The Activation of Mesenchymal Stem Cells by Glioblastoma Microvesicles Alters Their Exosomal Secretion of miR-100-5p, miR-9-5p and let-7d-5p

Cross-Talk Between Cancer and Its Cellular Environment-A Role in Cancer Progression

The tumor microenvironment is a dynamic and complex three-dimensional network comprising the extracellular matrix and diverse non-cancerous cells, including fibroblasts, adipocytes, endothelial cells and various immune cells (lymphocytes T and B, NK cells, dendritic cells, monocytes/macrophages, myeloid-derived suppressor cells, and innate lymphoid cells). A constantly and rapidly growing number of studies highlight the critical role of these cells in shaping cancer survival, metastatic potential and therapy resistance. This review provides a synthesis of current knowledge on the modulating role of the cellular microenvironment in cancer progression and response to treatment.

Transcriptional landscape of the interaction of human Mesenchymal Stem Cells with Glioblastoma in bioprinted co-cultures

BACKGROUND

The interaction between mesenchymal stem cells (MSC) and Glioblastoma (GBM), although potentially of the highest importance, is ill-understood. This is due, in part, to the lack of relevant experimental models. The similarity between the in vitro situations and the in vivo situation can be improved by 3D co-culture as it reproduces key cell-cell interactions between the tumor microenvironment (TME) and cancer cells.

METHODS

MSC Can acquired characteristics of cancer associated fibroblasts (CAF) by being cultured with conditioned medium from GBM cultures and thus are called MSCCAF. We co Cultured MSCCAF with patient derived GBM in a scaffold 3D bioprinted model. We studied the response to current GBM therapy (e.g. Temozolomide + /Radiation) on the co cultures by bulk transcriptomic (RNA Seq) and epigenetic (ATAC Seq) analyses RESULTS: The transcriptomic modifications induced by standard GBM treatment in bioprinted scaffolds of mono- or co-cultures of GBM ± MSC can be analyzed. We found that mitochondrial encoded OXPHOS genes are overexpressed under these conditions and are modified by both co-culture and treatment (chemotherapy ± radiation). We have identified two new markers of MSC/GBM interactions, one epigenetically regulated (i.e. TREM-1) associated with an increased overall survival in GBM patients and another implicated in post-transcriptional regulation (i.e. the long non-coding RNA, miR3681HG), which is associated with a reduced overall survival in GBM patients.

Identification and validation of potential prognostic biomarkers in glioblastoma via the mesenchymal stem cell infiltration level

Aims

Mesenchymal stem cells (MSCs) are key components in promoting glioblastoma (GBM) progression. This study aimed to explore new therapeutic targets and related pathogenic mechanisms based on different MSCs infiltration levels in GBM patients.

Methods

We estimated the relationship between cell infiltration and prognosis of GBM. Subsequently, key risk genes were identified and prognostic models were constructed by LASSO-Cox analysis. The risk genes were validated by five independent external cohorts, single-cell RNA analysis, and immunohistochemistry of human GBM tissues. TIDE analysis predicted responsiveness to immune checkpoint inhibitors in different risk groups.

Results

The MSCs infiltration level was negatively associated with survival in GBM patients. LOXL1, LOXL4, and GUCA1A are key risk genes that promote GBM progression and may act through complex intercellular communication.

Conclusion

This research has provided a comprehensive study for exploring the MSCs infiltration environment on GBM progression, which could shed light on novel biomarkers and mechanisms involved in GBM progression.

Exosomes: Their role in the diagnosis, progression, metastasis, and treatment of glioblastoma

Exosomes are crucial for the growth and spread of glioblastomas, an aggressive form of brain cancer. These tiny vesicles play a crucial role in the activation of signaling pathways and intercellular communication. They can also transfer a variety of biomolecules such as proteins, lipids and nucleic acids from donor to recipient cells. Exosomes can influence the immune response by regulating the activity of immune cells, and they are crucial for the growth and metastasis of glioblastoma cells. In addition, exosomes contribute to drug resistance during treatment, which is a major obstacle in the treatment of glioblastoma. By studying them, the diagnosis and prognosis of glioblastoma can be improved. Due to their high biocompatibility and lack of toxicity, they have become an attractive option for drug delivery. The development of exosomes as carriers of specific therapeutic agents could overcome some of the obstacles to effective treatment of glioblastoma. In this review, we address the potential of exosomes for the treatment of glioblastoma and show how they can be modified for this purpose.

