1
|
Siemund AL, Hanewald T, Kowarz E, Marschalek R. MLL-AF4 and a murinized pSer-variant thereof are turning on the nucleolar stress pathway. Cell Biosci 2022; 12:47. [PMID: 35468859 PMCID: PMC9036721 DOI: 10.1186/s13578-022-00781-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 03/29/2022] [Indexed: 11/22/2022] Open
Abstract
Background Recent pathomolecular studies on the MLL-AF4 fusion protein revealed that the murinized version of MLL-AF4, the MLL-Af4 fusion protein, was able to induce leukemia when expressed in murine or human hematopoietic stem/progenitor cells (Lin et al. in Cancer Cell 30:737–749, 2016). In parallel, a group from Japan demonstrated that the pSer domain of the AF4 protein, as well as the pSer domain of the MLL-AF4 fusion is able to bind the Pol I transcription factor complex SL1 (Okuda et al. in Nat Commun 6:8869, 2015). Here, we investigated the human MLL-AF4 and a pSer-murinized version thereof for their functional properties in mammalian cells. Gene expression profiling studies were complemented by intracellular localization studies and functional experiments concerning their biological activities in the nucleolus. Results Based on our results, we have to conclude that MLL-AF4 is predominantly localizing inside the nucleolus, thereby interfering with Pol I transcription and ribosome biogenesis. The murinized pSer-variant is localizing more to the nucleus, which may suggest a different biological behavior. Of note, AF4-MLL seems to cooperate at the molecular level with MLL-AF4 to steer target gene transcription, but not with the pSer-murinized version of it. Conclusion This study provides new insights and a molecular explanation for the described differences between hMLL-hAF4 (not leukemogenic) and hMLL-mAf4 (leukemogenic). While the human pSer domain is able to efficiently recruit the SL1 transcription factor complex, the murine counterpart seems to be not. This has several consequences for our understanding of t(4;11) leukemia which is the most frequent leukemia in infants, childhood and adults suffering from MLL-r acute leukemia. Supplementary Information The online version contains supplementary material available at 10.1186/s13578-022-00781-y.
Collapse
|
2
|
Okuda H, Miyamoto R, Takahashi S, Kawamura T, Ichikawa J, Harada I, Tamura T, Yokoyama A. RNA-binding proteins of KHDRBS and IGF2BP families control the oncogenic activity of MLL-AF4. Nat Commun 2022; 13:6688. [PMID: 36335100 PMCID: PMC9637093 DOI: 10.1038/s41467-022-34558-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 10/27/2022] [Indexed: 11/08/2022] Open
Abstract
Chromosomal translocation generates the MLL-AF4 fusion gene, which causes acute leukemia of multiple lineages. MLL-AF4 is a strong oncogenic driver that induces leukemia without additional mutations and is the most common cause of pediatric leukemia. However, establishment of a murine disease model via retroviral transduction has been difficult owning to a lack of understanding of its regulatory mechanisms. Here, we show that MLL-AF4 protein is post-transcriptionally regulated by RNA-binding proteins, including those of KHDRBS and IGF2BP families. MLL-AF4 translation is inhibited by ribosomal stalling, which occurs at regulatory sites containing AU-rich sequences recognized by KHDRBSs. Synonymous mutations disrupting the association of KHDRBSs result in proper translation of MLL-AF4 and leukemic transformation. Consequently, the synonymous MLL-AF4 mutant induces leukemia in vivo. Our results reveal that post-transcriptional regulation critically controls the oncogenic activity of MLL-AF4; these findings might be valuable in developing novel therapies via modulation of the activity of RNA-binding proteins.
