Figure 1.

LncRNA HOTAIR is highly expressed in breast CSCs.A, MCF-7 ALDH1+ and MDA-MB-453 ALDH1+ cells sorted by FACS were cultured in medium and then examined under microscope. Cells were magnified by 100 folds and the scale bar represented 10 μm. B, CD44 and CD24 were detected by Western blotting in the indicated cells. β-actin was used as an internal control. C, the growth rate of the ALDH+ or ALDH- cells was measured by MTT. Results were shown as means ± SD. D, the Caspase 3/7 activity was measured with or without paclitaxel (1 μM) treatments in the indicated cells. Results were shown as means ± SD. E, ALDH+ or ALDH- breast cancer cells were transplanted into the subcutaneous area of the left or right limb of the nude mouse and the tumors were examined 1 month after the injection. The number of mice employed in this experiment was ten and the scale bar represented 1 cm. F, breast CSCs (ALDH+) and non-CSCs (ALDH-) sorted from the corresponding cell lines by FACS were subjected to the analysis of HOTAIR by real-time PCR. Relative gene expression was normalized to endogenous β-actin. Results are shown as means ± SD. G, HOTAIR was analyzed in oncosphere and non-oncosphere cells derived from three breast cell lines. Results are shown as means ± SD. H, breast CSCs were fractionated followed by quantitative real-time PCR for the detection of the corresponding transcripts. β-actin and GAPDH were served as positive controls for cytoplasmic gene expression. U6 RNA was served as a positive control for nuclear gene expression. Data are representative of at least three independent experiments. ∗p < 0.05, ∗∗p < 0.01 by two-tailed Student’s t test. CSC, cancer stem cell; HOTAIR, Hox transcript antisense intergenic RNA.