Fig. 2

Validation of the differentially expressed cellular surface protein CDC50A in SP cells that might contain cancer initiating cells. A, B As detected by western blotting, the expression of CDC50A in SP cells of SKOV3 and A2780 cells increased significantly (p = 0.002 and 0.019, respectively). Gray values of bands were measured with ImageJ software (National Institute of Health). Most SP cells were CDC50A-positive cells, as determined by flow cytometry. The grouping of blots cropped from different gels. The blots were cut prior to hybridisation with antibodies. The raw data with detail description was shown in Supplementary Fig. 6. C The membrane distribution of CDC50A was validated by immunofluorescence in SP and non-SP SKOV3 cells. Nuclei were stained with PI. Scale bar, 50 μm. D The ratios of CDC50A-positive cells in five other ovarian cancer cell lines, in addition to SKOV3 and A2780 cells, were evaluated by flow cytometry. CDC50A-positive cells (0.4% ~ 1.5%) were observed in ovarian cancer cells, which was similar to other common biomarkers of cancer stem cells