PARENT SESSION

(M550) VALIDATION OF AN ANIMAL MODEL OF ENDOMETRIOSIS USING DNA MICROARRAYS.

Ruiz, Lynnette¹, Appleyard, Caroline¹, Rivera, Elizabeth¹, Santiago, Olga¹, Flores, Idhaliz¹, ¹ Ponce School of Medicine, Ponce, Puerto Rico

ABSTRACT- The etiology of endometriosis is unknown and the early steps in the pathogenesis of this disease still require elucidation. Animal models have been proposed as a feasible alternative to study the initiating events leading to survival and establishment of endometriotic implants in ectopic sites. However, it has been debated whether nonprimate animal models accurately represent the disease. The aim of this study was to validate a rat model of endometriosis using DNA microarrays. Endometriosis was surgically-induced by suturing uterine horn implants next to the mesentery of the small intestine. Control rats received sutures with no implants. After 60 days, tissues (endometriotic implants and uterus) were obtained and total RNA was isolated using standard protocols (Trizol, Invitrogen). Total RNA from four endometriotic implants was pooled and Cy5-labeled cDNA was synthesized, while Cy3-labeled cDNA was synthesized using uterine RNA from a control rat. Gene expression levels were analyzed after hybridizing experimental and control labeled cDNA to PIQOR™ Toxicology Rat Microarrays (Memorec Biotec) containing 1252 genes. Cy5/Cy3 ratios were determined and genes with ≥2-fold higher or ≤0.5-fold lower expression levels were selected as significantly differentially-expressed. We observed increased expression of genes which have previously been shown to be upregulated in endometriosis patients, including growth factors, inflammatory cytokines/receptors, tumor invasion/metastasis factors, adhesion molecules, and anti-apoptotic factors. In conclusion, this study presents evidence in support of this surgically-induced rat model as an appropriate and invaluable tool to study the natural history of endometriosis.

KEY WORDS: endometriosis, animal model, DNA microarrays, rat