Monitoring the genomic stability of in vitro cultured rat bone-marrow-derived mesenchymal stem cells

Abstract

Bone-marrow-derived mesenchymal stem cells (MSCs) are multipotent cells capable of selfrenewal and differentiation into multiple cell types. Accumulating preclinical and clinical evidence indicates that MSCs are good candidates to use as cell therapy in many degenerative diseases. For MSC clinical applications, an adequate number of cells are necessary so an extensive expansion is required. However, spontaneous immortalization and malignant transformation of MSCs after culture expansion have been reported in human and mouse, while very few data are present for rat MSCs (rMSCs). In this study, we monitored the chromosomal status of rMSCs at several passages in vitro, also testing the influence of four different cell culture conditions. We first used the conventional traditional cytogenetic techniques, in order to have the opportunity to observe even minor structural abnormalities and to identify low-degree mosaic conditions. Then, a more detailed genomic analysis was conducted by array comparative genomic hybridization. We demonstrated that, irrespective of culture conditions, rMSCs manifested a markedly aneuploid karyotype and a progressive chromosomal instability in all the passages we analyzed and that they are anything but stable during in vitro culture. Despite the fact that the risk of neoplastic transformation associated with this genomic instability needs to be further addressed and considering the apparent genomic stability reported for in vitro cultured human MSCs (hMSCs), our findings underline the fact that rMSCs may not in fact be a good model for effectively exploring the full clinical therapeutic potential of hMSCs.

MSC Microvesicles for the Treatment of Lung Disease: A New Paradigm for Cell-Free Therapy

“…Even if MSCs maintain their differentiation potential and differentiation markers after genetic manipulation or expansion in culture, these properties do not ensure immunomodulatory and regenerative capacity. Moreover, bone marrow-derived MSCs are the best characterized and have been shown to have cytoprotective effects; yet, they have also been reported to accumulate genetic mutations after extensive expansion (9,28,81). This genomic instability may account for the unusual in vitro behavior, with early cultures growing rapidly, but eventually giving rise to heterogenous populations with variable properties that are often unable to reproduce the protective MSC effect.…”

Uncultured Marrow Mononuclear Cells Delivered Within Fibrin Glue Hydrogels to Porous Scaffolds Enhance Bone Regeneration Within Critical-Sized Rat Cranial Defects

“…[22][23][24] Limited long-term data are available to adequately understand the risks of using culture-expanded MSC in clinical therapy, and, although early reports are promising, 25 a number of concerns, including those of genomic instability and resultant tumorigenesis, remain. [26][27][28][29][30] Additionally, it is unclear how patient-to-patient variability and changes in cellular function related to age or other demographic factors may impact the use and success of such cell-based therapies.…”

Nuclear Transcription Factor Kappa B Downregulation Reduces Chemoresistance in Bone Marrow-derived Cells Through P-glycoprotein Modulation

“…According to Foudah et al, some morphological changes were observed in the culture of rat BMDCs under basal conditions. Stage 16 BMDCs became morphologically more homogeneous with a fibroblast-like phenotype, but were smaller with increasing passages (Figure 1) (22).…”

“…BMDCs can differentiate into osteoblasts and mature osteoblasts that express markers such as alkaline phosphatase (ALP), type I collagen, and osteocalcin (21). Interestingly, the differentiation capacity of rat mesenchymal stem cells (MSCs) is restricted after a few weeks of culture, and their proliferation and osteogenic differentiation ability are increased as demonstrated in the study of Foudah et al (22). Osteoblast progenitor deregulation can generate osteosarcoma, which is characterized by high local aggressiveness, poor prognosis due to high resistance to drugs, and high metastatic incidence, which causes early recurrent disease (23,24).…”