Mesenchymal Stem Cells Increase Drug Tolerance of A431 Cells Only in 3D Spheroids, Not in 2D Co-Cultures

Mesenchymal stem cells (MSCs) are an integral part of the tumor microenvironment (TME); however, their role is somewhat controversial: conflicting reports suggest that, depending on the stage of tumor development, MSCs can either support or suppress tumor growth and spread. Additionally, the influence of MSCs on drug resistance is also ambiguous. Previously, we showed that, despite MSCs proliferating significantly more slowly than cancer cells, there are chemotherapeutic drugs which proved to be similarly toxic to both cell types. Here we established 2D co-cultures and 3D co-culture spheroids from different ratios of GFP-expressing, adipose tissue-derived MSCs and A431 epidermoid carcinoma cells tagged with mCherry to investigate the effect of MSCs on cancer cell growth, survival, and drug sensitivity. We examined the cytokine secretion profile of mono- and co-cultures, explored the inner structure of the spheroids, applied MSC-(nutlin-3) and cancer cell-targeting (cisplatin) treatments separately, monitored the response with live-cell imaging and identified a new, double-fluorescent cell type emerging from these cultures. In 2D co-cultures, no effect on proliferation or drug sensitivity was observed, regardless of the changes in cytokine secretion induced by the co-culture. Conversely, 3D spheroids developed a unique internal structure consisting of MSCs, which significantly improved cancer cell survival and resilience to treatment, suggesting that physical proximity and cell-cell connections are required for MSCs to considerably affect nearby cancer cells. Our results shed light on MSC-cancer cell interactions and could help design new, better treatment options for tumors.

Glioblastoma-Associated Mesenchymal Stem/Stromal Cells and Cancer-Associated Fibroblasts: Partners in Crime?

Tumor-associated mesenchymal stem/stromal cells (TA-MSCs) have been recognized as attractive therapeutic targets in several cancer types, due to their ability to enhance tumor growth and angiogenesis and their contribution to an immunosuppressive tumor microenvironment (TME). In glioblastoma (GB), mesenchymal stem cells (MSCs) seem to be recruited to the tumor site, where they differentiate into glioblastoma-associated mesenchymal stem/stromal cells (GA-MSCs) under the influence of tumor cells and the TME. GA-MSCs are reported to exert important protumoral functions, such as promoting tumor growth and invasion, increasing angiogenesis, stimulating glioblastoma stem cell (GSC) proliferation and stemness, mediating resistance to therapy and contributing to an immunosuppressive TME. Moreover, they could act as precursor cells for cancer-associated fibroblasts (CAFs), which have recently been identified in GB. In this review, we provide an overview of the different functions exerted by GA-MSCs and CAFs and the current knowledge on the relationship between these cell types. Increasing our understanding of the interactions and signaling pathways in relevant models might contribute to future regimens targeting GA-MSCs and GB-associated CAFs to inhibit tumor growth and render the TME less immunosuppressive.

Extracellular vesicles produced by irradiated endothelial or Glioblastoma stem cells promote tumor growth and vascularization modulating tumor microenvironment

BACKGROUND

Glioblastoma (GBM) is the most lethal primary brain tumor in adult, characterized by highly aggressive and infiltrative growth. The current therapeutic management of GBM includes surgical resection followed by ionizing radiations and chemotherapy. Complex and dynamic interplay between tumor cells and tumor microenvironment drives the progression and contributes to therapeutic resistance. Extracellular vesicles (EVs) play a crucial role in the intercellular communication by delivering bioactive molecules in the surrounding milieu modulating tumor microenvironment.