Collapse
Affiliation(s)
- Hiroshi Okuda
- grid.272242.30000 0001 2168 5385Tsuruoka Metabolomics Laboratory, National Cancer Center, Tsuruoka, Yamagata Japan ,grid.268441.d0000 0001 1033 6139Department of Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa Japan
| | - Ryo Miyamoto
- grid.272242.30000 0001 2168 5385Tsuruoka Metabolomics Laboratory, National Cancer Center, Tsuruoka, Yamagata Japan
| | - Satoshi Takahashi
- grid.272242.30000 0001 2168 5385Tsuruoka Metabolomics Laboratory, National Cancer Center, Tsuruoka, Yamagata Japan ,grid.258799.80000 0004 0372 2033Department of Hematology and Oncology, Kyoto University Graduate School of Medicine, Kyoto, Kyoto Japan
| | - Takeshi Kawamura
- grid.26999.3d0000 0001 2151 536XResearch Center for Advanced Science and Technology (RCAST), The University of Tokyo, Bunkyo, Tokyo Japan
| | - Juri Ichikawa
- grid.268441.d0000 0001 1033 6139Department of Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa Japan
| | - Ibuki Harada
- grid.268441.d0000 0001 1033 6139Department of Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa Japan
| | - Tomohiko Tamura
- grid.268441.d0000 0001 1033 6139Department of Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa Japan ,grid.268441.d0000 0001 1033 6139Advanced Medical Research Center, Yokohama City University, Yokohama, Kanagawa Japan
| | - Akihiko Yokoyama
- grid.272242.30000 0001 2168 5385Tsuruoka Metabolomics Laboratory, National Cancer Center, Tsuruoka, Yamagata Japan ,grid.272242.30000 0001 2168 5385National Cancer Center Research Institute, Chuo, Tokyo Japan
| |
Collapse
|
3
|
Suzuki H, Abe R, Shimada M, Hirose T, Hirose H, Noguchi K, Ike Y, Yasui N, Furugori K, Yamaguchi Y, Toyoda A, Suzuki Y, Yamamoto T, Saitoh N, Sato S, Tomomori-Sato C, Conaway RC, Conaway JW, Takahashi H. The 3' Pol II pausing at replication-dependent histone genes is regulated by Mediator through Cajal bodies' association with histone locus bodies. Nat Commun 2022; 13:2905. [PMID: 35614107 PMCID: PMC9133132 DOI: 10.1038/s41467-022-30632-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 05/10/2022] [Indexed: 11/09/2022] Open
Abstract
Non-polyadenylated mRNAs of replication-dependent histones (RDHs) are synthesized by RNA polymerase II (Pol II) at histone locus bodies (HLBs). HLBs frequently associate with Cajal bodies (CBs), in which 3'-end processing factors for RDH genes are enriched; however, this association's role in transcription termination of RDH genes remains unclear. Here, we show that Pol II pauses immediately upstream of transcript end sites of RDH genes and Mediator plays a role in this Pol II pausing through CBs' association with HLBs. Disruption of the Mediator docking site for Little elongation complex (LEC)-Cap binding complex (CBC)-Negative elongation factor (NELF), components of CBs, interferes with CBs' association with HLBs and 3' Pol II pausing, resulting in increased aberrant unprocessed RDH gene transcripts. Our findings suggest Mediator's involvement in CBs' association with HLBs to facilitate 3' Pol II pausing and subsequent 3'-end processing of RDH genes by supplying 3'-end processing factors.
Collapse
Affiliation(s)
- Hidefumi Suzuki
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Ryota Abe
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Miho Shimada
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Tomonori Hirose
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Hiroko Hirose
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Keisuke Noguchi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Yoko Ike
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Nanami Yasui
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Kazuki Furugori
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Yuki Yamaguchi
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama, Kanagawa, 226-8501, Japan
| | - Atsushi Toyoda
- Comparative Genomics Laboratory, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Yutaka Suzuki
- Laboratory of Systems Genomics, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan
| | - Tatsuro Yamamoto
- Division of Cancer Biology, The Cancer Institute of JFCR, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan
| | - Noriko Saitoh
- Division of Cancer Biology, The Cancer Institute of JFCR, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan
| | - Shigeo Sato
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Chieri Tomomori-Sato
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Ronald C Conaway
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA.,Department of Biochemistry & Molecular Biology, University of Kansas Medical Center, Kansas City, MO, 66160, USA
| | - Joan W Conaway
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA.,Department of Biochemistry & Molecular Biology, University of Kansas Medical Center, Kansas City, MO, 66160, USA
| | - Hidehisa Takahashi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan.
| |
Collapse
|
4
|
Takahashi S, Kanai A, Okuda H, Miyamoto R, Komata Y, Kawamura T, Matsui H, Inaba T, Takaori-Kondo A, Yokoyama A. HBO1-MLL interaction promotes AF4/ENL/P-TEFb-mediated leukemogenesis. eLife 2021; 10:e65872. [PMID: 34431785 PMCID: PMC8387021 DOI: 10.7554/elife.65872] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 08/12/2021] [Indexed: 12/27/2022] Open
Abstract
Leukemic oncoproteins cause uncontrolled self-renewal of hematopoietic progenitors by aberrant gene activation, eventually causing leukemia. However, the molecular mechanism underlying aberrant gene activation remains elusive. Here, we showed that leukemic MLL fusion proteins associate with the HBO1 histone acetyltransferase (HAT) complex through their trithorax homology domain 2 (THD2) in various human cell lines. MLL proteins associated with the HBO1 complex through multiple contacts mediated mainly by the ING4/5 and PHF16 subunits in a chromatin-bound context where histone H3 lysine 4 tri-methylation marks were present. Of the many MLL fusions, MLL-ELL particularly depended on the THD2-mediated association with the HBO1 complex for leukemic transformation. The C-terminal portion of ELL provided a binding platform for multiple factors including AF4, EAF1, and p53. MLL-ELL activated gene expression in murine hematopoietic progenitors by loading an AF4/ENL/P-TEFb (AEP) complex onto the target promoters wherein the HBO1 complex promoted the association with AEP complex over EAF1 and p53. Moreover, the NUP98-HBO1 fusion protein exerted its oncogenic properties via interaction with MLL but not its intrinsic HAT activity. Thus, the interaction between the HBO1 complex and MLL is an important nexus in leukemic transformation, which may serve as a therapeutic target for drug development.
