Fig. 1

Isolation and characterization of CSC-like cells from the human endometrial cancer cell line HHUA. A Flow cytometric determination of the distributions of the side population (SP) and main population (MP) in living HHUA cells stained with Hoechst 33342 in the absence (left) or presence (right) of reserpine. Treatment with 50 μM reserpine resulted in the disappearance of the SP fraction. B Expression of ABCG2, MDR1 and ACTB mRNAs in HHUA-SP and -MP cells as determined by qRT-PCR. Expression of MDR1 and CTNNB1 mRNAs in HHUA-SP and -MP cells as determined by real-time RT-PCR. C Proliferation of HHUA-SP and -MP cells as determined by MTS assay. Each point indicates the mean ± SEM absorbance at 490 nm obtained from three independent experiments using three individual samples. *, P < 0.05, vs. DMSO control, based on Student’s t-test. D Colony formation ability of HHUA-SP and -MP cells. HHUA-SP and -MP cells were cultured in the cloning plates as indicated and then stained with Giemsa solution. The bar graph shows the mean ± SEM colony number obtained from three independent experiments. *, P < 0.05, based on Student’s t-test. E Cell invasion ability of HHUA-SP and -MP cells as determined by cell invasion assay. Each bar indicates the mean ± SEM number of invading cells obtained from three independent experiments using three individual samples, *, P < 0.05, based on Student’s t-test. F Weight and gross appearance of tumors derived from HHUA-SP and -MP cells at 6 weeks after inoculation into the subcutaneous tissue of nude mice. Each dot indicates the tumor weight of an individual mouse. *, P < 0.05, based on Student’s t-test. Scale bars, 1 mm. G Hematoxylin and eosin and immunofluorescence staining of HHUA-SP or -MP-derived tumors using antibodies against vimentin (VM) and MDR1 or CTNNB1. DAPI was used for nuclear staining. Scale bars, 1 mm (yellow) and 200 μm (white)