Figure 1. Gene expression differences in healthy and endometriotic stroma.

Gene expression in normal endometrial stromal cells (EIUM; n = 6) and endometriotic stromal cells (OSIS; n = 6) treated with (+) or without (−) IVD was examined by (A) principal component analysis and (B) hierarchical clustering based upon on the 45,429 probes from the gene expression array (letters B, G, H, I, L, and M denote EIUM; O, P, Q, R, U, and X, denote OSIS). (C) The morphological features of EIUM and OSIS with and without IVD are shown using H&E (left 4 panels) and by immunofluorescence for ACTA2 counterstained with DAPI (right 4 panels). Scale bars represent 50 µm. Based on the array, differentially expressed genes were identified between (D) healthy and diseased cells, matched for IVD treatment and also as (E) a consequence of IVD for each cell type. The Venn diagrams show the total numbers of up- and downregulated genes identified in each comparison. A signature panel of key genes identified from these comparisons was validated by qPCR in the panels on the right. The disease status was the main effect impacting gene expression of ESR1, PGR, NR5A1, ALDH1A2, MMP11, and HOXC6 (connecting bars; p<0.05; 2-way ANOVA). A significant interaction was observed between disease status and IVD treatment for ESR2, CYP19A1, FOXO1, HAND2, PRL, and IGFBP1 (lower case letters indicate significantly different groups; p<0.05; Tukey's).