Developing Implantable Scaffolds to Enhance Neural Stem Cell Therapy for Post-Operative Glioblastoma.

Pre-clinical and clinical studies have shown that engineered tumoricidal neural stem cells (tNSCs) are a promising treatment strategy for the aggressive brain cancer glioblastoma (GBM). Yet, stabilizing human tNSCs within the surgical cavity following GBM resection is a significant challenge. As a critical step toward advancing engineered human NSC therapy for GBM, we used a preclinical variant of the clinically utilized NSC line HB1.F3.CD and mouse models of human GBM resection/recurrence to identify a polymeric scaffold capable of maximizing the transplant, persistence, and tumor kill of NSC therapy for post-surgical GBM. Using kinetic bioluminescence imaging, we found that tNSCs delivered into the mouse surgical cavity wall by direct injection persisted only 3 days. We found that delivery of tNSCs into the cavity on nanofibrous electrospun poly-l-lactic acid scaffolds extended tNSC persistence to 8 days. Modifications to fiber surface coating, diameter, and morphology of the scaffold failed to significantly extend tNSC persistence in the cavity. In contrast, tNSCs delivered into the post-operative cavity on gelatin matrices (GEMs) persisted 8-fold longer as compared to direct injection. GEMs remained permissive to tumor-tropic homing, as tNSCs migrated off the scaffolds and into invasive tumor foci both in vitro and in vivo. To mirror envisioned human brain tumor trials, we engineered tNSCs to express the prodrug/enzyme thymidine kinase (tNSCstk) and transplanted the therapeutic cells in the post-operative cavity of mice bearing resected orthotopic patient-derived GBM xenografts. Following administration of the prodrug ganciclovir, residual tumor volumes in mice receiving GEM/tNSCs were reduced by 10-fold at day 35, and median survival was extended from 31 to 46 days. Taken together, these data begin to define design parameters for effective scaffold/tNSC composites and suggest a new approach to maximizing the efficacy of tNSC therapy in human patient trials.

Generation and Profiling of Tumor-Homing Induced Neural Stem Cells from the Skin of Cancer Patients.

The conversion of human fibroblasts into personalized induced neural stem cells (iNSCs) that actively seek out tumors and deliver cytotoxic agents is a highly promising approach for treating various types of cancer. However, the ability to generate iNSCs from the skin of cancer patients has not been explored. Here, we take an important step toward clinical application by generating iNSCs from skin biopsies of human patients undergoing treatment for the aggressive brain cancer, glioblastoma (GBM). We then utilized a panel of functional and genomic studies to investigate the efficacy and tumor-homing capacity of these patient-derived cells, as well as genomic analysis, to characterize the impact of interpatient variability on this personalized cell therapy. From the skin-tissue biopsies, we established fibroblasts and transdifferentiated the cells into iNSCs. Genomic and functional testing revealed marked variability in growth rates, therapeutic agent production, and gene expression during fibroblast-to-iNSC conversion among patient lines. In vivo testing showed patient-derived iNSCs home to tumors, yet rates and expression of homing-related pathways varied among patients. With the use of surgical-resection mouse models of invasive human cluster of differentiation 133+ (CD133+) GBM cells and serial kinetic imaging, we found that "high-performing" patient-derived iNSC lines reduced the volume of GBM cells 60-fold and extended survival from 28 to 45 days. Treatment with "low-performing" patient lines had minimal effect on tumor growth, but the anti-tumor effect could be rescued by increasing the intracavity dose. Together, these data show, for the first time, that tumor-homing iNSCs can be generated from the skin of cancer patients and efficaciously suppress tumor growth. We also begin to define genetic markers that could be used to identify cells that will contain the most effective attributes for tumor homing and kill in human patients, including high gene expression of the semaphorin-3B (SEMA3B), which is known to be involved in neuronal cell migration. These studies should serve as an important guide toward clinical GBM therapy, where the personalized nature of optimized iNSC therapy has the potential to avoid transplant rejection and maximize treatment durability.

