Fig. 6

Knockdown of FOSL1 inhibits spheroid growth and stemness of TNBC. (A) Schematics of FOSL1 knockdown by lentiviral infection and 3D culture. HCC1806 cells expressing FOSL1 or control shRNAs were cultured in 3D for 7 days and images were captured. Bar graphs depict the growth of 3D spheroids. Data, mean ± SEM: ***, p < 0.001 (n = 3). (B) Schematics of FOSL1 knockdown by lentiviral infection and mammosphere formation assay. HCC1806 cells expressing FOSL1 or control shRNAs were seeded for mammosphere formation assay. Representative images of mammosphere are shown and the bar graph depicts the numbers of mammosphere. Data, mean ± SEM: ***, p < 0.001 (n = 3). (C) ALDH activity of cells derived from HCC1806 with or without FOSL1 knockdown, measured by AldeRed ALDH Detection assay. Cell populations with high ALDH activity were quantified and depicted in bar graphs. Data, mean ± SEM: **, p < 0.01; ***, p < 0.001 (n = 3). (D) RT-qPCR showed the mRNA level of ALDH1A1 in control or FOSL1-depleted HCC1806 cells. Data, mean ± SEM: ***, p < 0.001 (n = 3). (E) HCC1806 cells expressing TCOF1 or empty vector were infected with control or FOSL1 shRNAs. Cells were continued to culture for 2 days, and then subjected to Western blot analysis for FOSL1 and TCOF1 or mammosphere formation assay. Data, mean ± SEM: *, p < 0.05 (n = 3)