Down-regulation of human telomeric protein TRF1 gene expression during myeloid differentiation in human hematopoietic cells.
The maintenance of telomere length is crucial for cell survival. Recently, it has been indicated that the human telomeric protein TRF1 is involved in the negative feedback mechanism that stabilizes telomere length. We studied TRF1 mRNA expression in hematopoietic cells to clarify the relation between TRF1 and telomerase by semiquantitative reverse transcriptase-polymerase chain reaction. In polymorphonuclear cells and monocytes isolated from peripheral blood, relatively low levels of TRF1 mRNA expression were seen, compared with those of lymphocytes and CD34+. We then assessed TRF1 mRNA expression in CD34+ cells cultured in vitro with growth factors. After 4 weeks of culture, all the cells showed myeloid differentiation, and telomerase activity was down-regulated. TRF1 mRNA was expressed in CD34+ cells but was down-regulated in cells cultured for 4 weeks. We conclude that TRF1 mRNA expression is down-regulated in accordance with telomerase down-regulation during the course of myeloid differentiation.
Otsuka
T
T
Cancer Center, Kyushu University Hospital, Fukuoka, Japan. otsukate@cancer.med.kyushu-u.ac.jp
Uchida
N
N
Arima
F
F
Shigematsu
H
H
Fukuyama
T
T
Maeda
M
M
Sugio
Y
Y
Itoh
Y
Y
Niho
Y
Y
D018952:Antigens, CD34 / Q000378:metabolism; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D015536:Down-Regulation; D018922:HL-60 Cells / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology / Q000502:physiology; D006801:Humans; D012333:RNA, Messenger / Q000096:biosynthesis; D020449:Repetitive Sequences, Amino Acid; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016615:Telomere; D035321:Telomeric Repeat Binding Protein 1; D014212:Tretinoin / Q000494:pharmacology
D018952:Antigens, CD34; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D035321:Telomeric Repeat Binding Protein 1; D014212:Tretinoin