Abstract 3833: Antitumor activity of novel reversible LSD1 inhibitor in preclinical models of AML and SCLC

Abstract

Abstract Introduction: Global changes in the epigenetic landscape are known as the hallmark in cancer and the histone demethylase Lysine-specific demethylase 1 (LSD1) is one of the novel targets for the therapy of various malignant diseases. Also LSD1 overexpression is associated with poor prognosis in various cancers. LSD1-mediated epigenetic modification is known to play a key role in the regulation of gene expression by removing the methyl groups from methylated lysine 4 and lysine 9 of histone H3. Alterations in histone methylation lead to aberrant silencing of expression of multiple genes involved in tumor survival and in cell cycle. Moreover, epigenetic dysregulation plays a critical role in pathogenesis of various types of cancers such as acute myeloid leukemia (AML) or small cell lung cancer (SCLC). In this study, we have characterized a novel LSD1 inhibitor and assessed its potential as a novel therapy for AML and SCLC patients. Materials and Methods: Novel LSD1 inhibitor, HM97211 and its derivatives were designed and synthesized as the active biologic inhibitory compound against the AML and SCLC cells. Biochemical enzyme assay was performed to identify enzyme selectivity of HM97211 derivatives. Standard proliferation assay, immunoblotting, and apoptosis analysis were carried out to validate the potency of HM97211 derivatives in AML and SCLC cell lines. In vivo anti-tumor activity was evaluated in AML and SCLC cell xenograft mice models. Tumor sizes were measured and tumor samples were analyzed to define the mechanisms of action. Results: HM97211 derivatives showed higher selectivity toward LSD1 compared to other FAD-utilizing enzyme as well as other epigenetic enzymes. HM97211 derivatives alter expression of various genes and induce differentiation and apoptosis, resulting in growth suppression in a panel of AML and SCLC cells. Moreover, HM97211 derivatives significantly induced programmed cell death in AML and SCLC cells. Oral administration of HM97211 derivatives inhibited tumor growth of human AML and SCLC xenograft models as a single agent at doses exhibiting significant. Efficacy of HM97211 derivatives was further evaluated in combination treatment with standard chemotherapies in human AML and SCLC xenograft model. Conclusion: Collectively, results of this study suggested that novel reversible LSD1 inhibitor, HM97211 derivatives, can be a strong therapeutic agent for AML and SCLC patients. Hanmi presents a new insight to epigenetics application in anticancer therapy. Citation Format: InHwan Bae, WonJeoun Kim, JiSook Kim, JiYoung Song, JungSoo Nam, Moonsub Lee, Jooyun Byun, Hyeongki Kim, TaeHun Song, Seokhyun Hong, KyuHang Lee, YoungGil Ahn, YoungHoon Kim, Kwee Hyun Suh. Antitumor activity of novel reversible LSD1 inhibitor in preclinical models of AML and SCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3833.