TY - JOUR A1 - Henriksson, Sofia A1 - Calderón-Montaño, José Manuel A1 - Solvie, Daniel A1 - Warpman Berglund, Ulrika A1 - Helleday, Thomas T1 - Overexpressed c-Myc sensitizes cells to TH1579, a mitotic arrest and oxidative DNA damage inducer JF - Biomolecules N2 - Previously, we reported that MTH1 inhibitors TH588 and TH1579 selectively induce oxidative damage and kill Ras-expressing or -transforming cancer cells, as compared to non-transforming immortalized or primary cells. While this explains the impressive anti-cancer properties of the compounds, the molecular mechanism remains elusive. Several oncogenes induce replication stress, resulting in under replicated DNA and replication continuing into mitosis, where TH588 and TH1579 treatment causes toxicity and incorporation of oxidative damage. Hence, we hypothesized that oncogene-induced replication stress explains the cancer selectivity. To test this, we overexpressed c-Myc in human epithelial kidney cells (HA1EB), resulting in increased proliferation, polyploidy and replication stress. TH588 and TH1579 selectively kill c-Myc overexpressing clones, enforcing the cancer cell selective killing of these compounds. Moreover, the toxicity of TH588 and TH1579 in c-Myc overexpressing cells is rescued by transcription, proteasome or CDK1 inhibitors, but not by nucleoside supplementation. We conclude that the molecular toxicological mechanisms of how TH588 and TH1579 kill c-Myc overexpressing cells have several components and involve MTH1-independent proteasomal degradation of c-Myc itself, c-Myc-driven transcription and CDK activation. KW - MTH1 KW - TH588 KW - TH1579 KW - c-Myc KW - replication stress KW - DNA damage KW - cell death KW - cancer Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297547 SN - 2218-273X VL - 12 IS - 12 ER - TY - JOUR A1 - Vučićević, Dubravka A1 - Gehre, Maja A1 - Dhamija, Sonam A1 - Friis-Hansen, Lennart A1 - Meierhofer, David A1 - Sauer, Sascha A1 - Ørom, Ulf Andersson T1 - The long non-coding RNA PARROT is an upstream regulator of c-Myc and affects proliferation and translation JF - Oncotarget N2 - Long non-coding RNAs are important regulators of gene expression and signaling pathways. The expression of long ncRNAs is dysregulated in cancer and other diseases. The identification and characterization of long ncRNAs is often challenging due to their low expression level and localization to chromatin. Here, we identify a functional long ncRNA, PARROT (Proliferation Associated RNA and Regulator Of Translation) transcribed by RNA polymerase II and expressed at a relatively high level in a number of cell lines. The PARROT long ncRNA is associated with proliferation in both transformed and normal cell lines. We characterize the long ncRNA PARROT as an upstream regulator of c-Myc affecting cellular proliferation and translation using RNA sequencing and mass spectrometry following depletion of the long ncRNA. PARROT is repressed during senescence of human mammary epithelial cells and overexpressed in some cancers, suggesting an important association with proliferation through regulation of c-Myc. With this study, we add to the knowledge of cytoplasmic functional long ncRNAs and extent the long ncRNA-Myc regulatory network in transformed and normal cells. KW - PARROT KW - c-Myc KW - long ncRNA KW - upstream regulator Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166519 VL - 7 IS - 23 ER - TY - JOUR A1 - Scognamiglio, Roberta A1 - Cabezas-Wallscheid, Nina A1 - Thier, Marc Christian A1 - Altamura, Sandro A1 - Reyes, Alejandro A1 - Prendergast, Áine M. A1 - Baumgärtner, Daniel A1 - Carnevalli, Larissa S. A1 - Atzberger, Ann A1 - Haas, Simon A1 - von Paleske, Lisa A1 - Boroviak, Thorsten A1 - Wörsdörfer, Philipp A1 - Essers, Marieke A. G. A1 - Kloz, Ulrich A1 - Eisenman, Robert N. A1 - Edenhofer, Frank A1 - Bertone, Paul A1 - Huber, Wolfgang A1 - van der Hoeven, Franciscus A1 - Smith, Austin A1 - Trumpp, Andreas T1 - Myc depletion induces a pluripotent dormant state mimicking diapause JF - Cell N2 - Mouse embryonic stem cells (ESCs) are maintained in a naive ground state of pluripotency in the presence of MEK and GSK3 inhibitors. Here, we show that ground-state ESCs express low Myc levels. Deletion of both c-myc and N-myc (dKO) or pharmacological inhibition of Myc activity strongly decreases transcription, splicing, and protein synthesis, leading to proliferation arrest. This process is reversible and occurs without affecting pluripotency, suggesting that Myc-depleted stem cells enter a state of dormancy similar to embryonic diapause. Indeed, c-Myc is depleted in diapaused blastocysts, and the differential expression signatures of dKO ESCs and diapaused epiblasts are remarkably similar. Following Myc inhibition, pre-implantation blastocysts enter biosynthetic dormancy but can progress through their normal developmental program after transfer into pseudo-pregnant recipients. Our study shows that Myc controls the biosynthetic machinery of stem cells without affecting their potency, thus regulating their entry and exit from the dormant state. KW - hematopoietic stem cells KW - leukemia inhibitory factor KW - c-Myc KW - N-Myc KW - gene expression KW - embryonic stem cells KW - self-renewal KW - protein synthesis Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-190868 VL - 164 IS - 4 ER -