeted agents at the tumor site. The present review provides an overview of exosomes and various aspects of the role of exosomes in cancer development, which include these items: exosomes in cancer diagnosis, exosomes and drug delivery, exosomes and drug resistance, exosomal microRNAs and exosomes in tumor microenvironment, etc. Cancer stem cells release exosomes that nurture tumors, promoting unwanted growth and regeneration, and these types of exosomes should be inhibited. Ironically, exosomes from other cells, such as hepatocytes or mesenchymal stem cells (MSCs), are vital for healing organs like the liver and repairing gastric ulcers. Without proper treatment, this healing process can backfire, potentially leading to disease progression or even cancer. What can be found from various studies about the role of exosomes in the field of cancer is that exosomes act like a double-edged sword; on the other hand, natural exosomes in the body may play an important role in the process and progression of cancer, but by engineering exosomes, they can be directed towards target therapy and targeted delivery of drugs to tumor cells. By examining the role and application of exosomes in various mechanisms of cancer, it is possible to help treat this disease more efficiently and quickly in preclinical and clinical research.

Exosomes derived from ccRCC cells confers fibroblasts activation to foster tumor progression through Warburg effect by downregulating PANK3

The interaction between tumor-derived exosomes and stroma plays a crucial role in tumor progression. However, the mechanisms through which tumor cells influence stromal changes are not yet fully understood. In our study, through single-cell sequencing analysis of clear cell renal cell carcinoma tissues at varying stages of progression, we determined that the proportion of cancer-associated fibroblasts (CAFs) in advanced renal cell carcinoma tissues was notably higher compared to localized renal cell carcinoma tissues. Comparison of transcriptome sequencing and energy metabolism tests between CAFs primarily isolated from advanced renal cell carcinoma tissues and normal fibroblasts (NFs) revealed the occurrence of the Warburg effect during the fibroblast activation process. Additionally, we observed an increase in glucose transporter GLUT1 expression, total reactive oxygen species (ROS) levels, lactic acid production, and subsequent excretion of excess lactic acid through monocarboxylate transporter-4 (MCT4) in CAFs. Interestingly, renal cancer cells were found to uptake lactic acid via MCT1 upon interaction with CAFs, thereby enhancing their malignant phenotypes. Furthermore, the down-regulation of PANK3 induced by exosomes derived from renal cancer cells was identified as a crucial step in fibroblast activation. These findings indicate that exosomes play a role in facilitating intercellular communication between renal cancer cells and fibroblasts. Targeting this communication pathway could potentially offer new strategies for the prevention and treatment of advanced renal cell carcinoma.

Engineering Exosomes for CNS Disorders: Advances, Challenges, and Therapeutic Potential

The development of targeted drugs for diseases of the central nervous system (CNS) is a significant challenge due to the structural complexity and functional specificities of these systems. Recently, exosomes have emerged as a promising therapeutic platform, given their unique capacity to traverse the blood-brain barrier and deliver bioactive molecules to target cells. This review examines recent advances in exosome research with a particular focus on CNS diseases, emphasizing their role as carriers of therapeutic cargo, including proteins, RNAs, and lipids. Nevertheless, significant challenges remain before exosome-based therapies can be translated from preclinical research to clinical applications. These include the need for scalable production and standardized isolation methods. Despite these hurdles, ongoing studies continue to shed light on the mechanisms of exosome-mediated neuroprotection and neurodegeneration. This paves the way for innovative therapeutic strategies to address CNS disorders.

Exosomes as Therapeutic and Diagnostic Tools: Advances, Challenges, and Future Directions

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.

FOXJ3, a novel tumor suppressor in neuroblastoma

Neuroblastoma (NB) poses a significant challenge in pediatric cancer care due to its aggressive nature and poor prognosis. While advances have been made in clinical treatments, therapy resistance remains a tough hurdle in NB treatment. While much research has focused on identifying oncogenes in NB, there has been less emphasis on understanding tumor suppressors. This study aimed to discover a new transcription factor that could address patient stage, risk level, and MYCN amplification status while exhibiting tumor-suppressive properties in NB patients. Using advanced bioinformatics techniques, we identified unique transcription factor signature that corresponded to patient characteristics. By analyzing regulon specificity scores, we prioritized Forkhead Box J3 (FOXJ3) as a potential novel driver transcription factor with tumor-suppressive functions in NB. Validation experiments on NB patients and patient-derived xenograft (PDX) tumors confirmed higher FOXJ3 expression in low-risk versus high-risk patients and in PDXs from diagnostic tumors versus relapse-specific tumors. Notably, the overexpression of FOXJ3 was associated with reduced cell density, proliferation, cells in S phase, colony-formation ability, transwell migration, neurosphere formation, spheroid diameter, and inhibition of AKT signaling in NB cells. Overall, these findings suggest that FOXJ3 functions as a novel tumor suppressor in NB, holding promise for potential therapeutic interventions.

Role of exosomes in diagnosis, prognostication, and treatment of pediatric solid tumors

Cancer is the second leading cause of death in children, and solid tumors make up 30% of childhood cancers. Molecular profiling of pediatric solid tumors allows a personalized approach to therapy, but this approach mostly relies on surgical biopsy, which is invasive and carries the risk of complications. Liquid biopsy serves as a reliable alternative and a minimally invasive tool for diagnosing, prognosticating, and residual disease monitoring in childhood cancers. This review outlines the potential of exosomes as informative liquid biopsies in pediatric solid tumors. Studies highlighting the potential applications and clinical utility of exosomes and their molecular constituents as prognosticators and therapies in common childhood solid tumors, including neuroblastoma, medulloblastoma, sarcoma, and hepatoblastoma, have been overviewed. We also discuss the limitations and technical challenges of utilizing exosomes for pediatric solid tumors.

Non-Coding RNAs in Cancer: Structure, Function, and Clinical Application

We are on the brink of a paradigm shift in both theoretical and clinical oncology. Genomic and transcriptomic profiling, alongside personalized approaches that account for individual patient variability, are increasingly shaping discourse. Discussions on the future of personalized cancer medicine are mainly dominated by the potential of non-coding RNAs (ncRNAs), which play a prominent role in cancer progression and metastasis formation by regulating the expression of oncogenic or tumor suppressor proteins at transcriptional and post-transcriptional levels; furthermore, their cell-free counterparts might be involved in intercellular communication. Non-coding RNAs are considered to be promising biomarker candidates for early diagnosis of cancer as well as potential therapeutic agents. This review aims to provide clarity amidst the vast body of literature by focusing on diverse species of ncRNAs, exploring the structure, origin, function, and potential clinical applications of miRNAs, siRNAs, lncRNAs, circRNAs, snRNAs, snoRNAs, eRNAs, paRNAs, YRNAs, vtRNAs, and piRNAs. We discuss molecular methods used for their detection or functional studies both in vitro and in vivo. We also address the challenges that must be overcome to enter a new era of cancer diagnosis and therapy that will reshape the future of oncology.

