Reactive oxygen species downregulate ARID1A expression via its promoter methylation during the pathogenesis of endometriosis.

OBJECTIVE: Oxidative stress caused by reactive oxygen species (ROS) plays an important role in the pathogenesis of endometriosis. The gene AT-rich interactive domain 1A (ARID1A), is frequently down regulated and inactivated in endometriosis. This report is focused on the molecular mechanism of the correlation between oxidative stress and ARID1A gene expression in endometrial cell oxidative damage model.

PATIENTS AND METHODS: In this study, the ARID1A gene expression level and its promoter methylation level were detected in 30 endometriosis and normal tissues. The primary endometrial cell was co-cultured with H2O2. Then, MDA and Gpx level were used to test the ROS level, RT-PCR was employed to detect the expression level of ARID1A. At last, the ARID1A gene promoter methylation level was detected by methylation-specific PCR (MSP). Finally, the expression level of DNMT1 was detected by both RT-PCR and Western blot.

RESULTS: The expression level of ARID1A gene was down regulated in endometriosis compared with normal tissues. The low expression level of ARID1A gene was associated with its promoter hyper-methylation. In H2O2 simulated endometrial cells, ARID1A gene expression level was decreased. Finally, ROS regulated ARID1A gene expression by changing the methylation level of ARID1A gene promoter. Finally, both the mRNA level and protein level of DNMT1 increased in H2O2 simulated endometrial cells.

CONCLUSIONS: In endometriosis, the down-regulated ofARID1A gene was highly correlated with its promoter hyper-methylation. ROS decreased the expression level of ARID1A gene via regulating methylation of its promoter which contributing to the understanding of the pathogenesis of endometriosis. The possible mechanism of ARID1A gene promoter hyper-methylation is ROS up-regulated DNMT1gene expression.