Intra-cavity stem cell therapy inhibits tumor progression in a novel murine model of medulloblastoma surgical resection

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.

Mesenchymal Stem Cells cause Telomere Length Reduction of Molt-4 Cells via Caspase-3, BAD and P53 Apoptotic Pathway

Mesenchymal stem cells (MSCs) as undifferentiated cells are specially considered in cell-based cancer therapy due to unique features such as multi-potency, pluripotency, and self-renewal. A multitude of cytokines secreted from MSCs are known to give such multifunctional attributes, but details of their role are yet to be unknown. In the present study, MSCs were cultured, characterized and co-cultured with Molt-4 cells as acute lymphoblastic leukemia cell line in a trans-well plate. Then, cultured Molt-4 alone and Molt-4 co-cultured with MSCs (10:1) were collected on day 7 and subjected to real time-PCR and Western blotting for gene and protein expression assessment, respectively. Ki-67/caspase-3 as well as telomere length were investigated by flow cytometry and real time-PCR, respectively. The results showed that MSCs caused significant decrease in telomere length as well as hTERT gene expression of Molt-4 cells. Also, gene and protein expression of BAD and P53 were significantly increased. Furthermore, the flow cytometry analysis indicated the decrease and increase of the Ki-67 and caspaspase-3 expression, respectively. It was concluded that MSCs co-cultured with Molt-4 cells could be involved in the promotion of Molt-4 cell apoptosis via caspase-3, BAD, and P53 expression. In addition, the decrease of telomere length is another effect of MSCs on Molt-4 leukemic cells.

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.

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.

Mesenchymal Stem Cells Promote Caspase Expression in Molt-4 Leukemia Cells Via GSK-3α/Β and ERK1/2 Signaling Pathways as a Therapeutic Strategy

BACKGROUND

Mesenchymal stem cells (MSCs) are considered an interesting tool in cell therapy due to their unique features such as self-renewal, multi-potency, and pluripotency. The multifunctional properties of these cells are being investigated in many studies. The current research examined the influence of MSCs on the Molt-4 cell line as acute lymphoblastic leukemia (ALL) cells.

METHODS

MSCs were cultured, characterized, and co-cultured with Molt-4 cells in a trans-well system. Then, cultured Molt-4 alone and Molt-4 co-cultured with MSCs (10:1) were collected on day 7 and subjected to western blotting for protein expression assessment. Telomerase activity as well as cell senescence, were investigated by PCR-ELISA TRAP assay and β-galactosidase activity measurement, respectively.

RESULTS

It was found that MSCs resulted in a significant increase in the pro-caspase-8 and cleaved-caspase 8 and 9 expression levels. Furthermore, protein expression levels of GSK-3α/β and ERK1/2 were significantly decreased. The results also showed that MSCs caused significant decreases and increases in telomerase and β-galactosidase enzyme activity of Molt-4 cells, respectively.

CONCLUSION

It was concluded that MSCs co-cultured with Molt-4 cells could be involved in the promotion of Molt-4 cell apoptosis and cell senescence via caspase-8, 9 cascade and GSK-3α/β and ERK1/2 signaling pathways.

Postoperative cancer treatments: In-situ delivery system designed on demand

The keys to the prevention of tumor recurrence after operation are the elimination of residual tumor cells and the reversal of microenvironments that induce recurrence. In the formulation of a treatment scheme, building an appropriate drug delivery system is essential. An in-situ drug delivery system (ISDDS) is regarded as an effective treatment route for postoperative use that increases drug delivery efficiency and mitigates side-effects. ISDDS technology has been considerably improved through a clearer understanding of the mechanisms of postoperative recurrence and the development of drug delivery materials. This paper describes the initiation and characteristics of postoperative recurrence mechanisms. Based on this information, design principles for ISDDS are proposed, and a variety of practical drug delivery systems that fulfil specific therapeutic needs are presented. Challenges and future opportunities related to the application of in-situ drug carriers for inhibiting cancer recurrence are also discussed.

Xeno- and transgene-free reprogramming of mesenchymal stem cells toward the cells expressing neural markers using exosome treatments

Neural stem cells (NSCs), capable of self-renew and differentiate into neural cells, hold promise for use in studies and treatments for neurological diseases. However, current approaches to obtain NSCs from a live brain are risky and invasive, since NSCs reside in the subventricular zone and the in the hippocampus dentate gyrus. Alternatively, mesenchymal stem cells (MSCs) could be a more available cell source due to their abundance in tissues and easier to access. However, MSCs are committed to producing mesenchymal tissue and are not capable of spontaneously differentiating into neural cells. Thus, the process of reprogramming of MSCs into neural cells to use in clinical and scientific settings has significantly impacted the advancement of regenerative medicine. Previously, our laboratory reported trans-differentiation of MSCs to neural cells through the induced pluripotent stem (iPS) cells state, which was produced by overexpression of the embryonic stem cell gene NANOG. In the current study, we demonstrate that treatment with exosomes derived from NSCs makes MSCs capable of expressing neural cell markers bypassing the generation of iPS cells. An epigenetic modifier, decitabine (5-aza-2'-deoxycytidine), enhanced the process. This novel Xeno and transgene-free trans-differentiation technology eliminates the issues associated with iPS cells, such as tumorigenesis. Thus, it may accelerate the development of neurodegenerative therapies and in vitro neurological disorder models for personalized medicine.

Cytokines secreted from bone marrow derived mesenchymal stem cells promote apoptosis and change cell cycle distribution of K562 cell line as clinical agent in cell transplantation

Mesenchymal stem cells (MSCs) are of special interest due their potential clinical use in cell-based therapy. Therapies engaging MSCs are showing increasing promise in the cancer treatment and anticancer drug screening applications. A multitude of growth factors and cytokines secreted from these cells are known to give such multifunctional properties, but details of their role are yet to be absolutely demonstrated. In this study, we have evaluated the influence of BMSCs on K562 cell line as chronic myeloid leukemia (CML) cells, with the use of a cytokine antibody array recognizing 34 cytokines. For this purpose, BMSCs were isolated and co-cultured with K562 cells; thereafter, cultured K562 alone and co-cultured K562 with BMSCs (10:1) were collected at day 7 and subjected to cell cycle distribution assay as well as annexin/PI analysis and Ki/caspase-3 assay for apoptosis assessment. In the following, the gene and protein expression levels of BAX and BCL-2 as pro- and anti-apoptotic agents were investigated. Furthermore, after 7 days’ treatment, culture medium was collected from both control and experimental groups for cytokine antibody array. It was found that BMSCs resulted in a robust increase in the number of cells at G₀/G₁ phase and arrest the G₀/G₁ phase as well as significantly inducing late apoptosis in K562 cells. The significant presence of TIMP-1 (tissue inhibitor of metalloproteinases-1), and moderate elevated signals for CINC-1 (cytokine-induced neutrophil chemoattractant-1) were obvious in the co-cultured conditioned media, but no significant increase was found in 32 other cytokines. It is concluded that co-culture of BMSCs with K562 cells could secrete a substantial amount of TIMP-1 and CINC-1. These cytokines could be involved in the inhibition of the K562 cell proliferation via BAX and caspase-3 cascade pathways.