The Role of Liquid Biopsy in Neuroblastoma: A Scoping Review

BACKGROUND

Neuroblastoma (NBL), is the most common, non-CNS solid tumor of childhood. This disease presents with unique biological and clinical challenges necessitating accurate diagnosis, prognosis assessment, treatment, and vigilant monitoring. Liquid biopsy is an upcoming, innovative, and non-invasive diagnostic modality. It has the potential to detect tumors and perform therapeutic monitoring through the analysis of circulating biomarkers in blood, urine, saliva, and other bodily fluids.

METHODOLOGY

This scoping review offers an in-depth exploration, of the current landscape of liquid biopsy-based biomarkers in NBL. The review looks at the clinical implications, prevalent challenges, and future outlook of their clinical applications in NBL. The scoping review adhered to the guidelines of the PRISMA extension for scoping reviews, known as PRISMA-ScR, as the skeletal framework. The review involved comprehensive searches for liquid biopsy-based biomarkers in NBL across multiple databases, including PUBMED, EMBASE, SCOPUS, and WEB of Science, without restrictions.

RESULTS

The scoping review process uncovered a significant body of literature (n = 201) that underwent meticulous scrutiny, ultimately leading to the final selection of studies (n = 15). The liquid biopsy biomarkers included circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), exosomes, and other entities in bodily fluids. Their evaluation focused on associations with clinical outcomes such as overall survival, event-free survival, and risk stratification in NBL.

CONCLUSION

Our findings highlight the potential of liquid biopsy biomarkers to revolutionize NBL diagnosis and therapeutic monitoring. This rapidly evolving frontier in pediatric oncology suggests significant advancements in precision medicine for the management of NBL.

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

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

Exosomal microRNAs: impact on cancer detection, treatment, and monitoring

Exosomes, measuring between 30 and 150 nm in diameter, are small vesicles enclosed by a lipid bilayer membrane. They are released by various cells in the body and carry a diverse payload of molecules, including proteins, lipids, mRNA, and different RNA species such as long non-coding RNA, circular RNA, and microRNA (miRNA). With lengths of approximately 19-22 nucleotides, miRNAs constitute the predominant cargo in exosomes and serve as crucial regulators of protein biosynthesis. In cancer detection, exosomal miRNAs show promise as non-invasive biomarkers due to their stability and presence in various bodily fluids, aiding in early detection and precise diagnosis with specific miRNA signatures linked to different cancer types. Moreover, exosomal miRNAs influence treatment outcomes by affecting cellular processes like cell growth, cell death, and drug resistance, thereby impacting response to therapy. Additionally, they serve as indicators of disease progression and treatment response, providing insights that can guide treatment decisions and improve patient care. Through longitudinal studies, changes in exosomal miRNA profiles have been observed to correlate with disease progression, metastasis, and response to therapy, highlighting their potential for real-time monitoring of tumor dynamics and treatment efficacy. Understanding the intricate roles of exosomal miRNAs in cancer biology offers opportunities for developing innovative diagnostic tools and therapeutic strategies tailored to individual patients, ultimately advancing precision medicine approaches and improving outcomes for cancer patients. This review aims to provide an understanding of the role of exosomal miRNAs in cancer detection, treatment, and monitoring, shedding light on their potential for revolutionising oncology practices and patient care.

microRNAs: critical targets for treating rheumatoid arthritis angiogenesis

Vascular neogenesis, an early event in the development of rheumatoid arthritis (RA) inflammation, is critical for the formation of synovial vascular networks and plays a key role in the progression and persistence of chronic RA inflammation. microRNAs (miRNAs), a class of single-stranded, non-coding RNAs with approximately 21-23 nucleotides in length, regulate gene expression by binding to the 3' untranslated region (3'-UTR) of specific mRNAs. Increasing evidence suggests that miRNAs are differently expressed in diseases associated with vascular neogenesis and play a crucial role in disease-related vascular neogenesis. However, current studies are not sufficient and further experimental studies are needed to validate and establish the relationship between miRNAs and diseases associated with vascular neogenesis, and to determine the specific role of miRNAs in vascular development pathways. To better treat vascular neogenesis in diseases such as RA, we need additional studies on the role of miRNAs and their target genes in vascular development, and to provide more strategic references. In addition, future studies can use modern biotechnological methods such as proteomics and transcriptomics to investigate the expression and regulatory mechanisms of miRNAs, providing a more comprehensive and in-depth research basis for the treatment of related diseases such as RA.

Extracellular vesicle-mediated regulation of imatinib resistance in chronic myeloid leukemia via the miR-629-5p/SENP2/PI3K/AKT/mTOR axis

BACKGROUND

Imatinib (IM) is the primary treatment for patients with chronic-phase CML (CML-CP). However, an increasing number of CML-CP patients have developed resistance to IM. Our study aims to explore the expression of miR-629-5p in extracellular vesicles (EVs) from both IM-sensitive (K562) and resistant (K562-Re) CML cell lines and to investigate the impact of regulating miR-629-5p expression on the biological characteristics of K562 and K562-Re cells.

METHODS

Assess miR-629-5p expression levels in IM-sensitive and resistant CML cell lines. Separate EVs and verify it. EVs from K562-Re cells were co-cultured with K562 cells to detect the expression level of miR-629-5p. Target genes of miR-629-5p were determined and validated through luciferase experiments. Examined by manipulating miR-629-5p expression in cells using transfection techniques. The expression level of phosphorylated proteins in the PI3K/AKT/mTOR signaling pathway after IM was detected in CML cell lines. In K562-Re cells, the expression level of phosphorylated protein in the PI3K/AKT/mTOR signaling pathway was detected after single transfection of miR-629-5p inhibitor and cotransfection of miR-629-5p inhibitor and siSENP2.

RESULTS

Increasing concentrations of EVs from K562-Re cells elevated miR-629-5p expression levels. The expression levels of miR-629-5p in CML cells varied with IM concentration and influenced the biological characteristics of cells. SENP2 was identified as a target gene of miR-629-5p. Furthermore, miR-629-5p was found to modulate the SENP2/PI3K/AKT/mTOR pathway, impacting IM resistance in CML cells.

CONCLUSION

EVs from IM-resistant CML cells alter the expression of miR-629-5p in sensitive cells, activating the SENP2/PI3K/AKT/mTOR pathway and leading to IM resistance.

miR-574-5p in epigenetic regulation and Toll-like receptor signaling

miR-574-5p is an unusual microRNA (miRNA) that is often upregulated or downregulated following exposure to irradiation or toxic chemicals; bacterial, parasitic or viral infection; and a variety of other disease conditions. Canonically, miR-574-5p epigenetically regulates the expression of many messenger RNAs (mRNAs) through miRNA-mediated posttranscriptional regulation, thereby affecting cellular physiology or pathophysiology and contributing to the pathogenesis or progression of a variety of diseases. However, recent studies have established that in addition to serving as a fine-tuning repressor of gene expression, miR-574-5p also stimulates gene expression as an endogenous ligand for Toll-like receptor-8/7 (TLR8/7). Indeed, the binding of miR-574-5p to TLR8/7 triggers the TLR signaling pathway, leading to the induction of interferons, inflammatory cytokines and autoimmune signaling. These findings suggest that miR-574-5p is not only an important epigenetic regulator of gene expression, but also an important regulator of immune and inflammatory responses. Abnormal miR-574-5p-TLR8/7 signaling has been shown to be tightly associated with inflammation-related cancers and a number of autoimmune disorders. miR-574-5p can serve as a potential biomarker for many diseases. Most importantly, miR-574-5p is a promising therapeutic target for the treatment or prevention of human disorders, especially infectious diseases, cancers and autoimmune diseases.

