TY - JOUR A1 - Berendzen, Kenneth W. A1 - Weiste, Christoph A1 - Wanke, Dierk A1 - Kilian, Joachim A1 - Harter, Klaus A1 - Dröge-Laser, Wolfgang T1 - Bioinformatic cis-element analyses performed in Arabidopsis and rice disclose bZIP- and MYB-related binding sites as potential AuxRE-coupling elements in auxin-mediated transcription N2 - Background: In higher plants, a diverse array of developmental and growth-related processes is regulated by the plant hormone auxin. Recent publications have proposed that besides the well-characterized Auxin Response Factors (ARFs) that bind Auxin Response Elements (AuxREs), also members of the bZIP- and MYB-transcription factor (TF) families participate in transcriptional control of auxin-regulated genes via bZIP Response Elements (ZREs) or Myb Response Elements (MREs), respectively. Results: Applying a novel bioinformatic algorithm, we demonstrate on a genome-wide scale that singular motifs or composite modules of AuxREs, ZREs, MREs but also of MYC2 related elements are significantly enriched in promoters of auxin-inducible genes. Despite considerable, species-specific differences in the genome structure in terms of the GC content, this enrichment is generally conserved in dicot (Arabidopsis thaliana) and monocot (Oryza sativa) model plants. Moreover, an enrichment of defined composite modules has been observed in selected auxin-related gene families. Consistently, a bipartite module, which encompasses a bZIP-associated G-box Related Element (GRE) and an AuxRE motif, has been found to be highly enriched. Making use of transient reporter studies in protoplasts, these findings were experimentally confirmed, demonstrating that GREs functionally interact with AuxREs in regulating auxin-mediated transcription. Conclusions: Using genome-wide bioinformatic analyses, evolutionary conserved motifs have been defined which potentially function as AuxRE-dependent coupling elements to establish auxin-specific expression patterns. Based on these findings, experimental approaches can be designed to broaden our understanding of combinatorial, auxin-controlled gene regulation. KW - Arabidopsis KW - Cis-elements KW - cis-element modules KW - Auxin-regulated transcription KW - AuxRE KW - bZIP KW - MYB KW - MYC Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75138 ER - TY - JOUR A1 - Effenberger, Madlen A1 - Bommert, Kathryn S. A1 - Kunz, Viktoria A1 - Kruk, Jessica A1 - Leich, Ellen A1 - Rudelius, Martina A1 - Bargou, Ralf A1 - Bommert, Kurt T1 - Glutaminase inhibition in multiple myeloma induces apoptosis via MYC degradation JF - Oncotarget N2 - Multiple Myeloma (MM) is an incurable hematological malignancy affecting millions of people worldwide. As in all tumor cells both glucose and more recently glutamine have been identified as important for MM cellular metabolism, however there is some dispute as to the role of glutamine in MM cell survival. Here we show that the small molecule inhibitor compound 968 effectively inhibits glutaminase and that this inhibition induces apoptosis in both human multiple myeloma cell lines (HMCLs) and primary patient material. The HMCL U266 which does not express MYC was insensitive to both glutamine removal and compound 968, but ectopic expression of MYC imparted sensitivity. Finally, we show that glutamine depletion is reflected by rapid loss of MYC protein which is independent of MYC transcription and post translational modifications. However, MYC loss is dependent on proteasomal activity, and this loss was paralleled by an equally rapid induction of apoptosis. These findings are in contrast to those of glucose depletion which largely affected rates of proliferation in HMCLs, but had no effects on either MYC expression or viability. Therefore, inhibition of glutaminolysis is effective at inducing apoptosis and thus serves as a possible therapeutic target in MM. KW - Multiple Myeloma KW - glutaminase inhibition KW - apoptosis KW - MYC Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170168 VL - 8 IS - 49 ER - TY - JOUR A1 - Hartmann, Oliver A1 - Reissland, Michaela A1 - Maier, Carina R. A1 - Fischer, Thomas A1 - Prieto-Garcia, Cristian A1 - Baluapuri, Apoorva A1 - Schwarz, Jessica A1 - Schmitz, Werner A1 - Garrido-Rodriguez, Martin A1 - Pahor, Nikolett A1 - Davies, Clare C. A1 - Bassermann, Florian A1 - Orian, Amir A1 - Wolf, Elmar A1 - Schulze, Almut A1 - Calzado, Marco A. A1 - Rosenfeldt, Mathias T. A1 - Diefenbacher, Markus E. T1 - Implementation of CRISPR/Cas9 Genome Editing to Generate Murine Lung Cancer Models That Depict the Mutational Landscape of Human