Fig. 2

CircRNA-CREIT significantly enhanced the chemosensitivity of TNBC cells in vitro and in vivo. A GO analysis of differentially expressed genes in circRNA-CREIT-overexpressing MDA-MB-231 cells based on RNA-seq data. B Violin plot showing circRNA-CREIT expression in chemosensitive and chemoresistant breast cancer tissues, detected by qRT-PCR assays. C ISH assay of circRNA-CREIT in chemosensitive and chemoresistant breast cancer tissues. Scale bars = 200 μm. D The impact of circRNA-CREIT overexpression on the cytotoxic effects of DOX is shown. Cell viability was detected by MTT assays. The IC50 values with the 95% CIs are presented. E Western blotting was performed to detect the expression of apoptosis pathway markers. F Images of the xenograft tumors. Scale bars = 10 mm. G Growth curves of xenograft tumors in different groups after treatment. H The tumor weights of the xenograft tumors. I Representative images of IHC staining for Ki67 and cleaved caspase-3 in different groups. Scale bars = 100 μm. J Representative morphologies of breast cancer patient-derived organoids (PDOs) treated with increasing DOX concentrations. Scale bars = 200 μm. K The IC50 values and 95% CIs of the PDOs are shown. Cell viability was measured by CCK8 assays. L Heatmap showing the IC50 value and relative circRNA-CREIT expression level of each PDO. Three independent experiments were conducted for each result. *p < 0.05; **p < 0.01; ***p < 0.001 compared with the controls