Now showing 1 - 4 of 4
  • 2017Journal Article
    [["dc.bibliographiccitation.firstpage","6334"],["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","Nucleic Acids Research"],["dc.bibliographiccitation.lastpage","6349"],["dc.bibliographiccitation.volume","45"],["dc.contributor.author","Mishra, Vivek Kumar"],["dc.contributor.author","Wegwitz, Florian"],["dc.contributor.author","Kosinsky, Robyn Laura"],["dc.contributor.author","Sen, Madhobi"],["dc.contributor.author","Baumgartner, Roland"],["dc.contributor.author","Wulff, Tanja"],["dc.contributor.author","Siveke, Jens T."],["dc.contributor.author","Schildhaus, Hans-Ulrich"],["dc.contributor.author","Najafova, Zeynab"],["dc.contributor.author","Kari, Vijayalakshmi"],["dc.contributor.author","Kohlhof, Hella"],["dc.contributor.author","Hessmann, Elisabeth"],["dc.contributor.author","Johnsen, Steven A."],["dc.date.accessioned","2018-11-07T10:22:37Z"],["dc.date.available","2018-11-07T10:22:37Z"],["dc.date.issued","2017"],["dc.description.abstract","Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer with a particularly dismal prognosis. Histone deacetylases (HDAC) are epigenetic modulators whose activity is frequently deregulated in various cancers including PDAC. In particular, class-I HDACs (HDAC 1, 2, 3 and 8) have been shown to play an important role in PDAC. In this study, we investigated the effects of the class Ispecific HDAC inhibitor (HDACi) 4SC-202 in multiple PDAC cell lines in promoting tumor cell differentiation. We show that 4SC-202 negatively affects TGF beta signaling and inhibits TGF beta-induced epithelial-tomesenchymal transition (EMT). Moreover, 4SC-202 markedly induced p21 (CDKN1A) expression and significantly attenuated cell proliferation. Mechanistically, genome-wide studies revealed that 4SC-202-induced genes were enriched for Bromodomain-containing Protein-4 (BRD4) and MYC occupancy. BRD4, a well-characterized acetyllysine reader, has been shown to play a major role in regulating transcription of selected subsets of genes. Importantly, BRD4 and MYC are essential for the expression of a subgroup of genes induced by class-I HDACi. Taken together, our study uncovers a previously unknown role of BRD4 and MYC in eliciting the HDACi-mediated induction of a subset of genes and provides molecular insight into the mechanisms of HDACi action in PDAC."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2017"],["dc.identifier.doi","10.1093/nar/gkx212"],["dc.identifier.isi","000403693000023"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/14605"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42309"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prĂĽfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1362-4962"],["dc.relation.issn","0305-1048"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Histone deacetylase class-I inhibition promotes epithelial gene expression in pancreatic cancer cells in a BRD4-and MYC-dependent manner"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]
    Details DOI WOS
  • 2017Journal Article
    [["dc.bibliographiccitation.artnumber","32"],["dc.bibliographiccitation.journal","Genome Biology"],["dc.bibliographiccitation.volume","18"],["dc.contributor.author","Xie, Wanhua"],["dc.contributor.author","Nagarajan, Sankari"],["dc.contributor.author","Baumgart, Simon J."],["dc.contributor.author","Kosinsky, Robyn Laura"],["dc.contributor.author","Najafova, Zeynab"],["dc.contributor.author","Kari, Vijayalakshmi"],["dc.contributor.author","Hennion, Magali"],["dc.contributor.author","Indenbirken, Daniela"],["dc.contributor.author","Bonn, Stefan"],["dc.contributor.author","Grundhoff, Adam"],["dc.contributor.author","Wegwitz, Florian"],["dc.contributor.author","Mansouri, Ahmed"],["dc.contributor.author","Johnsen, Steven A."],["dc.date.accessioned","2018-11-07T10:27:18Z"],["dc.date.available","2018-11-07T10:27:18Z"],["dc.date.issued","2017"],["dc.description.abstract","Background: Monoubiquitination of H2B (H2Bub1) is a largely enigmatic histone modification that has been linked to transcriptional elongation. Because of this association, it has been commonly assumed that H2Bub1 is an exclusively positively acting histone modification and that increased H2Bub1 occupancy correlates with increased gene expression. In contrast, depletion of the H2B ubiquitin ligases RNF20 or RNF40 alters the expression of only a subset of genes. Results: Using conditional Rnf40 knockout mouse embryo fibroblasts, we show that genes occupied by low to moderate amounts of