Engineered Mesenchymal Stem Cell/Nanomedicine Spheroid as an Active Drug Delivery Platform for Combinational Glioblastoma Therapy.

Mesenchymal stem cell (MSC) has been increasingly applied to cancer therapy because of its tumor-tropic capability. However, short retention at target tissue and limited payload option hinder the progress of MSC-based cancer therapy. Herein, we proposed a hybrid spheroid/nanomedicine system, comprising MSC spheroid entrapping drug-loaded nanocomposite, to address these limitations. Spheroid formulation enhanced MSC's tumor tropism and facilitated loading of different types of therapeutic payloads. This system acted as an active drug delivery platform seeking and specifically targeting glioblastoma cells. It enabled effective delivery of combinational protein and chemotherapeutic drugs by engineered MSC and nanocomposite, respectively. In an in vivo migration model, the hybrid spheroid showed higher nanocomposite retention in the tumor tissue compared with the single MSC approach, leading to enhanced tumor inhibition in a heterotopic glioblastoma murine model. Taken together, this system integrates the merits of cell- and nanoparticle- mediated drug delivery with the tumor-homing characteristics of MSC to advance targeted combinational cancer therapy.

Sustained Delivery of Doxorubicin via Acetalated Dextran Scaffold Prevents Glioblastoma Recurrence after Surgical Resection.

The primary cause of mortality for glioblastoma (GBM) is local tumor recurrence following standard-of-care therapies, including surgical resection. With most tumors recurring near the site of surgical resection, local delivery of chemotherapy at the time of surgery is a promising strategy. Herein drug-loaded polymer scaffolds with two distinct degradation profiles were fabricated to investigate the effect of local drug delivery rate on GBM recurrence following surgical resection. The novel biopolymer, acetalated dextran (Ace-DEX), was compared with commercially available polyester, poly(l-lactide) (PLA). Steady-state doxorubicin (DXR) release from Ace-DEX scaffolds was found to be faster when compared with scaffolds composed of PLA, in vitro. This increased drug release rate translated to improved therapeutic outcomes in a novel surgical model of orthotopic glioblastoma resection and recurrence. Mice treated with DXR-loaded Ace-DEX scaffolds (Ace-DEX/10DXR) resulted in 57% long-term survival out to study completion at 120 days compared with 20% survival following treatment with DXR-loaded PLA scaffolds (PLA/10DXR). Additionally, all mice treated with PLA/10DXR scaffolds exhibited disease progression by day 38, as defined by a 5-fold growth in tumor bioluminescent signal. In contrast, 57% of mice treated with Ace-DEX/10DXR scaffolds displayed a reduction in tumor burden, with 43% exhibiting complete remission. These results underscore the importance of polymer choice and drug release rate when evaluating local drug delivery strategies to improve prognosis for GBM patients undergoing tumor resection.

Neural stem cell therapy for cancer.

Cancers of the brain remain one of the greatest medical challenges. Traditional surgery and chemo-radiation therapy are unable to eradicate diffuse cancer cells and tumor recurrence is nearly inevitable. In contrast to traditional regenerative medicine applications, engineered neural stem cells (NSCs) are emerging as a promising new therapeutic strategy for cancer therapy. The tumor-homing properties allow NSCs to access both primary and invasive tumor foci, creating a novel delivery platform. NSCs engineered with a wide array of cytotoxic agents have been found to significantly reduce tumor volumes and markedly extend survival in preclinical models. With the recent launch of new clinical trials, the potential to successfully manage cancer in human patients with cytotoxic NSC therapy is moving closer to becoming a reality.

Engineering toxin-resistant therapeutic stem cells to treat brain tumors.