METHODS

In this study, we isolated by ultracentrifugation EVs from GBM stem-like cell (GSC) lines and human microvascular endothelial cells (HMVECs) exposed or not to ionizing irradiation. After counting and characterization, we evaluated the effects of exposure of GSCs to EVs isolated from endothelial cells and vice versa. The RNA content of EVs isolated from GSC lines and HMVECs exposed or not to ionizing irradiation, was analyzed by RNA-Seq. Periostin (POSTN) and Filamin-B (FLNB) emerged in gene set enrichment analysis as the most interesting transcripts enriched after irradiation in endothelial cell-derived EVs and GSC-derived EVs, respectively. POSTN and FLNB expression was modulated and the effects were analyzed by in vitro assays.

RESULTS

We confirmed that ionizing radiations increased EV secretion by GSCs and normal endothelial cells, affected the contents of and response to cellular secreted EVs. Particularly, GSC-derived EVs decreased radiation-induced senescence and promoted migration in HMVECs whereas, endothelial cell-derived EVs promoted tumorigenic properties and endothelial differentiation of GSCs. RNA-Seq analysis of EV content, identified FLNB and POSTN as transcripts enriched in EVs isolated after irradiation from GSCs and HMVECs, respectively. Assays performed on POSTN overexpressing GSCs confirmed the ability of POSTN to mimic the effects of endothelial cell-derived EVs on GSC migration and clonogenic abilities and transdifferentiation potential. Functional assays performed on HMVECs after silencing of FLNB supported its role as mediator of the effects of GSC-derived EVs on senescence and migration.

CONCLUSION

In this study, we identified POSTN and FLNB as potential mediators of the effects of EVs on GSC and HMVEC behavior confirming that EVs play a crucial role in the intercellular communication by delivering bioactive molecules in the surrounding milieu modulating tumor microenvironment.

Dual impacts of mesenchymal stem cell-derived exosomes on cancer cells: unravelling complex interactions

Mesenchymal stem cells (MSCs) are multipotent, self-renewing stromal cells found in a variety of adult tissues. MSCs possess a remarkable ability to migrate towards tumor sites, known as homing. This homing process is mediated by various factors, including chemokines, growth factors, and extracellular matrix components present in the tumor microenvironment. MSCs release extracellular vesicles known as exosomes (MSC-Exos), which have been suggested to serve a key role in mediating a wide variety of MSC activities. Through cell-cell communication, MSC-Exos have been shown to alter recipient cell phenotype or function and play as a novel cell-free alternative for MSC-based cell therapy. However, MSC recruitment to tumors allows for their interaction with cancer cells and subsequent regulation of tumor behavior. MSC-Exos act as tumor niche modulators via transferring exosomal contents, such as specific proteins or genetic materials, to the nearby cancer cells, leading to either promotion or suppression of tumorigenesis, angiogenesis, and metastasis, depending on the specific microenvironmental cues and recipient cell characteristics. Consequently, there is still a debate about the precise relationship between tumor cells and MSC-Exos, and it is unclear how MSC-Exos impacts tumor cells. Although the dysregulation of miRNAs is caused by the progression of cancer, they also play a direct role in either promoting or inhibiting tumor growth as they act as either oncogenes or tumor suppressors. The utilization of MSC-Exos may prove to be an effective method for restoring miRNA as a means of treating cancer. This review aimed to present the existing understanding of the impact that MSC-Exos could have on cancer. To begin with, we presented a brief explanation of exosomes, MSCs, and MSC-Exos. Following this, we delved into the impact of MSC-Exos on cancer growth, EMT, metastasis, angiogenesis, resistance to chemotherapy and radiotherapy, and modulation of the immune system. Opposing effects of mesenchymal stem cells-derived exosomes on cancer cells.

