Anti-tumor effects of canine adipose tissue-derived mesenchymal stromal cell-based interferon-β gene therapy and cisplatin in a mouse melanoma model

Nanotechnology and bioengineering approaches to improve the potency of mesenchymal stem cell as an off-the-shelf versatile tumor delivery vehicle

Targeting actionable mutations in oncogene-driven cancers and the evolution of immuno-oncology are the two prominent revolutions that have influenced cancer treatment paradigms and caused the emergence of precision oncology. However, intertumoral and intratumoral heterogeneity are the main challenges in both fields of precision cancer treatment. In other words, finding a universal marker or pathway in patients suffering from a particular type of cancer is challenging. Therefore, targeting a single hallmark or pathway with a single targeted therapeutic will not be efficient for fighting against tumor heterogeneity. Mesenchymal stem cells (MSCs) possess favorable characteristics for cellular therapy, including their hypoimmune nature, inherent tumor-tropism property, straightforward isolation, and multilineage differentiation potential. MSCs can be loaded with various chemotherapeutics and oncolytic viruses. The combination of these intrinsic features with the possibility of genetic manipulation makes them a versatile tumor delivery vehicle that can be used for in vivo selective tumor delivery of various chemotherapeutic and biological therapeutics. MSCs can be used as biofactory for the local production of chemical or biological anticancer agents at the tumor site. MSC-mediated immunotherapy could facilitate the sustained release of immunotherapeutic agents specifically at the tumor site, and allow for the achievement of therapeutic concentrations without the need for repetitive systemic administration of high therapeutic doses. Despite the enthusiasm evoked by preclinical studies that used MSC in various cancer therapy approaches, the translation of MSCs into clinical applications has faced serious challenges. This manuscript, with a critical viewpoint, reviewed the preclinical and clinical studies that have evaluated MSCs as a selective tumor delivery tool in various cancer therapy approaches, including gene therapy, immunotherapy, and chemotherapy. Then, the novel nanotechnology and bioengineering approaches that can improve the potency of MSC for tumor targeting and overcoming challenges related to their low localization at the tumor sites are discussed.

The Dual Role of Mesenchymal Stem Cells in Cancer Pathophysiology: Pro-Tumorigenic Effects versus Therapeutic Potential

Mesenchymal stem/stromal cells (MSCs) are multipotent cells involved in numerous physiological events, including organogenesis, the maintenance of tissue homeostasis, regeneration, or tissue repair. MSCs are increasingly recognized as playing a major, dual, and complex role in cancer pathophysiology through their ability to limit or promote tumor progression. Indeed, these cells are known to interact with the tumor microenvironment, modulate the behavior of tumor cells, influence their functions, and promote distant metastasis formation through the secretion of mediators, the regulation of cell-cell interactions, and the modulation of the immune response. This dynamic network can lead to the establishment of immunoprivileged tissue niches or the formation of new tumors through the proliferation/differentiation of MSCs into cancer-associated fibroblasts as well as cancer stem cells. However, MSCs exhibit also therapeutic effects including anti-tumor, anti-proliferative, anti-inflammatory, or anti-oxidative effects. The therapeutic interest in MSCs is currently growing, mainly due to their ability to selectively migrate and penetrate tumor sites, which would make them relevant as vectors for advanced therapies. Therefore, this review aims to provide an overview of the double-edged sword implications of MSCs in tumor processes. The therapeutic potential of MSCs will be reviewed in melanoma and lung cancers.

"Bioinspired" Membrane-Coated Nanosystems in Cancer Theranostics: A Comprehensive Review

Achieving precise cancer theranostics necessitates the rational design of smart nanosystems that ensure high biological safety and minimize non-specific interactions with normal tissues. In this regard, "bioinspired" membrane-coated nanosystems have emerged as a promising approach, providing a versatile platform for the development of next-generation smart nanosystems. This review article presents an in-depth investigation into the potential of these nanosystems for targeted cancer theranostics, encompassing key aspects such as cell membrane sources, isolation techniques, nanoparticle core selection, approaches for coating nanoparticle cores with the cell membrane, and characterization methods. Moreover, this review underscores strategies employed to enhance the multi-functionality of these nanosystems, including lipid insertion, membrane hybridization, metabolic engineering, and genetic modification. Additionally, the applications of these bioinspired nanosystems in cancer diagnosis and therapeutics are discussed, along with the recent advances in this field. Through a comprehensive exploration of membrane-coated nanosystems, this review provides valuable insights into their potential for precise cancer theranostics.

