Mesenchymal stem cell (MSC)-derived exosomes as novel vehicles for delivery of miRNAs in cancer therapy.

Mesenchymal stem cells (MSCs) are known as promising sources for cancer therapy and can be utilized as vehicles in cancer gene therapy. MSC-derived exosomes are central mediators in the therapeutic functions of MSCs, known as the novel cell-free alternatives to MSC-based cell therapy. MSC-derived exosomes show advantages including higher safety as well as more stability and convenience for storage, transport and administration compared to MSCs transplant therapy. Unmodified MSC-derived exosomes can promote or inhibit tumors while modified MSC-derived exosomes are involved in the suppression of cancer development and progression via the delivery of several therapeutics molecules including chemotherapeutic drugs, miRNAs, anti-miRNAs, specific siRNAs, and suicide gene mRNAs. In most malignancies, dysregulation of miRNAs not only occurs as a consequence of cancer progression but also is directly involved during tumor initiation and development due to their roles as oncogenes (oncomiRs) or tumor suppressors (TS-miRNAs). MiRNA restoration is usually achieved by overexpression of TS-miRNAs using synthetic miRNA mimics and viral vectors or even downregulation of oncomiRs using anti-miRNAs. Similar to other therapeutic molecules, the efficacy of miRNAs restoration in cancer therapy depends on the effectiveness of the delivery system. In the present review, we first provided an overview of the properties and potentials of MSCs in cancer therapy as well as the application of MSC-derived exosomes in cancer therapy. Finally, we specifically focused on harnessing the MSC-derived exosomes for the aim of miRNA delivery in cancer therapy.

MicroRNAs and exosomes: Cardiac stem cells in heart diseases.

Treating cardiovascular diseases with cardiac stem cells (CSCs) is a valid treatment among various stem cell-based therapies. With supplying the physiological need for cardiovascular cells as their main function, under pathological circumstances, CSCs can also reproduce the myocardial cells. Although studies have identified many of CSCs' functions, our knowledge of molecular pathways that regulate these functions is not complete enough. Either physiological or pathological studies have shown, stem cells proliferation and differentiation could be regulated by microRNAs (miRNAs). How miRNAs regulate CSC behavior is an interesting area of research that can help us study and control the function of these cells in vitro; an achievement that may be beneficial for patients with cardiovascular diseases. The secretome of stem and progenitor cells has been studied and it has been determined that exosomes are the main source of their secretion which are very small vesicles at the nanoscale and originate from endosomes, which are secreted into the extracellular space and act as key signaling organelles in intercellular communication. Mesenchymal stem cells, cardiac-derived progenitor cells, embryonic stem cells, induced pluripotent stem cells (iPSCs), and iPSC-derived cardiomyocytes release exosomes that have been shown to have cardioprotective, immunomodulatory, and reparative effects. Herein, we summarize the regulation roles of miRNAs and exosomes in cardiac stem cells.

Novel application of adipose-derived mesenchymal stem cells via producing antiangiogenic factor TSP-1 in lung metastatic melanoma animal model.

Human adipose tissue derived mesenchymal stem cells (hAD-MSCS) with suppressive immunogenicity, homing to injury, inflammatory, and cancer sites can be suitable for gene therapy. PiggyBac (PB) is a type of transposon vector applied in mammalian systems and could overcome some limitations of other transposon and viral vectors. In this study, the therapeutic potential hAD-MSCs expressing thrombospondin-1 (TSP-1) is assessed through tail vein injection in C57BL/6 models bearing melanoma mice. Twenty days after injection, antiangiogenic effects and number of activated T. cells are assessed by Immunohistochemistry (IHC) method. Apoptosis value is analyzed by tunnel assay. Mice survival and numbers of nodules in mice lungs also are assessed. By western blotting, value of TSP-1, Bax and Bcl2 expression are assessed. The result revealed that hAD-MSCs.TSP-1 can inhibit angiogenesis and induce apoptosis and activated T. cells in a significant manner in C57BL/6 mice models bearing melanoma. Survival also significantly increased and number of nodules decreased, value of Bax and TSP-1 expression increased and value of Bcl2 expression decreased. In conclusion, our result showed that hAD-MSC. TSP-1 can be applied as an effective delivery vehicle in lung metastatic melanoma therapy.

Liposomal gp100 vaccine combined with CpG ODN sensitizes established B16F10 melanoma tumors to anti PD-1 therapy.

