Similar biological characteristics of human embryonic stem cell lines with normal and abnormal karyotypes

BACKGROUND: Human embryonic stem cell (hESC) lines derived from poor quality embryos usually have either normal or abnormal karyotypes. However, it is still unclear whether their biological characteristics are similar. METHODS: Seven new hESC lines were established using discarded embryos. Five cell lines had normal karyotype, one was with an unbalanced Robertsonian translocation and one had a triploid karyotype. Their biological character-istics, short tandem repeat loci, HLA typing, differentiation capability and imprinted gene, DNA methylation and X chromosome inactivation status were compared between different cell lines. RESULTS: All seven hESC lines had similar biological characteristics regardless of karyotype (five normal and two abnormal), such as expression of stage-specific embryonic antigen (SSEA)-4, tumor-rejection antigen (TRA)-1-81 and TRA-1-60 proteins, transcrip-tion factor octamer binding protein 4 mRNA, no detectable expression of SSEA-1 protein and high levels of alkaline phosphatase activity. All cell lines were able to undergo differentiation. Imprinted gene expression and DNA methyl-ation were also similar among these cell lines. Non-random X chromosome inactivation patterns were found in XX cell lines. CONCLUSIONS: The present results suggest that hESC lines with abnormal karyotype are also useful exper-imental materials for cell therapy, developmental biology and genetic research