Cytokine sustained delivery for cancer therapy; special focus on stem cell- and biomaterial- based delivery methods

As immune regulators, cytokines serve critical role as signaling molecules in response to danger, tissue damage, or injury. Importantly, due to their vital role in immunological surveillance, cytokine therapy has become a promising therapeutics for cancer therapy. Cytokines have, however, been used only in certain clinical settings. Two key characteristics of cytokines contribute to this clinical translational challenge: first, they are highly pleiotropic, and second, in healthy physiology, they are typically secreted and act very locally in tissues. Systemic administration of the cytokines can consequently result in serious side effects. Thus, scientists have sought various strategies to circumvent theses hurdles. Recent in vivo reports signify that cytokine delivery platforms can increase their safety and therapeutic efficacy in tumor xenografts. Meanwhile, cytokine delivery using multipotent stem cells, in particular mesenchymal stem/stromal cells (MSCs), and also a diversity of particles and biomaterials has demonstrated greater capability in this regards. Herein, we take a glimpse into the recent advances in cytokine sustained delivery using stem cells and also biomaterials to ease safe and effective treatments of a myriad of human tumors.

Recent advancements to engineer mesenchymal stem cells and their extracellular vesicles for targeting and destroying tumors

Mesenchymal stem cells (MSCs) have the ability to migrate into tumor sites and release growth factors to modulate the tumor microenvironment. MSC therapy have shown a dual role in cancers, promoting or inhibiting. However, MSCs could be used as a carrier of anticancer agents for targeted tumor therapy. Recent technical improvements also allow engineering MSCs to improve tumor-targeting properties, protect anticancer agents, and decrease the cytotoxicity of drugs. While some of MSC functions are mediated through their secretome, MSCs-derived extracellular vesicles (EVs) are also proposed as a possible viechle for cancer therapy. EVs allow efficient loading of anticancer agents and have an intrinsic ability to target tumor cells, making them suitable for targeted therapy of tumors. In addition, the specificity and selectivity of EVs to the tumor sites could be enhanced by surface modification. In this review, we addressed the current approaches used for engineering MSCs and EVs to effectively target tumor sites and deliver anticancer agents.

Chemo-drugs in cell microparticles reset antitumor activity of macrophages by activating lysosomal P450 and nuclear hnRNPA2B1

Macrophages in tumors (tumor-associated macrophages, TAMs), a major population within most tumors, play key homeostatic functions by stimulating angiogenesis, enhancing tumor cell growth, and suppressing antitumor immunity. Resetting TAMs by simple, efficacious and safe approach(s) is highly desirable to enhance antitumor immunity and attenuate tumor cell malignancy. Previously, we used tumor cell-derived microparticles to package chemotherapeutic drugs (drug-MPs), which resulted in a significant treatment outcome in human malignant pleural effusions via neutrophil recruitments, implicating that drug-MPs might reset TAMs, considering the inhibitory effects of M2 macrophages on neutrophil recruitment and activation. Here, we show that drug-MPs can function as an antitumor immunomodulator by resetting TAMs with M1 phenotype and IFN-β release. Mechanistically, drug molecules in tumor MPs activate macrophage lysosomal P450 monooxygenases, resulting in superoxide anion formation, which further amplifies lysosomal ROS production and pH value by activating lysosomal NOX2. Consequently, lysosomal Ca²⁺ signaling is activated, thus polarizing macrophages towards M1. Meanwhile, the drug molecules are delivered from lysosomes into the nucleus where they activate DNA sensor hnRNPA2B1 for IFN-β production. This lysosomal-nuclear machinery fully arouses the antitumor activity of macrophages by targeting both lysosomal pH and the nuclear innate immunity. These findings highlight that drug-MPs can act as a new immunotherapeutic approach by revitalizing antitumor activity of macrophages. This mechanistic elucidation can be translated to treat malignant ascites by drug-MPs combined with PD-1 blockade.

Exosomes derived from stem cells of human deciduous exfoliated teeth inhibit angiogenesis in vivo and in vitro via the transfer of miR-100-5p and miR-1246

Background

Anti-angiogenic therapy has been shown to be a promising strategy for anti-tumor treatment. Increasing evidence indicates that tumor angiogenesis is affected by exosomes that are secreted by mesenchymal stem cells (MSCs), but whether exosomes derived from MSCs suppress or promote angiogenesis remain paradoxical. The purpose of this study focused on understanding the potential role of exosomes derived from stem cells of human deciduous exfoliated teeth (SHED-Exos) in regulating angiogenesis and the underlying molecular mechanism.