Mesenchymal Stem Cell-Derived Exosomes: A Novel Approach to Diabetes-Associated Cognitive Impairment

The progression of diabetes frequently results in a myriad of neurological disorders, including ischemic stroke, depression, blood-brain barrier impairment, and cognitive dysfunction. Notably, diabetes-associated cognitive impairment, a prevalent comorbidity during the course of diabetes, progressively affects patients' cognitive abilities and may reciprocally influence diabetes management, thereby severely impacting patients' quality of life. Extracellular vesicles, particularly nanoscale exosomes, have garnered considerable attention in recent years. These exosomes carry and transfer various functional molecules, such as proteins, lipids, and diverse non-coding RNAs, serving as novel regulators and communicators in intercellular interactions. Of particular interest, mesenchymal stem cell-derived exosomes (MSC-Exos) have been reported to traverse the blood-brain barrier and ameliorate intracerebral pathologies. This review elucidates the role of MSC-Exos in diabetes-related cognitive impairment, with a focus on their applications as biomarkers, modulation of neuronal regeneration and synaptic plasticity, anti-inflammatory properties, antioxidative effects, and their involvement in regulating the functionality of β-amyloid proteins during the course of cognitive impairment. The immense therapeutic potential of MSC-Exos in the treatment of diabetes-induced cognitive dysfunction is emphasized.

miR-100-5p activation of the autophagy response through inhibiting the mTOR pathway and suppression of cerebral infarction progression in mice

In recent years, the association between microRNAs (miRNAs) and autophagy in cerebral infarction (CI) has attracted increasingly more attention. The mammalian target of the rapamycin (mTOR) pathway is a key protein regulating the autophagy response. miR-100-5p can bind to the mTOR protein, but its role in CI remains unclear yet. This experiment aims to clarify the role of miR-100-5p in CI. Bioinformatics analysis was performed to screen differentiated expressed functional genes between CI tissue and normal tissue specimens. In vivo experiments: the mouse model of CI was established by middle cerebral artery occlusion (MCAO) methods, After being treated with miR-100-5p-overexpressing lentivirus, the amount of terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL)-positive fluorescence and the fluorescent expression level of mTOR protein were significantly inhibited in the CI region. Western blotting analysis showed that miR-100-5p inhibited the protein expression level of phosphorylated mTOR and total mTOR and enhanced the expression of autophagy-related proteins Beclin, microtubule-associated protein light chain 3II (LC-3II), and autophagy-related gene 7 (ATG-7). For in vitro experiment, after the BV-2 cells were successfully infected with the control lentivirus and miR-100-5p-overexpression lentivirus, they were stimulated with 1% hypoxia and low-glucose medium in a tri-gas incubator for 24 h. It was found that miR-100-5p could significantly lower the protein expression level of phosphorylated mTOR and total mTOR, and increase the expression of the Beclin, LC-3II, ATG-7 autophagy related proteins. miR-100-5p promotes the autophagy response through binding to mTOR protein, thereby inhibiting apoptosis and delaying the progression of CI.

Prognosis and Immune Landscapes in Glioblastoma Based on Gene-Signature Related to Reactive-Oxygen-Species

Glioblastoma (GBM) is the most malignant and aggressive primary brain tumor and is highly resistant to current therapeutic strategies. Previous studies have demonstrated that reactive oxygen species (ROS) play an important role in the regulation of signal transduction and immunosuppressive environment in GBM. To further study the role of ROS in prognosis, tumor micro-environment (TME) and immunotherapeutic response in GBM, an ROS-related nine-gene signature was constructed using the Lasso-Cox regression method and validated using three other datasets in our research, based on the hallmark ROS-pathway-related gene sets and the Cancer Genome Atlas GBM dataset. Differences in prognosis, TME scores, immune cell infiltration, immune checkpoint expression levels, and drug sensitivity between high-risk and low-risk subgroups were analyzed using R software. Collectively, our research uncovered a novel ROS-related prognostic model for primary GBM, which could prove to be a potential tool for clinical diagnosis of GBM, and help assess the immune and molecular characteristics of ROS in the tumorigenesis and immunosuppression of GBM. Our research also revealed that the expressions of ROS-related genes-HSPB1, LSP1, and PTX3-were closely related to the cell markers of tumor-associated macrophages (TAMs) and M2 macrophages validated by quantitative RT-PCR, suggesting them could be potential targets of immunotherapy for GBM.

