Six1 regulates leukemia stem cell maintenance in acute myeloid leukemia

Molecular genetic changes in acute myeloid leukemia (AML) play crucial roles in leukemogenesis, including recurrent chromosome translocations, epigenetic/spliceosome mutations and transcription factor aberrations. Six1, a transcription factor of the Sine oculis homeobox (Six) family, has been shown to transform normal hematopoietic progenitors into leukemia in cooperation with Eya. However, the specific role and the underlying mechanism of Six1 in leukemia maintenance remain unexplored. Here, we showed increased expression of SIX1 in AML patients and murine leukemia stem cells (c‐Kit+ cells, LSCs). Importantly, we also observed that a higher level of Six1 in human patients predicts a worse prognosis. Notably, knockdown of Six1 significantly prolonged the survival of MLL‐AF9‐induced AML mice with reduced peripheral infiltration and tumor burden. AML cells from Six1‐knockdown (KD) mice displayed a significantly decreased number and function of LSC, as assessed by the immunophenotype, colony‐forming ability and limiting dilution assay. Further analysis revealed the augmented apoptosis of LSC and decreased expression of glycolytic genes in Six1 KD mice. Overall, our data showed that Six1 is essential for the progression of MLL‐AF9‐induced AML via maintaining the pool of LSC.

[1]  Cheng Cheng Zhang,et al.  The distinct metabolic profile of hematopoietic stem cells reflects their location in a hypoxic niche. , 2010, Cell stem cell.

[2]  Honglin Liu,et al.  Six1: A critical transcription factor in tumorigenesis , 2015, International journal of cancer.

[3]  Benjamin J. Raphael,et al.  Genomic and epigenomic landscapes of adult de novo acute myeloid leukemia. , 2013, The New England journal of medicine.

[4]  David E. Muench,et al.  c-Myc and Cancer Metabolism , 2012, Clinical Cancer Research.

[5]  C. So,et al.  Epigenetic therapies by targeting aberrant histone methylome in AML: molecular mechanisms, current preclinical and clinical development , 2016, Oncogene.

[6]  Richard A. Moore,et al.  Recurrent DGCR8, DROSHA, and SIX homeodomain mutations in favorable histology Wilms tumors. , 2015, Cancer cell.

[7]  William J. Israelsen,et al.  Cell-State-Specific Metabolic Dependency in Hematopoiesis and Leukemogenesis , 2014, Cell.

[8]  Zhaoming Li,et al.  Six1 Promotes Proliferation of Pancreatic Cancer Cells via Upregulation of Cyclin D1 Expression , 2013, PloS one.

[9]  A. Chinnaiyan,et al.  A role for the MLL fusion partner ENL in transcriptional elongation and chromatin modification. , 2007, Blood.

[10]  M. Suematsu,et al.  Regulation of the HIF-1alpha level is essential for hematopoietic stem cells. , 2010, Cell stem cell.

[11]  T. Chevassut,et al.  Genomic landscapes and clonality of de novo AML. , 2013, The New England journal of medicine.

[12]  D. Ma,et al.  SIX1 promotes tumor lymphangiogenesis by coordinating TGFβ signals that increase expression of VEGF-C. , 2014, Cancer research.

[13]  John J. Shin,et al.  Threshold insulin-pump interruption to reduce hypoglycemia. , 2013, The New England journal of medicine.

[14]  Jason W Locasale,et al.  Quantitative determinants of aerobic glycolysis identify flux through the enzyme GAPDH as a limiting step , 2014, eLife.

[15]  Eckart Meese,et al.  Mutations in the SIX1/2 pathway and the DROSHA/DGCR8 miRNA microprocessor complex underlie high-risk blastemal type Wilms tumors. , 2015, Cancer cell.

[16]  C. Laclef,et al.  Thymus, kidney and craniofacial abnormalities in Six1 deficient mice , 2003, Mechanisms of Development.