H2Bub1 are selectively regulated in response to Rnf40 deletion, whereas genes marked by high levels of H2Bub1 are mostly unaffected by Rnf40 loss. Furthermore, we find that decreased expression of RNF40-dependent genes is highly associated with widespread narrowing of H3K4me3 peaks. H2Bub1 promotes the broadening of H3K4me3 to increase transcriptional elongation, which together lead to increased tissue- specific gene transcription. Notably, genes upregulated following Rnf40 deletion, including Foxl2, are enriched for H3K27me3, which is decreased following Rnf40 deletion due to decreased expression of the Ezh2 gene. As a consequence, increased expression of some RNF40-\"suppressed\" genes is associated with enhancer activation via FOXL2. Conclusion: Together these findings reveal the complexity and context-dependency whereby one histone modification can have divergent effects on gene transcription. Furthermore, we show that these effects are dependent upon the activity of other epigenetic regulatory proteins and histone modifications."],["dc.identifier.doi","10.1186/s13059-017-1159-5"],["dc.identifier.isi","000394828000003"],["dc.identifier.pmid","28209164"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/14250"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/43221"],["dc.notes.intern","Merged from goescholar"],["dc.notes.intern","In goescholar not merged with http://resolver.sub.uni-goettingen.de/purl?gs-1/14993 but duplicate"],["dc.notes.status","zu prĂĽfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Biomed Central Ltd"],["dc.relation.issn","1474-760X"],["dc.rights","CC BY 4.0"],["dc.rights.access","openAccess"],["dc.rights.holder","The Author(s)."],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","RNF40 regulates gene expression in an epigenetic context-dependent manner"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]
    Details DOI PMID PMC WOS
  • 2019Journal Article
    [["dc.bibliographiccitation.artnumber","98"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Clinical Epigenetics"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Schneider, Deborah"],["dc.contributor.author","Chua, Robert L"],["dc.contributor.author","Molitor, Nicole"],["dc.contributor.author","Hamdan, Feda H"],["dc.contributor.author","Rettenmeier, Eva M"],["dc.contributor.author","Prokakis, Evangelos"],["dc.contributor.author","Mishra, Vivek K"],["dc.contributor.author","Kari, Vijayalakshmi"],["dc.contributor.author","Wegwitz, Florian"],["dc.contributor.author","Johnsen, Steven A"],["dc.contributor.author","Kosinsky, Robyn L"],["dc.date.accessioned","2019-07-09T11:51:58Z"],["dc.date.available","2019-07-09T11:51:58Z"],["dc.date.issued","2019"],["dc.description.abstract","Abstract Background Colorectal cancer (CRC) is the fourth leading cause of cancer-related deaths worldwide, and deciphering underlying molecular mechanism is essential. The loss of monoubiquitinated histone H2B (H2Bub1) was correlated with poor prognosis of CRC patients and, accordingly, H2Bub1 was suggested as a tumor-suppressive mark. Surprisingly, our previous work revealed that the H2B ubiquitin ligase RING finger protein 40 (RNF40) might exert tumor-promoting functions. Here, we investigated the effect of RNF40 loss on tumorigenic features of CRC cells and their survival in vitro. Methods We evaluated the effects of RNF40 depletion in several human CRC cell lines in vitro. To evaluate cell cycle progression, cells were stained with propidium iodide and analyzed by flow cytometry. In addition, to assess apoptosis rates, caspase 3/7 activity was assessed in a Celigo® S-based measurement and, additionally, an Annexin V assay was performed. Genomic occupancy of H2Bub1, H3K79me3, and H3K27ac was determined by chromatin immunoprecipitation. Transcriptome-wide effects of RNF40 loss were evaluated based on mRNA-seq results, qRT-PCR, and Western blot. To rescue apoptosis-related effects, cells were treated with Z-VAD-FMK. Results Human CRC cell lines displayed decreased cell numbers in vitro after RNF40 depletion. While the differences in confluence were not mediated by changes in cell cycle progression, we discovered highly increased apoptosis rates after RNF40 knockdown due to elevated caspase 3/7 activity. This effect can be explained by reduced mRNA levels of anti-apoptotic and upregulation of pro-apoptotic BCL2 family members. Moreover, the direct occupancy of the RNF40-mediated H2B monoubiquitination was observed in the transcribed region of anti-apoptotic genes. Caspase inhibition