Fig. 1: RACK1 is required for breast cancer cell proliferation in vitro and tumor growth in vivo. | Cell Death & Disease

Fig. 1: RACK1 is required for breast cancer cell proliferation in vitro and tumor growth in vivo.

From: RACK1 facilitates breast cancer progression by competitively inhibiting the binding of β-catenin to PSMD2 and enhancing the stability of β-catenin

Fig. 1

A–B Western blotting (A) and qRT-PCR (B) analysis of RACK1 expression in lentivirus-infected MDA-231 and BT549 cells expressing RACK1-specific shRNAs. C CCK8 analysis of the effect of RACK1 knockdown on the proliferative capacity of two breast cancer cell lines (two-way ANOVA test). D Colony formation assay showed that RACK1 knockdown decreased the proliferation rate of breast cancer cells. E, F Western blotting (E) and qRT-PCR (F) analysis of RACK1 expression in control, RACK1-silenced cells and RACK1-silenced cells after infection with lentivirus expressing RACK1-Flag in MDA-231 cells. G–H CCK8 (G) and colony formation (H) analysis of the proliferative capacity of control (n = 3), RACK1-silenced cells and cells with restored RACK1 expression in MDA-231 cells. I Tumor growth curves of mice inoculated with MDA-231 cells expressing different levels of RACK1 (n = 6). J Representative images of tumors from mice inoculated with the indicated MDA-231 cells. K The weight of tumors in the RACK1 knockdown group was significantly smaller than those in the control and rescued groups. L Hematoxylin and eosin (HE) and immunohistochemical (IHC) staining of Ki67 in paraffin sections of mouse tumor specimens. Scale bar, 50 μm. M Facet boxplot showed that the protein level expression of RACK1 was upregulated in breast cancer (BRCA) patients (n = 133) compared to normal tissues (n = 18) in the TCPA database (P < 0.05, LogFC > 1). N RACK1 was positively correlated with Ki67 expression in breast cancer tissues in the TCPA database. O, P Analysis of the Project Score database (based on genome-wide pooled CRISPR knockdown screen) revealed that RACK1 is a core fitness gene in almost all cell lines (O) and breast cancer cell lines (P). Q Cell cycle analysis showed that knockdown of RACK1 resulted in a significantly increased proportion of G2/M phase. R Western blot analysis of cyclin B1, cyclin D1 and cyclin E1 expression in control and RACK1-silenced breast cancer cells. The relative expression of the proteins was quantified by grayscale using Image J software. All data are expressed as the mean ± SD; *p < 0.05. **p < 0.01, ***p < 0.001, ****p < 0.0001 and ns p > 0.05 versus control, N = 3.

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