In recent years, in light of the promising potentials of mesenchymal stromal/stem cells (MSCs) for carrying therapeutic anticancer genes, a complete revisitation on old chemotherapy-based paradigms has been established. This review attempted to bring forward and introduce the novel therapeutic opportunities of using genetically engineered MSCs. The simplicities and advantages of MSCs for medical applications make them a unique and promising option in the case of cancer therapy. Some of the superiorities of using MSCs as therapeutic gene micro-carriers are the easy cell-extraction procedures and their abundant proliferation capacity in vitro without losing their main biological properties. Targeted therapy by using MSCs as the delivery vehicles of therapeutic genes is a new approach in the treatment of various types of cancers. Some of the distinct properties of MSCs, such as tumor-tropism, non-immunogenicity, stimulatory effect on the anti-inflammatory molecules, inhibitory effect on inflammatory responses, non-toxicity against the normal tissues, and easy processes for the clinical use, have formed the basis of attention to MSCs. They can be easily used for the treatment of damaged or injured tissues, regenerative medicine, and immune disorders. This review focused on the drugability of MSCs and their potential for the delivery of candidate anticancer genes. It also briefly reviewed the vectors and methods used for MSC-mediated gene therapy of malignancies. Also, the challenges, limitations, and considerations in using MSCs for gene therapy of cancer and the new methods developed for resolution of these problems are reviewed.

Given the failure of conventional treatments for glioblastoma, gene therapy has gained interest considerable in recent years. Gliomas are associated with a state of immunosuppression, which appears to be partially mediated by an increase in secretion of transforming growth factor-b (TGF-b) from glioma cells. Decorin, a small proteoglycan which can bind to and inactivate TGF-b, has been successfully used as an antitumor strategy on stably transfected tumor cells and has been shown to cause growth suppression in neoplastic cells of various histological origins. In this paper, we investigated the use of gene therapy to deliver the decorin transgene in a site-specific manner in an experimental model of intracranial gliomas. Our aim was to inhibit the glioma-associated immunosuppressive state, and prolong the survival of tumor-bearing rats.We studied the effects of decorin gene transfer in the rat CNS-1 glioma model. To assess the effect of ectopic expression of decorin on glioma progression in vivo, stably transfected CNS-1 cells expressing decorin were implanted into the brain parenchyma of syngeneic Lewis rats. The rats implanted with CNS-1 cells expressing decorin survived significantly longer than those in the control groups which received CNS-1 cells that did not express decorin (Po.0001). We then investigated whether the survival observed with decorin expressing cells could be mimicked in vivo, using recombinant adenoviruses (RAds) expressing the decorin gene under the control of two different promoters: the human immediate-early cytomegalovirus (h-IE-CMV) and the glial fibrillary acidic protein (GFAP). In vivo results showed that administration of RAd expressing the human decorin under the control of h-IE-CMV promoter has a small, but significant effect in prolonging the survival of experimental tumor bearing rats (Po.0001). Our data indicate that ectopic decorin expression has the potential to slow glioma progression in vivo. Our results also indicate that expression of decorin has to be present in all cells which constitute the intracranial tumor mass for the inhibition of tumor growth and prolongation of the life expectancy of tumor-bearing rats to be effective.

Studies on patient-specific human-induced pluripotent stem cells (hiPSCs) as well as a series of autologous growth factors presumably will reveal their many benefits for cell base replacement therapy in type 1 diabetes mellitus (TIDM) patients in the future. For this purpose, we established a multistep protocol by adding platelet-rich plasma (PRP) that induce the hiPSCs into insulin-producing cells (IPCs). We present here a differentiation protocol consisting of five stages in two groups including protocol with PRP and without PRP. Charac-teristics of derived IPCs in both groups were evaluated at the mRNA and protein levels, cell cycle and viability in the end stage of cell differentiation. The in vitro studies indicated the treatment of hiPSCs in the protocol with PRP resulting in differentiated cells with strong characteristics of IPCs including islet-like cells, the expression of mature and functional pancreatic beta cell specific marker genes. In addition to these pancreatic specific markers were detected by immunochemistry and Western blot. Our differentiated cells in two groups secreted insulin and C-peptide in a glucose stimulation test by ELISA showing in vitro functional. The results of the cell cycle assay confirmed that differentiation has been done. We reported for the first time that PRP might be ideal additive in the culture medium to induce pancreatic differentiation in the hiPSCs. This study provides a new approach to investigate the role of PRP in pancreatic differentiation protocols and enhance the feasibility of using patient-specific iPSCs and autologous PRP for future beta cells replacement therapies for T1DM. J. Cell. Physiol. 232: 2878-2886, 2017. © 2016 Wiley Periodicals, Inc.

Breast cancer is one of the most prevalent cancers in women. Triple‐negative breast cancer consists 15% to 20% of breast cancer cases and has a poor prognosis. Cancerous transformation has several causes one of which is dysregulation of microRNAs (miRNAs) expression. Exosomes can transfer miRNAs to neighboring and distant cells. Thus, exosomal miRNAs can transfer cancerous phenotype to distant cells. We used gene expression omnibus (GEO) datasets and miRNA target prediction tools to find overexpressed miRNA in breast cancer cells and their target genes, respectively. Exosomes were extracted from MDA‐MB‐231 and MCF‐7 cells and characterized. Overexpression of the miRNAs of MDA‐MB‐231 cells and their exosomes were analyzed using quantitative Real‐time PCR. The target genes expression was also evaluated in the cell lines. Luciferase assay was performed to confirm the miRNAs: mRNAs interactions. Finally, MCF‐7 cells were treated with MDA‐MB‐231 cells’ exosomes. The target genes expression was evaluated in the recipient cells. GSE60714 results indicated that miR‐9 and miR‐155 were among the overexpressed miRNAs in highly metastatic triple negative breast cancer cells and their exosomes. Bioinformatic studies showed that these two miRNAs target PTEN and DUSP14 tumor suppressor genes. Quantitative Real‐time PCR confirmed the overexpression of the miRNAs and downregulation of their targets. Luciferase assay confirmed that the miRNAs target PTEN and DUSP14. Treatment of MCF‐7 cells with MDA‐MB‐231 cells’ exosomes resulted in target genes downregulation in MCF‐7 cells. We found that miR‐9 and miR‐155 were enriched in metastatic breast cancer exosomes. Therefore, exosomal miRNAs can transfer from cancer cells to other cells and can suppress their target genes in the recipient cells.