Methods

Exosomes were isolated from supernatants of SHED cells using an exosome purification kit and were characterized by transmission electron microscopy, nanoparticle tracking analysis and western blot analysis. Cell Counting Kit-8, flow cytometric assays, western blots, wound healing and transwell migration assays were performed to characterize the roles of SHED-Exos on cell proliferation, apoptosis and migration of human umbilical vein endothelial cells (HUVECs). The anti-angiogenic activity of SHED-Exos was assessed via a tube formation assay of endothelial cells and angiogenesis-related factors were analyzed by western blotting. In vivo, we used the chick chorioallantoic membrane (CAM) assay and an oral squamous cell carcinoma (OSCC) xenograft transplantation model with nude mice that received multi-point injections at three-day intervals to evaluate the effects on angiogenesis. Furthermore, the sequencing of microRNAs (miRNAs) in SHED-Exos was performed to investigate the underlying anti-angiogenic mechanism.

Results

The results showed that SHED-Exos inhibit cell proliferation and migration and induce apoptosis in HUVECs. SHED-Exos suppress the tube-like structure formation of HUVECs in vitro. SHED-Exos downregulate several angiogenesis-related factors, including VEGFA, MMP-9 and ANGPT1. In vivo, the chick CAM assay verified that treatment with SHED-Exos inhibits micro-vascular formation, and importantly, significantly reduces the micro-vascular formation of tumors generated from xenografted OSCC cells, which was associated with the inhibition of tumor growth in vivo. Mechanistically, our data suggested that SHED-Exos are enriched with miR-100-5p and miR-1246 and are transferred to endothelial cells, which results in decreased tube formation via the down-regulation of VEGFA expression.

Conclusions

These results demonstrate that SHED-Exos inhibit angiogenesis in vitro and in vivo, which suggests that SHED-Exos could potentially serve as a novel and effective therapeutic approach for anti-angiogenic treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02764-9.

Mesenchymal Stem/Stromal Cells as a Vehicle for Cytokine Delivery: An Emerging Approach for Tumor Immunotherapy

Pro-inflammatory cytokines can effectively be used for tumor immunotherapy, affecting every step of the tumor immunity cycle. Thereby, they can restore antigen priming, improve the effector immune cell frequencies in the tumor microenvironment (TME), and eventually strengthen their cytolytic function. A renewed interest in the anticancer competencies of cytokines has resulted in a substantial promotion in the number of trials to address the safety and efficacy of cytokine-based therapeutic options. However, low response rate along with the high toxicity associated with high-dose cytokine for reaching desired therapeutic outcomes negatively affect their clinical utility. Recently, mesenchymal stem/stromal cells (MSCs) due to their pronounced tropism to tumors and also lower immunogenicity have become a promising vehicle for cytokine delivery for human malignancies. MSC-based delivery of the cytokine can lead to the more effective immune cell-induced antitumor response and provide sustained release of target cytokines, as widely evidenced in a myriad of xenograft models. In the current review, we offer a summary of the novel trends in cytokine immunotherapy using MSCs as a potent and encouraging carrier for antitumor cytokines, focusing on the last two decades' animal reports.

Mesenchymal Stem/Stromal Cell-Based Delivery: A Rapidly Evolving Strategy for Cancer Therapy

Mesenchymal stem/stromal cell (MSC)-based therapy has become an attractive and advanced scientific research area in the context of cancer therapy. This interest is closely linked to the MSC-marked tropism for tumors, suggesting them as a rational and effective vehicle for drug delivery for both hematological and solid malignancies. Nonetheless, the therapeutic application of the MSCs in human tumors is still controversial because of the induction of several signaling pathways largely contributing to tumor progression and metastasis. In spite of some evidence supporting that MSCs may sustain cancer pathogenesis, increasing proofs have indicated the suppressive influences of MSCs on tumor cells. During the last years, a myriad of preclinical and some clinical studies have been carried out or are ongoing to address the safety and efficacy of the MSC-based delivery of therapeutic agents in diverse types of malignancies. A large number of studies have focused on the MSC application as delivery vehicles for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), chemotherapeutic drug such as gemcitabine (GCB), paclitaxel (PTX), and doxorubicin (DOX), prodrugs such as 5-fluorocytosine (5-FC) and ganciclovir (GCV), and immune cell-activating cytokines along with oncolytic virus. In the current review, we evaluate the latest findings rendering the potential of MSCs to be employed as potent gene/drug delivery vehicle for inducing tumor regression with a special focus on the in vivo reports performed during the last two decades.

