Supplementary Material for: BIBR1532 affects endometrial cell proliferation, migration and invasion in endometriosis via telomerase inhibition and MAPK signaling

Objectives: The effect of telomerase inhibitor BIBR1532 on endometriotic cells was investigated to explore the inhibitory effect of targeting telomerase on endometriosis. Design: In vitro primary cell culture study. Participants/Materials: Primary endometrial cells derived from eutopic and ectopic endometrium in patients with endometriosis. Setting: University hospital. Methods: Paired eutopic and ectopic endometrial cells were collected from 6 patients from January 2018 to July 2021. A TRAP assay was performed to detect the telomerase activity of the cells. MTT, cell cycle, apoptosis, migration and invasion assays were performed to study the inhibitory effect of BIBR1532. Enrichment analysis was performed to identify the key pathways involved in endometriosis progression and telomerase action. Then, western blotting was used to investigate the expression of related proteins. Results: BIBR1532 treatment significantly inhibited the growth of eutopic and ectopic endometrial cells, with apoptosis and cell cycle signaling involved. Migration and invasion, important characteristics for the establishment of ectopic lesions, were also inhibited by BIBR1532. The MAPK signaling cascade, related to telomerase and endometriosis, was decreased in eutopic and ectopic endometrial stromal cells with the treatment of BIBR1532. Limitations: The severe side effects of telomerase inhibitors might be the main obstacle to clinical application, so it is necessary to find better drug delivery methods in vivo. Conclusions: The telomerase inhibitor BIBR1532 affects endometrial cell proliferation, migration and invasion in endometriosis.