Collapse
Affiliation(s)
- Satoshi Takahashi
- Tsuruoka Metabolomics Laboratory, National Cancer CenterTsuruokaJapan
- Department of Hematology and Oncology, Kyoto University Graduate School of MedicineKyotoJapan
| | - Akinori Kanai
- Department of Molecular Oncology and Leukemia Program Project, Research Institute for Radiation Biology and Medicine, Hiroshima UniversityHiroshimaJapan
| | - Hiroshi Okuda
- Tsuruoka Metabolomics Laboratory, National Cancer CenterTsuruokaJapan
| | - Ryo Miyamoto
- Tsuruoka Metabolomics Laboratory, National Cancer CenterTsuruokaJapan
| | - Yosuke Komata
- Tsuruoka Metabolomics Laboratory, National Cancer CenterTsuruokaJapan
| | | | - Hirotaka Matsui
- Department of Molecular Laboratory Medicine, Faculty of Life Sciences, Kumamoto UniversityKumamotoJapan
| | - Toshiya Inaba
- Department of Molecular Oncology and Leukemia Program Project, Research Institute for Radiation Biology and Medicine, Hiroshima UniversityHiroshimaJapan
| | - Akifumi Takaori-Kondo
- Department of Hematology and Oncology, Kyoto University Graduate School of MedicineKyotoJapan
| | - Akihiko Yokoyama
- Tsuruoka Metabolomics Laboratory, National Cancer CenterTsuruokaJapan
- Department of Hematology and Oncology, Kyoto University Graduate School of MedicineKyotoJapan
- Division of Hematological Malignancy, National Cancer Center Research InstituteTokyoJapan
| |
Collapse
|
5
|
Li J, Lee YK, Fu W, Whalen AM, Estable MC, Raftery LA, White K, Weiner L, Brissette JL. Modeling by disruption and a selected-for partner for the nude locus. EMBO Rep 2020; 22:e49804. [PMID: 33369874 PMCID: PMC7926259 DOI: 10.15252/embr.201949804] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 11/03/2020] [Accepted: 11/20/2020] [Indexed: 12/25/2022] Open
Abstract
A long‐standing problem in biology is how to dissect traits for which no tractable model exists. Here, we screen for genes like the nude locus (Foxn1)—genes central to mammalian hair and thymus development—using animals that never evolved hair, thymi, or Foxn1. Fruit flies are morphologically disrupted by the FOXN1 transcription factor and rescued by weak reductions in fly gene function, revealing molecules that potently synergize with FOXN1 to effect dramatic, chaotic change. Strong synergy/effectivity in flies is expected to reflect strong selection/functionality (purpose) in mammals; the more disruptive a molecular interaction is in alien contexts (flies), the more beneficial it will be in its natural, formative contexts (mammals). The approach identifies Aff4 as the first nude‐like locus, as murine AFF4 and FOXN1 cooperatively induce similar cutaneous/thymic phenotypes, similar gene expression programs, and the same step of transcription, pre‐initiation complex formation. These AFF4 functions are unexpected, as AFF4 also serves as a scaffold in common transcriptional‐elongation complexes. Most likely, the approach works because an interaction's power to disrupt is the inevitable consequence of its selected‐for power to benefit.
Collapse
Affiliation(s)
- Jian Li
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, NY, USA.,Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Yun-Kyoung Lee
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, NY, USA
| | - Wenyu Fu
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, NY, USA.,Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Anne M Whalen
- Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Mario C Estable
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Laurel A Raftery
- Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Kristin White
- Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Lorin Weiner
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, NY, USA.,Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Janice L Brissette
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, NY, USA.,Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| |
Collapse
|
6
|
Miyamoto R, Okuda H, Kanai A, Takahashi S, Kawamura T, Matsui H, Kitamura T, Kitabayashi I, Inaba T, Yokoyama A. Activation of CpG-Rich Promoters Mediated by MLL Drives MOZ-Rearranged Leukemia. Cell Rep 2020; 32:108200. [DOI: 10.1016/j.celrep.2020.108200] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 07/28/2020] [Accepted: 09/03/2020] [Indexed: 01/04/2023] Open
|
7
|
Liu H, Lee S, Zhang Q, Chen Z, Zhang G. The potential underlying mechanism of the leukemia caused by MLL-fusion and potential treatments. Mol Carcinog 2020; 59:839-851. [PMID: 32329934 DOI: 10.1002/mc.23204] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 04/07/2020] [Accepted: 04/07/2020] [Indexed: 12/12/2022]
Abstract
A majority of infant and pediatric leukemias are caused by the mixed-lineage leukemia gene (MLL) fused with a variety of candidates. Several underlying mechanisms have been proposed. One currently popular view is that truncated MLL1 fusion and its associated complex constitutively hijacks super elongation complex, including positive transcription elongation factor b, CDK9, and cyclin T1 complex and DOT1L, to enhance the expression of transcription factors that maintain or restore stemness of leukocytes, as well as prevent the differentiation of hematopoietic progenitor cells. An alternative emerging view proposes that MLL1-fusion promotes the recruitment of TATA binding protein and RNA polymerase II (Pol II) initiation complex, so as to increase the expression levels of target genes. The fundamental mechanism of both theories are gain of function for truncated MLL1 fusions, either through Pol II elongation or initiation. Our recent progress in transcription regulation of paused Pol II through JMJD5, JMJD6, and JMJD7, combined with the repressive role of H3K4me3 revealed by others, prompted us to introduce a contrarian hypothesis: the failure to shut down transcribing units by MLL-fusions triggers the transformation: loss of function of truncated MLL1 fusions coupled with the loss of conversion of H3K4me1 to H3K4me3, leading to the constitutive expression of transcription factors that are in charge of maintenance of hematopoietic progenitor cells, may trigger the transformation of normal cells into cancer cells. Following this track, a potential treatment to eliminate these fusion proteins, which may ultimately cure the disease, is proposed.
