Fig. 2: TCOF1 promotes TNBC spheroid growth and tumour growth in vivo.

a MDA-MB-468 and HCC1806 cells expressing tet-on TCOF1 gRNA or vector control (CTL) were treated with doxycycline (dox; 100 ng/ml) for 5 days. Whole-cell lysates were subjected to immunoblotting. Experiments in a were repeated >3 times independently with similar results. b MDA-MB-468 and HCC1806 cells with or without TCOF1 knockout were cultured for colony-formation assay for 14 days. Representative images are shown. Colony number was counted and depicted in the bar graph. Error bars, mean ± SEM of three independent experiments. **p < 0.01; ***p < 0.001. c Schematic of 3D CellTiter-Glo assay. Left panel, representative pictures of spheroids. Bar graphs depict growth of MDA-MB-468 and HCC1806 spheroids with or without TCOF1 knockout. Error bars, mean ± SEM of three independent experiments. ***p < 0.001. d MDA-MB-468 cells expressing TCOF1 with a mutation on PAM sequence (TCOF1 mut) or control vector were infected with tet-on TCOF1 or CTL gRNA. Cells were cultured in 3D for 6 days, followed by 3D CellTiter-Glo assay. Error bars, mean ± SEM of three independent experiments. **p < 0.01; ***p < 0.001. Whole-cell lysates were subjected to immunoblotting. e Table summarising the effect of TCOF1 knockout on spheroid growth of different TNBC lines. f, g MDA-MB-468 xenograft growth (f) and tumour weight (g) upon TCOF1 knockout. Error bars, mean ± SEM (number of tumour of each condition n = 7). *p < 0.05; **p < 0.01. h Picture of MDA-MB-468 tumours. i, j HCC1806 xenograft growth (i) and tumour weight (j) upon TCOF1 knockout. Error bars, mean ± SEM (number of tumour of each condition n = 6). **p < 0.01. k Picture of HCC1806 tumours. p values were calculated by two-sided Student’s t test in b–d, f, g, i, j.