Tumor-derived extracellular vesicles convey solute transporters to induce bioenergetic dependence shift contributing to treatment resistance

Rationale: Growing evidence points to the tumor microenvironment's role in developing drug resistance. A key element of this microenvironment is inter-cellular communication, which includes the release of membrane-encapsulated vesicles containing various cargo, known as extracellular vesicles (EVs). Understanding how EVs contribute to acquired resistance holds significant clinical implications. Methods: Differential centrifugation-based methods were used to isolate EVs from established cell lines and human plasma. TMT labeling proteomics analysis of EVs revealed an abundance of metabolic transporter proteins. Increased expression of SLC1A5 in EVs of patient-derived plasma and cell lines rendered resistant to tyrosine kinase inhibitors and its relationship with progression-free survival was assessed using Kaplan-Meier survival plot. Gene knockdown and overexpression of SLC1A5 were used to validate its effect on Tyrosine kinase inhibitor (TKI) resistance. Co-culture assays using inserts was used to evaluate the effect of resistant EVs on normal fibroblasts and epithelial cells. Next, mouse-derived tumor slices (MDTS) were cultured in vitro to assess the effect of resistant EVs. Results: We report here that TKI-sensitive cells are rendered resistant upon incubation with EVs derived from TKI-resistant cell lines. Metabolic transporters, in particular SLC1A5 and SLC25A5, are upregulated in EVs derived from TKI-resistant cells and plasma from patients harbouring TKI-resistant tumors and in TKI-resistant cell lines. Furthermore, we also provide evidence for the increased abundance of pSTAT3 and the stemness marker ALDH1A1 upon EV-induced resistance. Notably, resistant EVs trigger phenotypic and functional switching of lung-derived fibroblasts into tumor-associated fibroblasts, significantly increasing their migratory and invasive capacities. Conclusions: Our findings support the role of metabolic transporters within tumor-derived EVs in reshaping the tumor microenvironment to promote therapy resistance, which could have potential diagnostic, prognostic, and therapeutic implications.

MicroRNA-155 and its exosomal form: Small pieces in the gastrointestinal cancers puzzle

Gastrointestinal (GI) cancers are common cancers that are responsible for a large portion of global cancer fatalities. Due to this, there is a pressing need for innovative strategies to identify and treat GI cancers. MicroRNAs (miRNAs) are short ncRNAs that can be considered either cancer-causing or tumor-inhibiting molecules. MicroRNA-155, also known as miR-155, is a vital regulator in various cancer types. This miRNA has a carcinogenic role in a variety of gastrointestinal cancers, including pancreatic, colon, and gastric cancers. Since the abnormal production of miR-155 has been detected in various malignancies and has a correlation with increased mortality, it is a promising target for future therapeutic approaches. Moreover, exosomal miR-155 associated with tumors have significant functions in communicating between cells and establishing the microenvironment for cancer in GI cancers. Various types of genetic material, such as specifically miR-155 as well as proteins found in cancer-related exosomes, have the ability to be transmitted to other cells and have a function in the advancement of tumor. Therefore, it is critical to conduct a review that outlines the diverse functions of miR-155 in gastrointestinal malignancies. As a result, we present a current overview of the role of miR-155 in gastrointestinal cancers. Our research highlighted the role of miR-155 in GI cancers and covered critical issues in GI cancer such as pharmacologic inhibitors of miRNA-155, miRNA-155-assosiated circular RNAs, immune-related cells contain miRNA-155. Importantly, we discussed miRNA-155 in GI cancer resistance to chemotherapy, diagnosis and clinical trials. Furthermore, the function of miR-155 enclosed in exosomes that are released by cancer cells or tumor-associated macrophages is also covered.

Extracellular vesicles as modulators of monocyte and macrophage function in tumors

The tumor microenvironment (TME) harbors several cell types, such as tumor cells, immune cells, and non-immune cells. These cells communicate through several mechanisms, such as cell-cell contact, cytokines, chemokines, and extracellular vesicles (EVs). Tumor-derived vesicles are known to have the ability to modulate the immune response. Monocytes are a subset of circulating innate immune cells and play a crucial role in immune surveillance, being recruited to tissues where they differentiate into macrophages. In the context of tumors, it has been observed that tumor cells can attract monocytes to the TME and induce their differentiation into tumor-associated macrophages with a pro-tumor phenotype. Tumor-derived EVs have emerged as essential structures mediating this process. Through the transfer of specific molecules and signaling factors, tumor-derived EVs can shape the phenotype and function of monocytes, inducing the expression of cytokines and molecules by these cells, thus modulating the TME towards an immunosuppressive environment.

The miR-29 family facilitates the activation of NK-cell immune responses by targeting the B7-H3 immune checkpoint in neuroblastoma

Neuroblastoma (NB) is a highly aggressive pediatric cancer that originates from immature nerve cells, presenting significant treatment challenges due to therapy resistance. Despite intensive treatment, approximately 50% of high-risk NB cases exhibit therapy resistance or experience relapse, resulting in poor outcomes often associated with tumor immune evasion. B7-H3 is an immune checkpoint protein known to inhibit immune responses. MicroRNAs (miRNAs) are small non-coding RNAs involved in post-transcriptional gene regulation. Our study aims to explore the impact of miRNAs on B7-H3 regulation, the anti-tumor immune response, and tumorigenicity in NB. Analysis of NB patients and patient-derived xenograft tumors revealed a correlation between higher B7-H3 expression and poorer patient survival. Notably, deceased patients exhibited a depletion of miR-29 family members (miR-29a, miR-29b, and miR-29c), which displayed an inverse association with B7-H3 expression in NB patients. Overexpression and knockdown experiments demonstrated that these miRNAs degrade B7-H3 mRNA, resulting in enhanced NK cell activation and cytotoxicity. In vivo, experiments provided further evidence that miR-29 family members reduce tumorigenicity, macrophage infiltration, and microvessel density, promote infiltration and activation of NK cells, and induce tumor cell apoptosis. These findings offer a rationale for developing more effective combination treatments that leverage miRNAs to target B7-H3 in NB patients.