[17]  K. Ikeda,et al.  Six family genes—structure and function as transcription factors and their roles in development , 2000, BioEssays : news and reviews in molecular, cellular and developmental biology.

[18]  T. Cheng,et al.  PBX3 is essential for leukemia stem cell maintenance in MLL‐rearranged leukemia , 2017, International journal of cancer.

[19]  Jie-xiong Tan,et al.  Expression and significance of Six1 and Ezrin in cervical cancer tissue , 2011, Tumor Biology.

[20]  T. Golub,et al.  Transformation from committed progenitor to leukaemia stem cell initiated by MLL–AF9 , 2006, Nature.

[21]  R. Marschalek.  MLL Leukemia and Future Treatment Strategies , 2015, Archiv der Pharmazie.

[22]  Wolfram Goessling,et al.  The Wnt/β-Catenin Pathway Is Required for the Development of Leukemia Stem Cells in AML , 2010, Science.

[23]  G. Semenza,et al.  Hypoxia-Inducible Factor 1 and Dysregulated c-Myc Cooperatively Induce Vascular Endothelial Growth Factor and Metabolic Switches Hexokinase 2 and Pyruvate Dehydrogenase Kinase 1 , 2007, Molecular and Cellular Biology.

[24]  Bob Löwenberg,et al.  Diagnosis and management of AML in adults: 2017 ELN recommendations from an international expert panel. , 2017, Blood.

[25]  Jennifer J. Johnson,et al.  Prenatal and postnatal myeloid cells demonstrate stepwise progression in the pathogenesis of MLL fusion gene leukemia. , 2003, Blood.

[26]  J. Locasale,et al.  The Warburg Effect: How Does it Benefit Cancer Cells? , 2016, Trends in biochemical sciences.

[27]  P. Aplan,et al.  Chromosomal rearrangements leading to MLL gene fusions: clinical and biological aspects. , 2008, Cancer research.

[28]  C. Dang,et al.  Deregulation of Glucose Transporter 1 and Glycolytic Gene Expression by c-Myc* , 2000, The Journal of Biological Chemistry.

[29]  G. Semenza,et al.  HIF-1 mediates metabolic responses to intratumoral hypoxia and oncogenic mutations. , 2013, The Journal of clinical investigation.

[30]  Anindya Dutta,et al.  p21 in cancer: intricate networks and multiple activities , 2009, Nature Reviews Cancer.

[31]  K. Davies,et al.  The mixed-lineage leukemia fusion partner AF4 stimulates RNA polymerase II transcriptional elongation and mediates coordinated chromatin remodeling. , 2007, Human molecular genetics.

[32]  Peng Zhang,et al.  Tet2 Regulates Osteoclast Differentiation by Interacting with Runx1 and Maintaining Genomic 5-Hydroxymethylcytosine (5hmC) , 2018, Genom. Proteom. Bioinform..

[33]  H. Ford,et al.  Six1 overexpression in mammary cells induces genomic instability and is sufficient for malignant transformation. , 2008, Cancer research.

[34]  Martin J Firth,et al.  Altered glucose metabolism in childhood pre-B acute lymphoblastic leukaemia , 2006, Leukemia.

[35]  S. Mi,et al.  MLL fusion proteins preferentially regulate a subset of wild-type MLL target genes in the leukemic genome. , 2011, Blood.

[36]  R. Pieters,et al.  NRIP3: a novel translocation partner of MLL detected in a pediatric acute myeloid leukemia with complex chromosome 11 rearrangements , 2009, Haematologica.

[37]  Y. Li,et al.  Transcriptional Regulation of the Warburg Effect in Cancer by SIX1. , 2018, Cancer cell.

[38]  K Watanabe,et al.  Effects of p21Waf1/Cip1/Sdi1 on cellular gene expression: implications for carcinogenesis, senescence, and age-related diseases. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[39]  J. Rowley,et al.  PBX3 is an important cofactor of HOXA9 in leukemogenesis. , 2013, Blood.

