Fig. 3

pRNA-EGFRapt-siXBP1 NPs silenced XBP1 expression, sensitizes MDA-MB-231 cells to doxorubicin treatment in vitro, reduces cell viability, impairs mammospheres forming ability, but not alters cell apoptosis and cell cycle. a RT-PCR result of XBP1 gene expression in MDA-MB-231 cells after treated with 50 nM NPs. (mean ± s.d., n = 3). ***, p < 0.001. b Western blot analysis of XBP1s and XBP1u expression in MDA-MB-231cells after pRNA-EGFRapt-siXBP1 NPs treatment for 72 h. c Flow cytometry analysis of MDA-MB-231 cells cell cycle alteration after treated by pRNA-EGFRapt-siXBP1 or pRNA-EGFRapt-siScr control, respectively. (mean ± s.d., n = 3). d Cell apoptosis determined by annexin V and 7AAD staining. e Cell viability analysis of MDA-MB-231 cells after treated by NPs or NPs plus dox for 72 h. (mean ± s.d., n = 5–7). ***, p < 0.001. f Quantification of soft agar colony formation in different groups. (mean ± s.d., n = 3). **, p < 0.01. **