New insight into the mechanism of p53 inducing leukemia cell apoptosis / 中华血液学杂志
Chinese Journal of Hematology
; (12): 640-643, 2003.
Article
in Zh
| WPRIM
| ID: wpr-354811
Responsible library:
WPRO
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression changes of intrinsic cytokines TGF-beta(1) and TNF-alpha, telomerase activity and bcl-2 during ongoing apoptosis of HL-60 and K562 cells induced by p53.</p><p><b>METHODS</b>pN53cG (Val135), a temperature sensitive p53 mutant, which behaved like wild type p53 (wt-p53) at 32.5 degrees C, were introduced into p53-null HL-60 and K562 cells respectively by lipofectin. In the presence of G418, HL-60-pN53cG and K562 pN53cG clones expressing p53 protein were selected. The ongoing expression of intrinsic cytokines (TGF-beta(1) and TNF-alpha), bcl-2 oncogene and hTERT mRNA during the apoptosis of HL-60 and K562 cells induced by p53 and the effects of exogenous p53 gene, TGF-beta(1) and TNF-alpha antisense PS-ODNS on the apoptosis of HL-60 and K562 cells and the expression of bcl-2 were studied by RT-PCR, quantitative RT-PCR, DNA fragmentation, TdT-mediated dUTP nick end labeling (TUNEL) and flow cytometery. The levels of secreted TGF-beta(1) and telomerase activity were detected by ELISA and PCR-ELISA, respectively.</p><p><b>RESULTS</b>(1) The expressions of intrinsic TGF-beta(1) and TNF-alpha mRNA were up-regulated, while that of bcl-2 and hTERT down-regulated. The levels of TGF-beta(1) in the supernatant of HL-60 and K562 cells were increased, and the level of telomerase activity decreased. (2) Antisense PS-ODNS of TGF-beta(1) and TNF-alpha could obviously inhibit the p53 inducing cell apoptosis, and restore bcl-2 mRNA and protein to pre-treated level.</p><p><b>CONCLUSIONS</b>Exogenous p53 induces leukemia cell apoptosis via up-regulating the expression of intrinsic TGF-beta(1) and TNF-alpha and down-regulating the expression of hTERT and bcl-2.</p>
Full text:
1
Index:
WPRIM
Main subject:
Pathology
/
Pharmacology
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Physiology
/
Plasmids
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RNA, Messenger
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Transfection
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Leukemia
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Gene Expression Regulation, Neoplastic
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DNA, Antisense
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Tumor Suppressor Protein p53
Limits:
Humans
Language:
Zh
Journal:
Chinese Journal of Hematology
Year:
2003
Type:
Article