Figure 5
Enhanced stemness of ERα36+ breast cancer cells and ALDH1A1 expression after tamoxifen treatment. (A) Increased mammosphere formation ability of FACS-sorted MCF-7-ERα36+ cells after treatment with E2 or 4-OHT. n = 3. (B) Increased ALDH1high population in MCF-7/ERα36 cells after E2 and 4-OHT treatment. Cells sorted by FACS were treated with indicated concentrations of 4-OHT or E2. (C) Increased ALDH1high population in xenograft tumors formed by MDA-MB 436 cells after E2 or tamoxifen treatment. Flow cytometry was used to assess the percentage of ALDH1high cells in the tumor xenografts. n = 4. (D) Quantitative real-time RT-PCR analysis showing a positive correlation between ALDH1A1 mRNA levels and ERα36 expression in MCF-7 and MDA-MB 436 breast cancer cells. (E) IHC staining showing ALDH1A1 in distant metastatic regions from breast cancer patients after tamoxifen treatment. Hematoxylin was used for counterstaining. Scale bars, 50 μm. (F) Box plot analysis showing higher ALDH1A1 IHC-scores in metastatic tumors as compared to matched primary tumor from 18 breast cancer patients. P value was calculated with Mann-Whitney U test. *P < 0.05.
