Establishment of novel molecular cancer therapy targeting telomerase and its clinical appication to gynecologic tumors

端粒酶靶向肿瘤新疗法的建立及其在妇科肿瘤中的临床应用

基本信息

批准号：
15390501
负责人：
KYO Satoru
金额：
$ 10.56万
依托单位：
Kanazawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15390501/
关键词：
hTERT Telomerase Telomere siRNA gene therapy cervical cancer テロメレーステロメア RNA i 子宮頚癌分子標的治療

项目摘要

Telomerase activation plays critical roles in tumor growth and progression in part through the maintenance of telomere structure. Indeed, the ubiquitous expression of telomerase in human cancers makes telomerase a promising target for cancer therapy. Genetic, pharmacologic and antisense methods to inhibit telomerase have been described ; however, in most cases, cancer cell death was observed only after many cell divisions. Here, using retroviral delivery of small interfering RHAs specific for the human telomerase reverse transcriptase (hTERT), we successfully inhibited telomerase activity in cervical cancer cell lines. Cells lacking hTERT expression exhibited significantly decreased telomerase activity and showed shortened telomeres and telomeric 3'-overhangs with passage. These cells entered the replicative senescence after considerable number of cell divisions. Notably, the proliferative rate of these cells was significantly impaired, compared to control cells with telomerase activity, even in low passage cells (PD 5). Likewise, colony-forming ability and tumorgenicity in mice were attenuated in low passage cells lacking hTERT. We further examined the effects of chemotherapy and ionizing radiation of cells in which hTERT expression is suppressed. Cells lacking hTERT showed a significantly increased sensitivity than control cells to ionizing radiation or chemotherapeutic agents that induce DNA double strand breaks, such as topoisomerase inhibitors or bleomycin. These findings suggest that a siRNA-based strategy can be applied to the development of novel telomerase inhibitors, whose anti-tumor effects may be enhanced in combination with ionizing radiation and chemotherapy.

端粒酶激活在肿瘤生长和进展中发挥着关键作用，部分是通过维持端粒结构来实现的。事实上，端粒酶在人类癌症中的普遍表达使得端粒酶成为癌症治疗的有希望的靶标。抑制端粒酶的遗传学、药理学和反义方法已被描述；然而，在大多数情况下，只有在多次细胞分裂后才能观察到癌细胞死亡。在这里，我们利用逆转录病毒递送人类端粒酶逆转录酶 (hTERT) 特异性的小干扰 RHA，成功抑制了宫颈癌细胞系中的端粒酶活性。缺乏 hTERT 表达的细胞表现出端粒酶活性显着降低，并随着传代表现出缩短的端粒和端粒 3' 突出端。这些细胞在经过大量细胞分裂后进入复制衰老。值得注意的是，与具有端粒酶活性的对照细胞相比，这些细胞的增殖率显着受损，即使在低传代细胞中（PD 5）也是如此。同样，在缺乏 hTERT 的低传代细胞中，小鼠的集落形成能力和致瘤性也减弱。我们进一步检查了化疗和电离辐射对 hTERT 表达受到抑制的细胞的影响。与对照细胞相比，缺乏 hTERT 的细胞对电离辐射或诱导 DNA 双链断裂的化疗剂（例如拓扑异构酶抑制剂或博来霉素）的敏感性显着增加。这些发现表明，基于 siRNA 的策略可应用于新型端粒酶抑制剂的开发，其与电离辐射和化疗相结合可增强其抗肿瘤作用。