Screening and Functional Characterization of Lysine Specific Demethylase 1 Inhibitors for Anticancer Therapy

• Main Authors: Tsai Yun Wu, 吳采芸
• Other Authors: H. C. Chen
• Format: Others
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/j6786t

碩士 === 長庚大學 === 生物醫學研究所 === 102 === Lysine-specific demethylase 1 (LSD1) was the first identified human histone demethylase, which catalyzed the demethylation of histone H3K4 or H3K9 through a FAD-dependent oxidative demethylation and played an important role in transcriptional regulation. It is reported that LSD1 was highly expressed in multiple types of cancer tissues. Our previous studies demonstrated that siRNA-mediated silencing of LSD1 progressively suppressed the proliferation and colony formation ability in several types of cultured cancer cells. Other studies also suggested that LSD1 inhibitors significantly suppressed the growth and proliferation of cancer stem cells (CSC). These observations indicated that LSD1 plays a critical role in tumor pathogenesis and also in maintaining the survival of cancer stem cell. Therefore, targeting LSD1 may provide a new therapeutic approach for cancer therapy. However, most LSD1 inhibitors currently used are monoamine oxidase inhibitors whose efficacy and specificity are not optimum for LSD1 enzymatic inhibition. Therefore, developing novel potent LSD1 inhibitors for anticancer treatment is an unmet medical need. In this study, we aimed to discover novel LSD1 inhibitors with high efficacy and specificity to against cancer cells. We purified LSD1 recombinant proteins and applied them to in-house in vitro histone demethylation assay for potential compound screening. Several known LSD1 inhibitors were used as reference compounds to assess the -viidemethylation assay. Under our assay conditions, the IC50 of RN-1 is around 5 μM, about 70 times higher than the reported data. We also established the cell-based LSD1 inhibition assays for the functional characterization of novel LSD1 inhibitors. The CC50 of cell cytotoxicity of RN-1 and 2-PCPA are 85 μM and 2.5 mM, respectively, similar to reported data. This suggests that we have established the in-house cell-based assay but the enzyme-based assay still needs to be further optimized. Once the assay is well-established, we will conduct high-throughput screening for novel LSD1 inhibitors.