OBJECTIVES: Program death 1 (PD-1)/ program death-ligand 1 (PD-L1) pathways, as the main inhibitory checkpoints, induce immunosuppression in the tumor microenvironment (TME). Despite the importance of inhibitor checkpoint receptor (ICR) blockers, their outcomes have been limited by the low immune response rate and induced acquired resistance. Pre-existing tumor-specific T cells is related to the improvement of their therapeutic efficacy. In the present study, we show that the combination of liposomal gp100 nanovaccine with anti PD-1 monoclonal antibody (mAb) potentiates the therapeutic effect in the melanoma model. MATERIALS AND METHODS: In this study, we first decorate the cationic liposome with gp10025-33 self-antigen and then characterize it. Mice bearing B16F10 melanoma tumors were vaccinated with different formulations of gp100 peptide (free or liposomal form) with or without CpG ODN adjuvant in combination with anti PD-1 mAb. RESULTS: Therapeutic combination of liposomal nanovaccine and CpG with anti PD-1 mAb, demonstrated the increased number of tumor infiltrated lymphocytes (TILs) in TME with the highest IFN-γ production and cytotoxic activity, which led to remarkable tumor regression. CONCLUSION: Our results demonstrated the synergism between Lip-peptide+CpG nanovaccine and anti PD-1 regime, which improved the therapeutic efficacy of PD-1 checkpoint blocker in melanoma mice models.

Vaccination with dendritic cells pulsed ex vivo with gp100 peptide-decorated liposomes enhances the efficacy of anti PD-1 therapy in a mouse model of melanoma.

BACKGROUND: Targeting antigens to dendritic cells (DCs) via nanoparticles is a powerful strategy which improves the efficacy of ex vivo antigen-pulsed DC vaccines. METHODS: In this study, liposomes were first decorated with gp10025-33 self-antigen and then characterized. Then, DCs were pulsed ex vivo with liposomal gp100 and injected subcutaneously in mice bearing B16F10 established melanoma tumors in combination with anti-PD-1 therapy. RESULTS: Treatment with liposomal pulsed DC vaccine elicited the strongest anticancer immunity and enhanced intratumoral immune responses based on infiltration of gp100-specific CD4+ and CD8+ T cells to the tumor leading to significant tumor growth regression and prolonged survival rate. Treatment with liposomal pulsed DC vaccine also markedly enhanced specific cytotoxic T lymphocytes (CTL) responses with a significant higher titer of IFN-γ in the spleen. Moreover, a significant increase of PD-1 expressing CD8+ tumor infiltrating lymphocytes (TILs) was detected in tumors. CONCLUSION: Our results demonstrate an optimum dose of liposomal gp100 significantly increases the efficacy of anti-PD-1 therapy in mice and might be an effective strategy to overcome resistance to anti-PD-1 therapy.

Ex vivo-generated dendritic cell-based vaccines in melanoma: the role of nanoparticulate delivery systems.

Melanoma is a poor immunogenic cancer and many treatment strategies have been used to enhance specific or nonspecific immunity against it. Dendritic cell (DC)-based cancer vaccine is the most effective therapies that have been used so far. Meanwhile, the efficacy of DC-based immunotherapy relies on critical factors relating to DCs such as the state of maturation and proper delivery of antigens. In this regard, the use of nanoparticulate delivery systems for effective delivery of antigen to ex vivo-generated DC-based vaccines that also poses adjuvanticity would be an ideal approach. In this review article, we attempt to summarize the role of different types of nanoparticulate antigen delivery systems used in the development of ex vivo-generated DC-based vaccines against melanoma and describe their adjuvanticity in mediation of DC maturation, cytoplasmic presentation of antigens to MHC class I molecules, which led to potent antigen-specific immune responses. As were represented, cationic liposomes were the most used approach, which suggest its potential applicability as delivery systems for further experiments in combination with either adjuvants or monoclonal antibodies.

Intranasal administration of endometrial mesenchymal stem cells as a suitable approach for Parkinson's disease therapy.

