TY - JOUR
T1 - Oligonucleotide N3′→P5′ phosphoramidates as efficient telomerase inhibitors
AU - Shea-Herbert, Brittney
AU - Pongracz, Krisztina
AU - Shay, Jerry W.
AU - Gryaznov, Sergei M.
N1 - Funding Information:
This work at UTSW was supported by the Geron Corporation, Menlo Park, CA. B Shea-Herbert was supported by a fellowship from DOD-BCRP DAMD17-00-1-0438. JW Shay is an Ellison Medical Foundation Senior Scholar and Southland Financial Corporation Distinguished Chair in Geriatric Research.
PY - 2002/1/21
Y1 - 2002/1/21
N2 - Human telomerase is a unique reverse transcriptase that is expressed in multiple cancers, but not in the vast majority of normal cells. The enzyme is responsible for telomere protection and maintenance, and supports the proliferative immortality of cancer cells. Thus, it has been proposed that the specific inhibition of telomerase activity in tumors might have significant and beneficial therapeutic effects. To this goal we have designed, synthesized, and evaluated several oligonucleotide N3′→P5′ phosphoramidates as telomerase inhibitors. These oligonucleotides are complementary to the template region of the RNA domain of telomerase (hTR). The prepared compounds were evaluated in HME50-5E breast epithelial cells, where their effects on telomerase activity were determined using a cell-based telomerase (TRAP) assay at 24 as well as 72 h after exposure to compounds. The oligo-N3′→P5′ phosphoramidate inhibited telomerase activity in cells in the presence of the cellular up-take enhancer (FuGENE6™) in a dose- and sequence-dependent manner, with IC50 values of approximately 1 nM. Inhibition of telomerase activity by this compound without the lipid carrier was not efficient. However, the isosequential oligonucleotide N3′→P5′ thio-phosphoramidate was able to inhibit telomerase activity with or without lipid carriers at nM, or low-μM concentrations, respectively. This inhibition of telomerase activity in HME50-5E cells by the oligonucleotide thio-phosphoramidates was also sequence specific. Long-term treatment of the cells with 0.5 μM of FuGENE6 formulated 13-mer thio-phosphoramidates, fully complementary to hTR, resulted in gradual telomere shortening, followed by cellular senescence and apoptosis, as would be predicted for a telomerase inhibitor. The mismatched control compound had no effect on cell proliferation. The results suggest that the oligonucleotide N3′→P5′ phosphoramidates, and particularly thio-phosphoramidates, might be further developed as selective anti-telomerase reagents.
AB - Human telomerase is a unique reverse transcriptase that is expressed in multiple cancers, but not in the vast majority of normal cells. The enzyme is responsible for telomere protection and maintenance, and supports the proliferative immortality of cancer cells. Thus, it has been proposed that the specific inhibition of telomerase activity in tumors might have significant and beneficial therapeutic effects. To this goal we have designed, synthesized, and evaluated several oligonucleotide N3′→P5′ phosphoramidates as telomerase inhibitors. These oligonucleotides are complementary to the template region of the RNA domain of telomerase (hTR). The prepared compounds were evaluated in HME50-5E breast epithelial cells, where their effects on telomerase activity were determined using a cell-based telomerase (TRAP) assay at 24 as well as 72 h after exposure to compounds. The oligo-N3′→P5′ phosphoramidate inhibited telomerase activity in cells in the presence of the cellular up-take enhancer (FuGENE6™) in a dose- and sequence-dependent manner, with IC50 values of approximately 1 nM. Inhibition of telomerase activity by this compound without the lipid carrier was not efficient. However, the isosequential oligonucleotide N3′→P5′ thio-phosphoramidate was able to inhibit telomerase activity with or without lipid carriers at nM, or low-μM concentrations, respectively. This inhibition of telomerase activity in HME50-5E cells by the oligonucleotide thio-phosphoramidates was also sequence specific. Long-term treatment of the cells with 0.5 μM of FuGENE6 formulated 13-mer thio-phosphoramidates, fully complementary to hTR, resulted in gradual telomere shortening, followed by cellular senescence and apoptosis, as would be predicted for a telomerase inhibitor. The mismatched control compound had no effect on cell proliferation. The results suggest that the oligonucleotide N3′→P5′ phosphoramidates, and particularly thio-phosphoramidates, might be further developed as selective anti-telomerase reagents.
KW - Oligonucleotide
KW - Phosphoramidates
KW - Telomerase inhibitors
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U2 - 10.1038/sj/onc/1205064
DO - 10.1038/sj/onc/1205064
M3 - Review article
C2 - 11850790
AN - SCOPUS:0037148567
SN - 0950-9232
VL - 21
SP - 638
EP - 642
JO - Oncogene
JF - Oncogene
IS - 1
ER -