Figure 4

Sphere formation and self-renew stem cell efficiency in BCSC derived from Orai1-KO MDA-MB-231 cells. A-C BCSC derived from WT MDA-MB-231 cells (WT; A) and Orai1-KO MDA-MB-231 cells (O1KO; B) were lysed and then subjected to 10% SDS-PAGE and Western blotting with anti-Orai1 antibody. Membranes were reprobed with the anti-β-actin antibody for protein loading control. Molecular masses indicated on the right were determined using molecular-mass markers run on the same gel. Blots are representative of four separate experiments. Bar graph represents Orai1 expression in WT and O1KO MDA-MB-231 cells. Data were statistically analyzed using Mann–Whitney U test. ***p < 0.001 as compared to WT MDA-MB-231 cells. (D–I) Formation of first generation mammospheres (D–F) and self-renewal capacity (G–I) of BCSC derived from WT and O1KO MDA-MB-231 cells was performed as described in Methods. Bar graphs represent mammosphere formation efficiency presented as mean ± SEM and expressed in percentage of the total cultured cells. Data were statistically analyzed using Mann–Whitney U test. **p < 0.01 as compared to WT MDA-MB-231 cells.