Pseudomonas exotoxin (PE) potently blocks protein synthesis by catalyzing the inactivation of elongation factor-2 (EF-2). Targeted PE-cytotoxins have been used as antitumor agents, although their effective clinical translation in solid tumors has been confounded by off-target delivery, systemic toxicity, and short chemotherapeutic half-life. To overcome these limitations, we have created toxin-resistant stem cells by modifying endogenous EF-2, and engineered them to secrete PE-cytotoxins that target specifically expressed (interleukin-13 receptor subunit alpha-2) or overexpressed (epidermal growth factor receptor) in glioblastomas (GBM). Molecular analysis correlated efficacy of PE-targeted cytotoxins with levels of cognate receptor expression, and optical imaging was applied to simultaneously track the kinetics of protein synthesis inhibition and GBM cell viability in vivo. The release of IL13-PE from biodegradable synthetic extracellular matrix (sECM) encapsulated stem cells in a clinically relevant GBM resection model led to increased long-term survival of mice compared to IL13-PE protein infusion. Moreover, multiple patient-derived GBM lines responded to treatment, underscoring its clinical relevance. In sum, integrating stem cell-based engineering, multimodal imaging, and delivery of PE-cytotoxins in a clinically relevant GBM model represents a novel strategy and a potential advancement in GBM therapy.

Development of exosome-encapsulated paclitaxel to overcome MDR in cancer cells.

Exosomes have recently come into focus as "natural nanoparticles" for use as drug delivery vehicles. Our objective was to assess the feasibility of an exosome-based drug delivery platform for a potent chemotherapeutic agent, paclitaxel (PTX), to treat MDR cancer. Herein, we developed different methods of loading exosomes released by macrophages with PTX (exoPTX), and characterized their size, stability, drug release, and in vitro antitumor efficacy. Reformation of the exosomal membrane upon sonication resulted in high loading efficiency and sustained drug release. Importantly, incorporation of PTX into exosomes increased cytotoxicity more than 50 times in drug resistant MDCKMDR1 (Pgp+) cells. Next, our studies demonstrated a nearly complete co-localization of airway-delivered exosomes with cancer cells in a model of murine Lewis lung carcinoma pulmonary metastases, and a potent anticancer effect in this mouse model. We conclude that exoPTX holds significant potential for the delivery of various chemotherapeutics to treat drug resistant cancers. FROM THE CLINICAL EDITOR: Exosomes are membrane-derived natural vesicles of ~40 - 200 nm size. They have been under extensive research as novel drug delivery vehicles. In this article, the authors developed exosome-based system to carry formulation of PTX and showed efficacy in the treatment of multi-drug resistant cancer cells. This novel system may be further developed to carry other chemotherapeutic agents in the future.

Correction: Specific transfection of inflamed brain by macrophages: A new therapeutic strategy for neurodegenerative diseases.

[This corrects the article DOI: 10.1371/journal.pone.0061852.].

Cell-based therapies for glioblastoma: Promising tools against tumor heterogeneity.

Glioblastoma (GBM) is a highly aggressive tumor with a devastating impact on quality-of-life and abysmal survivorship. Patients have very limited effective treatment options. The successes of targeted small molecule drugs and immune checkpoint inhibitors seen in various solid tumors have not translated to GBM, despite significant advances in our understanding of its molecular, immune, and microenvironment landscapes. These discoveries, however, have unveiled GBM's incredible heterogeneity and its role in treatment failure and survival. Novel cellular therapy technologies are finding successes in oncology and harbor characteristics that make them uniquely suited to overcome challenges posed by GBM, such as increased resistance to tumor heterogeneity, modularity, localized delivery, and safety. Considering these advantages, we compiled this review article on cellular therapies for GBM, focusing on cellular immunotherapies and stem cell-based therapies, to evaluate their utility. We categorize them based on their specificity, review their preclinical and clinical data, and extract valuable insights to help guide future cellular therapy development.

Longitudinal 3-D Visualization of Microvascular Disruption and Perfusion Changes in Mice During the Evolution of Glioblastoma Using Super-Resolution Ultrasound.

