Cell culture

Human endometrium epithelial cells (EEC) were purchased from BeNa Culture Collection (Beijing, China) and cultured in Eagle's minimum essential medium with 10% FBS. Human endometrial cancer Ishikawa and RL95-2 cells were purchased from Shanghai GeneChem Co., Ltd. Cells were cultured in DMEM supplemented with 10% FBS at 37°C in a humidified atmosphere with 5% CO₂. For siRNA transfection, when confluence reached 80–90%, cells were transfected with negative control siRNA, (5′-AGCAUGCAUGAGUACCCAGCC-3′) or CACNA2D3 siRNA (5′-CUGCGUUUGCAGACAAUCUAA-3′) using Lipofectamine^® 3000 (Invitrogen; Thermo Fisher Scientific, Inc.) according to the manufacturer's protocol. After 48 h, transfected cells were prepared for subsequent experiments.