Browsing by Author "Li, Fengling"
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Item A chemical probe targeting the PWWP domain alters NSD2 nucleolar localization(2022) Dilworth, David; Hanley, Ronan P; Ferreira de Freitas, Renato; Allali-Hassani, Abdellah; Zhou, Mengqi; Mehta, Naimee; Marunde, Matthew R; Ackloo, Suzanne; Carvalho Machado, Raquel Arminda; Khalili Yazdi, Aliakbar; Owens, Dominic D G; Vu, Victoria; Nie, David Y; Alqazzaz, Mona; Marcon, Edyta; Li, Fengling; Chau, Irene; Bolotokova, Albina; Qin, Su; Lei, Ming; Liu, Yanli; Szewczyk, Magdalena M; Dong, Aiping; Kazemzadeh, Sina; Abramyan, Tigran; Popova, Irina K; Hall, Nathan W; Meiners, Matthew J; Cheek, Marcus A; Gibson, Elisa; Kireev, Dmitri; Greenblatt, Jack F; Keogh, Michael-C; Min, Jinrong; Brown, Peter J; Vedadi, Masoud; Arrowsmith, Cheryl H; Barsyte-Lovejoy, Dalia; James, Lindsey I; Schapira, MatthieuNuclear receptor-binding SET domain-containing 2 (NSD2) is the primary enzyme responsible for the dimethylation of lysine 36 of histone 3 (H3K36), a mark associated with active gene transcription and intergenic DNA methylation. In addition to a methyltransferase domain, NSD2 harbors two proline-tryptophan-tryptophan-proline (PWWP) domains and five plant homeodomains (PHDs) believed to serve as chromatin reading modules. Here, we report a chemical probe targeting the N-terminal PWWP (PWWP1) domain of NSD2. UNC6934 occupies the canonical H3K36me2-binding pocket of PWWP1, antagonizes PWWP1 interaction with nucleosomal H3K36me2 and selectively engages endogenous NSD2 in cells. UNC6934 induces accumulation of endogenous NSD2 in the nucleolus, phenocopying the localization defects of NSD2 protein isoforms lacking PWWP1 that result from translocations prevalent in multiple myeloma (MM). Mutations of other NSD2 chromatin reader domains also increase NSD2 nucleolar localization and enhance the effect of UNC6934. This chemical probe and the accompanying negative control UNC7145 will be useful tools in defining NSD2 biology.Item Dual EZH2 and EHMT2 histone methyltransferase inhibition increases biological efficacy in breast cancer cells(2015-08-21) Curry, Edward; Green, Ian; Chapman-Rothe, Nadine; Shamsaei, Elham; Kandil, Sarah; Cherblanc, Fanny L; Payne, Luke; Bell, Emma; Ganesh, Thota; Srimongkolpithak, Nitipol; Caron, Joachim; Li, Fengling; Uren, Anthony G; Snyder, James P; Vedadi, Masoud; Fuchter, Matthew J; Brown, RobertAbstract Background Many cancers show aberrant silencing of gene expression and overexpression of histone methyltransferases. The histone methyltransferases (HKMT) EZH2 and EHMT2 maintain the repressive chromatin histone methylation marks H3K27me and H3K9me, respectively, which are associated with transcriptional silencing. Although selective HKMT inhibitors reduce levels of individual repressive marks, removal of H3K27me3 by specific EZH2 inhibitors, for instance, may not be sufficient for inducing the expression of genes with multiple repressive marks. Results We report that gene expression and inhibition of triple negative breast cancer cell growth (MDA-MB-231) are markedly increased when targeting both EZH2 and EHMT2, either by siRNA knockdown or pharmacological inhibition, rather than either enzyme independently. Indeed, expression of certain genes is only induced upon dual inhibition. We sought to identify compounds which showed evidence of dual EZH2 and EHMT2 inhibition. Using a cell-based assay, based on the substrate competitive EHMT2 inhibitor BIX01294, we have identified proof-of-concept compounds that induce re-expression of a subset of genes consistent with dual HKMT inhibition. Chromatin immunoprecipitation verified a decrease in silencing marks and an increase in permissive marks at the promoter and transcription start site of re-expressed genes, while Western analysis showed reduction in global levels of H3K27me3 and H3K9me3. The compounds inhibit growth in a panel of breast cancer and lymphoma cell lines with low to sub-micromolar IC50s. Biochemically, the compounds are substrate competitive inhibitors against both EZH2 and EHMT1/2. Conclusions We have demonstrated that dual inhibition of EZH2 and EHMT2 is more effective at eliciting biological responses of gene transcription and cancer cell growth inhibition compared to inhibition of single HKMTs, and we report the first dual EZH2-EHMT1/2 substrate competitive inhibitors that are functional in cells.Item Identification of a C2′-fluorinated SAH analogue(Canadian Science Publishing, 2020-02-20) Labbe, Marc-Olivier; Li, Fengling; Chau, Irene; Xiong, Zijian; Santhakumar, Vijayaratnam; Dostie, Starr; Guindon, YvanThe progress towards the development of a nucleoside analogue with inhibitory properties against SETDB1, a histone methyltransferase (HMT) is described. Based on the structure of the natural cofactor S-adenosyl-L-methionine (SAM), novel fluorinated nucleoside analogues were synthesized. Two of these compounds bearing a C2'-F and C5'-primary amine moiety showed moderate inhibition of SETDB1, a lysine HMT for which there is only one reported inhibitor.