Glioblastoma is an aggressive brain cancer with a very poor prognosis in which less than 6% of patients survive more than five-year post-diagnosis. The outcome of this disease for many patients may be improved by early detection. This could provide clinicians with the information needed to take early action for treatment. In this work, we present the utilization of a non-invasive, fully volumetric ultrasonic imaging method to assess microvascular change during the evolution of glioblastoma in mice. Volumetric ultrasound localization microscopy (ULM) was used to observe statistically significant ( ) reduction in the appearance of functional vasculature over the course of three weeks. We also demonstrate evidence suggesting the reduction of vascular flow for vessels peripheral to the tumor. With an 82.5% consistency rate in acquiring high-quality vascular images, we demonstrate the possibility of volumetric ULM as a longitudinal method for microvascular characterization of neurological disease.

Utilizing induced neural stem cell-based delivery of a cytokine cocktail to enhance chimeric antigen receptor-modified T-cell therapy for brain cancer.

Chimeric antigen receptor (CAR)-modified T-cell therapy has shown enormous clinical promise against blood cancers, yet efficacy against solid tumors remains a challenge. Here, we investigated the potential of a new combination cell therapy, where tumor-homing induced neural stem cells (iNSCs) are used to enhance CAR-T-cell therapy and achieve efficacious suppression of brain tumors. Using in vitro and in vivo migration assays, we found iNSC-secreted RANTES/IL-15 increased CAR-T-cell migration sixfold and expansion threefold, resulting in greater antitumor activity in a glioblastoma (GBM) tumor model. Furthermore, multimodal imaging showed iNSC delivery of RANTES/IL-15 in combination with intravenous administration of CAR-T cells reduced established orthotopic GBM xenografts 2538-fold within the first week, followed by durable tumor remission through 60 days post-treatment. By contrast, CAR-T-cell therapy alone only partially controlled tumor growth, with a median survival of only 19 days. Together, these studies demonstrate the potential of combined cell therapy platforms to improve the efficacy of CAR-T-cell therapy for brain tumors.

Injectable pH Thermo-Responsive Hydrogel Scaffold for Tumoricidal Neural Stem Cell Therapy for Glioblastoma Multiforme.

Glioblastoma multiforme (GBM) is the most common malignant brain tumor in adults and despite recent advances in treatment modalities, GBM remains incurable. Injectable hydrogel scaffolds are a versatile delivery system that can improve delivery of drug and cell therapeutics for GBM. In this report, we investigated an injectable nanocellulose/chitosan-based hydrogel scaffold for neural stem cell encapsulation and delivery. Hydrogels were prepared using thermogelling beta-glycerophosphate (BGP) and hydroxyethyl cellulose (HEC), chitosan (CS), and cellulose nanocrystals (CNCs). We evaluated the impact of neural stem cells on hydrogel gelation kinetics, microstructures, and degradation. Furthermore, we investigated the biomaterial effects on cell viability and functionality. We demonstrated that the incorporation of cells at densities of 1, 5 and 10 million does not significantly impact rheological and physical properties CS scaffolds. However, addition of CNCs significantly prolonged hydrogel degradation when cells were seeded at 5 and 10 million per 1 mL hydrogel. In vitro cell studies demonstrated high cell viability, release of TRAIL at therapeutic concentrations, and effective tumor cell killing within 72 h. The ability of these hydrogel scaffolds to support stem cell encapsulation and viability and maintain stem cell functionality makes them an attractive cell delivery system for local treatment of post-surgical cancers.

Use of FLOSEAL® as a scaffold and its impact on induced neural stem cell phenotype, persistence, and efficacy.