Collapse
Affiliation(s)
- Haolin Liu
- Department of Biomedical Research, National Jewish Health, and Department of Immunology and Microbiology, Anschutz Medical Center, University of Colorado, Denver, Colorado
| | - Schuyler Lee
- Department of Biomedical Research, National Jewish Health, and Department of Immunology and Microbiology, Anschutz Medical Center, University of Colorado, Denver, Colorado
| | - Qianqian Zhang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Agriculture University, Beijing, China
| | - Zhongzhou Chen
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Agriculture University, Beijing, China
| | - Gongyi Zhang
- Department of Biomedical Research, National Jewish Health, and Department of Immunology and Microbiology, Anschutz Medical Center, University of Colorado, Denver, Colorado
| |
Collapse
|
8
|
Takahashi S, Yokoyama A. The molecular functions of common and atypical MLL fusion protein complexes. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194548. [PMID: 32320750 DOI: 10.1016/j.bbagrm.2020.194548] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/19/2020] [Accepted: 03/31/2020] [Indexed: 12/17/2022]
Abstract
Mixed-lineage leukemia (MLL) fuses with a variety of partners to produce a functionally altered MLL complex that is not expressed in normal cells, which transforms normal hematopoietic progenitors into leukemia cells. Because more than 80 fusion partners have been identified to date, the molecular functions of MLL fusion protein complexes appear diverse. However, over the past decade, the common functions utilized for leukemic transformation have begun to be elucidated. It appears that most (if not all) MLL fusion protein complexes utilize the AF4/ENL/P-TEFb and DOT1L complexes to some extent. Based on an understanding of the underlying molecular mechanisms, several molecular targeting drugs are being developed, opening paths to novel therapies. Here, we review the recent progress made in identifying the molecular functions of various MLL fusions and categorize the numerous fusion partners into several functionally-distinct groups to help discern commonalities and differences among various MLL fusion protein complexes.
Collapse
Affiliation(s)
- Satoshi Takahashi
- Tsuruoka Metabolomics Laboratory, National Cancer Center, Tsuruoka, Japan; Department of Hematology and Oncology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akihiko Yokoyama
- Tsuruoka Metabolomics Laboratory, National Cancer Center, Tsuruoka, Japan; National Cancer Center Research Institute, Tokyo, Japan.
| |
Collapse
|
9
|
The reciprocal world of MLL fusions: A personal view. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194547. [PMID: 32294539 DOI: 10.1016/j.bbagrm.2020.194547] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/12/2020] [Accepted: 03/22/2020] [Indexed: 01/28/2023]
Abstract
Over the last 15 years the Diagnostic Center of Acute Leukemia (DCAL) at the Frankfurt University has diagnosed and elucidated the Mixed Lineage Leukemia (MLL) recombinome with >100 MLL fusion partners. When analyzing all these different events, balanced chromosomal translocations were found to comprise the majority of these cases (~70%), while other types of genetic rearrangements (3-way-translocations, spliced fusions, 11q inversions, interstitial deletions or insertion of chromosomal fragments into other chromosomes) account for about 30%. In nearly all those complex cases, functional fusion proteins can be produced by transcription, splicing and translation. With a few exceptions (10 out of 102 fusion genes which were per se out-of-frame), all these genetic rearrangements produced a direct MLL fusion gene, and in 94% of cases an additional reciprocal fusion gene. So far, 114 patients (out of 2454 = ~5%) have been diagnosed only with the reciprocal fusion allele, displaying no MLL-X allele. The fact that so many MLL rearrangements bear at least two fusion alleles, but also our findings that several direct MLL fusions were either out-of-frame fusions or missing, raises the question about the function and importance of reciprocal MLL fusions. Recent findings also demonstrate the presence of reciprocal MLL fusions in sarcoma patients. Here, we want to discuss the role of reciprocal MLL fusion proteins for leukemogenesis and beyond.
