Fig. 4

B7-H4 deficiency enhances breast cancer stem cells and chemoresistance. A–D In vivo tumorigenicity of breast cancer cells was performed in the subcutaneous xenograft mouse model at limiting dilutions. Tumors were isolated from nude mice 25 days postinoculation, and then, tumor mass and tumor xenograft rate were calculated (A, C). Tumor diameters in SKBR3 (B) and MDA-MB-231 (D) with or without B7-H4 KO and OE were measured every other day after xenografting. E The methylation markers DNMT1 and SETDB2 were examined by qPCR. F Immunofluorescence investigated the expression levels of H3K27me3 in SKBR3-WT and SKBR3-KO cells. Scale bar = 10 μm. G Quantifying IC50 values of commonly used chemotherapeutic agents on SKBR3-WT and SKBR3-KO cells were investigated by using MTT assay. Dox: Doxorubicin; Oxa: Oxaliplatin; 5-Fu: Fluorouracil; and Gef: Gefitinib. Data are represented as mean ± SEM of three independent experiments, and tumor xenograft rate was calculated by chi-squared test. Statistical assessment of the tumor growth curves was determined by one-way ANOVA (B and D). (*p < 0.05)