Induced neural stem cells (iNSCs) have emerged as a promising therapeutic platform for glioblastoma (GBM). iNSCs have the innate ability to home to tumor foci, making them ideal carriers for antitumor payloads. However, the in vivo persistence of iNSCs limits their therapeutic potential. We hypothesized that by encapsulating iNSCs in the FDA-approved, hemostatic matrix FLOSEAL®, we could increase their persistence and, as a result, therapeutic durability. Encapsulated iNSCs persisted for 95 days, whereas iNSCs injected into the brain parenchyma persisted only 2 weeks in mice. Two orthotopic GBM tumor models were used to test the efficacy of encapsulated iNSCs. In the GBM8 tumor model, mice that received therapeutic iNSCs encapsulated in FLOSEAL® survived 30 to 60 days longer than mice that received nonencapsulated cells. However, the U87 tumor model showed no significant differences in survival between these two groups, likely due to the more solid and dense nature of the tumor. Interestingly, the interaction of iNSCs with FLOSEAL® appears to downregulate some markers of proliferation, anti-apoptosis, migration, and therapy which could also play a role in treatment efficacy and durability. Our results demonstrate that while FLOSEAL® significantly improves iNSC persistence, this alone is insufficient to enhance therapeutic durability.

Next-generation Tumor-homing Induced Neural Stem Cells as an Adjuvant to Radiation for the Treatment of Metastatic Lung Cancer.

The spread of non-small cell lung cancer (NSCLC) to the leptomeninges is devastating with a median survival of only a few months. Radiation offers symptomatic relief, but new adjuvant therapies are desperately needed. Spheroidal, human induced neural stem cells (hiNeuroS) secreting the cytotoxic protein, TRAIL, have innate tumoritropic properties. Herein, we provide evidence that hiNeuroS-TRAIL cells can migrate to and suppress growth of NSCLC metastases in combination with radiation. In vitro cell tracking and post-mortem tissue analysis showed that hiNeuroS-TRAIL cells migrate to NSCLC tumors. Importantly, isobolographic analysis suggests that TRAIL with radiation has a synergistic cytotoxic effect on NSCLC tumors. In vivo, mice treated with radiation and hiNeuroS-TRAIL showed significant (36.6%) improvements in median survival compared to controls. Finally, bulk mRNA sequencing analysis showed both NSCLC and hiNeuroS-TRAIL cells showed changes in genes involved in migration following radiation. Overall, hiNeuroS-TRAIL cells +/- radiation have the capacity to treat NSCLC metastases.

A novel molecule integrating therapeutic and diagnostic activities reveals multiple aspects of stem cell-based therapy.

Stem cells are promising therapeutic delivery vehicles; however pre-clinical and clinical applications of stem cell-based therapy would benefit significantly from the ability to simultaneously determine therapeutic efficacy and pharmacokinetics of therapies delivered by engineered stem cells. In this study, we engineered and screened numerous fusion variants that contained therapeutic (TRAIL) and diagnostic (luciferase) domains designed to allow simultaneous investigation of multiple events in stem cell-based therapy in vivo. When various stem cell lines were engineered with the optimized molecule, SRL(O)L(2)TR, diagnostic imaging showed marked differences in the levels and duration of secretion between stem cell lines, while the therapeutic activity of the molecule showed the different secretion levels translated to significant variability in tumor cell killing. In vivo, simultaneous diagnostic and therapeutic monitoring revealed that stem cell-based delivery significantly improved pharmacokinetics and anti-tumor effectiveness of the therapy compared to intravenous or intratumoral delivery. As treatment for highly malignant brain tumor xenografts, tracking SRL(O)L(2)TR showed stable stem cell-mediated delivery significantly regressed peripheral and intracranial tumors. Together, the integrated diagnostic and therapeutic properties of SRL(O)L(2)TR answer critical questions necessary for successful utilization of stem cells as novel therapeutic vehicles.

Intravenously Infused Stem Cells for Cancer Treatment.

Despite the recent influx of immunotherapies and small molecule drugs to treat tumors, cancer remains a leading cause of death in the United States, in large part due to the difficulties of treating metastatic cancer. Stem cells, which are inherently tumoritropic, provide a useful drug delivery vehicle to target both primary and metastatic tumors. Intravenous infusions of stem cells carrying or secreting therapeutic payloads show significant promise in the treatment of cancer. Stem cells may be engineered to secrete cytotoxic products, loaded with oncolytic viruses or nanoparticles containing small molecule drugs, or conjugated with immunotherapies. Herein we describe these preclinical and clinical studies, discuss the distribution and migration of stem cells following intravenous infusion, and examine both the limitations of and the methods to improve the migration and therapeutic efficacy of tumoritropic, therapeutic stem cells.

