Abstract
Purpose: To explore differential gene expression between autologous eutopic and ectopic endometrium and the effect of phases, infertility, and severity of disease on this.
Methods: cDNA arrays followed by post hoc analysis for 1190 selected human genes were performed to analyze transcript expression in autologous eutopic and ectopic endometrial samples obtained from 6 proven fertile and 4 subfertile volunteers with endometriosis (stage 3: n=5; stage 4: n=5) during either the proliferative (n=7) or secretory (n= 3) phase.
Results: cDNA-based expression array analysis appeared sensitive, precise, and reliable in unsupervised analysis and quantitative RT-PCR. Sample clustering analysis revealed maximal cluster coefficient (C=0.8) between eutopic and ectopic clusters for all pairs, followed by that yielded by phases of cycle (C=0.6); fertility history (C=0.3), and stages of severity (C=0.3) had marginal effects. Of 42 genes showing differential regulation in pooled analysis, 3 genes (CAGA, MT2A, and VIM) were up-regulated and 39 genes including EPHA2, FOXM1, HPSE, ITGA5, ITGAE, ITGB3, PAEP, and TGFBR1 were down-regulated in ectopic endometrium. The high transcript number of AFP, ALOX15, F2RL1, and PRKCG in proliferative phase eutopic endometrium appears to be a potential biomarker for endometriosis.
Conclusions: Differential expression of specific genes appeared as distinguishing features for ectopic endometrium compared with eutopic endometrium; many of them might be associated with poor cellular integrity of endometriotic cells. However, ectopic endometrium did not show overt molecular indication of tumorigenic potential.