Fig. 2.

PC4 knockdown suppresses breast cancer cell growth both in vitro and in vivo. a Gene Set Enrichment Analysis (GSEA) comparing the gene sets of Proliferation in PC4^high (n = 78) and PC4^low (n = 77) breast cancer patients. Data was obtained from GSE9893. NES means normalized enrichment score. b Two shRNAs (shPC4–1 and shPC4–2) were used to establish the stable PC4 knockdown cell lines (MDA-MB-231 and MCF-7 cells). The PC4 knockout efficiency were examined by western blot. c Cell viability of MDA-MB-231 and MCF-7 cells was measured using CCK-8 assay at 24 h, 48 h, 72 h and 96 h after PC4 knockdown. d The clone formation assay of MDA-MB-231 and MCF-7 cells after PC4 knockdown. e Statistical analysis of the data derived from (d). Experiments were repeated three times independently. f MDA-MB-231 cells with stable PC4-knockdown were inoculated into female nude mice. Tumor growth curves were measured every 2 days, and the tumor volume was estimated using the following formula: volume = length×width²/2. g and h The dissected xenografts were photographed and weighed at the endpoint. All data indicate the mean ± SD. *p < 0.05, **p < 0.01