Developing Bioinspired Three-Dimensional Models of Brain Cancer to Evaluate Tumor-Homing Neural Stem Cell Therapy.

Engineered neural stem cells (NSCs) have recently emerged as a promising therapy. Acting as a tumor-homing drug-delivery system, NSCs migrate through brain tissue to seek out primary and invasive tumor foci. NSCs can deliver therapeutic agents, such as TNFα-related apoptosis-inducing ligand, directly to the tumor and suppress glioblastoma (GBM) in murine models. While the mainstays for evaluating NSC migration and efficacy have been two-dimensional chemotaxis assays and mouse models, these low-throughput and small-scale systems limit our ability to implant and track these cells for human translation. To circumvent these challenges, we developed a three-dimensional culture system using a matrix of poly-l-lactic acid 6100 microfibers suspended in agar. These bioinspired brain matrices were used to model tumor growth, NSC migration, and efficacy of NSC therapy at small and human scale. Kinetic fluorescent imaging confirmed growth of tumors in both small and human-sized bioinspired brain matrix. Tumors proliferated 50-fold and 3-fold for GBM and human metastatic breast cancer, respectively, over 7 days. We next explored the impact of tumor location on NSC migration. When NSCs were implanted 2 mm lateral from the tumor foci, NSCs colocalized with the GBM within 7 days. In models of multifocal disease, NSCs were found to colocalize with multiple tumors, preferentially migrating to tumor foci closest to the site of NSC implantation. Lastly, therapeutic NSCs were implanted at increasing distances (0, 2, 5, or 10 mm) laterally from GBM foci to investigate the effects of distance on NSC efficacy. Serial imaging showed reduced fluorescence at tumor sites, implicating GBM apoptosis across all distances. NSCs coinjected with tumor induced a near-complete response in <10 days, while NSCs implanted 10 mm laterally from the tumor induced a near-complete response by day 30. Lastly, GBM foci were established in each hemisphere of the model and control or therapeutic NSCs were implanted adjacent to tumor cells in the right hemisphere. Kinetic imaging showed that NSC therapy attenuated progression of GBM foci, while GBM cells treated with control NSC expanded rapidly over 21 days. In conclusion, we developed a new bioinspired model that supports growth of human brain cancer cells and enables rapid tracking of NSC therapy. Impact statement Tumor-homing and tumor-killing-engineered neural stem cell (NSC) therapies have shown immense promise in both preclinical and clinical trials. However, as cell therapies continue to evolve, cost-effective and high-throughput screening assays are needed to assess the proliferation, migration, and efficacy of these cells. In this study, we developed a bioinspired brain matrix for the evaluation of engineered NSCs. Importantly, this matrix is easy to fabricate, scalable, and allows for sterile real-time, noninvasive imaging using our custom bioreactor. We then utilized the bioinspired brain matrix system to answer key questions around the tumor-homing migration and efficacy of engineered NSC therapies that are challenging to address with traditional models.

Personalized-induced neural stem cell therapy: Generation, transplant, and safety in a large animal model.

