Gryaznov Sergei, Asai Akira, Oshima Yuko, Yamamoto Yoshihiro, Pongracz Krisztina, Pruzan Ronald, Wunder Ellen, Piatyszek Mieczyslaw, Li Shihong, Chin Allison, Harley Calvin, Akinaga Shiro, Yamashita Yoshinori
Geron Corporation, Menlo Park, California 94025, USA.
Nucleosides Nucleotides Nucleic Acids. 2003 May-Aug;22(5-8):577-81. doi: 10.1081/NCN-120021958.
Human telomerase is a reverse transcriptase that is expressed in essentially all cancer cells, but not in the vast majority of normal somatic cells. Therefore, the specific inhibition of telomerase activity in tumors might have significant beneficial therapeutic effects. We have designed and evaluated oligonucleotide N3' --> P5' thio-phosphoramidates as telomerase template antagonists. In biochemical cell-free assays 11-13-mer thio-phosphoramidate oligonucleotides demonstrated sequence specific and dose dependent inhibition of telomerase with pico-molar IC50 values. Optimization of the oligonucleotide sequence and length resulted in the identification of a 13-mer-oligonucleotide thio-phosphoramidate GRN163 as a drug development candidate. In cell cultures GRN163 was able to inhibit telomerase activity in the absence of cationic lipid with approximately 1 microM IC50 values. Telomerase inhibition by GRN163 produced gradual telomere shortening, followed by cellular senescence and/or apoptosis of cancer derived cell lines.
人端粒酶是一种逆转录酶，基本上在所有癌细胞中都有表达，但在绝大多数正常体细胞中不表达。因此，特异性抑制肿瘤中端粒酶的活性可能具有显著的有益治疗效果。我们设计并评估了寡核苷酸N3'→P5'硫代磷酰胺酯作为端粒酶模板拮抗剂。在无细胞生化分析中，11 - 13聚体硫代磷酰胺酯寡核苷酸表现出对端粒酶的序列特异性和剂量依赖性抑制，其半数抑制浓度（IC50）值为皮摩尔级别。对寡核苷酸序列和长度的优化导致鉴定出一种13聚体硫代磷酰胺酯GRN163作为药物开发候选物。在细胞培养中，GRN163能够在不存在阳离子脂质的情况下抑制端粒酶活性，其IC50值约为1微摩尔。GRN163对端粒酶的抑制导致端粒逐渐缩短，随后癌细胞系发生细胞衰老和/或凋亡。