Recent advances in regenerative medicine strategies for cancer treatment

Cancer stands as one of the most leading causes of death worldwide, while one of the most significant challenges in treating it is revealing novel alternatives to predict, diagnose, and eradicate tumor cell growth. Although various methods, such as surgery, chemotherapy, and radiation therapy, are used today to treat cancer, its mortality rate is still high due to the numerous shortcomings of each approach. Regenerative medicine field, including tissue engineering, cell therapy, gene therapy, participate in cancer treatment and development of cancer models to improve the understanding of cancer biology. The final intention is to convey fundamental and laboratory research to effective clinical treatments, from the bench to the bedside. Proper interpretation of research attempts helps to lessen the burden of treatment and illness for patients. The purpose of this review is to investigate the role of regenerative medicine in accelerating and improving cancer treatment. This study examines the capabilities of regenerative medicine in providing novel cancer treatments and the effectiveness of these treatments to clarify this path as much as possible and promote advanced future research in this field.

Comparative analysis of canine mesenchymal stem cells and bone marrow-derived mononuclear cells

Background and aim:

Mesenchymal stem cells (MSCs), which have multi-lineage differentiation potentials, are a promising source for regenerative medicine. However, the focus of study of MSCs is shifting from the characterization of the differentiation potential to their secretion potential for cell transplantation. Tissue regeneration and the attenuation of immune responses are thought to be affected by the secretion of multiple growth factors and cytokines by MSCs. However, the secretion potential of MSCs profiling remains incompletely characterized. In this study, we focused on the secretion ability related and protein mRNA expression of dog adipose tissue-derived MSCs (AT-MSC), bone marrow (BM)-derived MSCs, and BM-derived mononuclear cells (BM-MNC).

Materials and Methods:

Real-time polymerase chain reaction analyses revealed mRNA expression of nine growth factors and seven interleukins in these types of cells and three growth factors protein expression were determined using Enzyme-linked immunosorbent assay.

Results:

For the BM-MNC growth factors, the mRNA expression of transforming growth factor-β (TGF-β) was the highest. For the BM-derived MSC (BM-MSC) and AT-MSC growth factors, the mRNA expression of vascular endothelial growth factor (VEGF) was highest. BM-MSCs and AT-MSCs showed similar expression profiles. In contrast, BM-MNCs showed unique expression profiles for hepatocyte growth factor and epidermal growth factor. The three types of cells showed a similar expression of TGF-β.

Conclusion:

We conclude that expression of cytokine proteins and mRNAs suggests involvement in tissue repair and protection.

Translational Animal Models Provide Insight Into Mesenchymal Stromal Cell (MSC) Secretome Therapy

The therapeutic potential of the mesenchymal stromal cell (MSC) secretome, consisting of all molecules secreted by MSCs, is intensively studied. MSCs can be readily isolated, expanded, and manipulated in culture, and few people argue with the ethics of their collection. Despite promising pre-clinical studies, most MSC secretome-based therapies have not been implemented in human medicine, in part because the complexity of bioactive factors secreted by MSCs is not completely understood. In addition, the MSC secretome is variable, influenced by individual donor, tissue source of origin, culture conditions, and passage. An increased understanding of the factors that make up the secretome and the ability to manipulate MSCs to consistently secrete factors of biologic importance will improve MSC therapy. To aid in this goal, we can draw from the wealth of information available on secreted factors from MSC isolated from veterinary species. These translational animal models will inspire efforts to move human MSC secretome therapy from bench to bedside.

The Current Status of Mesenchymal Stromal Cells: Controversies, Unresolved Issues and Some Promising Solutions to Improve Their Therapeutic Efficacy

Mesenchymal stromal cells (MSCs) currently constitute the most frequently used cell type in advanced therapies with different purposes, most of which are related with inflammatory processes. Although the therapeutic efficacy of these cells has been clearly demonstrated in different disease animal models and in numerous human phase I/II clinical trials, only very few phase III trials using MSCs have demonstrated the expected potential therapeutic benefit. On the other hand, diverse controversial issues on the biology and clinical applications of MSCs, including their specific phenotype, the requirement of an inflammatory environment to induce immunosuppression, the relevance of the cell dose and their administration schedule, the cell delivery route (intravascular/systemic vs. local cell delivery), and the selected cell product (i.e., use of autologous vs. allogeneic MSCs, freshly cultured vs. frozen and thawed MSCs, MSCs vs. MSC-derived extracellular vesicles, etc.) persist. In the current review article, we have addressed these issues with special emphasis in the new approaches to improve the properties and functional capabilities of MSCs after distinct cell bioengineering strategies.

