All animal studies were performed in the Laboratory Animal Center of Sun Yat-sen University and conducted in accordance with the institutional policies for animal care. Approximately 5 x 10⁶ MMQ_vector cells or MMQ_circOMA1 cells in 150 uL were injected into the right flank of BALB/c nude mice (total of 12 female mice, 4-6 weeks, SCXK2021-0029). After tumor formation (10 days), mice were randomly divided into four groups (n = 3 mice/group) as follows: vector (saline solution, intraperitoneally injected), circOMA1 (saline solution, intraperitoneally injected), vector + CAB (0.5 mg/kg, intraperitoneally injected), and circOMA1 + CAB (0.5 mg/kg, intraperitoneally injected) in accordance with previous studies. CAB was injected intraperitoneally every 2 days for 14 days. The size of the tumor was measured every 3 days. On Day 15, mice were anesthetized with 0.3% pentobarbital sodium solution and then sacrificed by cervical dislocation, and the xenograft tumors were removed and weighed.

Seven-to-8-week-old C57BL/6 female mice were obtained and 17-b-estradiol-3-benzoate (30 ug/kg, Sigma) was administered to each mouse every day for 3 days. We removed uterine horns from the donor mice and added them to saline. Endometrium was cut into 1 mm2 fragments. The endometrial fragments from each uterine horn were suspended in 0.3 ml saline and injected into the peritoneal cavities of recipient mice with an 18-gauge needle. At 8 days (5 days after the operation), endometrial-like lesions were established, and they were randomly divided into two groups (each group contained 12 mice). In the experimental group, each mouse received erastin (20 mg/kg/day) by intraperitoneal injection over a 7-day period. In the control group, DMSO was used instead of erastin.