Collapse
|
10
|
Crosstalk between 14-3-3θ and AF4 enhances MLL-AF4 activity and promotes leukemia cell proliferation. Cell Oncol (Dordr) 2019; 42:829-845. [PMID: 31493143 DOI: 10.1007/s13402-019-00468-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/19/2019] [Indexed: 01/14/2023] Open
Abstract
PURPOSE The t(4;11)(q21;q23) translocation characterizes a form of acute lymphoblastic leukemia with a poor prognosis. It results in a fusion gene encoding a chimeric transcription factor, MLL-AF4, that deregulates gene expression through a variety of still controversial mechanisms. To provide new insights into these mechanisms, we examined the interaction between AF4, the most common MLL fusion partner, and the scaffold protein 14-3-3θ, in the context of t(4;11)-positive leukemia. METHODS Protein-protein interactions were analyzed using immunoprecipitation and in vitro binding assays, and by fluorescence microscopy in t(4;11)-positive RS4;11 and MV4-11 leukemia cells and in HEK293 cells. Protein and mRNA expression levels were determined by Western blotting and RT-qPCR, respectively. A 5-bromo-2'-deoxyuridine assay and an annexin V/propidium iodide assay were used to assess proliferation and apoptosis rates, respectively, in t(4;11)-positive and control cells. Chromatin immunoprecipitation was performed to assess binding of 14-3-3θ and AF4 to a specific promoter element. RESULTS We found that AF4 and 14-3-3θ are nuclear interactors, that 14-3-3θ binds Ser588 of AF4 and that 14-3-3θ forms a complex with MLL-AF4. In addition, we found that in t(4;11)-positive cells, 14-3-3θ knockdown decreased the expression of MLL-AF4 target genes, induced apoptosis and hampered cell proliferation. Moreover, we found that 14-3-3θ knockdown impaired the recruitment of AF4, but not of MLL-AF4, to target chromatin. Overall, our data indicate that the activity of the chimeric transcription factor MLL-AF4 depends on the cellular availability of 14-3-3θ, which triggers the transactivating function and subsequent degradation of AF4. CONCLUSIONS From our data we conclude that the scaffold protein 14-3-3θ enhances the aberrant activity of the chimeric transcription factor MLL-AF4 and, therefore, represents a new player in the molecular pathogenesis of t(4;11)-positive leukemia and a new promising therapeutic target.
Collapse
|
11
|
Affiliation(s)
- Rolf Marschalek
- Institute of Pharmaceutical Biology / Diagnostic Center of Acute Leukemia, University of Frankfurt, Frankfurt/Main, Germany
| |
Collapse
|
12
|
Yokoyama A. RNA Polymerase II-Dependent Transcription Initiated by Selectivity Factor 1: A Central Mechanism Used by MLL Fusion Proteins in Leukemic Transformation. Front Genet 2019; 9:722. [PMID: 30693017 PMCID: PMC6339877 DOI: 10.3389/fgene.2018.00722] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/21/2018] [Indexed: 11/13/2022] Open
Abstract
Cancer cells transcribe RNAs in a characteristic manner in order to maintain their oncogenic potentials. In eukaryotes, RNA is polymerized by three distinct RNA polymerases, RNA polymerase I, II, and III (RNAP1, RNAP2, and RNAP3, respectively). The transcriptional machinery that initiates each transcription reaction has been purified and characterized. Selectivity factor 1 (SL1) is the complex responsible for RNAP1 pre-initiation complex formation. However, whether it plays any role in RNAP2-dependent transcription remains unclear. Our group previously found that SL1 specifically associates with AF4 family proteins. AF4 family proteins form the AEP complex with ENL family proteins and the P-TEFb elongation factor. Similar complexes have been independently characterized by several different laboratories and are often referred to as super elongation complex. The involvement of AEP in RNAP2-dependent transcription indicates that SL1 must play an important role in RNAP2-dependent transcription. To date, this role of SL1 has not been appreciated. In leukemia, AF4 and ENL family genes are frequently rearranged to form chimeric fusion genes with MLL. The resultant MLL fusion genes produce chimeric MLL fusion proteins comprising MLL and AEP components. The MLL portion functions as a targeting module, which specifically binds chromatin containing di-/tri-methylated histone H3 lysine 36 and non-methylated CpGs. This type of chromatin is enriched at the promoters of transcriptionally active genes which allows MLL fusion proteins to selectively bind to transcriptionally-active/CpG-rich gene promoters. The fusion partner portion, which recruits other AEP components and SL1, is responsible for activation of RNAP2-dependent transcription. Consequently, MLL fusion proteins constitutively activate the transcription of previously-transcribed MLL target genes. Structure/function analysis has shown that the ability of MLL fusion proteins to transform hematopoietic progenitors depends on the recruitment of AEP and SL1. Thus, the AEP/SL1-mediated gene activation pathway appears to be the central mechanism of MLL fusion-mediated transcriptional activation. However, the molecular mechanism by which SL1 activates RNAP2-dependent transcription remains largely unclear. This review aims to cover recent discoveries of the mechanism of transcriptional activation by MLL fusion proteins and to introduce novel roles of SL1 in RNAP2-dependent transcription by discussing how the RNAP1 machinery may be involved in RNAP2-dependent gene regulation.
