Chromosomal stability of mesenchymal stromal cells during in vitro culture

Background aims Mesenchymal stromal cells (MSCs) are being investigated for use in cell therapy. The extensive in vitro expansion necessary to obtain sufficient cells for clinical use increases the risk that genetically abnormal cells will arise and be propagated during cell culture. Genetic abnormalities may lead to transformation and poor performance in clinical use, and are a critical safety concern for cell therapies using MSCs. Methods We used spectral karyotyping (SKY) to investigate the genetic stability of human MSCs from ten donors during passaging. Results Our data indicate that chromosomal abnormalities exist in MSCs at early passages and can be clonally propagated. The karyotypic abnormalities observed during our study diminished during passage. Conclusions Karyotyping of MSCs reveals characteristics which may be valuable in deciding the suitability of cells for further use. Karyotypic analysis is useful for monitoring the genetic stability of MSCs during expansion.