Differentiation Induction and Proliferation Inhibition by A Cell-Free Approach for Delivery of Exogenous miRNAs to Neuroblastoma Cells Using Mesenchymal Stem Cells

Mesenchymal Stem Cell-Derived Extracellular Vesicles in Cancer Therapy Resistance: from Biology to Clinical Opportunity

Mesenchymal stem cells (MSCs) are a type of stromal cells characterized by their properties of self-renewal and multi-lineage differentiation, which make them prominent in regenerative medicine. MSCs have shown significant potential for the treatment of various diseases, primarily through the paracrine effects mediated by soluble factors, specifically extracellular vesicles (EVs). MSC-EVs play a crucial role in intercellular communication by transferring various bioactive substances, including proteins, RNA, DNA, and lipids, highlighting the contribution of MSC-EVs in regulating cancer development and progression. Remarkably, increasing evidence indicates the association between MSC-EVs and resistance to various types of cancer treatments, including radiotherapy, chemotherapy, targeted therapy, immunotherapy, and endocrinotherapy. In this review, we provide an overview of the recent advancements in the biogenesis, isolation, and characterization of MSC-EVs, with an emphasis on their functions in cancer therapy resistance. The clinical applications and future prospects of MSC-EVs for mitigating cancer therapy resistance and enhancing drug delivery are also discussed. Elucidating the role and mechanism of MSC-EVs in the development of treatment resistance in cancer, as well as evaluating the clinical significance of MSC-EVs, is crucial for advancing our understanding of tumor biology. Meanwhile, inform the development of effective treatment strategies for cancer patients in the future.

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.

Mesenchymal stem cell-derived exosomes as new tools for delivery of miRNAs in the treatment of cancer

Although ongoing medical research is working to find a cure for a variety of cancers, it continues to be one of the major causes of death worldwide. Chemotherapy and immunotherapy, as well as surgical intervention and radiation therapy, are critical components of cancer treatment. Most anti-cancer drugs are given systemically and distribute not just to tumor tissues but also to normal tissues, where they may cause side effects. Furthermore, because anti-cancer drugs have a low delivery efficiency, some tumors do not respond to them. As a result, tumor-targeted drug delivery is critical for improving the safety and efficacy of anti-cancer treatment. Exosomes are microscopic extracellular vesicles that cells produce to communicate with one another. MicroRNA (miRNA), long non-coding RNA (lncRNA), small interfering RNA (siRNA), DNA, protein, and lipids are among the therapeutic cargos found in exosomes. Recently, several studies have focused on miRNAs as a potential therapeutic element for the treatment of cancer. Mesenchymal stem cells (MSC) have been known to have angiogenic, anti-apoptotic, anti-inflammatory and immunomodulatory effects. Exosomes derived from MSCs are gaining popularity as a non-cellular alternative to MSC-based therapy, as this method avoids unwanted lineage differentiation. Therefore more research have focused on transferring miRNAs to mesenchymal stem cells (MSC) and targeting miRNA-loaded exosomes to cancer cells. Here, we initially gave an overview of the characteristics and potentials of MSC as well as the use of MSC-derived exosomes in cancer therapy. Finally, we emphasized the utilization of MSC-derived exosomes for miRNA delivery in the treatment of cancer.

Exosomes as Neurological Nanosized Machines

In the past few decades, nanomedicine research has advanced dramatically. In spite of this, traditional nanomedicine faces major obstacles, such as blood-brain barriers, low concentrations at target sites, and rapid removal from the body. Exosomes as natural extracellular vesicles contain special bioactive molecules for cell-to-cell communications and nervous tissue function, which could overcome the challenges of nanoparticles. Most recently, microRNAs, long noncoding RNA, and circulating RNA of exosomes have been appealing because of their critical effect on the molecular pathway of target cells. In this review, we have summarized the important role of exosomes of noncoding RNAs in the occurrence of brain diseases.

Adipose stem cells-released extracellular vesicles as a next-generation cargo delivery vehicles: a survey of minimal information implementation, mass production and functional modification

OBJECTIVES

To investigate current situation of minimal information implementation highlighted by minimal information for studies of extracellular vesicles 2018 (MISEV2018) guidelines, and explore technological advances towards mass production and functional modification in aesthetic, plastic and reconstructive surgery.

METHODS

Original articles on extracellular vesicles (EVs) of adipose stem cells (ASCs) were identified. Statistics upon minimal information for EVs research, such as species, cell types, culture conditions, conditioned media harvesting parameters, EVs isolation/storage/identification/quantification, functional uptake and working concentration, were analyzed.

RESULTS

The items of cell culture conditions such as passage number, seeding density, conditioned media harvesting time, functional uptake and working concentration were poorly documented, with a reporting percentage of 47.13%, 54.02%, 29.89%, 62.07% and 36.21%, respectively. However, there were some studies not reporting information of ASCs origin, culture medium, serum, EVs isolation methods, quantification and identification of EVs, accounting for 3.45%, 10.34%, 6.90%, 3.45%, 18.39% and 4.02%, respectively. Serum deprivation and trophic factors stimuli were attempted for EVs mass production. Several technological advances towards functional modification included hypoxia pre-condition, engineering EVs and controlled release. Presently, ASCs EVs have been applied in multiple fields, including diabetic/non-diabetic wound healing, angiogenesis, inflammation modulation, fat grafting, hair regeneration, antiaging, and healing and regeneration of cartilage/bone/peripheral nerve/tendon.

CONCLUSION

Our results highlight normative reporting of ASCs EVs in functional studies to increase reliability and reproducibility of scientific publications. The advances towards mass production and functional modification of ASCs EVs are also recommended to enhance therapeutic effects.