[40]  M. Krzywinski,et al.  New insights to the MLL recombinome of acute leukemias , 2009, Leukemia.

[41]  S. Armstrong,et al.  AF10 regulates progressive H3K79 methylation and HOX gene expression in diverse AML subtypes. , 2014, Cancer cell.

[42]  M. Cleary,et al.  Immortalization and leukemic transformation of a myelomonocytic precursor by retrovirally transduced HRX–ENL , 1997, The EMBO journal.

[43]  Ping Huang,et al.  Liver Med23 ablation improves glucose and lipid metabolism through modulating FOXO1 activity , 2014, Cell Research.

[44]  Daisuke Nakada,et al.  Cell intrinsic and extrinsic regulation of leukemia cell metabolism , 2016, International Journal of Hematology.

[45]  Wenzheng Zhang,et al.  Dot1a-AF9 Complex Mediates Histone H3 Lys-79 Hypermethylation and Repression of ENaCα in an Aldosterone-sensitive Manner* , 2006, Journal of Biological Chemistry.

[46]  M. D. Boer,et al.  The MLL recombinome of acute leukemias , 2006, Leukemia.

[47]  G. Hamard,et al.  Altered myogenesis in Six1-deficient mice , 2003, Development.

[48]  G. Smyth,et al.  ELDA: extreme limiting dilution analysis for comparing depleted and enriched populations in stem cell and other assays. , 2009, Journal of immunological methods.

[49]  C. Laclef,et al.  Six1 is required for the early organogenesis of mammalian kidney , 2003, Development.

[50]  U. Testa.  Leukemia stem cells , 2011, Annals of Hematology.

[51]  S. Fan,et al.  Suppression of tumorigenesis and metastasis of hepatocellular carcinoma by shRNA interference targeting on homeoprotein Six1 , 2010, International journal of cancer.

[52]  R A Jungmann,et al.  c-Myc transactivation of LDH-A: implications for tumor metabolism and growth. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[53]  Xia Li,et al.  Six1 transcription factor is critical for coordination of epithelial, mesenchymal and vascular morphogenesis in the mammalian lung. , 2011, Developmental biology.

[54]  R. Slany,et al.  Pbx3 and Meis1 cooperate through multiple mechanisms to support Hox-induced murine leukemia , 2015, Haematologica.

[55]  J. Klawitter,et al.  Abnormalities in Glucose Uptake and Metabolism in Imatinib-Resistant Human BCR-ABL–Positive Cells , 2009, Clinical Cancer Research.

[56]  HemaExplorer: a Web server for easy and fast visualization of gene expression in normal and malignant hematopoiesis. , 2012, Blood.

[57]  Kongming Wu,et al.  The DACH/EYA/SIX gene network and its role in tumor initiation and progression , 2016, International journal of cancer.

[58]  S. Mi,et al.  Identification of functional cooperative mutations of SETD2 in human acute leukemia , 2014, Nature Genetics.

[59]  A. Elkahloun,et al.  PBX3 and MEIS1 Cooperate in Hematopoietic Cells to Drive Acute Myeloid Leukemias Characterized by a Core Transcriptome of the MLL-Rearranged Disease. , 2016, Cancer research.

[60]  M. Berridge,et al.  The level of glycolytic metabolism in acute myeloid leukemia blasts at diagnosis is prognostic for clinical outcome , 2011, Journal of leukocyte biology.

[61]  J. Asara,et al.  Metabolic signature identifies novel targets for drug resistance in multiple myeloma. , 2015, Cancer Research.

[62]  Kenta Nakai,et al.  PrognoScan: a new database for meta-analysis of the prognostic value of genes , 2009, BMC Medical Genomics.

[63]  H. Ford,et al.  The SIX1-EYA transcriptional complex as a therapeutic target in cancer , 2015, Expert opinion on therapeutic targets.

[64]  Scott A. Armstrong,et al.  MLL translocations, histone modifications and leukaemia stem-cell development , 2007, Nature Reviews Cancer.