Abstract:

BACKGROUND: Under the differentiation into cardiomyocytes in vitro, few studies have addressed whether human umbilical cord blood-derived mesenchymal stem cells (UCB-derived MSCs) can maintain their normal physiological properties. i.e. whether reach the biological safety standards of seed cells.
OBJECTIVE: To analyze the changes of chromosome karyotype, telomerase activity and tumorigenicity under a condition of cardiomyocyte differentiated from human UCB-derived MSCs that were isolated and cultured in vitro.
METHODS: Karyotypes were analyzed in UCB-derived MSCs from the third passage that was isolated and cultured in vitro using chromosome G-banding technique and samples following the seventh passage of cells differentiating into cardiomyocytes. Cell telomerase activity and cell cycle-related genes cyclinA, cdk2, C-fos, h-TERT, c-myc and p53 expression were analyzed. The nude mice carcinogenic test was performed to test the tumorigenicity of cells.
RESULTS AND CONCLUSION: No abnormal changes in the chromosome karyotype and telomerase activity were detected in human UCB-derived MSCs following in vitro cardiomyocyte culture up to the seventh passage. There were no c-myc, p53, h-TERT and C-fos expressions in tested cells. Any abnormal changes such as skin nodules or doubtful focus in the nude mice could not be found. These are consistent with the National Medical Product Biology Evaluation Criterion.