GATA3 controls luminal breast cancer predominantly through differential regulation of DACH1, THSD4 and BCL2 genes. (A-D) Expression levels of GATA3 target genes stratify patients by ER status in the same cohorts of patients as used in Figure 1. Each sub-figure presents two patient groups. P-values are presented at the upper-left corner of each graph. (E) GATA3 has opposite effects on THSD4, BCL2 and DACH1 in normal cells and cancer cells, respectively. Expression levels of specified genes after transfections of GATA3 relative to vector into indicated cells are presented. (F) Upregulation of THSD4, BCL2 and DACH1 by GATA3 is independent of ER expression: relative levels of the indicated genes after transfection of GATA3 or empty vector into MDA-MB-231 cells are presented. (G) Deregulation of THSD4, BCL2 and DACH1 during tumorigenesis: hMEC were transformed by sequential introduction of the three genetic elements detailed in the figure. Effect of GATA3 expression at each step was assessed as above. (H) Representative expression of GATA3 following transfection. Results shown in figures E-G are average ± standard error of three to five independent experiments. (*) P-value <0.1; (**) P-value <0.05. ER, estrogen receptor; GATA3, GATA binding protein 3; hMEC, human mammary epithelial cells.