Collapse
Affiliation(s)
- Akihiko Yokoyama
- Tsuruoka Meatabolomics Laboratory, National Cancer Center, Yamagata, Japan
| |
Collapse
|
13
|
Differential expression of cyclin-dependent kinases in the adult human retina in relation to CDK inhibitor retinotoxicity. Arch Toxicol 2019; 93:659-671. [PMID: 30617560 DOI: 10.1007/s00204-018-2376-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 12/10/2018] [Indexed: 01/21/2023]
Abstract
Cyclin-dependent kinases (CDKs) are a family of kinases associated predominantly with cell cycle control, making CDK inhibitors interesting candidates for anti-cancer therapeutics. However, retinal toxicity (loss of photoreceptors) has been associated with CDK inhibitors, including the pan-CDK inhibitor AG-012896. The purpose of this research was to use a novel planar sectioning technique to determine CDK expression profiles in the ex vivo human retina with the aim of identifying isoforms responsible for CDK retinotoxicity. Four CDK isoforms (CDK11, 16, 17 and 18) were selected as a result of IC50 data comparing neurotoxic (AG-012986 and NVP-1) and non-neurotoxic (dinaciclib and NVP-2) CDK inhibitors, with IC50s at CDK11 showing a clear difference between the neurotoxic and non-neurotoxic drugs. CDK11 was maximally expressed in the photoreceptor layer, whereas CDK16, 17 and 18 showed maximal expression in the inner nuclear layer. CDK5 (an isoform associated with retinal homeostasis) was maximally expressed in the retinal ganglion cell layer. Apart from CDK18, each isoform showed expression in the photoreceptor layer. The human Müller cell line MIO-M1 expressed CDK5, 11, 16 and 17 and AG-01298 (0.02-60 µM) caused a dose-dependent increase in MIO-M1 cell death. In conclusion, CDK11 appears the most likely candidate for mediation of photoreceptor toxicity. RNA profiling can be used to determine the distribution of genes of interest in relation to retinal toxicity in the human retina.
Collapse
|
14
|
Kotani S, Yoda A, Kon A, Kataoka K, Ochi Y, Shiozawa Y, Hirsch C, Takeda J, Ueno H, Yoshizato T, Yoshida K, Nakagawa MM, Nannya Y, Kakiuchi N, Yamauchi T, Aoki K, Shiraishi Y, Miyano S, Maeda T, Maciejewski JP, Takaori-Kondo A, Ogawa S, Makishima H. Molecular pathogenesis of disease progression in MLL-rearranged AML. Leukemia 2018; 33:612-624. [PMID: 30209403 PMCID: PMC6462875 DOI: 10.1038/s41375-018-0253-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 06/25/2018] [Accepted: 08/07/2018] [Indexed: 02/07/2023]
Abstract
Leukemic relapse is frequently accompanied by progressively aggressive clinical course. To understand the molecular mechanism of leukemic relapse, MLL/AF9-transformed mouse leukemia cells were serially transplanted in C57BL/6 mice (N = 96) by mimicking repeated recurrences, where mutations were monitored by exome sequencing (N = 42). The onset of leukemia was progressively promoted with advanced transplants, during which increasing numbers of somatic mutations were acquired (P < 0.005). Among these, mutations in Ptpn11 (p.G60R) and Braf (p.V637E) corresponded to those identified in human MLL-AML, while recurrent mutations affecting Msn (p.R295C) were observed only in mouse but not in human MLL-AML. Another mutated gene of interest was Gnb2 which was reported to be recurrently mutated in various hematological neoplasms. Gnb2 mutations (p.G77R) were significantly increased in clone size (P = 0.007) and associated with earlier leukemia onset (P = 0.011). GNB2 transcripts were significantly upregulated in human MLL-AML compared to MLL-negative AML (P < 0.05), which was supported by significantly increased Gnb2 transcript induced by MLL/AF9 overexpression (P < 0.001). In in vivo model, both mutation and overexpression of GNB2 caused leukemogenesis, and downregulation of GNB2 expression reduced proliferative potential and survival benefit, suggesting a driver role of GNB2. In conclusion, alterations of driver genes over time may play an important role in the progression of MLL-AML.
