Safety and Biodistribution of Human Bone Marrow-Derived Mesenchymal Stromal Cells Injected Intrathecally in Non-Obese Diabetic Severe Combined Immunodefi ciency Mice: Preclinical Study

BACKGROUND: Mesenchymal stromal cells (MSCs) have potent immunomodulatory and neuroprotective properties, and have been tested in neurodegenerative diseases resulting in meaningful clinical improvements. Regulatory guidelines specify the need to perform preclinical studies prior any clinical trial, including biodistribution assays and tumourigenesis exclusion. We conducted a preclinical study of human bone marrow MSCs (hBM-MSCs) injected by intrathecal route in Non-Obese Diabetic Severe Combined Immunodeficiency mice, to explore cellular biodistribution and toxicity as a privileged administration method for cell therapy in Friedreich's Ataxia. METHODS: For this purpose, 3 × 10⁵ cells were injected by intrathecal route in 12 animals (experimental group) and the same volume of culture media in 6 animals (control group). Blood samples were collected at 24 h (n = 9) or 4 months (n = 9) to assess toxicity, and nine organs were harvested for histology and safety studies. Genomic DNA was isolated from all tissues, and mouse GAPDH and human β2M and β-actin genes were amplified by qPCR to analyze hBM-MSCs biodistribution. RESULTS: There were no deaths nor acute or chronic toxicity. Hematology, biochemistry and body weight were in the range of normal values in all groups. At 24 h hBM-MSCs were detected in 4/6 spinal cords and 1/6 hearts, and at 4 months in 3/6 hearts and 1/6 brains of transplanted mice. No tumours were found. CONCLUSION: This study demonstrated that intrathecal injection of hBM-MSCs is safe, non toxic and do not produce tumors. These results provide further evidence that hBM-MSCs might be used in a clinical trial in patients with FRDA.

Glioma cells promote expression of cancer-related genes in human bone marrow-derived mesenchymal stromal cells in vitro / 中国神经精神疾病杂志

Objective We investigated the expression profile of cancer related genes in hMSCs co-cultured with U251 glioma cells, to evaluate the risk of malignant transformation of hMSCs in glioma environment. Methods hMSCs were co-cultured with U251 glioma cells for 5 days and the expression profile of cancer-related genes were investigated by using microarray assay, followed by Real-time quantitative RT-PCR and Western blot. Results Of the 440 cancer-re?lated genes covered by Oligo GEArray Human Cancer Microarray OHS-802, SPINT2, TK1, STC1, MMP1, CCND1, SORT1, SEPT6, CDC20, SHB, CDK5, RELA, XRCC4, KIT, CTPS, CAPNS1 and ETV6 were significantly upregulated (>3-fold) whereas none was downregulated in hMSCs co-cultured with U251 glioma cells. The upregulation of oncogenes KIT, CAPNS1, TK1, MMP1, CCND1, CDC20, RELA and STC1 in co-cultured hMSCs were confirmed by Real-time quan? titative RT-PCR. The upregulation of protein expression of oncogenes KIT, MMP1, CCND1 and RELA were detected by Western blot. Conclusion The present study demonstrates that co-culture of hMSCs with human glioma cells leads to up?regulation of some important oncogenes in hMSCs, indicating the tumorigenic potential of hMSCs in glioma environment.