Fig. 4

a Relative mRNA hTERT and SOX2 expression in passage 2 of CV-MSC. Data calibrated to embryonic stem cells (hESC) control, expression of which is considered one for both genes. Normalization to the housekeeping gene GAPDH. Results expressed as mean ± SD. b RT-PCR product for hTERT (145 bp) in CV-MSC passage 2 and hESC positive control run on 2% agarose gel. c hTERT splicing variant RT-PCR products in hCMSC passage 2 and hESC control run on 2% agarose gel. hTERT was 457 bp in full length (+α + β) and 421 bp (–α + β), 275 bp (+α–β), and 239 bp (–α–β) in the variants. d Immunofluorescence CV-MSC in passage 4 stained for hTERT (i, ii) and SOX2 (iii, iv). Primary antibodies labeled with Alexa Fluor 488 (i–iv). Cells nuclei counterstained with DAPI (i, iii) and F-actin fibers with Rodhamine-TRITC (i–iv). Scale = 10 μm. e Western blot analysis to detect hTERT and SOX2 proteins in CV-MSC in passage (p) 4 and 10. hESC as positive control included. f Representative images of passage 4 hCMSC (i) after subjecting to soft agar assay. A tumorigenic cell line, LN319, included as positive control, developing tumoroids identifiable after 4 weeks (ii). Scale = 50 μm. CV chorionic villi, MSC mesenchymal stromal cells, hTERT human telomerase reverse transcriptase, SOX2 sex determining region Y-box 2