MSC.sTRAIL Has Better Efficacy than MSC.FL-TRAIL and in Combination with AKTi Blocks Pro-Metastatic Cytokine Production in Prostate Cancer Cells

The therapeutic effect of MSCs and their extracellular vesicles on neuroblastoma

Neuroblastoma is a common inflammatory-related cancer during infancy. Standard treatment modalities including surgical interventions, high-dose chemotherapy, radiotherapy, and immunotherapy are not able to increase survival rate and reduce tumor relapse in high-risk patients. Mesenchymal stem cells (MSCs) are known for their tumor-targeting and immunomodulating properties. MSCs could be engineered to express anticancer agents (i.e., growth factors, cytokines, pro-apoptotic agents) or deliver oncolytic viruses in the tumor microenvironment. As many functions of MSCs are mediated through their secretome, researchers have tried to use extracellular vesicles (EVs) from MSCs for targeted therapy of neuroblastoma. Here, we reviewed the studies to figure out whether the use of MSCs could be worthwhile in neuroblastoma therapy or not. Native MSCs have shown a promoting or inhibiting role in cancers including neuroblastoma. Therefore, MSCs are proposed as a vehicle to deliver anticancer agents such as oncolytic viruses to the neuroblastoma tumor microenvironment. Although modified MSCs or their EVs have been shown to suppress the tumorigenesis of neuroblastoma, further pre-clinical and clinical studies are required to come to a conclusion.

Mesenchymal stem cells and their extracellular vesicles in urological cancers: Prostate, bladder, and kidney

Mesenchymal stem cells (MSCs) are recognized for their remarkable ability to differentiate into multiple cell types. They are also known to possess properties that can fight cancer, leading to attempts to modify MSCs for use in anticancer treatments. However, MSCs have also been found to participate in pathways that promote tumor growth. Many studies have been conducted to explore the potential of MSCs for clinical applications, but the results have been inconclusive, possibly due to the diverse nature of MSC populations. Furthermore, the conflicting roles of MSCs in inhibiting tumors and promoting tumor growth hinder their adaptation to anticancer therapies. Antitumorigenic and protumorigenic properties of MSCs in urological cancers such as bladder, prostate, and renal are not as well established, and data comparing them are still limited. MSCs hold significant promise as a vehicle for delivering anticancer agents and suicide genes to tumors. Presently, numerous studies have concentrated on the products derived from MSCs, such as extracellular vesicles (EVs), as a form of cell-free therapy. This work aimed to review and discuss the current knowledge of MSCs and their EVs in urological cancer therapy.

Identification of the role of autophagy-related TNFSF10/ hsa-let-7a-5p axis in vitiligo development and potential herbs exploring based on a bioinformatics analysis

Background

Vitiligo is a common clinical disorder caused by the destruction of epidermal melanocytes, which is often associated with autoimmune mechanisms. Autophagy plays a crucial role in maintaining cellular homeostasis and exhibits close associations with various autoimmune disorders. While dysautophagy of melanocytes is associated with vitiligo pathogenesis, there is a lack of studies on autophagy-related genes (ARGs) in blood samples from individuals with vitiligo.

Methods

Blood samples from individuals with vitiligo and healthy controls were compared to identify differentially expressed genes (DEGs), which were subsequently subjected to further analysis. Then, miRNAs correlated with core genes were predicted by five distinct online tools, and those miRNAs that appeared in three or more tools at the same time were chosen for further enrichment analysis. Furthermore, in vitro experiments of targeting core genes were conducted.

Results

The results showed that there were a total of 30 ARGs among DEGs, with 13 up-regulated genes and 17 down-regulated genes. Based on the functional enrichment analysis of DEGs and projected miRNAs, we hypothesized that autophagy and apoptosis may synergistically contribute to the progression of vitiligo, with the TNFSF10/hsa-let-7a-5p axis potentially playing an important role that should not be ignored. In addition, epigallocatechin-3-gallate (EGCG) was found to be the common component in BAI GUO, CHA YE, and MEI ZHOU JIN LV MEI, which were discovered to be potential in vitiligo treatment by inducing cell autophagy and apoptosis targeting TNFSF10.

