Differential gene expression in retinoic acid-induced differentiation of acute promyelocytic leukemia cells, NB4 and HL-60 cells.
Acute promyelocytic leukemia (APL) is characterized by a specific chromosome translocation t(15;17), which results in the fusion of the promyelocytic leukemia gene (PML) and retinoic acid receptor alpha gene (RARalpha). APL can be effectively treated with the cell differentiation inducer all-trans retinoic acid (ATRA). NB4 cells, an acute promyelocytic leukemia cell line, have the t(15;17) translocation and differentiate in response to ATRA, whereas HL-60 cells lack this chromosomal translocation, even after differentiation by ATRA. To identify changes in the gene expression patterns of promyelocytic leukemia cells during differentiation, we compared the gene expression profiles in NB4 and HL-60 cells with and without ATRA treatment using a cDNA microarray containing 10,000 human genes. NB4 and HL-60 cells were treated with ATRA (10(-6)M) and total RNA was extracted at various time points (3, 8, 12, 24, and 48h). Cell differentiation was evaluated for cell morphology changes and CD11b expression. PML/RARalpha degradation was studied by indirect immunofluoresence with polyclonal PML antibodies. Typical morphologic and immunophenotypic changes after ATRA treatment were observed both in NB4 and HL-60 cells. The cDNA microarray identified 119 genes that were up-regulated and 17 genes that were down-regulated in NB4 cells, while 35 genes were up-regulated and 36 genes were down-regulated in HL60 cells. Interestingly, we did not find any common gene expression profiles regulated by ATRA in NB4 and HL-60 cells, even though the granulocytic differentiation induced by ATRA was observed in both cell lines. These findings suggest that the molecular mechanisms and genes involved in ATRA-induced differentiation of APL cells may be different and cell type specific. Further studies will be needed to define the important molecular pathways involved in granulocytic differentiation by ATRA in APL cells.
Department of Biochemistry, College of Medicine, Hanyang University, Seoul, Republic of Korea.
Ki-Hwan
KH
Lee
Mi-Yoon
MY
Chang
Joon-Ik
JI
Ahn
Dong-Hyun
DH
Yu
Sung-Soo
SS
Jung
Jung-Hye
JH
Choi
Yun-Hee
YH
Noh
Yong-Sung
YS
Lee
Myung-Ju
MJ
Ahn
D002454:Cell Differentiation; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D018922:HL-60 Cells; D006801:Humans; D007700:Kinetics; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D016177:Macrophage-1 Antigen / Q000378:metabolism; D009363:Neoplasm Proteins / Q000032:analysis / Q000145:classification / Q000235:genetics / Q000502:physiology; D009687:Nuclear Proteins; D020411:Oligonucleotide Array Sequence Analysis; D000071156:Promyelocytic Leukemia Protein; D012334:RNA, Neoplasm / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000032:analysis; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
D016177:Macrophage-1 Antigen; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D000071156:Promyelocytic Leukemia Protein; D012334:RNA, Neoplasm; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; C070576:PML protein, human; D014212:Tretinoin