Collapse
Affiliation(s)
- Shinichi Kotani
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan.,Department of Hematology and Oncology, Kyoto University, Kyoto, Japan
| | - Akinori Yoda
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Ayana Kon
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | - Keisuke Kataoka
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | - Yotaro Ochi
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan.,Department of Hematology and Oncology, Kyoto University, Kyoto, Japan
| | - Yusuke Shiozawa
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | - Cassandra Hirsch
- Department of Translational Hematology and Oncology Research, Cleveland Clinic, Taussig Cancer Institute, Cleveland, OH, USA
| | - June Takeda
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan.,Department of Hematology and Oncology, Kyoto University, Kyoto, Japan
| | - Hiroo Ueno
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | | | - Kenichi Yoshida
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | | | - Yasuhito Nannya
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | - Nobuyuki Kakiuchi
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | - Takuji Yamauchi
- Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Kosuke Aoki
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | - Yuichi Shiraishi
- Laboratory of DNA Information Analysis, Human Genome Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Satoru Miyano
- Laboratory of DNA Information Analysis, Human Genome Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Takahiro Maeda
- Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Center for Cellular and Molecular Medicine, Kyushu University Hospital, Fukuoka, Japan
| | - Jaroslaw P Maciejewski
- Department of Translational Hematology and Oncology Research, Cleveland Clinic, Taussig Cancer Institute, Cleveland, OH, USA
| | | | - Seishi Ogawa
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan.
| | - Hideki Makishima
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan. .,Department of Translational Hematology and Oncology Research, Cleveland Clinic, Taussig Cancer Institute, Cleveland, OH, USA.
| |
Collapse
|
15
|
Malouf C, Ottersbach K. Molecular processes involved in B cell acute lymphoblastic leukaemia. Cell Mol Life Sci 2018; 75:417-446. [PMID: 28819864 PMCID: PMC5765206 DOI: 10.1007/s00018-017-2620-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 08/01/2017] [Accepted: 08/04/2017] [Indexed: 12/19/2022]
Abstract
B cell leukaemia is one of the most frequent malignancies in the paediatric population, but also affects a significant proportion of adults in developed countries. The majority of infant and paediatric cases initiate the process of leukaemogenesis during foetal development (in utero) through the formation of a chromosomal translocation or the acquisition/deletion of genetic material (hyperdiploidy or hypodiploidy, respectively). This first genetic insult is the major determinant for the prognosis and therapeutic outcome of patients. B cell leukaemia in adults displays similar molecular features as its paediatric counterpart. However, since this disease is highly represented in the infant and paediatric population, this review will focus on this demographic group and summarise the biological, clinical and epidemiological knowledge on B cell acute lymphoblastic leukaemia of four well characterised subtypes: t(4;11) MLL-AF4, t(12;21) ETV6-RUNX1, t(1;19) E2A-PBX1 and t(9;22) BCR-ABL1.
Collapse
Affiliation(s)
- Camille Malouf
- MRC Centre for Regenerative Medicine, The University of Edinburgh, 5 Little France Drive, Edinburgh, EH16 4UU, UK
| | - Katrin Ottersbach
- MRC Centre for Regenerative Medicine, The University of Edinburgh, 5 Little France Drive, Edinburgh, EH16 4UU, UK.
| |
Collapse
|
16
|
Pharmacological perturbation of CDK9 using selective CDK9 inhibition or degradation. Nat Chem Biol 2017; 14:163-170. [PMID: 29251720 DOI: 10.1038/nchembio.2538] [Citation(s) in RCA: 336] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 11/09/2017] [Indexed: 01/06/2023]
Abstract
Cyclin-dependent kinase 9 (CDK9), an important regulator of transcriptional elongation, is a promising target for cancer therapy, particularly for cancers driven by transcriptional dysregulation. We characterized NVP-2, a selective ATP-competitive CDK9 inhibitor, and THAL-SNS-032, a selective CDK9 degrader consisting of a CDK-binding SNS-032 ligand linked to a thalidomide derivative that binds the E3 ubiquitin ligase Cereblon (CRBN). To our surprise, THAL-SNS-032 induced rapid degradation of CDK9 without affecting the levels of other SNS-032 targets. Moreover, the transcriptional changes elicited by THAL-SNS-032 were more like those caused by NVP-2 than those induced by SNS-032. Notably, compound washout did not significantly reduce levels of THAL-SNS-032-induced apoptosis, suggesting that CDK9 degradation had prolonged cytotoxic effects compared with CDK9 inhibition. Thus, our findings suggest that thalidomide conjugation represents a promising strategy for converting multi-targeted inhibitors into selective degraders and reveal that kinase degradation can induce distinct pharmacological effects compared with inhibition.
Collapse
|
17
|
Okuda H, Yokoyama A. In vivo Leukemogenesis Model Using Retrovirus Transduction. Bio Protoc 2017; 7:e2627. [PMID: 34595295 DOI: 10.21769/bioprotoc.2627] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/21/2017] [Accepted: 10/31/2017] [Indexed: 11/02/2022] Open
Abstract
Various genetic alterations such as chromosomal translocation cause leukemia. For examples, gene rearrangements of the mixed-lineage leukemia (MLL) gene generate MLL fusion genes, whose products are potent oncogenic drivers in acute leukemia. To better understand the mechanism of disease onset, several murine leukemia models using retroviral gene transduction, xenograft, or Cre-mediated chromosomal translocation have been developed over the past twenty years. Particularly, a retroviral gene transduction-mediated murine leukemia model has been frequently used in the leukemia research field. Here, we describe the detailed protocol for this model.