Conclusion

It was the first time that TNFSF/hsa-let-7a-5p was discovered to be involved in the development of vitiligo through autophagy and apoptosis. Meanwhile, we observed that BAI GUO, CHA YE, and MEI ZHOU JIN LV MEI were promising to treat vitiligo by regulating autophagy and apoptosis via TNFSF10. These findings could lead to new directions for investigating the pathogenesis and therapy of vitiligo.

Generation of magnetic biohybrid microrobots based on MSC.sTRAIL for targeted stem cell delivery and treatment of cancer

Background

Combining the power of magnetic guidance and the biological activities of stem cells transformed into biohybrid microrobots holds great promise for the treatment of several diseases including cancer.

Results

We found that human MSCs can be readily loaded with magnetic particles and that the resulting biohybrid microrobots could be guided by a rotating magnetic field. Rotating magnetic fields have the potential to be applied in the human setting and steer therapeutic stem cells to the desired sites of action in the body. We could demonstrate that the required loading of magnetic particles into stem cells is compatible with their biological activities. We examined this issue with a particular focus on the expression and functionality of therapeutic genes inside of human MSC-based biohybrid microrobots. The loading with magnetic particles did not cause a loss of viability or apoptosis in the human MSCs nor did it impact on the therapeutic gene expression from the cells. Furthermore, the therapeutic effect of the gene products was not affected, and the cells also did not lose their migration potential.

Conclusion

These results demonstrate that the fabrication of guidable MSC-based biohybrid microrobots is compatible with their biological and therapeutic functions. Thus, MSC-based biohybrid microrobots represent a novel way of delivering gene therapies to tumours as well as in the context of other diseases.

Mesenchymal stem cells- an excellent therapeutic agent for cancer

Despite rapid advancement in research of diagnostics and therapeutics, cancer is the most dangerous disease-causing millions of deaths worldwide. Many of the conventional anticancer therapies can even lead to developing resistance to therapy and recurrence of cancer. To find a new, alternative treatment strategy for a variety of ailments scientists and researchers have turned their attention to cell therapies and regenerative medicine. Stem cells are now being researched for their extensive potential application in therapy for several incurable illnesses including cancer. One of the most often employed cell types for regenerative medicine is mesenchymal stem cells. Mesenchymal stem cells (MSCs) are considered a promising source of stem cells in personalized cell-based therapies. The inherent tumor tropic and immune-modulatory properties of MSCs can be used to target cancer cells. This review aims to focus on the anticancer properties of MSCs and their effect on different signaling pathways. Later on, we discuss the advantages of engineered MSCs over non-engineered MSCsin cancer therapy.

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.

Engineered sTRAIL-armed MSCs overcome STING deficiency to enhance the therapeutic efficacy of radiotherapy for immune checkpoint blockade

Radiotherapy (RT) mainly elicits antitumor immunity via the cGAS/STING axis for type I interferon (IFN) production. However, dysregulation of cGAS/STING constrains radiotherapy-induced antitumor immunity and type I IFN-dependent cell death and is associated with shorter survival of patients with colorectal cancer (CRC). Due to their tumor tropism, mesenchymal stem cells (MSCs) have shown the potential to deliver therapeutic genes for cancer therapy. Here, we showed that MSCs enhance the sensitivity to RT by inducing TRAIL-dependent cell death and remodel the tumor microenvironment by recruiting CD8⁺ immune cells to upregulate PD-L1 in the tumor. By engineering MSCs to express CRC-specific soluble TRAIL via adenovirus-associated virus 2 (AAV2), we found that the therapeutic activity of MSC-sTRAIL was superior to that of MSCs alone when combined with RT. Combined treatment with MSC-sTRAIL and RT significantly reduced cell viability and increased apoptosis by inducing TRAIL-dependent cell death in STING-deficient colorectal cancer cells. MSC-sTRAIL directly triggered TRAIL-dependent cell death to overcome the deficiency of the cGAS/STING axis. Moreover, these combination treatments of MSC-sTRAIL and RT significantly remodeled the tumor microenvironment, which was more suitable for anti-PD-L1 immunotherapy. Taken together, this therapeutic strategy represents a novel targeted treatment option for patients with colorectal cancer, especially cGAS/STING-deficient patients.