Role of Mesenchymal Stem/Stromal Cells in Modulating Ischemia/Reperfusion Injury: Current State of the Art and Future Perspectives

Ischemia/reperfusion injury (IRI) is a multistep damage that occurs in several tissues when a blood flow interruption is inevitable, such as during organ surgery or transplantation. It is responsible for cell death and tissue dysfunction, thus leading, in the case of transplantation, to organ rejection. IRI takes place during reperfusion, i.e., when blood flow is restored, by activating inflammation and reactive oxygen species (ROS) production, causing mitochondrial damage and apoptosis of parenchymal cells. Unfortunately, none of the therapies currently in use are definitive, prompting the need for new therapeutic approaches. Scientific evidence has proven that mesenchymal stem/stromal cells (MSCs) can reduce inflammation and ROS, prompting this cellular therapy to also be investigated for treatment of IRI. Moreover, it has been shown that MSC therapeutic effects were mediated in part by their secretome, which appears to be involved in immune regulation and tissue repair. For these reasons, mediated MSC paracrine function might be key for injury amelioration upon IRI damage. In this review, we highlight the scientific literature on the potential beneficial use of MSCs and their products for improving IRI outcomes in different tissues/organs, focusing in particular on the paracrine effects mediated by MSCs, and on the molecular mechanisms behind these effects.

Stem Cells for Cancer Therapy: Translating the Uncertainties and Possibilities of Stem Cell Properties into Opportunities for Effective Cancer Therapy

Cancer recurrence and drug resistance following treatment, as well as metastatic forms of cancer, are trends that are commonly encountered in cancer management. Amidst the growing popularity of personalized medicine and targeted therapy as effective cancer treatment, studies involving the use of stem cells in cancer therapy are gaining ground as promising translational treatment options that are actively pursued by researchers due to their unique tumor-homing activities and anti-cancer properties. Therefore, this review will highlight cancer interactions with commonly studied stem cell types, namely, mesenchymal stroma/stem cells (MSC), induced pluripotent stem cells (iPSC), iPSC-derived MSC (iMSC), and cancer stem cells (CSC). A particular focus will be on the effects of paracrine signaling activities and exosomal miRNA interaction released by MSC and iMSCs within the tumor microenvironment (TME) along with their therapeutic potential as anti-cancer delivery agents. Similarly, the role of exosomal miRNA released by CSCs will be further discussed in the context of its role in cancer recurrence and metastatic spread, which leads to a better understanding of how such exosomal miRNA could be used as potential forms of non-cell-based cancer therapy.

Activation of Dynamin-Related Protein 1 and Induction of Mitochondrial Apoptosis by Exosome-Rifampicin Nanoparticles Exerts Anti-Osteosarcoma Effect

PURPOSE

To investigate induction of cell death in Osteosarcoma (OS) using the anti-tuberculosis drug, rifampicin, loaded into exosomes.

PATIENTS AND METHODS

BMSC-exosomes were isolated by ultracentrifugation and loaded ultrasonically with rifampicin. Nanoparticle exosome-rifampicin (EXO-RIF) was added to the OS cell-lines, 143B and MG63, in vitro, to observe the growth inhibitory effect. In vivo experiments were conducted by injecting fluorescently labeled EXO-RIF through the tail vein of 143B cell xenograft nude mice and tracking distribution. Therapeutic and toxic side-effects were analyzed systemically.

RESULTS

Sonication resulted in encapsulation of rifampicin into exosomes. Exosome treatment accelerated the entry of rifampicin into OS cells and enhanced the actions of rifampicin in inhibiting OS proliferation, migration and invasion. Cell cycle arrest at the G2/M phase was observed. Dynamin-related protein 1 (Drp1) was activated by EXO-RIF and caused mitochondrial lysis and apoptosis. Exosome treatment targeted rifampicin to the site of OS, causing OS apoptosis and improving mouse survival in vivo.