SAP30, an oncogenic driver of progression, poor survival, and drug resistance in neuroblastoma

Neuroblastoma is the most devastating extracranial solid malignancy in children. Despite an intense treatment regimen, the prognosis for high-risk neuroblastoma patients remains poor, with less than 40% survival. So far, MYCN amplification status is considered the most prognostic factor but corresponds to only ∼25% of neuroblastoma patients. Therefore, it is essential to identify a better prognosis and therapy response marker in neuroblastoma patients. We applied robust bioinformatic data mining tools, such as weighted gene co-expression network analysis, cisTarget, and single-cell regulatory network inference and clustering on two neuroblastoma patient datasets. We found Sin3A-associated protein 30 (SAP30), a driver transcription factor positively associated with high-risk, progression, stage 4, and poor survival in neuroblastoma patient cohorts. Tumors of high-risk neuroblastoma patients and relapse-specific patient-derived xenografts showed higher SAP30 levels. The advanced pharmacogenomic analysis and CRISPR-Cas9 screens indicated that SAP30 essentiality is associated with cisplatin resistance and further showed higher levels in cisplatin-resistant patient-derived xenograft tumor cell lines. Silencing of SAP30 induced cell death in vitro and led to a reduced tumor burden and size in vivo. Altogether, these results indicate that SAP30 is a better prognostic and cisplatin-resistance marker and thus a potential drug target in high-risk neuroblastoma.

Targeting the innate immune system in pediatric and adult AML

While the introduction of T cell-based immunotherapies has improved outcomes in many cancer types, the development of immunotherapies for both adult and pediatric AML has been relatively slow and limited. In addition to the need to identify suitable target antigens, a better understanding of the immunosuppressive tumor microenvironment is necessary for the design of novel immunotherapy approaches. To date, most immune characterization studies in AML have focused on T cells, while innate immune lineages such as monocytes, granulocytes and natural killer (NK) cells, received less attention. In solid cancers, studies have shown that innate immune cells, such as macrophages, myeloid-derived suppressor cells and neutrophils are highly plastic and may differentiate into immunosuppressive cells depending on signals received in their microenvironment, while NK cells appear to be functionally impaired. Hence, an in-depth characterization of the innate immune compartment in the TME is urgently needed to guide the development of immunotherapeutic interventions for AML. In this review, we summarize the current knowledge on the innate immune compartment in AML, and we discuss how targeting its components may enhance T cell-based- and other immunotherapeutic approaches.

TLR8 aggravates skin inflammation and fibrosis by activating skin fibroblasts in systemic sclerosis

OBJECTIVES

Innate immunity significantly contributes to SSc pathogenesis. TLR8 is an important innate immune mediator that is implicated in autoimmunity and fibrosis. However, the expression, mechanism of action, and pathogenic role of TLR8 in SSc remain unclear. The aim of this study was to explore the roles and underlying mechanisms of TLR8 in SSc.

METHODS

The expression of TLR8 was analysed, based on a public dataset, and then verified in skin tissues and skin fibroblasts of SSc patients. The role of TLR8 in inflammation and fibrosis was investigated using a TLR8-overexpression vector, activator (VTX-2337), inhibitor (cu-cpt-8m), and TLR8 siRNA in skin fibroblasts. The pathogenic role of TLR8 in skin inflammation and fibrosis was further validated in a bleomycin (BLM)-induced mouse skin inflammation and fibrosis model.

RESULTS

TLR8 levels were significantly elevated in SSc skin tissues and myofibroblasts, along with significant activation of the TLR8 pathway. In vitro studies showed that overexpression or activation of TLR8 by a recombinant plasmid or VTX-2337 upregulated IL-6, IL-1β, COL I, COL III and α-SMA in skin fibroblasts. Consistently, both TLR8-siRNA and cu-cpt-8m reversed the phenotypes observed in TLR8-activating fibroblasts. Mechanistically, TLR8 induces skin fibrosis and inflammation in a manner dependent on the MAPK, NF-κB and SMAD2/3 pathways. Subcutaneous injection of cu-cpt-8m significantly alleviated BLM-induced skin inflammation and fibrosis in vivo.

CONCLUSION

TLR8 might be a promising therapeutic target for improving the treatment strategy for skin inflammation and fibrosis in SSc.

Extracellular Vesicles for Childhood Cancer Liquid Biopsy

Liquid biopsy involves the utilization of minimally invasive or noninvasive techniques to detect biomarkers in biofluids for disease diagnosis, monitoring, or guiding treatments. This approach is promising for the early diagnosis of childhood cancer, especially for brain tumors, where tissue biopsies are more challenging and cause late detection. Extracellular vesicles offer several characteristics that make them ideal resources for childhood cancer liquid biopsy. Extracellular vesicles are nanosized particles, primarily secreted by all cell types into body fluids such as blood and urine, and contain molecular cargos, i.e., lipids, proteins, and nucleic acids of original cells. Notably, the lipid bilayer-enclosed structure of extracellular vesicles protects their cargos from enzymatic degradation in the extracellular milieu. Proteins and nucleic acids of extracellular vesicles represent genetic alterations and molecular profiles of childhood cancer, thus serving as promising resources for precision medicine in cancer diagnosis, treatment monitoring, and prognosis prediction. This review evaluates the recent progress of extracellular vesicles as a liquid biopsy platform for various types of childhood cancer, discusses the mechanistic roles of molecular cargos in carcinogenesis and metastasis, and provides perspectives on extracellular vesicle-guided therapeutic intervention. Extracellular vesicle-based liquid biopsy for childhood cancer may ultimately contribute to improving patient outcomes.

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.

Prospects and challenges of noncoding-RNA-mediated inhibition of heat shock protein 90 for cancer therapy

Heat Shock Protein 90 (HSP90) is a potential drug target for cancer therapy as it is often dysregulated in several cancers, including lung, breast, pancreatic, and prostate cancers. In cancer, HSP90 fails to maintain the structural and functional integrity of its several client proteins which are involved in the hallmarks of cancer such as cell proliferation, invasion, migration, angiogenesis, and apoptosis. Several small molecule inhibitors of HSP90 have been shown to exhibit anticancer effects in vitro and in vivo animal models. However, a few of them are currently under clinical studies. The status and potential limitations of these inhibitors are discussed here. Studies demonstrate that several noncoding RNAs (ncRNAs) such as microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) regulate HSP90 and its client proteins to modulate cellular processes to exhibit oncogenic or tumor suppressing properties. Over the last decade, miRNAs and lncRNAs have drawn significant interest from the scientific community as therapeutic agents or targets for clinical applications. Here, we discuss the detailed mechanistic regulation of HSP90 and its client proteins by ncRNAs. Moreover, we highlight the significance of these ncRNAs as potential therapeutic agents/targets, and the challenges associated with ncRNA-based therapies. This article aims to provide a holistic view on HSP90-regulating ncRNAs for the development of novel therapeutic strategies to combat cancer.

Non-coding RNAs in disease: from mechanisms to therapeutics

Non-coding RNAs (ncRNAs) are a heterogeneous group of transcripts that, by definition, are not translated into proteins. Since their discovery, ncRNAs have emerged as important regulators of multiple biological functions across a range of cell types and tissues, and their dysregulation has been implicated in disease. Notably, much research has focused on the link between microRNAs (miRNAs) and human cancers, although other ncRNAs, such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), are also emerging as relevant contributors to human disease. In this Review, we summarize our current understanding of the roles of miRNAs, lncRNAs and circRNAs in cancer and other major human diseases, notably cardiovascular, neurological and infectious diseases. Further, we discuss the potential use of ncRNAs as biomarkers of disease and as therapeutic targets.

