Abstract 6210: Loss of inflammation-related genes and inflammation inhibitors effectively targets ER- breast cancer cell metastasis

Abstract

Abstract The anti-estrogen tamoxifen is a highly effective hormonal therapy for hormonal (HR+) breast cancer patients. However, the estrogen receptor-negative, progesterone receptor-positive (ER-/PR+) subtype does not receive the benefits of tamoxifen. Therefore ER-/PR+ breast cancer have a poor clinical outcome, but drug development for ER-/PR+ breast cancer is not well studied. Here, we found that gene expression in ER-/PR+ HR+ breast cancer is positively related to triple negative breast cancer (TNBC) and not HR+ breast cancer using 4,319 breast cancer patients database. Especially, inflammation-related genes, A20/TNFAIP3, CDC20 and CASP1/Caspase-1, which are highly expressed in TNBC, are also upregulated in ER-/PR+ HR+ breast cancer. Suppression of A20/TNFAIP3, CDC20 and CASP1 inhibit cancer cell growth and metastasis in ERα KO (ER-/PR+) cell lines. Interestingly, loss of ERα in HR+ cell lines is not responsive to tamoxifen, but highly sensitive to inflammation inhibitor, Ac-YVAD-CHO. In in vitro and ex vivo models, inflammation inhibitor specifically blocks ER-/PR+ tumor proliferation and migration. These findings suggest that the inflammation inhibitor might be the first potential target therapy for ER-/PR+ HR breast cancer patients. Citation Format: Chaeun (Christine) Song, Val J. Lowe, SeungBaek Lee. Loss of inflammation-related genes and inflammation inhibitors effectively targets ER- breast cancer cell metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6210.