PMID- 32552847 OWN - NLM STAT- MEDLINE DCOM- 20210517 LR - 20240329 IS - 1756-8722 (Electronic) IS - 1756-8722 (Linking) VI - 13 IP - 1 DP - 2020 Jun 17 TI - The lncRNA LAMP5-AS1 drives leukemia cell stemness by directly modulating DOT1L methyltransferase activity in MLL leukemia. PG - 78 LID - 10.1186/s13045-020-00909-y [doi] LID - 78 AB - BACKGROUND: Mixed-lineage leukemia (MLL) gene rearrangements trigger aberrant epigenetic modification and gene expression in hematopoietic stem and progenitor cells, which generates one of the most aggressive subtypes of leukemia with an apex self-renewal. It remains a challenge to directly inhibit rearranged MLL itself because of its multiple fusion partners and the poorly annotated downstream genes of MLL fusion proteins; therefore, novel therapeutic targets are urgently needed. METHODS: qRT-PCR, receiver operating characteristic (ROC), and leukemia-free survival analysis were used to validate LAMP5-AS1 (LAMP5 antisense 1) expression and evaluate its clinical value. We performed in vitro and in vivo experiments to investigate the functional relevance of LAMP5-AS1 in MLL leukemia progression and leukemia cell stemness. RNA electrophoretic mobility shift assays (EMSA), histone methyltransferase assay, RNA pull-down assay, and RNA fluorescence in situ hybridization (FISH) were used to validate the relationship between LAMP5-AS1 and the methyltransferase activity of DOT1L. The downstream ectopic target genes of LAMP5-AS1/DOT1L were validated by the chromatin immunoprecipitation (ChIP) and western blot. RESULTS: We discovered that a long noncoding RNA (lncRNA) LAMP5-AS1 can promote higher degrees of H3K79 methylation, followed by upregulated expression of the self-renewal genes in the HOXA cluster, which are responsible for leukemia stemness in context of MLL rearrangements. We found that LAMP5-AS1 is specifically overexpressed in MLL leukemia patients (n = 58) than that in the MLL-wt leukemia (n = 163) (p < 0.001), and the patients with a higher expression level of LAMP5-AS1 exhibited a reduced 5-year leukemia-free survival (p < 0.01). LAMP5-AS1 suppression significantly reduced colony formation and increased differentiation of primary MLL leukemia CD34+ cells. Mechanistically, LAMP5-AS1 facilitated the methyltransferase activity of DOT1L by directly binding its Lys-rich region of catalytic domain, thus promoting the global patterns of H3K79 dimethylation and trimethylation in cells. These observations supported that LAMP5-AS1 upregulated H3K79me2/me3 and the transcription of DOT1L ectopic target genes. CONCLUSIONS: This is the first study that a lncRNA regulates the self-renewal program and differentiation block in MLL leukemia cells by facilitating the methyltransferase activity of DOT1L and global H3K79 methylation, showing its potential as a therapeutic target for MLL leukemia. FAU - Wang, Wen-Tao AU - Wang WT AD - MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. FAU - Chen, Tian-Qi AU - Chen TQ AD - MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. FAU - Zeng, Zhan-Cheng AU - Zeng ZC AD - MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. FAU - Pan, Qi AU - Pan Q AD - MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. FAU - Huang, Wei AU - Huang W AD - MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. FAU - Han, Cai AU - Han C AD - MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. FAU - Fang, Ke AU - Fang K AD - MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. FAU - Sun, Lin-Yu AU - Sun LY AD - MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. FAU - Yang, Qian-Qian AU - Yang QQ AD - MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. FAU - Wang, Dan AU - Wang D AD - Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangzhou, 510060, Guangdong, China. FAU - Luo, Xue-Qun AU - Luo XQ AD - The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China. FAU - Sun, Yu-Meng AU - Sun YM AD - MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. fengzhihualuo@163.com. FAU - Chen, Yue-Qin AU - Chen YQ AUID- ORCID: 0000-0002-5140-1993 AD - MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China. lsscyq@mail.sysu.edu.cn. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20200617 PL - England TA - J Hematol Oncol JT - Journal of hematology & oncology JID - 101468937 RN - 0 (Histones) RN - 0 (Homeodomain Proteins) RN - 0 (KMT2A protein, human) RN - 0 (LAMP5 protein, human) RN - 0 (Lysosomal Membrane Proteins) RN - 0 (Oncogene Proteins, Fusion) RN - 0 (RNA, Antisense) RN - 0 (RNA, Messenger) RN - 0 (RNA, Neoplasm) RN - 0 (RNA, Small Interfering) RN - 0 (Recombinant Fusion Proteins) RN - 149025-06-9 (Myeloid-Lymphoid Leukemia Protein) RN - 157907-48-7 (HoxA protein) RN - EC 2.1.1.- (DOT1L protein, human) RN - EC 2.1.1.43 (Histone-Lysine N-Methyltransferase) RN - K3Z4F929H6 (Lysine) SB - IM EIN - J Hematol Oncol. 2021 Mar 11;14(1):42. PMID: 33706768 MH - Animals MH - Cell Self Renewal/*genetics MH - Child, Preschool MH - Female MH - Gene Expression Regulation, Leukemic/genetics MH - Genetic Vectors/genetics MH - Heterografts MH - Histone-Lysine N-Methyltransferase/genetics/*metabolism MH - Histones/metabolism MH - Homeodomain Proteins/metabolism MH - Humans MH - Infant MH - Leukemia, Myeloid, Acute/enzymology/genetics/pathology MH - Lysine/metabolism MH - Lysosomal Membrane Proteins/*genetics MH - Male MH - Methylation MH - Mice MH - Mice, Inbred NOD MH - Mice, SCID MH - Myeloid-Lymphoid Leukemia Protein/genetics MH - Neoplastic Stem Cells/*enzymology MH - Oncogene Proteins, Fusion/genetics MH - Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/enzymology/*genetics/pathology MH - Primary Cell Culture MH - Protein Processing, Post-Translational MH - RNA Interference MH - RNA, Antisense/*genetics MH - RNA, Messenger/genetics MH - RNA, Neoplasm/*genetics MH - RNA, Small Interfering/genetics/pharmacology MH - Recombinant Fusion Proteins/metabolism MH - Specific Pathogen-Free Organisms MH - Tumor Cells, Cultured MH - Tumor Stem Cell Assay PMC - PMC7302350 OTO - NOTNLM OT - DOT1L OT - H3K79 methylation OT - LAMP5-AS1 OT - MLL leukemia OT - cell stemness OT - lncRNA COIS- The authors declare that they have no competing interests. EDAT- 2020/06/20 06:00 MHDA- 2021/05/18 06:00 PMCR- 2020/06/17 CRDT- 2020/06/20 06:00 PHST- 2020/04/16 00:00 [received] PHST- 2020/05/28 00:00 [accepted] PHST- 2020/06/20 06:00 [entrez] PHST- 2020/06/20 06:00 [pubmed] PHST- 2021/05/18 06:00 [medline] PHST- 2020/06/17 00:00 [pmc-release] AID - 10.1186/s13045-020-00909-y [pii] AID - 909 [pii] AID - 10.1186/s13045-020-00909-y [doi] PST - epublish SO - J Hematol Oncol. 2020 Jun 17;13(1):78. doi: 10.1186/s13045-020-00909-y.