Overcoming drug resistance with specific nano scales to targeted therapy: Focused on metastatic cancers

Metastatic cancer, which accounts for the majority of cancer fatalities, is a difficult illness to treat. Currently used cancer treatments include radiation therapy, chemotherapy, surgery, and targeted treatment (immune, gene, and hormonal). The disadvantages of these treatments include a high risk of tumor recurrence and surgical complications that may result in permanent deformities. On the other hand, most chemotherapy drugs are small molecules, which usually have unfavorable side effects, low absorption, poor selectivity, and multi-drug resistance. Anticancer drugs can be delivered precisely to the cancer spot by encapsulating them to reduce side effects. Stimuli-responsive nanocarriers can be used for drug release at cancer sites and provide target-specific delivery. As previously stated, metastasis is the primary cause of cancer-related mortality. We have evaluated the usage of nano-medications in the treatment of some metastatic tumors.

Genetics and beyond: Precision Medicine Real-World Data for Patients with Cervical, Vaginal or Vulvar Cancer in a Tertiary Cancer Center

Advances in molecular tumor diagnostics have transformed cancer care. However, it remains unclear whether precision oncology has the same impact and transformative nature across all malignancies. We conducted a retrospective analysis of patients with human papillomavirus (HPV)-related gynecologic malignancies who underwent comprehensive molecular profiling and subsequent discussion at the interdisciplinary Molecular Tumor Board (MTB) of the University Hospital, LMU Munich, between 11/2017 and 06/2022. We identified a total cohort of 31 patients diagnosed with cervical (CC), vaginal or vulvar cancer. Twenty-two patients (fraction: 0.71) harbored at least one mutation. Fifteen patients (0.48) had an actionable mutation and fourteen (0.45) received a recommendation for a targeted treatment within the MTB. One CC patient received a biomarker-guided treatment recommended by the MTB and achieved stable disease on the mTOR inhibitor temsirolimus for eight months. Factors leading to non-adherence to MTB recommendations in other patient cases included informed patient refusal, rapid deterioration, stable disease, or use of alternative targeted but biomarker-agnostic treatments such as antibody-drug conjugates or checkpoint inhibitors. Despite a remarkable rate of actionable mutations in HPV-related gynecologic malignancies at our institution, immediate implementation of biomarker-guided targeted treatment recommendations remained low, and access to targeted treatment options after MTB discussion remained a major challenge.

Contribution of plasma MicroRNA-21, MicroRNA-155 and circulating monocytes plasticity to childhood neuroblastoma development and induction treatment outcome

Neuroblastoma (NB) accounts for 15% of all pediatric cancer fatalities (NB). Biomarkers that facilitate early NB detection are needed because by the time of diagnosis, over half of NBs had spread. MicroRNA-21(miR-21) and miR-155 are involved in cancer biology due to their immune modulation functions. Altered monocyte subset distribution is thought to be involved in a number of solid tumors due to its immunological role. We aimed to investigate the expression levels of miR-21 and miR-155 and their association with circulating monocytes subsets in NB and to evaluate if they correlate to the disease pathogenesis and outcome.

PATIENTS AND METHODS

This case control study involved 79 children classified into 39 newly diagnosed NB children and 40 age and sex matched healthy children. Real-time PCR was used to assess the expression of plasma miR-21 and miR-155. The frequency of circulating monocytes subsets was assessed by flow cytometry.

RESULTS

NB group showed significant up-regulation in expression of miR-21(20.9 folds) and miR-155 (1.8 folds) when compared to the control group (p < 0.001) and (p = 0.02) respectively. Also, frequency of circulating intermediate monocytes revealed significant up regulation in children with NB. In NB patients, there was a positive correlation between miR-21 and frequency of total and intermediate monocytes (r = 0.5 p < 0.001 and r = 0.7, p < 0.001, respectively). We found no discernible differences when we compared study markers between the high risk and intermediate risk groups. In addition, no significant difference was seen in study markers when patients were sub-grouped according to their induction treatment response. ROC curve analysis revealed that miR-21 up-regulation distinguished NB in childhood at an AUC of 0.94 (82% sensitivity and 100% specificity) while miR-155 up-regulation had less capacity to distinguish NB in childhood at an AUC of 0.65 (38% sensitivity and 93% specificity).

CONCLUSION

miR-21 can be utilized as a sensitive biomarker for childhood NB development. In pediatric NB, miR-21 was linked to intermediate monocyte plasticity. Both, miR-21 and miR-155 had no impact on NB outcome.

Exploring Optimal Biomarker Sources: A Comparative Analysis of Exosomes and Whole Plasma in Fasting and Non-Fasting Conditions for Liquid Biopsy Applications

The study of liquid biopsy with plasma samples is being conducted to identify biomarkers for clinical use. Exosomes, containing nucleic acids and metabolites, have emerged as possible sources for biomarkers. To evaluate the effectiveness of exosomes over plasma, we analyzed the small non-coding RNAs (sncRNAs) and metabolites extracted from exosomes in comparison to those directly extracted from whole plasma under both fasting and non-fasting conditions. We found that sncRNA profiles were not affected by fasting in either exosome or plasma samples. Our results showed that exosomal sncRNAs were found to have more consistent profiles. The plasma miRNA profiles contained high concentrations of cell-derived miRNAs that were likely due to hemolysis. We determined that certain metabolites in whole plasma exhibited noteworthy concentration shifts in relation to fasting status, while others did not. Here, we propose that (1) fasting is not required for a liquid biopsy study that involves both sncRNA and metabolomic profiling, as long as metabolites that are not influenced by fasting status are selected, and (2) the utilization of exosomal RNAs promotes robust and consistent findings in plasma samples, mitigating the impact of batch effects derived from hemolysis. These findings advance the optimization of liquid biopsy methodologies for clinical applications.

Targeting the myeloid microenvironment in neuroblastoma

Myeloid cells (granulocytes and monocytes/macrophages) play an important role in neuroblastoma. By inducing a complex immunosuppressive network, myeloid cells pose a challenge for the adaptive immune system to eliminate tumor cells, especially in high-risk neuroblastoma. This review first summarizes the pro- and anti-tumorigenic functions of myeloid cells, including granulocytes, monocytes, macrophages, and myeloid-derived suppressor cells (MDSC) during the development and progression of neuroblastoma. Secondly, we discuss how myeloid cells are engaged in the current treatment regimen and explore novel strategies to target these cells in neuroblastoma. These strategies include: (1) engaging myeloid cells as effector cells, (2) ablating myeloid cells or blocking the recruitment of myeloid cells to the tumor microenvironment and (3) reprogramming myeloid cells. Here we describe that despite their immunosuppressive traits, tumor-associated myeloid cells can still be engaged as effector cells, which is clear in anti-GD2 immunotherapy. However, their full potential is not yet reached, and myeloid cell engagement can be enhanced, for example by targeting the CD47/SIRPα axis. Though depletion of myeloid cells or blocking myeloid cell infiltration has been proven effective, this strategy also depletes possible effector cells for immunotherapy from the tumor microenvironment. Therefore, reprogramming of suppressive myeloid cells might be the optimal strategy, which reverses immunosuppressive traits, preserves myeloid cells as effectors of immunotherapy, and subsequently reactivates tumor-infiltrating T cells.

