Fig. 4: USP27X promotes the proliferation, invasion and metastasis of BC cells by up-regulating CBX2.

A, B In MCF7 cells, three independent shRNAs were used to knock down CBX2. CBX2 was overexpressed in BT549. A CBX2 protein expression level was detected by IB analysis, and (B) CBX2 mRNA level was detected by qRT-PCR analysis. C USP27X was knocked down in CBX2-overexpressing MDA-MB-231 cells. CBX2 was knocked down in BT549 cells overexpressing USP27X. Cell growth was examined by colony formation. D Cell treatment with ctrl, two USP27X shRNA (1&2) and USP27X shRNA (1&2) + overexpressed CBX2, leads to a significant decrease and increase of the colony number. E Cell treatment with vector, overexpressed USP27X and overexpressed USP27X + CBX2 shRNA leads to a significant increase and decrease. F The indicated cells were subcutaneously injected (1 × 10⁶ cells per mouse) into nude mice (n = 5) of MDA-MB-231. Tumor growth curve (G) and weight (H) were analyzed. I The indicated cells were subcutaneously injected (1 × 10⁶ cells per mouse) into nude mice (n = 5) of BT549. Tumor growth curve (J) and weight (K) were analyzed. L–N The indicated cells were injected into the mammary fat pad of female NOD-SCID mice (5-6 weeks old, n = 6) of BT549 and MDA-MB-231 (L). The number of pulmonary metastatic nodules was counted and quantified of BT549 (M) and MDA-MB-231 (N). Data are represented as mean ± SD of three independent experiments. ***P < 0.001, 1-way ANOVA with Dunnett’s post test (B, D, E, G, H, J, K, M, N).