A novel telomerase template antagonist (GRN163) as a potential anticancer agent.
A novel telomerase template antagonist (GRN163) as a potential anticancer agent.
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发表时间：
2003-07
期刊：
影响因子：
11.2
通讯作者：
A. Asai;Y. Oshima;Yoshihiro Yamamoto;T. Uochi;H. Kusaka;S. Akinaga;Y. Yamashita;K. Pongracz
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作者：
A. Asai;Y. Oshima;Yoshihiro Yamamoto;T. Uochi;H. Kusaka;S. Akinaga;Y. Yamashita;K. Pongracz
端粒酶，负责增殖永生的酶，基本上在所有癌细胞中表达，但在大多数正常人类细胞中不表达。因此，特异性端粒酶抑制可能是一种副作用少的通用抗癌疗法。我们设计了N3 '->P5'硫代氨基磷酸酯（thio-phosphoramidate，N3 '-> P5'）寡核苷酸作为端粒酶模板拮抗剂，发现它们与端粒酶RNA亚基形成稳定双链体的能力是抗端粒酶活性的关键因素。在生物化学测定中，11-13聚体的寡核苷酸表现出对端粒酶的序列和剂量依赖性抑制，IC（50）值<1 nM。序列、长度和生物利用度的优化导致选择13聚体的寡核苷酸GRN 163作为药物开发候选物。在无细胞测定中，GRN 163在45 +/-7 pM下抑制端粒酶，并且在存在和不存在载体的情况下，在各种肿瘤细胞系中分别在约1 nM和约0.3-1.0 μ M下抑制端粒酶。GRN 163与端粒引物竞争结合，主要是因为与人端粒酶RNA（hTR）组分杂交。在培养物中用GRN 163处理的肿瘤细胞经历端粒缩短，随后在通常与初始端粒长度相关的一段时间后细胞衰老或凋亡。在腹侧DU 145（前列腺癌）异种移植模型中，肠胃外施用GRN 163在没有总体毒性的情况下引起肿瘤生长的抑制。这些数据表明，GRN 163具有作为抗癌剂进行额外开发的显著潜力。
Telomerase, the enzyme responsible for proliferative immortality, is expressed in essentially all cancer cells, but not in most normal human cells. Thus, specific telomerase inhibition is potentially a universal anticancer therapy with few side effects. We designed N3'-->P5' thio-phosphoramidate (NPS) oligonucleotides as telomerase template antagonists and found that their ability to form stable duplexes with the telomerase RNA subunit was the key factor for antitelomerase activity. In biochemical assays 11-13-mer NPS oligonucleotides demonstrated sequence- and dose-dependent inhibition of telomerase with IC(50) values <1 nM. Optimization of the sequence, length, and bioavailability resulted in the selection of a 13-mer NPS oligonucleotide, GRN163, as a drug development candidate. GRN163 inhibited telomerase in a cell-free assay at 45 +/- 7 pM, and in various tumor cell lines at approximately 1 nM and approximately 0.3-1.0 micro M in the presence and absence of carriers, respectively. GRN163 was competitive with telomeric primer binding, primarily because of hybridization to human telomerase RNA (hTR) component. Tumor cells treated with GRN163 in culture underwent telomere shortening, followed by cellular senescence or apoptosis after a period of time that generally correlated with initial telomere length. In a flank DU145 (prostate cancer) xenograft model, parenterally administered GRN163 caused suppression of tumor growth in the absence of gross toxicity. These data demonstrate that GRN163 has significant potential for additional development as an anticancer agent.