Targeting tumor-associated macrophage: an adjuvant strategy for lung cancer therapy

The emergence of immunotherapy has revolutionized the treatment landscape for various types of cancer. Nevertheless, lung cancer remains one of the leading causes of cancer-related mortality worldwide due to the development of resistance in most patients. As one of the most abundant groups of immune cells in the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play crucial and complex roles in the development of lung cancer, including the regulation of immunosuppressive TME remodeling, metabolic reprogramming, neoangiogenesis, metastasis, and promotion of tumoral neurogenesis. Hence, relevant strategies for lung cancer therapy, such as inhibition of macrophage recruitment, TAM reprograming, depletion of TAMs, and engineering of TAMs for drug delivery, have been developed. Based on the satisfactory treatment effect of TAM-targeted therapy, recent studies also investigated its synergistic effect with current therapies for lung cancer, including immunotherapy, radiotherapy, chemotherapy, anti-epidermal growth factor receptor (anti-EGFR) treatment, or photodynamic therapy. Thus, in this article, we summarized the key mechanisms of TAMs contributing to lung cancer progression and elaborated on the novel therapeutic strategies against TAMs. We also discussed the therapeutic potential of TAM targeting as adjuvant therapy in the current treatment of lung cancer, particularly highlighting the TAM-centered strategies for improving the efficacy of anti-programmed cell death-1/programmed cell death-ligand 1 (anti-PD-1/PD-L1) treatment.

MiR-181a targets STING to drive PARP inhibitor resistance in BRCA- mutated triple-negative breast cancer and ovarian cancer

BACKGROUND

Poly (ADP-ribose) polymerase inhibitors (PARPi) are approved for the treatment of BRCA-mutated breast cancer (BC), including triple-negative BC (TNBC) and ovarian cancer (OvCa). A key challenge is to identify the factors associated with PARPi resistance; although, previous studies suggest that platinum-based agents and PARPi share similar resistance mechanisms.

METHODS

Olaparib-resistant (OlaR) cell lines were analyzed using HTG EdgeSeq miRNA Whole Transcriptomic Analysis (WTA). Functional assays were performed in three BRCA-mutated TNBC cell lines. In-silico analysis were performed using multiple databases including The Cancer Genome Atlas, the Genotype-Tissue Expression, The Cancer Cell Line Encyclopedia, Genomics of Drug Sensitivity in Cancer, and Gene Omnibus Expression.

RESULTS

High miR-181a levels were identified in OlaR TNBC cell lines (p = 0.001) as well as in tumor tissues from TNBC patients (p = 0.001). We hypothesized that miR-181a downregulates the stimulator of interferon genes (STING) and the downstream proinflammatory cytokines to mediate PARPi resistance. BRCA1 mutated TNBC cell lines with miR-181a-overexpression were more resistant to olaparib and showed downregulation in STING and the downstream genes controlled by STING. Extracellular vesicles derived from PARPi-resistant TNBC cell lines horizontally transferred miR-181a to parental cells which conferred PARPi-resistance and targeted STING. In clinical settings, STING levels were positively correlated with interferon gamma (IFNG) response scores (p = 0.01). In addition, low IFNG response scores were associated with worse response to neoadjuvant treatment including PARPi for high-risk HER2 negative BC patients (p = 0.001). OlaR TNBC cell lines showed resistance to platinum-based drugs. OvCa cell lines resistant to platinum showed resistance to olaparib. Knockout of miR-181a significantly improved olaparib sensitivity in OvCa cell lines (p = 0.001).

CONCLUSION

miR-181a is a key factor controlling the STING pathway and driving PARPi and platinum-based drug resistance in TNBC and OvCa. The miR-181a-STING axis can be used as a potential marker for predicting PARPi responses in TNBC and OvCa tumors.

Upregulation of exosome secretion from tumor-associated macrophages plays a key role in the suppression of anti-tumor immunity

Macrophages play a pivotal role in tumor immunity. We report that reprogramming of macrophages to tumor-associated macrophages (TAMs) promotes the secretion of exosomes. Mechanistically, increased exosome secretion is driven by MADD, which is phosphorylated by Akt upon TAM induction and activates Rab27a. TAM exosomes carry high levels of programmed death-ligand 1 (PD-L1) and potently suppress the proliferation and function of CD8+ T cells. Analysis of patient melanoma tissues indicates that TAM exosomes contribute significantly to CD8+ T cell suppression. Single-cell RNA sequencing analysis showed that exosome-related genes are highly expressed in macrophages in melanoma; TAM-specific RAB27A expression inversely correlates with CD8+ T cell infiltration. In a murine melanoma model, lipid nanoparticle delivery of small interfering RNAs (siRNAs) targeting macrophage RAB27A led to better T cell activation and sensitized tumors to anti-programmed cell death protein 1 (PD-1) treatment. Our study demonstrates tumors use TAM exosomes to combat CD8 T cells and suggests targeting TAM exosomes as a potential strategy to improve immunotherapies.

Role of exosomes in the development, diagnosis, prognosis and treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. It is characterized by occult onset resulting in most patients being diagnosed at advanced stages and with poor prognosis. Exosomes are nanoscale vesicles with a lipid bilayer envelope released by various cells under physiological and pathological conditions, which play an important role in the biological information transfer between cells. There is growing evidence that HCC cell-derived exosomes may contribute to the establishment of a favorable microenvironment that supports cancer cell proliferation, invasion, and metastasis. These exosomes not only provide a versatile platform for diagnosis but also serve as a vehicle for drug delivery. In this paper, we review the role of exosomes involved in the proliferation, migration, and metastasis of HCC and describe their application in HCC diagnosis and treatment. We also discuss the prospects of exosome application in HCC and the research challenges.

Doxorubicin and other anthracyclines in cancers: Activity, chemoresistance and its overcoming

Anthracyclines have been important and effective treatments against a number of cancers since their discovery. However, their use in therapy has been complicated by severe side effects and toxicity that occur during or after treatment, including cardiotoxicity. The mode of action of anthracyclines is complex, with several mechanisms proposed. It is possible that their high toxicity is due to the large set of processes involved in anthracycline action. The development of resistance is a major barrier to successful treatment when using anthracyclines. This resistance is based on a series of mechanisms that have been studied and addressed in recent years. This work provides an overview of the anthracyclines used in cancer therapy. It discusses their mechanisms of activity, toxicity, and chemoresistance, as well as the approaches used to improve their activity, decrease their toxicity, and overcome resistance.

Role of non-coding RNAs in neuroblastoma

Neuroblastoma is known as the most prevalent extracranial malignancy in childhood with a neural crest origin. It has been widely accepted that non-coding RNAs (ncRNAs) play important roles in many types of cancer, including glioma and gastrointestinal cancers. They may regulate the cancer gene network. According to recent sequencing and profiling studies, ncRNAs genes are deregulated in human cancers via deletion, amplification, abnormal epigenetic, or transcriptional regulation. Disturbances in the expression of ncRNAs may act either as oncogenes or as anti-tumor suppressor genes, and can lead to the induction of cancer hallmarks. ncRNAs can be secreted from tumor cells inside exosomes, where they can be transferred to other cells to affect their function. However, these topics still need more study to clarify their exact roles, so the present review addresses different roles and functions of ncRNAs in neuroblastoma.

