title: A novel PAD4/SOX4/PU.1 signaling pathway is involved in the committed differentiation of acute promyelocytic leukemia cells into granulocytic cells.
abstract: All-trans retinoic acid (ATRA) treatment yields cure rates > 80% through proteasomal degradation of the PML-RARα fusion protein that typically promotes acute promyelocytic leukemia (APL). However, recent evidence indicates that ATRA can also promote differentiation of leukemia cells that are PML-RARα negative, such as HL-60 cells. Here, gene expression profiling of HL-60 cells was used to investigate the alternative mechanism of impaired differentiation in APL. The expression of peptidylarginine deiminase 4 (PADI4), encoding PAD4, a protein that post-translationally converts arginine into citrulline, was restored during ATRA-induced differentiation. We further identified that hypermethylation in the PADI4 promoter was associated with its transcriptional repression in HL-60 and NB4 (PML-RARα positive) cells. Functionally, PAD4 translocated into the nucleus upon ATRA exposure and promoted ATRA-mediated differentiation. Mechanistic studies using RNAi knockdown or electroporation-mediated delivery of PADI4, along with chromatin immunoprecipitation, helped identify PU.1 as an indirect target and SOX4 as a direct target of PAD4 regulation. Indeed, PAD4 regulates SOX4-mediated PU.1 expression, and thereby the differentiation process, in a SOX4-dependent manner. Taken together, our results highlight an association between PAD4 and DNA hypermethylation in APL and demonstrate that targeting PAD4 or regulating its downstream effectors may be a promising strategy to control differentiation in the clinic.
authors.affiliation: Department of Hemato-Oncology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Key Medical Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology of Shandong, Jinan, Shandong, China.
authors.forename: Guanhua
authors.initials: G
authors.lastname: Song
authors.affiliation: Department of Hemato-Oncology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Key Medical Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology of Shandong, Jinan, Shandong, China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Shi
authors.affiliation: Department of Hemato-Oncology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Key Medical Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology of Shandong, Jinan, Shandong, China.
authors.forename: Yuqi
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Department of Hemato-Oncology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Key Medical Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology of Shandong, Jinan, Shandong, China.
authors.forename: Linchang
authors.initials: L
authors.lastname: Yu
authors.affiliation: Research Center for Medicinal Biotechnology, Shandong Academy of Medicinal Sciences, Jinan, Shandong, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Hemato-Oncology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Key Medical Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology of Shandong, Jinan, Shandong, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Hemato-Oncology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Key Medical Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology of Shandong, Jinan, Shandong, China.
authors.forename: Lianlian
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Hemato-Oncology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Key Medical Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology of Shandong, Jinan, Shandong, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Han
authors.affiliation: Department of Hemato-Oncology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Key Medical Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology of Shandong, Jinan, Shandong, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Ren
authors.affiliation: Department of Hemato-Oncology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Key Medical Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology of Shandong, Jinan, Shandong, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Qianfoshan Hospital of Shandong, Jinan, Shandong, China.
authors.forename: Kehong
authors.initials: K
authors.lastname: Bi
authors.affiliation: Department of Hemato-Oncology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Key Medical Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology of Shandong, Jinan, Shandong, China.
authors.forename: Guosheng
authors.initials: G
authors.lastname: Jiang
mesh_terms: D021581:Active Transport, Cell Nucleus; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D045744:Cell Line, Tumor; D047369:Chromatin Immunoprecipitation; D004247:DNA / Q000378:metabolism; D019175:DNA Methylation / Q000235:genetics; D006098:Granulocytes / Q000166:cytology*; D018922:HL-60 Cells; D006801:Humans; D006867:Hydrolases / Q000235:genetics / Q000378:metabolism*; D015473:Leukemia, Promyelocytic, Acute / Q000473:pathology*; D015514:Oncogene Proteins, Fusion; D011401:Promoter Regions, Genetic / Q000235:genetics; D000080002:Protein-Arginine Deiminase Type 4; D000076342:Protein-Arginine Deiminases; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D055751:SOXC Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D015534:Trans-Activators / Q000378:metabolism*; D014212:Tretinoin / Q000494:pharmacology*; D000099232:Proto-Oncogene Protein Spi-1
chemical_list: D000970:Antineoplastic Agents; D004247:DNA; D006867:Hydrolases; D015514:Oncogene Proteins, Fusion; D000080002:Protein-Arginine Deiminase Type 4; D000076342:Protein-Arginine Deiminases; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D055751:SOXC Transcription Factors; D015534:Trans-Activators; D014212:Tretinoin; D000099232:Proto-Oncogene Protein Spi-1; C083431:SOX4 protein, human; C093476:promyelocytic leukemia-retinoic acid receptor alpha fusion oncoprotein; C000629235:PADI4 protein, human
keywords: PADI4; differentiation; leukemia; methylation