Figure 2

Bag-culture does not affect vitality, expression profile, DNA content and telomerase activity of ITSCs. (A) The amount of trypan blue-negative ITSCs (viability) and total cell numbers (doubling time) during bag- and three-dimensional-culture reveals no significant changes in vitality and proliferation (biological triplicates, P <0.05 is considered statistically significant; unpaired t-test, two-tailed, confidence interval: 95%; dots represent doubling times of ITSCs derived from separate donors). (B) Reverse transcription PCR analysis revealing unchanged expression of ITSC-specific neural crest and stemness transcripts in bag-cultivated ITSCs. (C) Representative flow cytometric analyses of PI-stained ITSCs after three weeks of bag- or three-dimensional-culture. Bag-cultured ITSCs exhibited a characteristic DNA content for diploid cells without any signs of polyploidy, although showing increased signals for apoptotic (sub G1) and mitotic cells (G2/M). (D) Real time Q-TRAP analysis depicting telomerase activity of ITSCs cultivated in bags over five passages (p5) and no significant changes during subcultivation up to passage 10 (p10) (technical triplicates, P <0.05 is considered statistically significant; unpaired t-test, two-tailed, confidence interval: 95%). U251 human astroglioma tumor cells served as positive control, negative control lacked template, n.d.: not detectable. ITSCs, inferior turbinate stem cells; PI, propidium iodide.