Fig. 2

Characterization of normal biological features of MEECs. A Normal response to DNA damage. DNA damage was induced by treatment of cells with 0.5 nM actinomycin D (Act D) for 24 h. The response was measured by the levels of p53 protein and its downstream target molecule p21. β-actin is a loading control. HeLa cells were as the control cells. The experiment was repeated three times; the representative data were shown. B Non-transformed property—soft agar assay. The assay showed that MEECs did not form cell colonies in soft agar after 30 days, while cancer cells (HeLa) formed cell colonies after 10 days of culture. The morphology of colonies was observed and photographed under the microscope. Magnification 10 ×. C Differentiation potential in matrigel 3D culture. Single-cell suspensions of HeLa cells and MEECs were cultured in a specifically differentiation medium (keratinocyte growth medium, Life Technologies) containing 5% matrigel for 7 days as described in “Materials and methods” section. The morphology of cell aggregates was stained by 0.5 μg/ml DAPI and photographed by fluorescence microscope. Magnification 10 ×