Recent advances in mesenchymal stem cell membrane-coated nanoparticles for enhanced drug delivery

Studies of nanomedicine have achieved dramatic progress in recent decades. However, the main challenges that traditional nanomedicine has to overcome include low accumulation at target sites and rapid clearance from the blood circulation. An interesting approach using cell membrane coating technology has emerged as a possible way to overcome these limitations, owing to the enhanced targeted delivery and reduced immunogenicity of cell membrane moieties. Mesenchymal stem cell (MSC) therapy has been investigated for treating various diseases, ranging from inflammatory diseases to tissue damage. Recent studies with engineered modified MSCs or MSC membranes have focused on enhancing cell therapeutic efficacy. Therefore, bioengineering strategies that couple synthetic nanoparticles with MSC membranes have recently received much attention due to their homing ability and tumor tropism. Given the various membrane receptors on their surfaces, MSC membrane-coated nanoparticles are an effective method with selective targeting properties, allowing entry into specific cells. Here, we review recent progress on the use of MSC membrane-coated nanoparticles for biomedical applications, particularly in the two main antitumor and anti-inflammatory fields. The combination of a bioengineered cell membrane and synthesized nanoparticles presents a wide range of possibilities for the further development of targeted drug delivery, showing the potential to enhance the therapeutic efficacy for treating various diseases.

Application of adipose-derived stem cells in photoaging: basic science and literature review

Photoaging is mainly induced by continuous exposure to sun light, causing multiple unwanted skin characters and accelerating skin aging. Adipose-derived stem cells(ADSCs) are promising in supporting skin repair because of their significant antioxidant capacity and strong proliferation, differentiation, and migration ability, as well as their enriched secretome containing various growth factors and cytokines. The identification of the mechanisms by which ADSCs perform these functions for photoaging has great potential to explore therapeutic applications and combat skin aging. We also review the basic mechanisms of UV-induced skin aging and recent improvement in pre-clinical applications of ADSCs associated with photoaging. Results showed that ADSCs are potential to address photoaging problem and might treat skin cancer. Compared with ADSCs alone, the secretome-based approaches and different preconditionings of ADSCs are more promising to overcome the current limitations and enhance the anti-photoaging capacity.

Enhancement of the Therapeutic Capacity of Mesenchymal Stem Cells by Genetic Modification: A Systematic Review

Background

The therapeutic capacity of mesenchymal stem cells (also known as mesenchymal stromal cells/MSCs) depends on their ability to respond to the need of the damaged tissue by secreting beneficial paracrine factors. MSCs can be genetically engineered to express certain beneficial factors. The aim of this systematic review is to compile and analyze published scientific literatures that report the use of engineered MSCs for the treatment of various diseases/conditions, to discuss the mechanisms of action, and to assess the efficacy of engineered MSC treatment.

Methods

We retrieved all published studies in PubMed/MEDLINE and Cochrane Library on July 27, 2019, without time restriction using the following keywords: “engineered MSC” and “therapy” or “manipulated MSC” and “therapy.” In addition, relevant articles that were found during full text search were added. We identified 85 articles that were reviewed in this paper.

Results

Of the 85 articles reviewed, 51 studies reported the use of engineered MSCs to treat tumor/cancer/malignancy/metastasis, whereas the other 34 studies tested engineered MSCs in treating non-tumor conditions. Most of the studies reported the use of MSCs in animal models, with only one study reporting a trial in human subjects. Thirty nine studies showed that the expression of beneficial paracrine factors would significantly enhance the therapeutic effects of the MSCs, whereas thirty three studies showed moderate effects, and one study in humans reported no effect. The mechanisms of action for MSC-based cancer treatment include the expression of “suicide genes,” induction of tumor cell apoptosis, and delivery of cytokines to induce an immune response against cancer cells. In the context of the treatment of non-cancerous diseases, the mechanism described in the reviewed papers included the expression of angiogenic, osteogenic, and growth factors.

Conclusion

The therapeutic capacity of MSCs can be enhanced by inducing the expression of certain paracrine factors by genetic modification. Genetically engineered MSCs have been used successfully in various animal models of diseases. However, the results should be interpreted cautiously because animal models might not perfectly represent real human diseases. Therefore, further studies are needed to explore the translational potential of genetically engineered MSCs.

