Figure 5.

Intracellular cholesterol involves in maintenance of BCSC stemness. A,B) Intracellular cholesterol was measured in lnc030‐knockdown (A) or SQLE‐knockdown (B) Hs578T, BT549, MCF‐7 derived spheres and their control spheres. Data are shown as means ± SD (*p < 0.05, **p < 0.01). C) Cholesterol amount in the randomly selected breast tumor tissue and their matched non‐tumor tissues were measured. Data are shown as means ± SD (n = 10, * p < 0.05, ** p < 0.01). D) The cholesterol concentration in lnc030 high or low expression BC tissues were measured. Data are shown as means ± SD (n = 40, ** p <0.01). E, F) c‐Myc and KLF4 proteins were detected by Western blotting in lnc030‐knockdown (E) and control BCSCs (F) under treatment with or without cholesterol (labeled Cho) at 5, 10, or 15 µM for 48 h. G,H) Sphere‐formation potentials were detected for the Lnc030‐knockdown and control breast cancer cells. Lnc030‐silenced cells were treated with cholesterol at 5, 10, or 15 µM for every 3 days in the suspend culture G) (a, p < 0.01, versus shNC + vehicle; b, p > 0.05, versus shNC + vehicle; ns, p > 0.05, versus sh lnc030#1 + vehicle; ** p < 0.01, versus sh lnc030#1 + vehicle; Scale bar, 100 µm); the control cells were treated with the optimum concentration (10 µM) of cholesterol(H) (**p < 0.01, sh lnc030 versus shNC; Scale bar, 100 µm). I) ALDH activity in breast cancer tissues with low or high levels of cholesterol was detected (n = 40, p < 0.0001).