Mesenchymal stem cells and prostate cancer: A concise review of therapeutic potentials and biological aspects

Prostate cancer (PCa) arises from a cancer stem or progenitor cell with homogenous characteristics, especially among the aging men population. Over the past decade, the increasing PCa incidence has led to significant changes in both disease diagnosis and treatment. Recently, the therapeutic aspects of stem cells in many cancers, including PCa, have been debatable. The new generation of PCa studies seek to present definitive treatments with reduced therapeutic side effects. Since discovering unique properties of stem cells in modulating immunity, selective migration to inflammatory regions, and secretion of various growth factors, they have been a promising therapeutic target. The existing properties of stem cell therapy bring new opportunities for cancer inhibition: transferring chemotherapeutics, activating prodrugs, affecting the expression of genes involved in cancer, genetically modifying the production of anti-cancer compounds, proteins, and/or deriving extracellular vesicles (EVs) containing therapeutic agents from stem cells. However, their dual properties in carcinogenicity as well as their ability to inhibit cancer result in particular limitations studying them after administration. A clear understanding of the interaction between MSCs and the prostate cancer microenvironment will provide crucial information in revealing the precise applications and new practical protocols for clinical use of these cells..

Mesenchymal stem cells: A living carrier for active tumor-targeted delivery

The strategy of using mesenchymal stem cells (MSCs) as a living carrier for active delivery of therapeutic agents targeting tumor sites has been attempted in a wide range of studies to validate the feasibility and efficacy for tumor treatment. This approach reveals powerful tumor targeting and tumor penetration. In addition, MSCs have been confirmed to actively participate in immunomodulation of the tumor microenvironment. Thus, MSCs are not inert delivery vehicles but have a strong impact on the fate of tumor cells. In this review, these active properties of MSCs are addressed to highlight the advantages and challenges of using MSCs for tumor-targeted delivery. In addition, some of the latest examples of using MSCs to carry a variety of anti-tumor agents for tumor-targeted therapy are summarized. Recent technologies to improve the performance and safety of this delivery strategy will be introduced. The advances, applications, and challenges summarized in this review will provide a general understanding of this promising strategy for actively delivering drugs to tumor tissues.

The Potential Applications of Stem Cells for Cancer Treatment

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Scientists encounter many obstacles in traditional cancer therapies, including the side effects on the healthy cells, drug resistance, tumor relapse, the short half-life of employed drugs in the blood circulation, and the improper delivery of drugs toward the tumor site. The unique traits of stem cells (SCs) such as self-renewal, differentiation, tumor tropism, the release of bioactive molecules, and immunosuppression have opened a new window for utilizing SCs as a novel tool in cancer treatment. In this regard, engineered SCs can secrete anti-cancer proteins or express enzymes used in suicide gene therapy which locally induce apoptosis in neoplastic cells via the bystander effect. These cells also stand as proper candidates to serve as careers for drug-loaded nanoparticles or to play suitable hosts for oncolytic viruses. Moreover, they harbor great potential to be employed in immunotherapy and combination therapy. However, tactful strategies should be devised to allow easier transplantation and protection of SCs from in vivo immune responses. In spite of the great hope concerning SCs application in cancer therapy, there are shortcomings and challenges to be addressed. This review tends to elaborate on recent advances on the various applications of SCs in cancer therapy and existing challenges in this regard.

