Abstract 5474: A new class of histone deacetylase inhibitors alleviate breast cancer cells growth and invasion capacity by targeting TIMP/MMP signaling

Background: Mounting epidemiological and experimental evidences strongly suggest that epigenetic processes including histone modifications are involved in the development of drug resistance in breast cancer. Histone deacetylases (HDACs) selective inhibition is an important strategy of anticancer drug discovery field. However, lack of HDACs isozymes selective inhibitors associated with adverse side effects that limits their clinical applications. We have recently reported new and selective HDACs inhibitors displaying varying HDAC isozyme selectivity degrees that resulted in increased histones acetylation and apoptosis induction in cancer cells. In the present study, we investigated molecular mechanisms underlying anticancer potential of these molecules in breast cancer cells. Experimental methods: Proliferation ability, invasion capacity, matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMP) major group’s gene expressions and protein levels, and the gelatinolytic activity of MMPs were analyzed after treatment of MCF-7 and MDA-MB-231 breast cancer cell lines with HDACs inhibitors compounds. Results and Discussions: Two compounds, identified as MAL-4 and MAL-5, were selected based on the half-maximal inhibitory concentration (IC50) in both breast cancer cells. Treatment of MCF-7 and MDA-MB-231 breast cancer cells with 5 µM MAL-4 and MAL-5 significantly induces TIMP-2 mRNA and protein levels whereas MMP-2 and MMP-9 content and activities were reduced. Further analyses showed that MAL-4 and MAL-5 attenuated invasion capability of breast cancer cells. Conclusion: We have demonstrated that the new compounds can be used as potential lead drug candidates for an effective anti-metastatic therapy mediated by HDAC inhibition in breast cancer. Citation Format: Khuloud Bajbouj, Lina Sahnoon, Abeer AL-Ali, Jasmin Shafarin, Leonie Binder, Reem Abdul Rehman, Rafat El-Awady, Taleb H. Al-Tel. A new class of histone deacetylase inhibitors alleviate breast cancer cells growth and invasion capacity by targeting TIMP/MMP signaling [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 5474.