[Inhibiting expression of human telomerase reverse transcriptase promotes degradation of survivin protein].
OBJECTIVE
The expression of Survivin in cancer cells highly correlates with that of human telomerase reverse transcriptase (hTERT). Both of them are ideal targets for cancer gene therapy. This study aimed to clarify if they regulate each other in cancer cells.


METHODS
The expressions of Survivin and hTERT in HeLa S3 cells were inhibited by antisense oligonucleotide respectively. Activity of telomerase was detected by telomerase repeat amplification (TRAP) assay. Protein and mRNA levels of Survivin were analyzed by Western blot and reverse transcription-polymerase chain reaction (RT-PCR) respectively. Proliferation of HeLa S3 cells was analyzed by MTT assay.


RESULTS
Inhibiting the expression of Survivin in HeLa S3 cells had no effects on telomerase activity. Inhibiting the expression of hTERT by antisense oligonucleotide No.14 decreased protein level of Survivin, which was negatively correlated with the concentration of No.14 (200-1 000 nmol/L), but didn't change mRNA level of survivin. The decrease of Survivin level was inhibited by proteasome inhibitor lactacystin and MG132. Furthermore, simultaneous inhibition of hTERT and survivin co-efficiently inhibited proliferation of HeLa S3 cells.


CONCLUSIONS
Inhibiting the expression of hTERT in HeLa S3 cells promotes ubiquitin-proteasome degradation of Survivin.
Mei
Zhu-Zhong
ZZ
Laboratory of Biochemistry and Molecular Biology, Institute of Radiation Medicine, Academy of Military Medical Science, Beijing, 100850, P.R.China.
Zheng
Xiao-Fei
XF
Dong
Yan
Y
Song
Yi
Y
Liu
Bin
B
Sun
Guo-Jing
GJ
Sun
Zhi-Xian
ZX
D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D049109:Cell Proliferation; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D007976:Leupeptins / Q000494:pharmacology; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis* / Q000235:genetics; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D000077022:Survivin; D019098:Telomerase / Q000378:metabolism*
C107489:BIRC5 protein, human; D015853:Cysteine Proteinase Inhibitors; D004268:DNA-Binding Proteins; D051034:Inhibitor of Apoptosis Proteins; D007976:Leupeptins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D000077022:Survivin; C067713:lactacystin; D019098:Telomerase; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde; D000111:Acetylcysteine