Mesenchymal stem cells-derived exosomes for drug delivery

Exosomes are extracellular vesicles secreted by various cells, mainly composed of lipid bilayers without organelles. In recent years, an increasing number of researchers have focused on the use of exosomes for drug delivery. Targeted drug delivery in the body is a promising method for treating many refractory diseases such as tumors and Alzheimer's disease (AD). Finding a suitable drug delivery carrier in the body has become a popular research today. In various drug delivery studies, the exosomes secreted by mesenchymal stem cells (MSC-EXOs) have been broadly researched due to their immune properties, tumor-homing properties, and elastic properties. While MSC-EXOs have apparent advantages, some unresolved problems also exist. This article reviews the studies on MSC-EXOs for drug delivery, summarizes the characteristics of MSC-EXOs, and introduces the primary production and purification methods and drug loading methods to provide solutions for existing problems and suggestions for future studies.

Mechanisms involved in selecting and maintaining neuroblastoma cancer stem cell populations, and perspectives for therapeutic targeting

Pediatric neuroblastomas (NBs) are heterogeneous, aggressive, therapy-resistant embryonal tumours that originate from cells of neural crest (NC) origin and in particular neuroblasts committed to the sympathoadrenal progenitor cell lineage. Therapeutic resistance, post-therapeutic relapse and subsequent metastatic NB progression are driven primarily by cancer stem cell (CSC)-like subpopulations, which through their self-renewing capacity, intermittent and slow cell cycles, drug-resistant and reversibly adaptive plastic phenotypes, represent the most important obstacle to improving therapeutic outcomes in unfavourable NBs. In this review, dedicated to NB CSCs and the prospects for their therapeutic eradication, we initiate with brief descriptions of the unique transient vertebrate embryonic NC structure and salient molecular protagonists involved NC induction, specification, epithelial to mesenchymal transition and migratory behaviour, in order to familiarise the reader with the embryonic cellular and molecular origins and background to NB. We follow this by introducing NB and the potential NC-derived stem/progenitor cell origins of NBs, before providing a comprehensive review of the salient molecules, signalling pathways, mechanisms, tumour microenvironmental and therapeutic conditions involved in promoting, selecting and maintaining NB CSC subpopulations, and that underpin their therapy-resistant, self-renewing metastatic behaviour. Finally, we review potential therapeutic strategies and future prospects for targeting and eradication of these bastions of NB therapeutic resistance, post-therapeutic relapse and metastatic progression.

The Potential of Mesenchymal Stromal Cells in Neuroblastoma Therapy for Delivery of Anti-Cancer Agents and Hematopoietic Recovery

Neuroblastoma is one of the most common pediatric cancers and a major cause of cancer-related death in infancy. Conventional therapies including high-dose chemotherapy, stem cell transplantation, and immunotherapy approach a limit in the treatment of high-risk neuroblastoma and prevention of relapse. In the last two decades, research unraveled a potential use of mesenchymal stromal cells in tumor therapy, as tumor-selective delivery vehicles for therapeutic compounds and oncolytic viruses and by means of supporting hematopoietic stem cell transplantation. Based on pre-clinical and clinical advances in neuroblastoma and other malignancies, we assess both the strong potential and the associated risks of using mesenchymal stromal cells in the therapy for neuroblastoma. Furthermore, we examine feasibility and safety aspects and discuss future directions for harnessing the advantageous properties of mesenchymal stromal cells for the advancement of therapy success.

Mesenchymal Stromal Cells in Neuroblastoma: Exploring Crosstalk and Therapeutic Implications

Neuroblastoma (NB) is the second most common solid cancer in childhood, accounting for 15% of cancer-related deaths in children. In high-risk NB patients, the majority suffers from metastasis. Despite intensive multimodal treatment, long-term survival remains <40%. The bone marrow (BM) is among the most common sites of distant metastasis in patients with high-risk NB. In this environment, small populations of tumor cells can persist after treatment (minimal residual disease) and induce relapse. Therapy resistance of these residual tumor cells in BM remains a major obstacle for the cure of NB. A detailed understanding of the microenvironment and its role in tumor progression is of utmost importance for improving the treatment efficiency of NB. In BM, mesenchymal stromal cells (MSCs) constitute an important part of the microenvironment, where they support hematopoiesis and modulate immune responses. Their role in tumor progression is not completely understood, especially for NB. Although MSCs have been found to promote epithelial-mesenchymal transition, tumor growth, and metastasis and to induce chemoresistance, some reports point toward a tumor-suppressive effect of MSCs. In this review, we aim to compile current knowledge about the role of MSCs in NB development and progression. We evaluate arguments that depict tumor-supportive versus -suppressive properties of MSCs in the context of NB and give an overview of factors involved in MSC-NB crosstalk. A focus lies on the BM as a metastatic niche, since that is the predominant site for NB metastasis and relapse. Finally, we will present opportunities and challenges for therapeutic targeting of MSCs in the BM microenvironment.

Molecular Delivery of Cytotoxic Agents via Integrin Activation

Integrins are cell adhesion receptors overexpressed in tumor cells. A direct inhibition of integrins was investigated, but the best inhibitors performed poorly in clinical trials. A gained attention towards these receptors arouse because they could be target for a selective transport of cytotoxic agents. Several active-targeting systems have been developed to use integrins as a selective cell entrance for some antitumor agents. The aim of this review paper is to report on the most recent results on covalent conjugates between integrin ligands and antitumor drugs. Cytotoxic drugs thus conjugated through specific linker to integrin ligands, mainly RGD peptides, demonstrated that the covalent conjugates were more selective against tumor cells and hopefully with fewer side effects than the free drugs.