Jiranan Chotitumnavee achieved her Doctor of Pharmacy degree from the Faculty of Pharmaceutical Science, Khon Kaen University, Thailand in 2016. In that time, she had an opportunity to be a research internship at National Synchrotron Radiation Research Center in Hsinchu, Taiwan for three months operating a project at IR beamline end-station. After graduation, she worked as a teacher assistant at Mahidol University, Thailand. Then, she got a scholarship to be a research student, and currently, she is the first-year PhD student in the graduate school of medical science, Kyoto Prefectural University of Medicine.
Histone lysine demethylases (KDMs) play an essential role in the demethylation process of histone lysine residues by the oxidative mechanism. Two families of histone lysine demethylases have been identified based on their structure and catalytic reaction, which are flavin-dependent lysine demethylases and Jumonji C-containing (JmjC) lysine demethylases. The JmjC lysine demethylases are Fe(II)/α-ketoglutarate (αKG)-dependent oxygenases. KDM5A, an isoform of the JmjC lysine demethylases was chosen as a target KDM in this work. KDM5A plays a pivotal role in removing the di-and tri-methylation mark of lysine 4 on histone 3 (H3K4). KDM5A is overexpressed in several human cancer cells including lung, gastric, breast, and liver cancers. KDM5A has been reported to be involved in tumor formation, metastasis and advance of drug resistance in human cancers, suggesting KDM5A as a potential target for cancer treatment. In this study, we designed αKG analogues as JmjC lysine demethylase inhibitors since αKG acts as a crucial cofactor of these enzymes. The inhibitory activity of the αKG analogues was evaluated by an AlphaScreen KDM5A enzymatic assay, and western blotting analysis was performed to examine the methylation level change of H3K4 in A549 lung cancer cell lines. The results of the enzymatic assay and western blotting analysis showed that an αKG analogue inhibited KDM5A activity significantly and its ester prodrug enhanced the methylation of H3K4 in a dose-dependent manner in A549 lung cancer cell lines. Thus, the αKG analogue is a promising lead for KDM5A inhibitors.
WEN-REN WU is a PhD student in the Institute of Biomedical Sciences at National Sun Yat-sen University. He is a molecular biologist. His research focus on cancer biology. He has published more than 15 papers in journals.
Purpose: Urinary bladder urothelial carcinoma (UBUC) is a common malignant disease in developed countries. Cell cycle dysregulation resulting in uncontrolled cell proliferation has been associated with UBUC development. This study aimed to explore the roles of TMCO1 in UBUCs. Experimental Design: Data mining, branched DNA assay, immunohistochemistry, xenograft, cell culture, quantitative RT-PCR, immunoblotting, stable and transient transfection, lentivirus production and stable knockdown, cell cycle, cell viability and proliferation, soft agar, wound healing, transwell migration and invasion, co-immunoprecipitation, immunocytochemistry, AKT serine/threonine kinase (AKT) activity assays and site-directed mutagenesis were used to study TMCO1 involvement in vivo and in vitro. Results: Data mining identified that the TMCO1 transcript was downregulated during the progression of UBUCs. In distinct UBUC-derived cell lines, changes in TMCO1 levels altered the cell-cycle distribution, cell viability, cell proliferation, colony formation and modulated the AKT pathway. TMCO1 recruited the PH domain and leucine rich repeat protein phosphatase 2 (PHLPP2) to dephosphorylate pAKT1(serine 473) (S473). Mutagenesis at S60 of the TMCO1 protein released TMCO1-induced cell cycle arrest and restored the AKT pathway in BFTC905 cells. Stable TMCO1 (wild-type) overexpression suppressed, while T33A and S60A mutants recovered, tumor size in xenograft mice. Conclusions: Clinical associations, xenograft mice and in vitro indications provide solid evidence that the TMCO1 gene is a novel tumor suppressor in UBUCs. TMCO1 dysregulates cell cycle progression via suppression of the AKT pathway, and S60 of the TMCO1 protein is crucial for its tumor suppressor roles.