HDGF-related protein 2 (HRP-2) is a member of the Hepatoma-Derived Growth Factor-related protein family that harbors the structured PWWP and Integrase Binding Domain, known to associate with methylated histone tails or cellular and viral proteins, respectively. Interestingly, HRP-2 is a paralog of Lens Epithelium Derived Growth Factor p75 (LEDGF/p75), which is essential for MLL-rearranged (MLL-r) leukemia but dispensable for hematopoiesis. Sequel to these findings, we investigated the role of HRP-2 in hematopoiesis and MLL-r leukemia. Protein interactions were investigated by co-immunoprecipitation and validated using recombinant proteins in NMR. A systemic knockout mouse model was used to study normal hematopoiesis and MLL-ENL transformation upon the different HRP-2 genotypes. The role of HRP-2 in MLL-r and other leukemic, human cell lines was evaluated by lentiviral-mediated miRNA targeting HRP-2. We demonstrate that MLL and HRP-2 interact through a conserved interface, although this interaction proved less dependent on menin than the MLL-LEDGF/p75 interaction. The systemic HRP-2 knockout mice only revealed an increase in neutrophils in the peripheral blood, whereas the depletion of HRP-2 in leukemic cell lines and transformed primary murine cells resulted in reduced colony formation independently of MLL-rearrangements. In contrast, primary murine HRP-2 knockout cells were efficiently transformed by the MLL-ENL fusion, indicating that HRP-2, unlike LEDGF/p75, is dispensable for the transformation of MLL-ENL leukemogenesis but important for leukemic cell survival.

• Klíčová slova
• animal model, cell culture, cell proliferation, hematopoietic stem cell, leukemia, molecular cell biology, nuclear magnetic resonance (NMR), protein complex, protein-protein interaction,
• MeSH
• adaptorové proteiny signální transdukční genetika   metabolismus   MeSH
• HEK293 buňky MeSH
• histonlysin-N-methyltransferasa genetika   metabolismus   MeSH
• karcinogeneze genetika   metabolismus   patologie   MeSH
• leukemie genetika   metabolismus   patologie   MeSH
• lidé MeSH
• myši knockoutované MeSH
• myši MeSH
• proteiny buněčného cyklu genetika   metabolismus   MeSH
• protoonkogenní protein MLL genetika   metabolismus   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• viabilita buněk MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• Hdgfl2 protein, mouse MeSH Prohlížeč
• histonlysin-N-methyltransferasa MeSH
• KMT2A protein, human MeSH Prohlížeč
• Kmt2a protein, mouse MeSH Prohlížeč
• proteiny buněčného cyklu MeSH
• protoonkogenní protein MLL MeSH
• PSIP1 protein, human MeSH Prohlížeč
• transkripční faktory MeSH

Transdifferentiation of fibroblasts into induced neuronal cells (iNs) by the neuron-specific transcription factors Brn2, Myt1l, and Ascl1 is a paradigmatic example of inter-lineage conversion across epigenetically distant cells. Despite tremendous progress regarding the transcriptional hierarchy underlying transdifferentiation, the enablers of the concomitant epigenome resetting remain to be elucidated. Here, we investigated the role of KMT2A and KMT2B, two histone H3 lysine 4 methylases with cardinal roles in development, through individual and combined inactivation. We found that Kmt2b, whose human homolog's mutations cause dystonia, is selectively required for iN conversion through suppression of the alternative myocyte program and induction of neuronal maturation genes. The identification of KMT2B-vulnerable targets allowed us, in turn, to expose, in a cohort of 225 patients, 45 unique variants in 39 KMT2B targets, which represent promising candidates to dissect the molecular bases of dystonia.

• Klíčová slova
• KMT2B, MLL2, cell fate conversion, dystonia, epigenetics, histone H3 lysine 4 methylation, induced neuronal cells, mouse embryonic fibroblasts, myocytes, transdifferentiation,
• MeSH
• buněčná diferenciace genetika   MeSH
• dystonie genetika   MeSH
• embryo savčí cytologie   MeSH
• epigeneze genetická MeSH
• fibroblasty cytologie   MeSH
• genetické asociační studie * MeSH
• histonlysin-N-methyltransferasa metabolismus   MeSH
• histony metabolismus   MeSH
• lidé MeSH
• lysin metabolismus   MeSH
• metylace MeSH
• myši knockoutované MeSH
• neurony metabolismus   patologie   MeSH
• protoonkogenní protein MLL metabolismus   MeSH
• transdiferenciace buněk * genetika   MeSH
• transkriptom genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• histonlysin-N-methyltransferasa MeSH
• histony MeSH
• Kmt2a protein, mouse MeSH Prohlížeč
• KMT2B protein, human MeSH Prohlížeč
• Kmt2d protein, mouse MeSH Prohlížeč
• lysin MeSH
• protoonkogenní protein MLL MeSH