The growth inhibitory effect of human gingiva-derived mesenchymal stromal cells expressing interferon-β on tongue squamous cell carcinoma cells and xenograft model

BACKGROUND

Interferon-β (IFN-β) is a cytokine with pleiotropic cellular functions, including antiviral, antiproliferative, and immunomodulatory activities. IFN-β inhibits multiple tumor cell growth in vitro. However, the contradiction between the therapeutic dose of IFN-β and its maximally tolerated dose is still inextricable in vivo. Human gingiva-derived mesenchymal stromal cells (GMSCs) represent promising vehicles for cancer gene therapy. This study evaluated the potential of GMSCs genetically engineered to produce IFN-β as a targeted gene delivery system to treat tongue squamous cell carcinoma (TSCC) in vitro and in vivo.

METHODS

A lentiviral vector encoding IFN-β was constructed and transfected into GMSCs to obtain IFN-β gene-modified GMSCs (GMSCs/IFN-β). Enzyme-linked immunosorbent assay (ELISA) was used to measure the IFN-β concentration in conditioned medium (CM) from GMSCs/IFN-β. The Cell Counting Kit-8 (CCK8), colony formation assay, and flow cytometry were used to detect the effects of GMSCs/IFN-β on TSCC cell line CAL27 cell growth and apoptosis in vitro. TSCC xenograft model was developed by subcutaneous injection of CAL27 cells into BALB/c nude mouse, and the role of intravenously injected GMSCs/IFN-β in engrafting in TSCC and controlling tumor progression was measured in vivo.

RESULTS

GMSCs/IFN-β expressed a high level of IFN-β. Both CCK8 and colony forming assay showed that GMSCs/IFN-β significantly inhibited the proliferation of CAL27 cells compared with the GMSCs, GMSCs/vector, or DMEM group. Flow cytometry analysis demonstrated that the CAL27 cell apoptosis rate was higher in the GMSCs/IFN-β group than in the other three groups. The in vivo experiment revealed that GMSCs/IFN-β engrafted selectively in TSCC xenograft and expressed a high level of IFN-β. There were smaller tumor volume and lower number of Ki67-positive cells in the GMSCs/IFN-β group than in the GMSCs, GMSCs/vector, or phosphate-buffered saline (PBS) group. Interestingly, GMSCs and GMSCs/vector also presented the potential of CAL27 cell growth inhibition in vitro and in vivo, although such an effect was weaker than GMSCs/IFN-β.

CONCLUSIONS

GMSCs/IFN-β inhibits the proliferation of TSCC cells in vitro and in vivo. These results provide evidence that delivery of IFN-β by GMSCs may be a promising approach to develop an effective treatment option for TSCC therapy.

Cell membrane camouflaged nanoparticles: a new biomimetic platform for cancer photothermal therapy

Targeted drug delivery by nanoparticles (NPs) is an essential technique to achieve the ideal therapeutic effect for cancer. However, it requires large amounts of work to imitate the biomarkers on the surface of the cell membrane and cannot fully retain the bio-function and interactions among cells. Cell membranes have been studied to form biomimetic NPs to achieve functions like immune escape, targeted drug delivery, and immune modulation, which inherit the ability to interact with the in vivo environments. Currently, erythrocyte, leukocyte, mesenchymal stem cell, cancer cell and platelet have been applied in coating photothermal agents and anti-cancer drugs to achieve increased photothermal conversion efficiency and decreased side effects in cancer ablation. In this review, we discuss the recent development of cell membrane-coated NPs in the application of photothermal therapy and cancer targeting. The underlying biomarkers of cell membrane-coated nanoparticles (CMNPs) are discussed, and future research directions are suggested.

Microarray based analysis of gene regulation by mesenchymal stem cells in breast cancer

Breast cancer is one of the most common malignant tumors with a high case-fatality rate among women. The present study aimed to investigate the effects of mesenchymal stem cells (MSCs) on breast cancer by exploring the potential underlying molecular mechanisms. The expression profile of GSE43306, which refers to MDA-MB-231 cells with or without a 1:1 ratio of MSCs, was downloaded from Gene Expression Omnibus database for differentially expressed gene (DEG) screening. The Database for Annotation, Visualization and Integrated Discovery was used for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for DEGs. The protein-protein interactional (PPI) network of DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins. The data was subsequently analyzed using molecular complex detection for sub-network mining of modules. Finally, DEGs in modules were analyzed using GO and KEGG pathway enrichment analyses. A total of 291 DEGs including 193 upregulated and 98 downregulated DEGs were obtained. Upregulated DEGs were primarily enriched in pathways including response to wounding (P=5.92×10^-7), inflammatory response (P=5.92×10^-4) and defense response (P=1.20×10^-2), whereas downregulated DEGs were enriched in pathways including the cell cycle (P=7.13×10^-4), mitotic cell cycle (P=6.81×10^-3) and M phase (P=1.72 ×10^-2). The PPI network, which contained 156 nodes and 289 edges, was constructed, and Fos was the hub node with the degree of 29. A total of 3 modules were mined from the PPI network. In total, 14 DEGs in module A were primarily enriched in GO terms, including response to wounding (P=4.77×10^-6), wounding healing (P=6.25×10^-7) and coagulation (P=1.13 ×10^-7), and these DEGs were also enriched in 1 KEGG pathway (complement and coagulation cascades; P=0.0036). Therefore, MSCs were demonstrated to exhibit potentially beneficial effects for breast cancer therapy. In addition, the screened DEGs, particularly in PPI network modules, including FN1, CD44, NGF, SERPINE1 and CCNA2, may be the potential target genes of MSC therapy for breast cancer.

