Gene expression profiling on FePro labeled bone marrow stromal cells

Superparamagnetic iron oxide nanoparticles (SPION) are increasingly used to label human bone marrow stromal cells (BMSCs, also called mesenchymal stem cells) to monitor their fate by in vivo MRI and histology after Prussian blue (PB) staining. SPION-labeling appears to be safe as assessed by in vitro differentiation of BMSCs, however, we chose to determine the effect of labeling on maintaining the “stemness” of cells within the BMSC population. Colony forming efficiency, CD146 expression, gene expression profiling, bone and myelosupportive stroma formation in vivo were evaluated. SPION-labeling did not alter these assays. Equivalent bone with host hematopoiesis was formed by SPION-labeled and unlabeled BMSCs. PB+ adipocytes were noted, definitively demonstrating their donor origin, as well as PB+ pericytes, indicative of self-renewal of the stem cell in the BMSC population. This study confirms that SPION labeling does not alter the differentiation potential of the subset of stem cells within BMSCs. We performed gene expression profiling on BMSCs labeled with FePro. For comparison, gene express profiling on human embryonic stem cells (hES) WA09 (H9) and adult cells: fibroblasts (FB), endothelial cells (EC) and smooth muscle cells (SMC) was conducted. Total RNA from PBMCs pooled from six normal donors was amplified into aRNA to serve as the reference.