Disease JF - Frontiers in Cell and Developmental Biology N2 - Lung cancer is the most common cancer worldwide and the leading cause of cancer-related deaths in both men and women. Despite the development of novel therapeutic interventions, the 5-year survival rate for non-small cell lung cancer (NSCLC) patients remains low, demonstrating the necessity for novel treatments. One strategy to improve translational research is the development of surrogate models reflecting somatic mutations identified in lung cancer patients as these impact treatment responses. With the advent of CRISPR-mediated genome editing, gene deletion as well as site-directed integration of point mutations enabled us to model human malignancies in more detail than ever before. Here, we report that by using CRISPR/Cas9-mediated targeting of Trp53 and KRas, we recapitulated the classic murine NSCLC model Trp53fl/fl:lsl-KRasG12D/wt. Developing tumors were indistinguishable from Trp53fl/fl:lsl-KRasG12D/wt-derived tumors with regard to morphology, marker expression, and transcriptional profiles. We demonstrate the applicability of CRISPR for tumor modeling in vivo and ameliorating the need to use conventional genetically engineered mouse models. Furthermore, tumor onset was not only achieved in constitutive Cas9 expression but also in wild-type animals via infection of lung epithelial cells with two discrete AAVs encoding different parts of the CRISPR machinery. While conventional mouse models require extensive husbandry to integrate new genetic features allowing for gene targeting, basic molecular methods suffice to inflict the desired genetic alterations in vivo. Utilizing the CRISPR toolbox, in vivo cancer research and modeling is rapidly evolving and enables researchers to swiftly develop new, clinically relevant surrogate models for translational research. KW - non-small cell lung cancer KW - CRISPR-Cas9 KW - mouse model KW - lung cancer KW - MYC KW - JUN Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230949 SN - 2296-634X VL - 9 ER - TY - JOUR A1 - Kunz, Viktoria A1 - Bommert, Kathryn S. A1 - Kruk, Jessica A1 - Schwinning, Daniel A1 - Chatterjee, Manik A1 - Stühmer, Thorsten A1 - Bargou, Ralf A1 - Bommert, Kurt T1 - Targeting of the E3 ubiquitin-protein ligase HUWE1 impairs DNA repair capacity and tumor growth in preclinical multiple myeloma models JF - Scientific Reports N2 - Experimental evidence suggests that ubiquitin-protein ligases regulate a number of cellular processes involved in tumorigenesis. We analysed the role of the E3 ubiquitin-protein ligase HUWE1 for pathobiology of multiple myeloma (MM), a still incurable blood cancer. mRNA expression analysis indicates an increase in HUWE1 expression levels correlated with advanced stages of myeloma. Pharmacologic as well as RNAi-mediated HUWE1 inhibition caused anti-proliferative effects in MM cell lines in vitro and in an MM1.S xenotransplantation mouse model. Cell cycle analysis upon HUWE1 inhibition revealed decreased S phase cell fractions. Analyses of potential HUWE1-dependent molecular functions did not show involvement in MYC-dependent gene regulation. However, HUWE1 depleted MM cells displayed increased DNA tail length by comet assay, as well as changes in the levels of DNA damage response mediators such as pBRCA1, DNA-polymerase beta, gamma H2AX and Mcl-1. Our finding that HUWE1 might thus be involved in endogenous DNA repair is further supported by strongly enhanced apoptotic effects of the DNA-damaging agent melphalan in HUWE1 depleted cells in vitro and in vivo. These data suggest that HUWE1 might contribute to tumour growth by endogenous repair of DNA, and could therefore potentially be exploitable in future treatment developments. KW - MYC KW - interacts KW - gene Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230632 VL - 10 ER - TY - JOUR A1 - Lorenzin, Francesca A1 - Benary, Uwe A1 - Baluapuri, Apoorva A1 - Walz, Susanne A1 - Jung, Lisa Anna A1 - von Eyss, Björn A1 - Kisker, Caroline A1 - Wolf, Jana A1 - Eilers, Martin A1 - Wolf, Elmar T1 - Different promoter affinities account for specificity in MYC-dependent gene regulation JF - eLife N2 - Enhanced expression of the MYC transcription factor is observed in the majority of tumors. Two seemingly conflicting models have been proposed for its function: one proposes that MYC enhances expression of all genes, while the other model suggests gene-specific regulation. Here, we have explored the hypothesis that specific gene expression profiles arise since promoters differ in affinity for MYC and high-affinity promoters are fully