Transformation of hESC-MSC. (a) PCR analysis of cellular DNA from MYC-transfected HuES9.E1 MSCs (E1-MYC 21.1), GFP transfected HuES9.E1 MSCs (E1-GFP) and the parental MSCs, HuES9.E1 (E1). DNA was amplified using primers specific for MYC exon 2 and exon 3, respectively. The expected PCR fragment size for the endogenous MYC gene was1.7 kb and for the transfected MYC cDNA was 0.36 kb as represented by the amplified fragment from the MYC-lentivirus. (b) Cell Morphology of transfected MSCs as observed under light microscopy. (c) Quantitative RT-PCR was performed on RNA from different passages of E1-MYC 21.1 and GFP-MSCs for the level of MYC and ACTIN mRNA. The relative MYC-transcript level was normalized to that in GFP-MSCs. (d) Relative telomerase activity. 1 μg of cell lysate protein was first used to extend a TS primer by telomerase activity and the telomerase product was then quantitated by real time PCR. The Ct value represented the amount of telomerase product and was therefore indirectly proportional to telomerase activity in the lysate. (e) Karyotpye analysis of E1-MYC 16.3 by G-banding. (f) Rate of cell cycling. Cells were labelled with CFDA and their fluorescence was monitored over time by flow cytometry. The loss of cellular fluorescence at each time point was used to calculate the number of cell division that the cells have undergone as described in Materials and Methods (Additional files 1).