Fig. 4: JQ1 represses BRD4/FOXD3-maintained miR-548d-3p expression.

a Real-time PCR assay was conducted to detect the expression of miR-548d-3p and miR-548d-5p with or without JQ1 (1 μM) treatment in BLBC cells. b Real-time PCR assay was performed to measure the expression of miR-548d-3p in shRNA control and BRD4-knockdown clones of MDA-MB-231 and BT549 cells. c Wild-type and miR-548d-3p-recognition-mutant JUND 3′UTR luciferase reporters were transfected into MDA-MB-231 and BT549 cells with or without miR-548d-3p mimic. Data are reported as mean ± SD. d JUND mRNA expression was examined in BLBC cells by real-time PCR assay in the absence or presence of mimic or inhibitor of miR-548d-3p. e Cell growth was detected with or without miR-548d-3p mimic in BLBC cell lines by CCK8 assay. Statistical data (mean ± SD) are shown (**P < 0.01, one-way ANOVA). f CCK8 assay was done to detect the effect of miR-548d-3p inhibitor on JQ1 in BLBC cell lines. Statistical data (mean ± SD) were shown (**P < 0.01, one-way ANOVA). g Luciferase assay was performed in HEK293T cells transfected with WT or deleted MIR548D1 promoter luciferase construct and FOXD3 or BRD4 plasmid. Data are showed as mean ± SD. h Luciferase assay was examined in BRD4-knockdown, FOXD3-knockdown or JQ1-treated MDA-MB-231 and BT549 cells. Data are reported as mean ± SD. i Endogenous FOXD3 or BRD4 was pulled down by specific antibodies in MDA-MB-231 cells to observe the FOXD3/BRD4 interaction as detected by immunoprecipitation-western blots. j Sequential chromatin immunoprecipitation-QPCR assays were done to measure the enrichment of BRD4 and FOXD3 at the MIR548D1 gene promoter in control, JQ1 (1 μM) treated, or FOXD3-knockdown BLBC cells. k Real-time PCR assays were done to examine the expression of miR-548d-3p in vector control and FOXD3-knockdown MDA-MB-231 and BT549 cells. l CCK8 assays were done in vector control or FOXD3-knockdown BLBC cells. Data are reported as mean ± SD (**P < 0.01, ***P < 0.001; one-way ANOVA). Source data are provided as a Source Data file.