Engineered Mesenchymal Stem Cells as an Anti-Cancer Trojan Horse

Cell-based gene therapy holds a great promise for the treatment of human malignancy. Among different cells, mesenchymal stem cells (MSCs) are emerging as valuable anti-cancer agents that have the potential to be used to treat a number of different cancer types. They have inherent migratory properties, which allow them to serve as vehicles for delivering effective therapy to isolated tumors and metastases. MSCs have been engineered to express anti-proliferative, pro-apoptotic, and anti-angiogenic agents that specifically target different cancers. Another field of interest is to modify MSCs with the cytokines that activate pro-tumorigenic immunity or to use them as carriers for the traditional chemical compounds that possess the properties of anti-cancer drugs. Although there is still controversy about the exact function of MSCs in the tumor settings, the encouraging results from the preclinical studies of MSC-based gene therapy for a large number of tumors support the initiation of clinical trials.

Current treatments for advanced melanoma and introduction of a promising novel gene therapy for melanoma (Review)

Metastatic melanoma is a fatal form of skin cancer that has a tendency to proliferate more rapidly than any other solid tumor. Since 2010, treatment options for metastatic melanoma have been developed including chemotherapies, checkpoint inhibition immunotherapies, e.g., anti‑cytotoxic T‑lymphocyte antigen‑4 (CTLA‑4) and anti‑programmed death‑1 (PD‑1), and molecular-targeted therapies, e.g., BRAF and MEK inhibitors. These treatments have shown not only high response rates yet also side‑effects and limitations. Notwithstanding its limitations, stem cell therapy has emerged as a new auspicious therapy for various tumor types. Since stem cells possess the ability to serve as a novel vehicle for delivering therapeutic or suicide genes to primary or metastatic cancer sites, these cells can function as part of gene‑directed enzyme prodrug therapy (GDEPT). This review focuses on introducing engineered neural stem cells (NSCs), which have tumor‑tropic behavior that allows NSCs to selectively approach primary and invasive tumor foci, as a potential gene therapy for melanoma. Therapy using engineered NSCs with cytotoxic agents resulted in markedly reduced tumor volumes and significantly prolonged survival rates in preclinical models of various tumor types. This review elucidates current treatment options for metastatic melanoma and introduces a promising NSC therapy.

Stem Cell Membrane-Coated Nanogels for Highly Efficient In Vivo Tumor Targeted Drug Delivery

Stem cell membrane-coated nanogels can effectively evade clearance of the immune system, enhance the tumor targeting properties and antitumor chemotherapy efficacy of gelatin nanogels loaded doxorubicin in mice.

Anti-tumor effect of adipose tissue derived-mesenchymal stem cells expressing interferon-β and treatment with cisplatin in a xenograft mouse model for canine melanoma

Adipose tissue-derived mesenchymal stem cells (AT-MSCs) are attractive cell-therapy vehicles for the delivery of anti-tumor molecules into the tumor microenvironment. The innate tropism of AT-MSCs for tumors has important implications for effective cellular delivery of anti-tumor molecules, including cytokines, interferon, and pro-drugs. The present study was designed to determine the possibility that the combination of stem cell-based gene therapy with low-dose cisplatin would improve therapeutic efficacy against canine melanoma. The IFN-β transduced canine AT-MSCs (cAT-MSC-IFN-β) inhibited the growth of LMeC canine melanoma cells in direct and indirect in vitro co-culture systems. In animal experiments using BALB/c nude mouse xenografts, which developed by injecting LMeC cells, the combination treatment of cAT-MSC-IFN-β and low-dose cisplatin significantly reduced tumor volume compared with the other treatment groups. Fluorescent microscopic analysis with a TUNEL (terminal deoxynucleotidyl transferase-mediated nick-end labeling) assay of tumor section provided evidence for homing of cAT-MSC-IFN-β to the tumor site and revealed that the combination treatment of cAT-MSC-IFN-β with low-dose cisplatin induced high levels of cell apoptosis. These findings may prove useful in further explorations of the application of these combined approaches to the treatment of malignant melanoma and other tumors.

