Differential gene expression, GATA1 target genes, and the chemotherapy sensitivity of Down syndrome megakaryocytic leukemia.
Children with Down syndrome (DS) with acute megakaryocytic leukemia (AMkL) have very high survival rates compared with non-DS AMkL patients. Somatic mutations identified in the X-linked transcription factor gene, GATA1, in essentially all DS AMkL cases result in the synthesis of a shorter (40 kDa) protein (GATA1s) with altered transactivation activity and may lead to altered expression of GATA1 target genes. Using the Affymetrix U133A microarray chip, we identified 551 differentially expressed genes between DS and non-DS AMkL samples. Transcripts for the bone marrow stromal-cell antigen 2 (BST2) gene, encoding a transmembrane glycoprotein potentially involved in interactions between leukemia cells and bone marrow stromal cells, were 7.3-fold higher (validated by real-time polymerase chain reaction) in the non-DS compared with the DS group. Additional studies confirmed GATA1 protein binding and transactivation of the BST2 promoter; however, stimulation of BST2 promoter activity by GATA1s was substantially reduced compared with the full-length GATA1. CMK sublines, transfected with the BST2 cDNA and incubated with HS-5 bone marrow stromal cells, exhibited up to 1.7-fold reduced cytosine arabinoside (ara-C)-induced apoptosis, compared with mock-transfected cells. Our results demonstrate that genes that account for differences in survival between DS and non-DS AMkL cases may be identified by microarray analysis and that differential gene expression may reflect relative transactivation capacities of the GATA1s and full-length GATA1 proteins.
Ge
Yubin
Y
Experimental and Clinical Therapeutics Program, Barbara Ann Karmanos Cancer Institute of Environmental Sciences, Wayne State University, Detroit, MI 48201, USA.
Dombkowski
Alan A
AA
LaFiura
Katherine M
KM
Tatman
Dana
D
Yedidi
Ravikiran S
RS
Stout
Mark L
ML
Buck
Steven A
SA
Massey
Gita
G
Becton
David L
DL
Weinstein
Howard J
HJ
Ravindranath
Yaddanapudi
Y
Matherly
Larry H
LH
Taub
Jeffrey W
JW
D002648:Child; D016000:Cluster Analysis; D003561:Cytarabine / Q000633:toxicity; D017931:DNA Primers; D004314:Down Syndrome / Q000150:complications / Q000235:genetics*; D050982:GATA1 Transcription Factor / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007947:Leukemia, Megakaryoblastic, Acute / Q000150:complications / Q000188:drug therapy* / Q000235:genetics*; D008156:Luciferases / Q000235:genetics; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; D003561:Cytarabine; D008156:Luciferases