Chemo-Sensitization of CD133+ Cancer Stem Cell Enhances the Effect of Mesenchymal Stem Cell Expressing TRAIL in Non-Small Cell Lung Cancer Cell Lines

Simple Summary

The anti-tumor properties of mesenchymal stem cell (MSCs) expressing TNF-related apoptosis inducing ligand (TRAIL) or MSC-TRAIL have been well documented by several reports. However, some tumors are resistant to TRAIL due to the existence of cancer stem cells (CSCs). Chemo-sensitization of tumors and their CSCs has been reported to enhance TRAIL-mediated inhibition. In this study, we examined the effect of pre-treatment using first-line chemotherapies on MSC-TRAIL-induced inhibition in non-small cell lung cancers (NSCLCs)–derived CSCs. We found that these chemotherapies were able to induce a chemo-sensitization effect to the CSC, thus improving the MSC-TRAIL-induced inhibition. We also noticed that the effect of chemo-sensitization was cell type specific and selecting chemotherapies for the right NSCLC subtypes might help in inducing a more meaningful combinatory effect. As such, this study has proven that chemo-sensitization of the CSCs was able to enhance the MSC-TRAIL-induced inhibition in NSCLC cell lines.

Abstract

Pre-clinical studies have demonstrated the efficacy of mesenchymal stem cells (MSCs) expressing tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) or MSC-TRAIL against several tumors. However, due to the existence of cancer stem cells (CSCs), some tumors, including non-small cell lung cancer (NSCLC), exhibit TRAIL resistance. This study was designed to evaluate the capacity of using first-line chemotherapies including cisplatin, 5-fluorouracil (5-FU) and vinorelbine to act as a chemo-sensitizer on CD133+ (prominin-1 positive) CSCs derived from NSCLC cell lines (A549, H460 and H2170) for the purpose of MSC-TRAIL-induced inhibition. We showed that MSC-TRAIL was resistant to all three chemotherapies compared to the NSCLC cell lines, suggesting that the chemotherapies had little effect on MSC-TRAIL viability. Pre-treatment using either cisplatin or 5-FU, but not with vinorelbine, was able to increase the efficacy of MSC-TRAIL to kill the TRAIL-resistant A549-derived CSCs. The study also demonstrated that both 5-FU and vinorelbine were an effective chemo-sensitizer, used to increase the anti-tumor effect of MSC-TRAIL against H460- and H2170-derived CSCs. Furthermore, pre-treatment using cisplatin was noted to enhance the effect of MSC-TRAIL in H460-derived CSCs; however, this effect was not detected in the H2170-derived CSCs. These findings suggest that a pre-treatment using certain chemotherapies in NSCLC could enhance the anti-tumor effect of MSC-TRAIL to target the CSCs, and therefore the combination of chemotherapies and MSC-TRAIL may serve as a novel approach for the treatment of NSCLC.

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.

Harnessing TRAIL-Induced Apoptosis Pathway for Cancer Immunotherapy and Associated Challenges

The immune cytokine tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has attracted rapidly evolving attention as a cancer treatment modality because of its competence to selectively eliminate tumor cells without instigating toxicity in vivo. TRAIL has revealed encouraging promise in preclinical reports in animal models as a cancer treatment option; however, the foremost constraint of the TRAIL therapy is the advancement of TRAIL resistance through a myriad of mechanisms in tumor cells. Investigations have documented that improvement of the expression of anti-apoptotic proteins and survival or proliferation involved signaling pathways concurrently suppressing the expression of pro-apoptotic proteins along with down-regulation of expression of TRAILR1 and TRAILR2, also known as death receptor 4 and 5 (DR4/5) are reliable for tumor cells resistance to TRAIL. Therefore, it seems that the development of a therapeutic approach for overcoming TRAIL resistance is of paramount importance. Studies currently have shown that combined treatment with anti-tumor agents, ranging from synthetic agents to natural products, and TRAIL could result in induction of apoptosis in TRAIL-resistant cells. Also, human mesenchymal stem/stromal cells (MSCs) engineered to generate and deliver TRAIL can provide both targeted and continued delivery of this apoptosis-inducing cytokine. Similarly, nanoparticle (NPs)-based TRAIL delivery offers novel platforms to defeat barricades to TRAIL therapeutic delivery. In the current review, we will focus on underlying mechanisms contributed to inducing resistance to TRAIL in tumor cells, and also discuss recent findings concerning the therapeutic efficacy of combined treatment of TRAIL with other antitumor compounds, and also TRAIL-delivery using human MSCs and NPs to overcome tumor cells resistance to TRAIL.

