Abstract 3049: Similarities between ovarian cancer and endometriosis: The role of STAT3

Abstract Endometriosis is a painful gynecological disease that affects over 190 million women worldwide. This disease is classified by the presence of endometrial-like cells growing in and around the female reproductive system. Instead of lining the uterus, these ectopic cells shed off and cluster together forming lesions that attach to different surfaces of the female reproductive system. In particular, endometriosis cells interact with and form lesions within the mesothelial cells that line the peritoneum. There is currently no cure, and many of the therapies aiming to help with pain management come with unfavorable tradeoffs. Our research on ovarian cancer led us to investigate potential overlapping characteristics with endometriosis. Growing ovarian cancer cells in 3D causes spheroids to form which mimic the physical features of tumors and are also able to better represent cell-cell and cell-environment interactions. Analysis of the endometriosis cell lines 12Z and hEM3 demonstrated that they could also form spheroids. As both ovarian cancer cells and endometriosis cells interact with mesothelial cells, we wanted to determine if endometriosis spheroids were able to clear the mesothelial layer comparable to ovarian cancer spheroids. Evaluation of 12Z and hEM3 cell lines demonstrated that endometriosis spheroids were able to undergo mesothelial clearance. While the exact cause of endometriosis is not known, different proteins have been identified as important factors in the progression of endometriosis. The Signal Transducer and Activator of Transcription 3 (STAT3) is a transcription factor involved in cell differentiation, proliferation, apoptosis resistance, angiogenesis, and metastasis. In endometriosis cell lines, STAT3 is constitutively active, which makes it a promising potential therapeutic target. To verify that STAT3 is important in endometriosis, siRNA was used to reduce the expression of STAT3 in two endometriosis cell lines, 12Z and hEM3. Both cell lines showed a decrease in cell viability. In addition, reducing the expression of STAT3 in the endometriosis cells appeared to decrease mesothelial clearance ability. Our lab previously identified statins as potential STAT3 inhibitors by using the Broad Institute’s CLUE tool. After statin treatment, 12Z and hEM3 spheroids showed a decrease in cell viability and clearance ability. Taken together, these data suggest that STAT3 plays a key role in endometriosis and that the repurposing of statins may provide a benefit to patients with endometriosis. Citation Format: Allison A. Kloeckner, Sarah R. Walker. Similarities between ovarian cancer and endometriosis: The role of STAT3 abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 3049.