CONCLUSION

The potent Drp1 agonist, rifampicin, induced OS apoptosis and exosome loading, improving OS targeting and mouse survival rates. EXO-RIF is a promising strategy for the treatment of diverse malignancies.

Comparative Analysis of Natural and Cytochalasin B-Induced Membrane Vesicles from Tumor Cells and Mesenchymal Stem Cells

To date, there are numerous protocols for the isolation of extracellular vesicles (EVs). Depending on the isolation method, it is possible to obtain vesicles with different characteristics, enriched with specific groups of proteins, DNA and RNA, which affect similar types of cells in the opposite way. Therefore, it is important to study and compare methods of vesicle isolation. Moreover, the differences between the EVs derived from tumor and mesenchymal stem cells are still poorly understood. This article compares EVs from human glioblastoma cells and mesenchymal stem cells (MSCs) obtained by two different methods, ultracentrifugation and cytochalasin B-mediated induction. The size of the vesicles, the presence of the main EV markers, the presence of nuclear and mitochondrial components, and the molecular composition of the vesicles were determined. It has been shown that EVs obtained by both ultracentrifugation and cytochalasin B treatment have similar features, contain particles of endogenous and membrane origin and can interact with monolayer cultures of tumor cells.

Current Status of Mesenchymal Stem/Stromal Cells for Treatment of Neurological Diseases

Neurological disorders include a wide spectrum of clinical conditions affecting the central and peripheral nervous systems. For these conditions, which affect hundreds of millions of people worldwide, generally limited or no treatments are available, and cell-based therapies have been intensively investigated in preclinical and clinical studies. Among the available cell types, mesenchymal stem/stromal cells (MSCs) have been widely studied but as yet no cell-based treatment exists for neurological disease. We review current knowledge of the therapeutic potential of MSC-based therapies for neurological diseases, as well as possible mechanisms of action that may be explored to hasten the development of new and effective treatments. We also discuss the challenges for culture conditions, quality control, and the development of potency tests, aiming to generate more efficient cell therapy products for neurological disorders.

Extracellular Vesicles Secreted by Glioma Stem Cells Are Involved in Radiation Resistance and Glioma Progression

Glioblastoma is the most aggressive brain tumour with short survival, partly due to resistance to conventional therapy. Glioma stem cells (GSC) are likely to be involved in treatment resistance, by releasing extracellular vesicles (EVs) containing specific molecular cargoes. Here, we studied the EVs secreted by glioma stem cells (GSC-EVs) and their effects on radiation resistance and glioma progression. EVs were isolated from 3 GSCs by serial centrifugation. NanoSight measurement, cryo-electron microscopy and live imaging were used to study the EVs size, morphology and uptake, respectively. The non-GSC glioma cell lines LN229 and U118 were utilised as a recipient cell model. Wound healing assays were performed to detect cell migration. Colony formation, cell viability and invadopodium assays were conducted to detect cell survival of irradiated recipient cells and cell invasion post GSC-EV treatment. NanoString miRNA global profiling was used to select for the GSC-EVs’ specific miRNAs. All three GSC cell lines secreted different amounts of EVs, and all expressed consistent levels of CD9 but different level of Alix, TSG101 and CD81. EVs were taken up by both LN229 and U118 recipient cells. In the presence of GSC-EVs, these recipient cells survived radiation exposure and initiated colony formation. After GSC-EVs exposure, LN229 and U118 cells exhibited an invasive phenotype, as indicated by an increase in cell migration. We also identified 25 highly expressed miRNAs in the GSC-EVs examined, and 8 of these miRNAs can target PTEN. It is likely that GSC-EVs and their specific miRNAs induced the phenotypic changes in the recipient cells due to the activation of the PTEN/Akt pathway. This study demonstrated that GSC-EVs have the potential to induce radiation resistance and modulate the tumour microenvironment to promote glioma progression. Future therapeutic studies should be designed to interfere with these GSC-EVs and their specific miRNAs.