Dysregulated Signalling Pathways Driving Anticancer Drug Resistance

One of the leading causes of death worldwide, in both men and women, is cancer. Despite the significant development in therapeutic strategies, the inevitable emergence of drug resistance limits the success and impedes the curative outcome. Intrinsic and acquired resistance are common mechanisms responsible for cancer relapse. Several factors crucially regulate tumourigenesis and resistance, including physical barriers, tumour microenvironment (TME), heterogeneity, genetic and epigenetic alterations, the immune system, tumour burden, growth kinetics and undruggable targets. Moreover, transforming growth factor-beta (TGF-β), Notch, epidermal growth factor receptor (EGFR), integrin-extracellular matrix (ECM), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), phosphoinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR), wingless-related integration site (Wnt/β-catenin), Janus kinase/signal transducers and activators of transcription (JAK/STAT) and RAS/RAF/mitogen-activated protein kinase (MAPK) signalling pathways are some of the key players that have a pivotal role in drug resistance mechanisms. To guide future cancer treatments and improve results, a deeper comprehension of drug resistance pathways is necessary. This review covers both intrinsic and acquired resistance and gives a comprehensive overview of recent research on mechanisms that enable cancer cells to bypass barriers put up by treatments, and, like "satellite navigation", find alternative routes by which to carry on their "journey" to cancer progression.

Chasing the Role of miRNAs in RCC: From Free-Circulating to Extracellular-Vesicle-Derived Biomarkers

Renal cell carcinoma (RCC) is the second most common cancer of the urinary system. The current therapeutic strategies are based on partial or total nephrectomy and/or targeted therapies based on immune checkpoint inhibitors to which patients are often refractory. Preventive and screening strategies do not exist and the few available biomarkers for RCC are characterized by a lack of sensitivity, outlining the need for novel noninvasive and sensitive biomarkers for early diagnosis and better disease monitoring. Blood liquid biopsy (LB) is a non- or minimally invasive procedure for a more representative view of tumor heterogeneity than a tissue biopsy, potentially allowing the real-time monitoring of cancer evolution. Growing interest is focused on the extracellular vesicles (EVs) secreted by either healthy or tumoral cells and recovered in a variety of biological matrices, blood included. EVs are involved in cell-to-cell crosstalk transferring their mRNAs, microRNAs (miRNAs), and protein content. In particular, transferred miRNAs may regulate tumorigenesis and proliferation also impacting resistance to apoptosis, thus representing potential useful biomarkers. Here, we present the latest efforts in the identification of circulating miRNAs in blood samples, focusing on the potential use of EV-derived miRNAs as RCC diagnostic and prognostic markers.

Spatiotemporal quantitative microRNA-155 imaging reports immune-mediated changes in a triple-negative breast cancer model

Introduction

MicroRNAs are small non-coding RNAs and represent key players in physiology and disease. Aberrant microRNA expression is central to the development and progression of cancer, with various microRNAs proposed as potential cancer biomarkers and drug targets. There is a need to better understand dynamic microRNA expression changes as cancers progress and their tumor microenvironments evolve. Therefore, spatiotemporal and non-invasive in vivo microRNA quantification in tumor models would be highly beneficial.

Methods

We developed an in vivo microRNA detector platform in which the obtained signals are positively correlated to microRNA presence, and which permitted stable expression in cancer cells as needed for long-term experimentation in tumor biology. It exploits a radionuclide-fluorescence dual-reporter for quantitative in vivo imaging of a microRNA of choice by radionuclide tomography and fluorescence-based downstream ex vivo tissue analyses. We generated and characterized breast cancer cells stably expressing various microRNA detectors and validated them in vitro.

Results

We found the microRNA detector platform to report on microRNA presence in cells specifically and accurately, which was independently confirmed by real-time PCR and through microRNA modulation. Moreover, we established various breast tumor models in animals with different levels of residual immune systems and observed microRNA detector read-outs by imaging. Applying the detector platform to the progression of a triple-negative breast cancer model, we found that miR-155 upregulation in corresponding tumors was dependent on macrophage presence in tumors, revealing immune-mediated phenotypic changes in these tumors as they progressed.

Conclusion

While applied to immunooncology in this work, this multimodal in vivo microRNA detector platform will be useful whenever non-invasive quantification of spatiotemporal microRNA changes in living animals is of interest.

Extracellular Vesicles Derived circSH3PXD2A Inhibits Chemoresistance of Small Cell Lung Cancer by miR-375-3p/YAP1

Introduction

Small cell lung cancer (SCLC) is a subtype of lung cancer with high malignancy and poor prognosis. Rapid acquisition of chemoresistance is one of the main reasons leading to clinical treatment failure of SCLC. Studies have indicated that circRNAs participate in multiple processes of tumor progression, including chemoresistance. However, the molecular mechanisms of circRNAs driving the chemoresistance of SCLC are not well specified.

Methods

The differentially expressed circRNAs were screened by transcriptome sequencing of chemoresistant and chemosensitive SCLC cells. The EVs of SCLC cells were isolated and identified by ultracentrifugation, Western blotting, transmission electron microscopy, nanoparticle tracking analysis and EVs uptake assays. The expression levels of circSH3PXD2A in serum and EVs of SCLC patients and healthy individuals were detected by qRT‒PCR. The characteristics of circSH3PXD2A were detected by Sanger sequencing, RNase R assay, nuclear-cytoplasmic fraction assay, and fluorescence in situ hybridization assay. The mechanisms of circSH3PXD2A inhibiting SCLC progression were studied by bioinformatics analysis, chemoresistance assay, proliferation assay, apoptosis assay, transwell assay, pull-down assay, luciferase reporting assay, and mouse xenograft assay.

Results

It was identified that the circSH3PXD2A was a prominently downregulated circRNA in chemoresistant SCLC cells. The expression level of circSH3PXD2A in EVs of SCLC patients was negatively associated with chemoresistance, and the combination of EVs-derived circSH3PXD2A and serum ProGRP (Progastrin-releasing peptide) levels had better indications for DDP-resistant SCLC patients. CircSH3PXD2A inhibited the chemoresistance, proliferation, migration, and invasion of SCLC cells through miR-375-3p/YAP1 axis in vivo and in vitro. SCLC cells cocultured with EVs secreted by circSH3PXD2A-overexpressing cells exhibited decreased chemoresistance and cell proliferation.

Conclusion

Our results manifest that EVs-derived circSH3PXD2A inhibits the chemoresistance of SCLC through miR-375-3p/YAP1 axis. Moreover, EVs-derived circSH3PXD2A may serve as a predictive biomarker for DDP-resistant SCLC patients.