Collapse
Affiliation(s)
- Hiroshi Okuda
- Tsuruoka Metabolomics Laboratory, National Cancer Center, Yamagata, Japan
| | - Akihiko Yokoyama
- Tsuruoka Metabolomics Laboratory, National Cancer Center, Yamagata, Japan
| |
Collapse
|
18
|
Okuda H, Yokoyama A. Myeloid Progenitor Transformation Assay. Bio Protoc 2017; 7:e2626. [PMID: 34595294 DOI: 10.21769/bioprotoc.2626] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/21/2017] [Accepted: 10/26/2017] [Indexed: 11/02/2022] Open
Abstract
Numerous oncogenes have been identified to cause leukemia. For example, chromosomal translocation generates various fusion genes of the mixed-lineage leukemia (MLL) gene and a partner gene in leukemia, whose gene products transform primary myeloid progenitors into an immortalized state. To characterize the transforming ability of leukemic oncogenes, researchers in the field have developed an ex vivo murine myeloid transformation assay using retroviral gene transduction and its protocol has been improved over the past 10 years. Here, we provide the detailed procedure for this assay.
Collapse
Affiliation(s)
- Hiroshi Okuda
- Tsuruoka Metabolomics Laboratory, National Cancer Center, Yamagata, Japan
| | - Akihiko Yokoyama
- Tsuruoka Metabolomics Laboratory, National Cancer Center, Yamagata, Japan
| |
Collapse
|
19
|
Okuda H, Stanojevic B, Kanai A, Kawamura T, Takahashi S, Matsui H, Takaori-Kondo A, Yokoyama A. Cooperative gene activation by AF4 and DOT1L drives MLL-rearranged leukemia. J Clin Invest 2017; 127:1918-1931. [PMID: 28394257 DOI: 10.1172/jci91406] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 02/16/2017] [Indexed: 11/17/2022] Open
Abstract
The eleven-nineteen leukemia (ENL) protein family, composed of ENL and AF9, is a common component of 3 transcriptional modulators: AF4-ENL-P-TEFb complex (AEP), DOT1L-AF10-ENL complex (referred to as the DOT1L complex) and polycomb-repressive complex 1 (PRC1). Each complex associates with chromatin via distinct mechanisms, conferring different transcriptional properties including activation, maintenance, and repression. The mixed-lineage leukemia (MLL) gene often fuses with ENL and AF10 family genes in leukemia. However, the functional interrelationship among those 3 complexes in leukemic transformation remains largely elusive. Here, we have shown that MLL-ENL and MLL-AF10 constitutively activate transcription by aberrantly inducing both AEP-dependent transcriptional activation and DOT1L-dependent transcriptional maintenance, mostly in the absence of PRC1, to fully transform hematopoietic progenitors. These results reveal a cooperative transcriptional activation mechanism of AEP and DOT1L and suggest a molecular rationale for the simultaneous inhibition of the MLL fusion-AF4 complex and DOT1L for more effective treatment of MLL-rearranged leukemia.
Collapse
|
20
|
Yokoyama A. Transcriptional activation by MLL fusion proteins in leukemogenesis. Exp Hematol 2016; 46:21-30. [PMID: 27865805 DOI: 10.1016/j.exphem.2016.10.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 10/14/2016] [Accepted: 10/29/2016] [Indexed: 12/16/2022]
Abstract
Chromosomal translocations involving the mixed lineage leukemia (MLL) gene cause aggressive leukemia. Fusion proteins of MLL and a component of the AF4 family/ENL family/P-TEFb complex (AEP) are responsible for two-thirds of MLL-associated leukemia cases. MLL-AEP fusion proteins trigger aberrant self-renewal of hematopoietic progenitors by constitutively activating self-renewal-related genes. MLL-AEP fusion proteins activate transcription initiation by loading the TATA-binding protein (TBP) to the TATA element via selectivity factor 1. Although AEP retains transcription elongation and mediator recruiting activities, the rate-limiting step activated by MLL-AEP fusion proteins appears to be the TBP-loading step. This is contrary to prevailing views, in which the recruitment of transcription elongation activities are emphasized. Here, I review recent advances towards elucidating the mechanisms underlying gene activation by MLL-AEP fusion proteins in leukemogenesis.
Collapse
Affiliation(s)
- Akihiko Yokoyama
- Department of Hematology and Oncology, Kyoto University Graduate School of Medicine, Kyoto, Japan; Division of Hematological Malignancy, National Cancer Center Research Institute, Tokyo, Japan.
| |
Collapse
|