Differential gene expression of eutopic endometrium and normal pelvic peritoneum in women with and without endometriosis

Abstract

Scope and Method of Study: To investigate differential gene expression in women with and without endometriosis. Women already undergoing laparoscopic surgery were recruited as normal and potential endometriosis participants. The normal participants were those women undergoing laparoscopic bilateral tubal ligation, and the endometriosis participants were those undergoing diagnostic laparoscopy to evaluate chronic pelvic pain. Sample collection included an endometrial aspiration, normal pelvic peritoneum, peritoneal fluid, and endometriotic lesion (in those with endometriosis). Total RNA was extracted from tissue samples and put through one round of amplification in the normal pelvic peritoneum studies. Human oligo microarrays with over 21,000 genes were utilized in the analysis. Pooled RNA from normal participants was hybridized against RNA from each endometriosis participant. Microarray analysis was performed utilizing GenePix Pro and GenePix Auto Processor. Microarray results were validated utilizing RT-PCR.

Findings and Conclusions: Seven women with and seven women without endometriosis were utilized in the microarray studies. In the comparison of gene expression in eutopic endometrium, 756 genes were found to be significantly up-regulated or down-regulated in the women with endometriosis versus a normal pool. KEGG pathway analysis revealed genes involved in the following pathways: cell communication, MAPK signaling, cytokine-cytokine receptor interaction, cell cycle, TGF-beta signaling, focal adhesion, cell adhesion, and ECM-receptor interaction. In the comparison of gene expression in normal pelvic peritoneum, 202 genes were found to be significantly up-regulated or down-regulated in women with endometriosis versus those without. These genes are involved in the following pathways: cytokine-cytokine receptor, cell cycle, focal adhesion, regulation of actin cytoskeleton, and leukocyte transendothelial migration.