ARID1A expression is down-regulated by oxidative stress in endometriosis and endometriosis-associated ovarian cancer

Oxidative stress is considered an important factor in the development of endometriosis, including its malignant transformation. Previous studies have found that AT-rich interactive domain 1A (ARID1A), a tumor suppressor gene, is frequently mutated and inactivated in endometriosis-associated ovarian cancer (EAOC), and such a change in this gene is considered an early event in malignant transformation. We observed oxidative stress status by measuring the activity of the antioxidant enzyme manganese superoxide dismutase (MnSOD), malondialdehyde (MDA), and ARID1A gene expression in tissue samples from patients with endometriosis, EAOC, or non–endometriosisassociated ovarian cancer (non-EAOC). We also induced oxidative stress in the cultured cells from patients with primary endometriosis by adding H₂O₂ and tested for any alteration of ARID1A gene expression based on different H₂O₂ concentrations. The results showed that MnSOD activity in endometriosis and EAOC was lower than in non-EAOC, but MDA levels were higher. This study also showed that oxidative stress reduced ARID1A gene expression.