PLZF-mediated control on c-kit expression in CD34(+) cells and early erythropoiesis.
The promyelocytic leukemia zinc-finger protein (PLZF) is a transcription factor and c-kit is a receptor tyrosine kinase associated with human disease, particularly in hematopoietic cells. MicroRNAs (miRs) are post-transcriptional regulators of gene expression, and c-kit has been described as a target of miRs-221 and -222 in erythropoiesis. In the present study, we identified c-kit as a target of PLZF in normal and leukemic cells. Particularly, in erythropoietic (E) culture of CD34(+) progenitors, PLZF is downregulated, whereas c-kit expression at both the mRNA and protein levels inversely increases during the first days of E differentiation. In functional experiments, PLZF transfection induces c-kit downregulation, inhibits E proliferation and delays differentiation, whereas PLZF knockdown induces opposite effects, independently of miRs-221 and -222 expression. The inverse correlation between PLZF and c-kit expression was found in normal CD34(+)38(+/-) hematopoietic progenitor/stem cells and in acute myeloid leukemias of M0/M1 French-American-British subtypes, suggesting that the control of PLZF on c-kit expression may be crucial at the level of the stem cell/progenitor compartment. Altogether, our data indicate a new mechanism of regulation of c-kit expression that involves a transcriptional control by PLZF in CD34(+) cells and early erythropoiesis.
Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy.
I
I
Spinello
M T
MT
Quaranta
L
L
Pasquini
E
E
Pelosi
E
E
Petrucci
A
A
Pagliuca
G
G
Castelli
G
G
Mariani
D
D
Diverio
R
R
Foà
U
U
Testa
C
C
Labbaye
D051997:ADP-ribosyl Cyclase 1 / Q000378:metabolism; D018952:Antigens, CD34 / Q000378:metabolism*; D015153:Blotting, Western; D002460:Cell Line; D049109:Cell Proliferation; D024202:Electrophoretic Mobility Shift Assay; D004920:Erythropoiesis; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D020014:K562 Cells; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism*; D007938:Leukemia / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008858:Microscopy, Phase-Contrast; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
D051997:ADP-ribosyl Cyclase 1; D018952:Antigens, CD34; D051741:Kruppel-Like Transcription Factors; D008156:Luciferases; D035683:MicroRNAs; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D019009:Proto-Oncogene Proteins c-kit; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C525709:MIR221, human; C525710:MIR222, human; C092037:ZBTB16 protein, human