[Effect of inhibition of telomerase activity on cisplatin-induced apoptosis in K562 cells].
OBJECTIVE
To explore the effect of human telomerase reverse transcriptase (hTERT) gene antisense oligodeoxynucleotide (ASODN) on telomerase activity and cisplatin-induced apoptosis in K562 cells.


METHODS
Telomerase activity was analyzed by using polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA), expression levels of hTERT protein by immunofluorescence and apoptosis by DNA gel electrophoresis and flow cytometry.


RESULTS
There was a marked decrease in both the percentage of hTERT protein positive cells and the telomerase activity in ASODN treated cell as compared with that in control and sense oligodeoxynucleotide (SODN)-treated cells; but no difference between the latter two groups. Agarose gel electrophoresis of genomic DNA from K562 cells treated with ASODN and cisplatin combination for 72 h showed typical DNA ladder; neither did DNA from K562 cells treated with SODN plus cisplatin nor cisplatin alone. Apoptosis rates of K562 cells treated with ASODN for 24 h and then with cisplatin for 72 h were significantly increased. There was statistically significant difference in the percentage of apoptotic cells between hTERT ASODN plus cisplatin group and SODN plus cisplatin or cisplatin alone group.


CONCLUSIONS
The hTERT gene ASODN could inhibit telomerase activity of K562 cells whereby it enhanced cisplatin-induced apoptosis of the cells.
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Department of Hematology, Jinan University Medical College, Guangzhou 510632, China.
Zhang
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D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D002945:Cisplatin / Q000494:pharmacology*; D004587:Electrophoresis, Agar Gel; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005434:Flow Cytometry; D006801:Humans; D020014:K562 Cells; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology; D016133:Polymerase Chain Reaction / Q000379:methods; D019098:Telomerase / Q000235:genetics / Q000378:metabolism*
D000970:Antineoplastic Agents; D020319:Oligodeoxyribonucleotides, Antisense; C509186:TERT protein, human; D019098:Telomerase; D002945:Cisplatin