In this study, we take an important step toward clinical translation by generating the first canine-induced neural stem cells (iNSCs). We explore key aspects of scale-up, persistence, and safety of personalized iNSC therapy in autologous canine surgery models. iNSCs are a promising new approach to treat aggressive cancers of the brain, including the deadly glioblastoma. Created by direct transdifferentiation of fibroblasts, iNSCs are known to migrate through the brain, track down invasive cancer foci, and deliver anticancer payloads that significantly reduce tumor burden and extend survival of tumor-bearing mice. Here, skin biopsies were collected from canines and converted into the first personalized canine iNSCs engineered to carry TNFα-related apoptosis-inducing ligand (TRAIL) and thymidine kinase (TK), as well as magnetic resonance imaging (MRI) contrast agents for in vivo tracking. Time-lapse analysis showed canine iNSCs efficiently migrate to human tumor cells, and cell viability assays showed both TRAIL and TK monotherapy markedly reduced tumor growth. Using intraoperative navigation and two delivery methods to closely mimic human therapy, canines received autologous iNSCs either within postsurgical cavities in a biocompatible matrix or via a catheter placed in the lateral ventricle. Both strategies were well tolerated, and serial MRI showed hypointense regions at the implant sites that remained stable through 86 days postimplant. Serial fluid sample testing following iNSC delivery showed the bimodal personalized therapy was well tolerated, with no iNSC-induced abnormal tissue pathology. Overall, this study lays an important foundation as this promising personalized cell therapy advances toward human patient testing.

Development of next-generation tumor-homing induced neural stem cells to enhance treatment of metastatic cancers.

Engineered tumor-homing neural stem cells (NSCs) have shown promise in treating cancer. Recently, we transdifferentiated skin fibroblasts into human-induced NSCs (hiNSC) as personalized NSC drug carriers. Here, using a SOX2 and spheroidal culture-based reprogramming strategy, we generated a new hiNSC variant, hiNeuroS, that was genetically distinct from fibroblasts and first-generation hiNSCs and had significantly enhanced tumor-homing and antitumor properties. In vitro, hiNeuroSs demonstrated superior migration to human triple-negative breast cancer (TNBC) cells and in vivo rapidly homed to TNBC tumor foci following intracerebroventricular (ICV) infusion. In TNBC parenchymal metastasis models, ICV infusion of hiNeuroSs secreting the proapoptotic agent TRAIL (hiNeuroS-TRAIL) significantly reduced tumor burden and extended median survival. In models of TNBC leptomeningeal carcinomatosis, ICV dosing of hiNeuroS-TRAIL therapy significantly delayed the onset of tumor formation and extended survival when administered as a prophylactic treatment, as well as reduced tumor volume while prolonging survival when delivered as established tumor therapy.

Cytotoxic Engineered Induced Neural Stem Cells as an Intravenous Therapy for Primary Non-Small Cell Lung Cancer and Triple-Negative Breast Cancer.

Converting human fibroblasts into personalized induced neural stem cells (hiNSC) that actively seek out tumors and deliver cytotoxic agents is a promising approach for treating cancer. Herein, we provide the first evidence that intravenously-infused hiNSCs secreting cytotoxic agent home to and suppress the growth of non-small cell lung cancer (NSCLC) and triple-negative breast cancer (TNBC). Migration of hiNSCs to NSCLC and TNBC in vitro was investigated using time-lapse motion analysis, which showed directional movement of hiNSCs to both tumor cell lines. In vivo, migration of intravenous hiNSCs to orthotopic NSCLC or TNBC tumors was determined using bioluminescent imaging (BLI) and immunofluorescent post-mortem tissue analysis, which indicated that hiNSCs colocalized with tumors within 3 days of intravenous administration and persisted through 14 days. In vitro, efficacy of hiNSCs releasing cytotoxic TRAIL (hiNSC-TRAIL) was monitored using kinetic imaging of co-cultures, in which hiNSC-TRAIL therapy induced rapid killing of both NSCLC and TNBC. Efficacy was determined in vivo by infusing hiNSC-TRAIL or control cells intravenously into mice bearing orthotopic NSCLC or TNBC and tracking changes in tumor volume using BLI. Mice treated with intravenous hiNSC-TRAIL showed a 70% or 72% reduction in NSCLC or TNBC tumor volume compared with controls within 14 or 21 days, respectively. Safety was assessed by hematology, blood chemistry, and histology, and no significant changes in these safety parameters was observed through 28 days. These results indicate that intravenous hiNSCs-TRAIL seek out and kill NSCLC and TNBC tumors, suggesting a potential new strategy for treating aggressive peripheral cancers.