Fig. 2

Suppression of Rack1 undermines the stemness of breast cancer cells. (A) The mRNA and Protein expression levels of Rack1 in control and three breast cancer cell lines with stable knockdown of Rack1 were determined by qRT-PCR and Western Blotting assays. (B) Representative results showed that breast cancer cells with Rack1 knockdown had significantly reduced colony forming ability compared to control groups. (C) Flow cytometric assays was used to determine the percentage of CD44 + CD24- cells in control or Rack1 knockdown MCF7 or MDA-MB-231 cells. (D) The control and Rack1-silenced cells were exposed to EPI at various concentrations for 48 h, and the viability and half-maximal inhibitory concentration (IC50) values of EPI in the indicated groups were determined using the CCK8 assay. (E) The sphere-forming ability was detected in shNC or shRack1 breast cancer cells. (F) In vivo limited dilution assay was used to detect the effect of Rack1 on breast cancer tumorigenesis. Tumors dissected from allograft mice (top), and corresponding estimated frequencies were shown (bottom). The data presented are expressed as mean ± SD, with statistical significance indicated as *P < 0.05, **P < 0.01, and ***P < 0.001