title: Upregulation of T-Cell-Specific Transcription Factor Expression in Pediatric T-Cell Acute Lymphoblastic Leukemia (T-ALL).
abstract: OBJECTIVE
  T-cell acute lymphoblastic leukemia (T-ALL) is associated with recurrent chromosomal aberrations andabnormal ectopic gene expression during T-cell development. In order to gain insight into the pathogenesis of T-ALLthis study aimed to measure the level of expression of 7 T-cell oncogenes (LMO2, LYL1, TAL1, TLX1, TLX3, BMI1, andCALM-AF10) in pediatric T-ALL patients Material and Methods: LMO2, LYL1, TLX1, TLX3, BMI1, TAL1, and CALM-AF10 expression was measured usingquantitative real-time PCR in 43 pediatric T-ALL patients.
  
  
  RESULTS
  A high level of expression of LMO2, LYL1, TAL1, and BMI1 genes was observed in a large group of T-ALL.Several gene expression signatures indicative of leukemic arrest at specific stages of normal thymocyte development(LYL1 and LMO2) were highly expressed during the cortical and mature stages of T-cell development. Furthermore,upregulated TAL1 and BMI1 expression was observed in all phenotypic subgroups. In all, 6 of the patients had TLX1and TLX3 proto-oncogene expression, which does not occur in normal cells, and none of the patients had CALM-AF10fusion gene transcription. Expression of LYL1 alone and LMO2-LYL1 co-expression were associated with mediastinalinvolvement; however, high-level oncogene expression was not predictive of outcome in the present pediatric T-ALLpatient group, but there was a trend towards a poor prognostic impact of TAL1 and/or LMO2 and/or LYL1 protooncogeneexpression.
  
  
  CONCLUSIONS
  Poor prognostic impact of TAL1 and/or LMO2 and/or LYL1 proto-oncogene expression indicate the needfor extensive study on oncogenic rearrangement and immunophenotypic markers in T-ALL, and their relationship totreatment outcome.
  
  
  BACKGROUND
  None declared.
authors.affiliation: İstanbul University, Department of Genetics, Institute of Experimental Medicine, İstanbul, Turkey.
authors.forename: Müge
authors.initials: M
authors.lastname: Sayitoğlu
authors.affiliation: İstanbul University, Department of Genetics, Institute of Experimental Medicine, İstanbul, Turkey.
authors.forename: Yücel
authors.initials: Y
authors.lastname: Erbilgin
authors.affiliation: İstanbul University, Department of Genetics, Institute of Experimental Medicine, İstanbul, Turkey.
authors.forename: Ozden
authors.initials: O
authors.lastname: Hatırnaz Ng
authors.affiliation: İstanbul University, Cerrahpaşa School of Medicine, Department of Pediatric Hematology, İstanbul, Turkey.
authors.forename: Inci
authors.initials: I
authors.lastname: Yıldız
authors.affiliation: İstanbul University, Cerrahpaşa School of Medicine, Department of Pediatric Hematology, İstanbul, Turkey.
authors.forename: Tiraje
authors.initials: T
authors.lastname: Celkan
authors.affiliation: İstanbul University, İstanbul School of Medicine, Department of Pediatric Hematology, İstanbul, Turkey.
authors.forename: Sema
authors.initials: S
authors.lastname: Anak
authors.affiliation: İstanbul University, İstanbul School of Medicine, Department of Pediatric Hematology, İstanbul, Turkey.
authors.forename: Omer
authors.initials: O
authors.lastname: Devecioğlu
authors.affiliation: Bakırköy Maternity and Children's Hospital, Department of Pediatrics, İstanbul, Turkey.
authors.forename: Gönül
authors.initials: G
authors.lastname: Aydoğan
authors.affiliation: Ministry of Health Şişli Etfal Teaching Hospital, Department of Pediatric Hematology, İstanbul, Turkey.
authors.forename: Serap
authors.initials: S
authors.lastname: Karaman
authors.affiliation: Kocaeli School of Medicine, Department of Pediatric Hematology, Kocaeli, Turkey.
authors.forename: Nazan
authors.initials: N
authors.lastname: Sarper
authors.affiliation: Ministry of Health Göztepe Teaching Hospital, Department of Pediatric Hematology, İstanbul, Turkey.
authors.forename: Cetin
authors.initials: C
authors.lastname: Timur
authors.affiliation: Ministry of Health Bakırköy Sadi Konuk Teaching Hospital, Department of Hematology, İstanbul, Turkey.
authors.forename: Umit
authors.initials: U
authors.lastname: Ure
authors.affiliation: İstanbul University, Department of Genetics, Institute of Experimental Medicine, İstanbul, Turkey.
authors.forename: Uğur
authors.initials: U
authors.lastname: Ozbek
keywords: Expression; Pediatric; T-ALL; Transcription factor; prognosis