title: Helicase-like transcription factor is a RUNX1 target whose downregulation promotes genomic instability and correlates with complex cytogenetic features in acute myeloid leukemia.
abstract: Helicase-like transcription factor is a SWI/SNF chromatin remodeling factor involved in various biological processes. However, little is known about its role in hematopoiesis. In this study, we measured helicase-like transcription factor mRNA expression in the bone marrow of 204 adult patients with de novo acute myeloid leukemia. Patients were dichotomized into low and high expression groups at the median level for clinicopathological correlations. Helicase-like transcription factor levels were dramatically reduced in the low expression patient group compared to those in the normal controls (n=40) (P<0.0001). Low helicase-like transcription factor expression correlated positively with French-American-British M4/M5 subtypes (P<0.0001) and complex cytogenetic abnormalities (P=0.02 for ≥3 abnormalities;P=0.004 for ≥5 abnormalities) but negatively with CEBPA double mutations (P=0.012). Also, low expression correlated with poorer overall (P=0.005) and event-free (P=0.006) survival in the intermediate-risk cytogenetic subgroup. Consistent with the more aggressive disease associated with low expression, helicase-like transcription factor knockdown in leukemic cells promoted proliferation and chromosomal instability that was accompanied by downregulation of mitotic regulators and impaired DNA damage response. The significance of helicase-like transcription factor in genome maintenance was further indicated by its markedly elevated expression in normal human CD34(+)hematopoietic stem cells. We further demonstrated that helicase-like transcription factor was a RUNX1 target and transcriptionally repressed by RUNX1-ETO and site-specific DNA methylation through a duplicated RUNX1 binding site in its promoter. Taken together, our findings provide new mechanistic insights on genomic instability linked to helicase-like transcription factor deregulation, and strongly suggest a tumor suppressor function of the SWI/SNF protein in acute myeloid leukemia.
authors.affiliation: Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Cina.
authors.forename: Chi Keung
authors.initials: CK
authors.lastname: Cheng
authors.affiliation: Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Cina.
authors.forename: Natalie P H
authors.initials: NP
authors.lastname: Chan
authors.affiliation: Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Cina.
authors.forename: Thomas S K
authors.initials: TS
authors.lastname: Wan
authors.affiliation: Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Cina.
authors.forename: Lai Ying
authors.initials: LY
authors.lastname: Lam
authors.affiliation: Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Cina.
authors.forename: Coty H Y
authors.initials: CH
authors.lastname: Cheung
authors.affiliation: Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Cina.
authors.forename: Terry H Y
authors.initials: TH
authors.lastname: Wong
authors.affiliation: Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Cina.
authors.forename: Rosalina K L
authors.initials: RK
authors.lastname: Ip
authors.affiliation: Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Cina Sir Y. K. Pao Centre for Cancer, Prince of Wales Hospital, Hong Kong, Cina.
authors.forename: Raymond S M
authors.initials: RS
authors.lastname: Wong
authors.affiliation: Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Cina State Key Laboratory in Oncology in South China, The Chinese University of Hong Kong, Cina margaretng@cuhk.edu.hk.
authors.forename: Margaret H L
authors.initials: MH
authors.lastname: Ng
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018952:Antigens, CD34 / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D001854:Bone Marrow Cells / Q000378:metabolism* / Q000473:pathology; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation; D002869:Chromosome Aberrations; D050676:Core Binding Factor Alpha 2 Subunit / Q000235:genetics* / Q000378:metabolism; D019175:DNA Methylation; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015973:Gene Expression Regulation, Leukemic; D042822:Genomic Instability; D006410:Hematopoiesis / Q000235:genetics; D006801:Humans; D059785:Karyotype; D015470:Leukemia, Myeloid, Acute / Q000235:genetics* / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D016019:Survival Analysis; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism
chemical_list: D018952:Antigens, CD34; D022762:CCAAT-Enhancer-Binding Proteins; C515848:CEBPA protein, human; D018797:Cell Cycle Proteins; D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins; C100023:HLTF protein, human; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C493728:RUNX1 protein, human; D014157:Transcription Factors