Mixed lineage leukemia (MLL) fusion-driven acute leukemias represent a genetically distinct subset of leukemias with poor prognosis. MLL forms a ternary complex with the lens epithelium-derived growth factor (LEDGF/p75) and MENIN. LEDGF/p75, a chromatin reader recognizing H3K36me3 marks, contributes to the association of the MLL multiprotein complex to chromatin. Formation of this complex is critical for the development of MLL leukemia. Available X-ray data represent only a partial structure of the LEDGF/p75-MLL-MENIN complex. Using nuclear magnetic resonance spectroscopy, we identified an additional LEDGF/p75-MLL interface, which overlaps with the binding site of known LEDGF/p75 interactors-HIV-1 integrase, PogZ, and JPO2. Binding of these proteins or MLL to LEDGF/p75 is mutually exclusive. The resolved structure, as well as mutational analysis, shows that the interaction is primarily sustained via two aromatic residues of MLL (F148 and F151). Colony-forming assays in MLL-AF9(+) leukemic cells expressing MLL interaction-defective LEDGF/p75 mutants revealed that this interaction is essential for transformation. Finally, we show that the clonogenic growth of primary murine MLL-AF9-expressing leukemic blasts is selectively impaired upon overexpression of a LEDGF/p75-binding cyclic peptide CP65, originally developed to inhibit the LEDGF/p75-HIV-1 integrase interaction. The newly defined protein-protein interface therefore represents a new target for the development of therapeutics against LEDGF/p75-dependent MLL fusion-driven leukemic disorders. Cancer Res; 74(18); 5139-51. ©2014 AACR.

• MeSH
• akutní myeloidní leukemie genetika   metabolismus   MeSH
• cílená molekulární terapie MeSH
• fúzní onkogenní proteiny genetika   metabolismus   MeSH
• histonlysin-N-methyltransferasa chemie   genetika   metabolismus   MeSH
• HIV-integrasa chemie   metabolismus   MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie MeSH
• mezibuněčné signální peptidy a proteiny chemie   genetika   metabolismus   MeSH
• MFC-7 buňky MeSH
• molekulární modely MeSH
• myši MeSH
• protoonkogenní protein MLL chemie   genetika   metabolismus   MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fúzní onkogenní proteiny MeSH
• histonlysin-N-methyltransferasa MeSH
• HIV-integrasa MeSH
• KMT2A protein, human MeSH Prohlížeč
• Kmt2a protein, mouse MeSH Prohlížeč
• lens epithelium-derived growth factor MeSH Prohlížeč
• mezibuněčné signální peptidy a proteiny MeSH
• protoonkogenní protein MLL MeSH

Activation of the MLL-ENL-ERtm oncogene initiates aberrant proliferation of myeloid progenitors. Here, we show induction of a fail-safe mechanism mediated by the DNA damage response (DDR) machinery that results in activation of the ATR/ATM-Chk1/Chk2-p53/p21(CIP1) checkpoint and cellular senescence at early stages of cellular transformation caused by a regulatable MLL-ENL-ERtm in mice. Furthermore, we identified the transcription program underlying this intrinsic anticancer barrier, and DDR-induced inflammatory regulators that fine-tune the signaling toward senescence, thereby modulating the fate of MLL-ENL-immortalized cells in a tissue-environment-dependent manner. Our results indicate that DDR is a rate-limiting event for acquisition of stem cell-like properties in MLL-ENL-ERtm-mediated transformation, as experimental inhibition of the barrier accelerated the transition to immature cell states and acute leukemia development.

• MeSH
• DNA vazebné proteiny genetika   MeSH
• fúzní onkogenní proteiny genetika   MeSH
• genový knockin MeSH
• histonlysin-N-methyltransferasa MeSH
• kofein farmakologie   MeSH
• kontrolní body buněčného cyklu genetika   MeSH
• leukemie genetika   MeSH
• lidé MeSH
• myši MeSH
• nádorová transformace buněk MeSH
• nádorové kmenové buňky patologie   MeSH
• poškození DNA * MeSH
• proliferace buněk MeSH
• protoonkogenní protein MLL genetika   MeSH
• regulace genové exprese u nádorů MeSH
• signální transdukce MeSH
• transkripční faktory genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA vazebné proteiny MeSH
• fúzní onkogenní proteiny MeSH
• histonlysin-N-methyltransferasa MeSH
• Kmt2a protein, mouse MeSH Prohlížeč
• kofein MeSH
• Mllt1 protein, mouse MeSH Prohlížeč
• protoonkogenní protein MLL MeSH
• transkripční faktory MeSH