Unleashing the power of NK cells in anticancer immunotherapy

Due to their physiological role in removing damaged cells, natural killer (NK) cells represent ideal candidates for cellular immunotherapy in the treatment of cancer. Thereby, the cytotoxicity of NK cells is regulated by signals on both, the NK cells as well as the targeted tumor cells, and the interplay and balance of these signals determine the killing capacity of NK cells. One promising avenue in cancer treatment is therefore the combination of NK cell therapy with agents that either help to increase the killing capacity of NK cells or sensitize tumor cells to an NK cell-mediated attack. In this mini-review, we present different strategies that can be explored to unleash the potential of NK cell immunotherapy. In particular, we summarize how modulation of apoptosis signaling within tumor cells can be exploited to sensitize tumor cells to NK cell-mediated cytotoxicity.

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.

Fas-threshold signalling in MSCs promotes pancreatic cancer progression and metastasis

Mesenchymal stem cells (MSCs) belong to the tumour microenvironment and have been implicated in tumour progression. We found that the number of MSCs significantly increased in tumour-burdened mice driven by Fas-threshold signalling. Consequently, MSCs lacking Fas lost their ability to induce metastasis development in a pancreatic cancer model. Mixing of MSCs with pancreatic cancer cells led to sustained production of the pro-metastatic cytokines CCL2 and IL6 by the stem cells. The levels of these cytokines were dependent on the number of MSCs, linking Fas-mediated MSC-proliferation to their capacity to promote tumour progression. Furthermore, we discovered that CCL2 and IL6 were induced by pancreatic cancer cell-derived IL1. Importantly, analysis of patient transcriptomic data revealed that high FasL expression correlates with high levels of MSC markers as well as increased IL6 and CCL2 levels in pancreatic tumours. Moreover, both FasL and CCL2 are linked to elevated levels of markers specific for monocytes known to possess further pro-metastatic activities. These results confirm our experimental findings of a FasL-MSC-IL1-CCL2/IL6 axis in pancreatic cancer and highlights the role of MSCs in tumour progression.

Enhanced inhibition of tumor growth using TRAIL-overexpressing adipose-derived stem cells in combination with the chemotherapeutic agent CPT-11 in castration-resistant prostate cancer

Background

This study investigated the inhibition of tumor growth in castrate-resistant prostate cancer (CRPC)-bearing mice by tumor necrosis factor–related apoptosis-inducing ligand (TRAIL)-overexpressing adipose-derived stem cells (ADSCs) (hTERT-ADSC.sTRAIL), which was enhanced by combined treatment with CPT-11.

Materials and methods

An hTERT-ADSC.sTRAIL cell line was established by transfection with a lentiviral vector (CLV-Ubic) encoding the human sTRAIL gene. Quantitative polymerase chain reaction and Western blots were performed to confirm gene overexpression. An invasion study for the selective migration ability toward PC3 cells was performed. In the in vivo study, the tumor volume in mice treated with ADSC. sTRAIL and CPT-11 was measured.