by Z-VAD-FMK treatment rescued apoptosis in RNF40-depleted cells. However, knockdown cells still displayed decreased tumorigenic features despite the absence of apoptosis. Conclusions Our findings reveal that RNF40 is essential for maintaining tumorigenic features of CRC cells in vitro by controlling the expression of genes encoding central apoptotic regulators."],["dc.identifier.doi","10.1186/s13148-019-0698-x"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16251"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/60054"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.publisher","BioMed Central"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","The E3 ubiquitin ligase RNF40 suppresses apoptosis in colorectal cancer cells"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]
    Details DOI
  • 2019Journal Article
    [["dc.bibliographiccitation.artnumber","4"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Clinical Epigenetics"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Kari, Vijayalakshmi"],["dc.contributor.author","Raul, Sanjay K"],["dc.contributor.author","Henck, Jana M"],["dc.contributor.author","Kitz, Julia"],["dc.contributor.author","Kramer, Frank"],["dc.contributor.author","Kosinsky, Robyn L"],["dc.contributor.author","Ăśbelmesser, Nadine"],["dc.contributor.author","Mansour, Wael Y"],["dc.contributor.author","Eggert, Jessica"],["dc.contributor.author","Spitzner, Melanie"],["dc.contributor.author","Najafova, Zeynab"],["dc.contributor.author","Bastians, Holger"],["dc.contributor.author","Grade, Marian"],["dc.contributor.author","Gaedcke, Jochen"],["dc.contributor.author","Wegwitz, Florian"],["dc.contributor.author","Johnsen, Steven A"],["dc.date.accessioned","2019-07-09T11:49:49Z"],["dc.date.available","2019-07-09T11:49:49Z"],["dc.date.issued","2019"],["dc.description.abstract","Abstract Background Disruptor of telomeric silencing 1-like (DOT1L) is a non-SET domain containing methyltransferase known to catalyze mono-, di-, and tri-methylation of histone 3 on lysine 79 (H3K79me). DOT1L-mediated H3K79me has been implicated in chromatin-associated functions including gene transcription, heterochromatin formation, and DNA repair. Recent studies have uncovered a role for DOT1L in the initiation and progression of leukemia and other solid tumors. The development and availability of small molecule inhibitors of DOT1L may provide new and unique therapeutic options for certain types or subgroups of cancer. Methods In this study, we examined the role of DOT1L in DNA double-strand break (DSB) response and repair by depleting DOT1L using siRNA or inhibiting its methyltransferase activity using small molecule inhibitors in colorectal cancer cells. Cells were treated with different agents to induce DNA damage in DOT1L-depleted or -inhibited cells and analyzed for DNA repair efficiency and survival. Further, rectal cancer patient samples were analyzed for H3K79me3 levels in order to determine whether it may serve as a potential marker for personalized therapy. Results Our results indicate that DOT1L is required for a proper DNA damage response following DNA double-strand breaks by regulating the phosphorylation of the variant histone H2AX (ÎłH2AX) and repair via homologous recombination (HR). Importantly, we show that small molecule inhibitors of DOT1L combined with chemotherapeutic agents that are used to treat colorectal cancers show additive effects. Furthermore, examination of H3K79me3 levels in rectal cancer patients demonstrates that lower levels correlate with a poorer prognosis. Conclusions In this study, we conclude that DOT1L plays an important role in an early DNA damage response and repair of DNA double-strand breaks via the HR pathway. Moreover, DOT1L inhibition leads to increased sensitivity to chemotherapeutic agents and PARP inhibition, which further highlights its potential clinical utility. Our results further suggest that H3K79me3 can be useful as a predictive and or prognostic marker for rectal cancer patients."],["dc.identifier.doi","10.1186/s13148-018-0601-1"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15787"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59638"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.publisher","BioMed Central"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","The histone methyltransferase DOT1L is required for proper DNA damage response, DNA repair, and modulates chemotherapy responsiveness"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]
    Details DOI