Role of exosomal noncoding RNA in esophageal carcinoma

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

Neuroblastoma: Emerging trends in pathogenesis, diagnosis, and therapeutic targets

Neuroblastoma (NB) accounts for about 13% of all pediatric cancer mortality and is the leading cause of pediatric cancer death for children aged 1 to 5 years. NB, a developmental malignancy of neural ganglia, originates from neural crest-derived cells, which undergo a defective sympathetic neuronal differentiation due to genomic and epigenetic aberrations. NB is a complex disease with remarkable biological and genetic variation and clinical heterogeneity, such as spontaneous regression, treatment resistance, and poor survival rates. Depending on its severity, NB is categorized as high-risk, intermediate-risk, and low-risk., whereas high-risk NB accounts for a high infant mortality rate. Several studies revealed that NB cells suppress immune cell activity through diverse signaling pathways, including exosome-based signaling pathways. Exosome signaling has been shown to modulate gene expression in the target immune cells and attenuate the signaling events through non-coding RNAs. Since high-risk NB is characterized by a low survival rate and high clinical heterogeneity with current intensive therapies, it is crucial to unravel the molecular events of pathogenesis and develop novel therapeutic targets in high-risk, relapsed, or recurrent tumors in NB to improve patient survival. This article discusses etiology, pathophysiology, risk assessment, molecular cytogenetics, and the contribution of extracellular vesicles, non-coding RNAs, and cancer stem cells in the tumorigenesis of NB. We also detail the latest developments in NB immunotherapy and nanoparticle-mediated drug delivery treatment options.

The role of tumor-derived extracellular vesicles containing noncoding RNAs in mediating immune cell function and its implications from bench to bedside

Extracellular vesicles (EVs) are membrane-encapsulated vesicles released by almost all cell types, which participate in intercellular communication by delivering different types of molecular cargoes, such as non-coding RNAs (ncRNAs). Accumulating evidence suggests that tumor-derived EVs act as a bridge for intercellular crosstalk between tumor cells and surrounding cells, including immune cells. Tumor-derived EVs containing ncRNAs (TEV-ncRNAs) mediate intercellular crosstalk to manipulate immune responses and affect the malignant phenotypes of cancer cells. In this review, we summarize the double-edged roles and the underlying mechanisms of TEV-ncRNAs in regulating innate and adaptive immune cells. We also highlight the advantages of using TEV-ncRNAs in liquid biopsies for cancer diagnosis and prognosis. Moreover, we outline the use of engineered EVs to deliver ncRNAs and other therapeutic agents for cancer therapy.

MicroRNAs as prospective biomarkers, therapeutic targets and pharmaceuticals in neuroblastoma

Neuroblastomas, the most prevalent malignant solid neoplasms of childhood, originate from progenitor cells of the sympathetic nervous system. Their genetic causation is diverse and involves multiple molecular mechanisms. This review highlights multiple roles of microRNA in neuroblastoma pathogenesis and discusses the prospects of harnessing these important natural regulator molecules as biomarkers, therapeutic targets and pharmaceuticals in neuroblastoma.

Recent advances in the roles of exosomal microRNAs in neuroblastoma

Exosomal miRNAs (exo-miRs), universally found in biofluids, tissues, and/or conditioned medium of the cell cultures play a significant role in cell - cell communication, thus driving cancer progression and metastasis. Very few studies have explored the role of exo-miRs in the progression of children’s cancer - neuroblastoma. In this mini review, I briefly summarize the existing literature on the role of exo-miRs in the pathogenesis of neuroblastoma.

Recent advances in the roles of exosomal microRNAs in neuroblastoma

Exosomal miRNAs (exo-miRs), universally found in biofluids, tissues, and/or conditioned medium of the cell cultures play a significant role in cell - cell communication, thus driving cancer progression and metastasis. Very few studies have explored the role of exo-miRs in the progression of children's cancer - neuroblastoma. In this mini review, I briefly summarize the existing literature on the role of exo-miRs in the pathogenesis of neuroblastoma.

Tumor-derived miRNAs as tumor microenvironment regulators for synergistic therapeutic options

MicroRNAs (miRNAs) are a class of non-coding RNAs that perform post-transcriptional gene regulation. This review focuses on the role of tumor cell-derived miRNAs in the regulation of the tumor microenvironment (TME) via receptor cell recoding, including angiogenesis, expression of immunosuppressive molecules, formation of radiation resistance, and chemoresistance. Furthermore, we discuss the potential of these molecules as adjuvant therapies in combination with chemotherapy, radiotherapy, or immunotherapy, as well as their advantages as efficacy predictors for personalized therapy. MiRNA-based therapeutic agents for tumors are currently in clinical trials, and while challenges remain, additional research on tumor-derived miRNAs is warranted, which may provide significant clinical benefits to cancer patients.

Innovative approaches in transforming microRNAs into therapeutic tools

MicroRNA (miRNA) is regarded as a prominent genetic regulator, as it can fine-tune an entire biological pathway by targeting multiple target genes. This characteristic makes miRNAs promising therapeutic tools to reinstate cell functions that are disrupted as a consequence of diseases. Currently, miRNA replacement by miRNA mimics and miRNA inhibition by anti-miRNA oligonucleotides are the main approaches to utilizing miRNA molecules for therapeutic purposes. Nevertheless, miRNA-based therapeutics are hampered by major issues such as off-target effects, immunogenicity, and uncertain delivery platforms. Over the past few decades, several innovative approaches have been established to minimize off-target effects, reduce immunostimulation, and provide efficient transfer to the target cells in which these molecules exert their function. Recent achievements have led to the testing of miRNA-based drugs in clinical trials, and these molecules may become next-generation therapeutics for medical intervention. Despite the achievement of exciting milestones, the dosage of miRNA administration remains unclear, and ways to address this issue are proposed. Elucidating the current status of the main factors of therapeutic miRNA would allow further developments and innovations to achieve safe therapeutic tools. This article is categorized under: RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > RNAi: Mechanisms of Action.

Therapy resistance in neuroblastoma: Mechanisms and reversal strategies

Neuroblastoma is one of the most common pediatric solid tumors that threaten the health of children, accounting for about 15% of childhood cancer-related mortality in the United States. Currently, multiple therapies have been developed and applied in clinic to treat neuroblastoma including chemotherapy, radiotherapy, targeted therapy, and immunotherapy. However, the resistance to therapies is inevitable following long-term treatment, leading to treatment failure and cancer relapse. Hence, to understand the mechanisms of therapy resistance and discover reversal strategies have become an urgent task. Recent studies have demonstrated numerous genetic alterations and dysfunctional pathways related to neuroblastoma resistance. These molecular signatures may be potential targets to combat refractory neuroblastoma. A number of novel interventions for neuroblastoma patients have been developed based on these targets. In this review, we focus on the complicated mechanisms of therapy resistance and the potential targets such as ATP-binding cassette transporters, long non-coding RNAs, microRNAs, autophagy, cancer stem cells, and extracellular vesicles. On this basis, we summarized recent studies on the reversal strategies to overcome therapy resistance of neuroblastoma such as targeting ATP-binding cassette transporters, MYCN gene, cancer stem cells, hypoxia, and autophagy. This review aims to provide novel insight in how to improve the therapy efficacy against resistant neuroblastoma, which may shed light on the future directions that would enhance the treatment outcomes and prolong the survival of patients with neuroblastoma.