This study aimed to investigate the therapeutic effects of intranasal administration of human endometrium-derived stem cells (HEDSCs) in the mouse model of Parkinson's disease (PD). Thirty days after intrastriatal injection of 6-OHDA, HEDSCs were administrated intranasally in three doses (104, 5 × 104 and 105 cells µl-1). During 120 days after stem cell administration, behavioral tests were examined. Then the mice were sacrificed and the fresh section of the substantia nigra pars compacta (SNpc) was used for detection of HEDSCs-GFP labeled by fluorescence microscopy method. In addition, immunohistochemistry was used to assay GFP, human neural Nestin, and tyrosine hydroxylase (TH) markers in the fixed brain tissue at the SNpc. Our data revealed that behavioral parameters were significantly improved after cell therapy. Fluorescence microscopy assay in fresh tissue and GFP analysis in fixed tissue were showed that the HEDSCs-GFP labeled migrated to SNpc. The data from immunohistochemistry revealed that the Nestin as a differential neuronal biomarker was expressed in SNpc. Also, TH as a dopaminergic neuron marker significantly increased after HEDSCs therapy in an optimized dose 5 × 104 cells µl-1. Our results suggest that intranasal administration of HEDSCs improve the PD symptoms in the mouse model of PD dose-dependent manner as a noninvasive method.

Stem cell-based therapy for Parkinson's disease with a focus on human endometrium-derived mesenchymal stem cells.

Parkinson's disease (PD) as an increasing clinical syndrome is a multifunctional impairment with systemic involvement. At present, therapeutic approaches such as l-3,4-dihydroxy-phenylalanine replacement therapy, dopaminergic agonist administration, and neurosurgical treatment intend to relieve PD symptoms which are palliative and incompetent in counteracting PD progression. These mentioned therapies have not been able to replace the lost cells and they could not effectively slow down the relentless neurodegenerative process. Till now, there is a lack of eligible treatment for PD, and stem cells therapy recently has been considered for PD treatment. In this review, we demonstrate how human stem cell technology especially human endometrium-derived stem cells have made advancement as a therapeutic source for PD compared with other treatments.

Arg399Gln substitution in XRCC1 as a prognostic and predictive biomarker for prostate cancer: Evidence from 8662 subjects and a structural analysis.

BACKGROUND: The Arg399Gln polymorphism in the X-ray repair cross-complementing group 1 gene (XRCC1) may alter the risk of prostate cancer (PCa). The present study aimed to investigate the association of the XRCC1-Arg399Gln polymorphism with PCa risk in an Iranian population, as followed by a meta-analysis and an in silico analysis. METHODS: In a case-control study, 360 subjects were included (180 men with PCa and 180 healthy controls). XRCC1-Arg399Gln genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism method. In the meta-analysis, 14 eligible studies were included to which our case-control data were added to estimate the pooled odds ratios. Some bioinformatics tools were employed to evaluate the effects of Arg399Gln substitution on molecular aspects of the XRCC1 protein. RESULTS: Our case-control study revealed a significant association between the XRCC1-Arg399Gln polymorphism and PCa risk. The data from overall meta-analysis showed significant associations between the mentioned polymorphism and PCa risk in allelic and recessive genetic models. In addition, we observed statistically significant associations in stratified analyses by ethnicity, sample size and source of controls. Our in silico analysis showed that Arg399Gln substitution could be damaging with respect to the function and structure of the XRCC1 protein. CONCLUSIONS: Based on these results, the XRCC1-Arg399Gln polymorphism might be a risk factor for PCa and it could be considered as a prognostic and predictive biomarker for susceptible men.

Chondrogenic differentiation of human scalp adipose-derived stem cells in Polycaprolactone scaffold and using Freeze Thaw Freeze method.

Human adipose tissue has been identified as a viable alternative source for mesenchymal stem cells. SADSCs were isolated from human scalp biopsy and then were characterized by Flow cytometry. SADSCS expressed CD90, CD44, and CD105 but did not express CD45 surface marker. Growth factors were used for chondrogenesis induction. Histology and immunohistology methods and gene expression by real-time PCR 14 days after induced cells have shown the feature of chondrocytes in their morphology and extracellular matrix in both inducing patterns of combination and cycling induction. Moreover, the expression of gene markers of chondrogenesis for example collagen type II aggrecan and SOX9 has shown by real-time PCR assay. Then, SADSCs were seeded alone on polycaprolatone (PCL) and with Freeze thaw Freeze (PCL+FTF) scaffolds and SADSCs differentiated toward the chondrogenic lineage and chondrogenesis induction were evaluated using scanning electron microcopy (SEM) and MTT assay. Our results showed that SADSCs were also similar to the other adipose-derived stem cells. Using TGF-beta3 and BMP-6 were effective for chondrogenesis induction. Therefore using of TGF-beta3 and BMP-6 growth factors may be the important key for in vitro chondrogenesis induction. The bio-composite of PCL+FTF nanofibrous scaffolds enhance the chondroblast differentiation and proliferation compared to PCL scaffolds .Therefore, our model will make it possible to study the mechanism of transition from chondroblast to chondrocyte.