Reconstructed stem cell nanoghosts: a natural tumor targeting platform

The ultimate goal in cancer therapy is achieving selective targeting of cancer cells. We report a novel delivery platform, based on nanoghosts (NGs) produced from the membranes of mesenchymal stem cells (MSCs). Encompassing MSC surface molecules, the MSC-NGs retained MSC-specific in vitro and in vivo tumor targeting capabilities and were cleared from blood-filtering organs. MSC-NGs were found to be biocompatible. Systemic administration of drug loaded MSC-NGs demonstrated 80% inhibition of human prostate cancer.

Encapsulated stem cells for cancer therapy

Stem cells have inherent tumor‑trophic migratory properties and can serve as vehicles for delivering effective, targeted therapy to isolated tumors and metastatic disease, making them promising anti‑cancer agents. Encapsulation of therapeutically engineered stem cells in hydrogels has been utilized to provide a physical barrier to protect the cells from hostile extrinsic factors and significantly improve the therapeutic efficacy of transplanted stem cells in different models of cancer. This review aims to discuss the potential of different stem cell types for cancer therapy, various engineered stem cell based therapies for cancer, stem cell encapsulation process and provide an in depth overview of current applications of therapeutic stem cell encapsulation in the highly malignant brain tumor, glioblastoma multiforme (GBM), as well as the prospects for their clinical translation.

Immunotherapeutic organoids: a new approach to cancer treatment

Therapeutic monoclonal antibodies have revolutionized the treatment of cancer and other diseases. However, several limitations of antibody-based treatments, such as the cost of therapy and the achievement of sustained plasma levels, should be still addressed for their widespread use as therapeutics. The use of cell and gene transfer methods offers additional benefits by producing a continuous release of the antibody with syngenic glycosylation patterns, which makes the antibody potentially less immunogenic. In vivo secretion of therapeutic antibodies by viral vector delivery or ex vivo gene modified long-lived autologous or allogeneic human mesenchymal stem cells may advantageously replace repeated injection of clinical-grade antibodies. Gene-modified autologous mesenchymal stem cells can be delivered subcutaneously embedded in a non-immunogenic synthetic extracellular matrix-based scaffold that guarantees the survival of the cell inoculum. The scaffold would keep cells at the implantation site, with the therapeutic protein acting at distance (immunotherapeutic organoid), and could be retrieved once the therapeutic effect is fulfilled. In the present review we highlight the practical importance of living cell factories for in vivo secretion of recombinant antibodies.

Journey of mesenchymal stem cells for homing: strategies to enhance efficacy and safety of stem cell therapy

Human mesenchymal stem cells (MSCs) communicate with other cells in the human body and appear to "home" to areas of injury in response to signals of cellular damage, known as homing signals. This review of the state of current research on homing of MSCs suggests that favorable cellular conditions and the in vivo environment facilitate and are required for the migration of MSCs to the site of insult or injury in vivo. We review the current understanding of MSC migration and discuss strategies for enhancing both the environmental and cellular conditions that give rise to effective homing of MSCs. This may allow MSCs to quickly find and migrate to injured tissues, where they may best exert clinical benefits resulting from improved homing and the presence of increased numbers of MSCs.

Antitumor activity from the combined application of poly(I:C) and chemotherapeutics in human metastatic pharyngeal cell lines

BACKGROUND

Toll-like receptor 3 (TLR3) activation in tumor cells induces apoptosis. We investigated the effect of TLR3 ligand (poly(I:C)) in combination with chemotherapeutics applied to human pharyngeal carcinoma cells as a possible antitumor therapy.

METHODS

Human pharyngeal cancer cell lines were studied (FaDu and Detroit 562). Cytotoxicity assays and apoptosis assays (annexin V staining and caspase 3/7 activity measurements) were used to investigate the cytotoxic effects. By using TLR3 siRNA we confirmed that the observed effect is TLR3-dependent.

RESULTS

We found that the combined application of poly(I:C) and chemotherapeutics (cisPt, HU, 5-FU and MTX) has a stronger inhibitory effect on cell growth in tumor cells expressing functional TLR3 as compared with a single treatment. This is a result of TLR3-dependent apoptosis.

CONCLUSION

Our study showed that a combined application of the two agents already being used in tumor therapy could lower the necessary dosage of chemotherapeutics, leading to fewer side effects.