Results

Carboxylesterase was generated from hTERT-ADSCs. The gene expression of sTRAIL from hTERT-ADSC.sTRAIL was shown. The directional migration of ADSC.sTRAIL cells toward PC3 cells was significantly stimulated by PC3 cells in vitro (P < 0.05). In the in vitro study, the viability of PC3 cells significantly decreased in the presence of ADSC.sTRAIL (62.7 ± 2.0%) and CPT-11 compared with that of CPT-11 alone (83.0 ± 1.0%) at a cell ratio as low as 0.05 (PC3: ADSC.sTRAIL) (P < 0.05). The proportion of apoptotic PC3 cells significantly increased in the presence of ADSC.sTRAIL (37.2 ± 2.1%) and CPT-11 compared with that of CPT-11 alone (16.5 ± 1.0%) (P < 0.05). In the in vivo study, the inhibition of tumor growth in CRPC-bearing mice by TRAIL-overexpressing adipose stem cells was enhanced by combined treatment with the chemotherapeutic agent CPT-11 compared with that in the treatment with cpt-11 alone. Immunohistochemical staining of the removed tumors showed anti-TRAIL–positive cells and apoptotic bodies after hTERT-ADSC.sTRAIL treatment or combined treatment with hTERT-ADSC.sTRAIL and CPT-11.

Conclusions

Therapeutic stem cells expressing sTRAIL genes combined with CPT-11 can provide a new strategy for treating CRPC in clinical trials using the patients’ own ADSCs.

TRAIL in oncology: From recombinant TRAIL to nano- and self-targeted TRAIL-based therapies

TNF-related apoptosis-inducing ligand (TRAIL) selectively induces the apoptosis pathway in tumor cells leading to tumor cell death. Because TRAIL induction can kill tumor cells, cancer researchers have developed many agents to target TRAIL and some of these agents have entered clinical trials in oncology. Unfortunately, these trials have failed for many reasons, including drug resistance, off-target toxicities, short half-life, and specifically in gene therapy due to the limited uptake of TRAIL genes by cancer cells. To address these drawbacks, translational researchers have utilized drug delivery platforms. Although, these platforms can improve TRAIL-based therapies, they are unable to sufficiently translate the full potential of TRAIL-targeting to clinically viable products. Herein, we first summarize the complex biology of TRAIL signaling, including TRAILs cross-talk with other signaling pathways and immune cells. Next, we focus on known resistant mechanisms to TRAIL-based therapies. Then, we discuss how nano-formulation has the potential to enhance the therapeutic efficacy of TRAIL protein. Finally, we specify strategies with the potential to overcome the challenges that cannot be addressed via nanotechnology alone, including the alternative methods of TRAIL-expressing circulating cells, tumor-targeting bacteria, viruses, and exosomes.

Targeting of CD133+ Cancer Stem Cells by Mesenchymal Stem Cell Expressing TRAIL Reveals a Prospective Role of Apoptotic Gene Regulation in Non-Small Cell Lung Cancer

Mesenchymal stem cells (MSCs) are emerging as vehicles for anti-tumor cytotherapy; however, investigation on its efficacy to target a specific cancer stem cell (CSC) population in non-small cell lung cancer (NSCLC) is lacking. Using assays to evaluate cell proliferation, apoptosis, and gene expression, we investigated the efficacy of MSCs expressing tumour necrosis factor (TNF)-related apoptosis inducing ligand (MSC-TRAIL) to target and destroy CD133+ (prominin-1 positive) NSCLC-derived CSCs. Characterization of TRAIL death receptor 5 (DR5) revealed that it was highly expressed in the CD133+ CSCs of both H460 and H2170 cell lines. The human MSC-TRAIL generated in the study maintained its multipotent characteristics, and caused significant tumor cell inhibition in NSCLC-derived CSCs in a co-culture. The MSC-TRAIL induced an increase in annexin V expression, an indicator of apoptosis in H460 and H2170 derived CD133+ CSCs. Through investigation of mitochondria membrane potential, we found that MSC-TRAIL was capable of inducing intrinsic apoptosis to the CSCs. Using pathway-specific gene expression profiling, we uncovered candidate genes such as NFKB1, BAG3, MCL1, GADD45A, and HRK in CD133+ CSCs, which, if targeted, might increase the sensitivity of NSCLC to MSC-TRAIL-mediated inhibition. As such, our findings add credibility to the utilization of MSC-TRAIL for the treatment of NSCLC through targeting of CD133+ CSCs.