occupied by physiological levels of MYC. We determined cellular MYC levels and used RNA- and ChIP-sequencing to correlate promoter occupancy with gene expression at different concentrations of MYC. Mathematical modeling showed that binding affinities for interactions of MYC with DNA and with core promoter-bound factors, such as WDR5, are sufficient to explain promoter occupancies observed in vivo. Importantly, promoter affinity stratifies different biological processes that are regulated by MYC, explaining why tumor-specific MYC levels induce specific gene expression programs and alter defined biological properties of cells. KW - MYC KW - promoter affinity KW - human KW - mathematical modeling KW - mouse KW - ChIP-sequencing KW - MIZ1 KW - cancer biology KW - cell biology KW - WDR5 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-162913 VL - 5 ER - TY - JOUR A1 - Otto, Christoph A1 - Kastner, Carolin A1 - Schmidt, Stefanie A1 - Uttinger, Konstantin A1 - Baluapuri, Apoorva A1 - Denk, Sarah A1 - Rosenfeldt, Mathias T. A1 - Rosenwald, Andreas A1 - Roehrig, Florian A1 - Ade, Carsten P. A1 - Schuelein-Voelk, Christina A1 - Diefenbacher, Markus E. A1 - Germer, Christoph-Thomas A1 - Wolf, Elmar A1 - Eilers, Martin A1 - Wiegering, Armin T1 - RNA polymerase I inhibition induces terminal differentiation, growth arrest, and vulnerability to senolytics in colorectal cancer cells JF - Molecular Oncology N2 - Ribosomal biogenesis and protein synthesis are deregulated in most cancers, suggesting that interfering with translation machinery may hold significant therapeutic potential. Here, we show that loss of the tumor suppressor adenomatous polyposis coli (APC), which constitutes the initiating event in the adenoma carcinoma sequence for colorectal cancer (CRC), induces the expression of RNA polymerase I (RNAPOL1) transcription machinery, and subsequently upregulates ribosomal DNA (rDNA) transcription. Targeting RNAPOL1 with a specific inhibitor, CX5461, disrupts nucleolar integrity, and induces a disbalance of ribosomal proteins. Surprisingly, CX5461-induced growth arrest is irreversible and exhibits features of senescence and terminal differentiation. Mechanistically, CX5461 promotes differentiation in an MYC-interacting zinc-finger protein 1 (MIZ1)- and retinoblastoma protein (Rb)-dependent manner. In addition, the inhibition of RNAPOL1 renders CRC cells vulnerable towards senolytic agents. We validated this therapeutic effect of CX5461 in murine- and patient-derived organoids, and in a xenograft mouse model. These results show that targeting ribosomal biogenesis together with targeting the consecutive, senescent phenotype using approved drugs is a new therapeutic approach, which can rapidly be transferred from bench to bedside. KW - CRC KW - CX5461 KW - MIZ1 KW - MYC KW - ribosome KW - RNAPOL1 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312806 VL - 16 IS - 15 ER - TY - JOUR A1 - Peter, Stefanie A1 - Bultinck, Jennyfer A1 - Myant, Kevin A1 - Jaenicke, Laura A. A1 - Walz, Susanne A1 - Müller, Judith A1 - Gmachl, Michael A1 - Treu, Matthias A1 - Boehmelt, Guido A1 - Ade, Casten P. A1 - Schmitz, Werner A1 - Wiegering, Armin A1 - Otto, Christoph A1 - Popov, Nikita A1 - Sansom, Owen A1 - Kraut, Norbert A1 - Eilers, Martin T1 - H Tumor cell-specific inhibition of MYC function using small molecule inhibitors of the HUWE1 ubiquitin ligase JF - EMBO Molecular Medicine N2 - Deregulated expression of MYC is a driver of colorectal carcinogenesis, necessitating novel strategies to inhibit MYC function. The ubiquitin ligase HUWE1 (HECTH9, ARF-BP1, MULE) associates with both MYC and the MYC-associated protein MIZ1. We show here that HUWE1 is required for growth of colorectal cancer cells in culture and in orthotopic xenograft models. Using high-throughput screening, we identify small molecule inhibitors of HUWE1, which inhibit MYC-dependent transactivation in colorectal cancer cells, but not in stem and normal colon epithelial cells. Inhibition of HUWE1 stabilizes MIZ1. MIZ1 globally accumulates on MYC target genes and contributes to repression of MYC-activated target genes upon HUWE1 inhibition. Our data show that transcriptional activation by MYC in colon cancer cells requires the continuous degradation of MIZ1 and identify a novel principle that allows for inhibition of MYC function in tumor cells. KW - colorectal cancer KW - HUWE1 KW - MIZ1 KW - MYC KW - ubiquitination KW - cancer KW - digestive system KW - pharmacology KW - drug discovery Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-118132 SN - 1757-4684 VL - 6 IS - 12 ER -