Mesenchymal stem cells: A new platform for targeting suicide genes in cancer.

One of the important strategies for the treatment of cancer is gene therapy which has the potential to exclusively eradicate malignant cells, without any damage to the normal tissues. Gene-directed enzyme prodrug therapy (GDEPT) is a two-step gene therapy approach, where a suicide gene is directed to tumor cells. The gene encodes an enzyme that expressed intracellularly where it is able to convert a prodrug into cytotoxic metabolites. Various delivery systems have been developed to achieve the appropriate levels of tumor restricted expression of chemotherapeutic drugs. Nowadays, mesenchymal stem cells (MSCs) have been drawing great attention as cellular vehicles for gene delivery systems. Inherent characteristics of MSCs make them particularly attractive gene therapy tools in cell therapy. They have been used largely for their remarkable homing property toward tumor sites and availability from many different adult tissues and show anti-inflammatory actions in some cases. They do not stimulate proliferative responses of lymphocytes, suggests that MSCs have low immunogenicity and could avoid immune rejection. This review summarizes the current state of knowledge about genetically modified MSCs that enable to co-transduce a variety of therapeutic agents including suicide genes (i.e., cytosine deaminase, thymidine kinase) in order to exert potent anti-carcinogenesis against various tumors growth. Moreover, we highlighted the role of exosomes released from MSCs as new therapeutic platform for targeting various therapeutic agents.

Morphology of Rat Hippocampal CA1 Neurons Following Modified Two and Four-Vessels Global Ischemia Models.

BACKGROUND: An appropriate animal model of ischemia stroke is essential for evaluation of different therapeutic methods. Two and four-vessel global ischemia models are one of the most common types of transient cerebral ischemia. OBJECTIVES: In this study, the morphology of rat hippocampal CA1 neurons in modified models of two and four-vessel ischemia and reperfusion were evaluated. MATERIALS AND METHODS: In this study, 20 Wistar rats were randomly divided into five groups. In group 2 and 3, both common carotid arteries were occluded for 10 minutes in either 3 or 24 hours of reperfusions, respectively. In group 4 and 5, both common carotid and vertebral arteries were occluded for 10 minutes in either 3 or 24 hours of reperfusions, respectively. Group 1 as control, underwent the whole surgery without any arteries occlusion. Hippocampi of the rats in all groups were processed and tissue sections were stained using the Nissl method. The morphology of CA1 neurons were studied under a light microscope and compared different groups. RESULTS: In all groups ischemic changes were apparently observed in hippocampus CA1 neurons. In two-vessel occlusion model, after 3 and 24 hours of reperfusions, ischemic cells accounted for 14.9% and 23.2%, respectively. In four-vessel occlusion model, after 3 and 24 hours of reperfusions, ischemic cells accounted for 7.6% and 44.9% (P < 0.0001), respectively. CONCLUSIONS: Modified four-vessel occlusion model resulted in significant ischemic changes after 24 hours of reperfusion in CA1 neurons of rat hippocampus.

Human endometrial stem cell neurogenesis in response to NGF and bFGF.

The potential of cell therapy is promising in nerve regeneration, but is limited by ethical considerations about the proper and technically safe source of stem cells. We report the successful differentiation of human EnSCs (endometrial stem cells) as a rich source of renewable and safe progenitors into high-efficiency cholinergic neurons. The extracellular signals of NGF (nerve growth factor) and bFGF (basic fibroblast growth factor) could induce cholinergic neuron differentiation. ChAT (choline acetyltransferase), MAP2 (microtubule associated protein 2) and NF-l (neurofilament L) increased after administration of bFGF and NGF to the EnSC cultures. trkC and FGFR2 (fibroblast growth factor receptor 2), which belong to the NGF and bFGF receptors respectively, were determined in populations of EnSCs. NGF, bFGF and their combination differentially influenced human EnSCs high efficiency differentiation. By inducing cholinergic neurons from EnSCs in a chemically defined medium, we could produce human neural cells without resorting to primary culture of neurons. This in vitro method provides an unlimited source of human neural cells and facilitates clinical applications of EnSCs for neurological diseases.