Fig 1: SPEN is coexpressed with RFX3 in breast cancer. a Growth curve of MCF10A cells treated with siRNA control or siRNA for SPEN. Data points represent the mean fluorescence values (±SEM) of three experiments performed in quadruplicates. b Cell cycle analyses performed with MCF10A cells treated with siRNA control or siRNA for SPEN. Bar graph represents the mean percentage of cells (±SEM) in each phase of the cell cycle in three independent experiments. c Growth curve of Hs578T cells treated with siRNA control or siRNA for SPEN. Data points represent the mean fluorescence values (±SEM) of three experiments performed in quadruplicates. d Cell cycle analyses performed with Hs578T cells treated with siRNA control or siRNA for SPEN. Bar graph represents the mean percentage of cells (±SEM) in each phase of the cell cycle in three independent experiments. e Venn diagram showing the intersection of the list of genes coexpressed with SPEN in T47D clones, genes downregulated by SPEN knockdown in MCF10A cells, and a curated list of genes involved in ciliary biology. The microarray data for this study can be found on ArrayExpress under the accession numbers [E-MTAB-4974 and E-MTAB-4975]. f Dot plot showing that SPEN and RFX3 RNA expression levels are strongly correlated in a cohort of 82 primary tumors from patients with triple-negative breast cancer. g Representative immunoblot (IB) showing RFX3 protein levels in T47D-CTL and T47D-SPEN as well as immunoprecipitated (IP) RFX3 protein levels in MCF10A and Hs578T cells treated with siRNA control or siRNA against SPEN. h Endpoint PCR performed on DNA immunoprecipitating with SPEN in T47D-SPEN and T47D-CTL, showing an interaction of SPEN with the RFX3 promoter in T47D-SPEN but not in T47D-CTL cells. *** P = 0.005; ** P = 0.01; * P = 0.05. siRNA Small interfering RNA, SPEN Split ends