Reprogramming murine telomerase rapidly inhibits the growth of mouse cancer cells in vitro and in vivo.
Reprogramming murine telomerase rapidly inhibits the growth of mouse cancer cells in vitro and in vivo.
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DOI：
10.1158/1535-7163.mct-09-0682
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发表时间：
2010-02
影响因子：
5.7
通讯作者：
Goldkorn A
中科院分区：
文献类型：
--
作者：
Xu T;Xu Y;Liao CP;Lau R;Goldkorn A
端粒酶在癌症中起着关键作用，促使人们寻求各种基于端粒酶的治疗策略。一种这样的策略，端粒酶干扰，利用癌细胞中的高端粒酶活性，重新编程端粒酶来编码“有毒的”端粒。到目前为止，端粒酶干扰已经在移植到小鼠体内的人类癌细胞中进行了测试，这种方法不会概括自发的恶性肿瘤，也没有提供关于宿主毒性的见解，因为人的端粒酶是以小鼠宿主为靶点的。为了解决这些局限性，我们设计并验证了两个针对小鼠端粒酶的新基因构建物：突变模板小鼠端粒酶RNA(MT-mTer)和针对野生型小鼠端粒酶RNA的siRNA(α-mTer-siRNA)。利用慢病毒在小鼠前列腺癌细胞中的传递，我们实现了α-mTer-siRNA介导的野生型mTer的击倒(80%的缺失)和MT-mTer的同时过表达(50倍)。我们证明了这两个结构有效地协同作用重新编程小鼠端粒酶，增加突变而不是野生型端粒重复，导致快速的端粒去封顶(DNA损伤灶增加5倍)。这反过来又导致快速而显著的细胞凋亡(90%的细胞)和生长抑制(活细胞质量减少90%)和体内(肿瘤移植物湿重减少75%)。综上所述，我们使用新的小鼠端粒酶靶向构建物证明了小鼠癌细胞对直接端粒酶干扰的易感性；这种方法现在可以用于研究端粒酶干扰在小鼠自发癌症模型中的真正治疗潜力。
Telomerase plays a critical role in cancer, prompting the pursuit of various telomerase-based therapeutic strategies. One such strategy, telomerase-interference, exploits the high telomerase activity in cancer cells and reprograms telomerase to encode “toxic” telomeres. To date, telomerase interference has been tested in human cancer cells xenografted into mice, an approach that does not recapitulate spontaneous malignancy and offers few insights about host toxicities, because human telomerase is targeted in a mouse host. To address these limitations, we designed and validated two new gene constructs specifically targeting mouse telomerase: Mutant template mouse telomerase RNA (MT-mTer) and siRNA against wild type mouse telomerase RNA (α-mTer-siRNA). Using lentiviral delivery in mouse prostate cancer cells, we achieved α-mTer-siRNA-mediated knockdown of wild type mTer (80% depletion) and concurrent overexpression of MT-mTer (50-fold). We showed that the two constructs effectively synergize to reprogram murine telomerase to add mutant instead of wild-type telomeric repeats, resulting in rapid telomeric uncapping (5-fold increase in DNA damage foci). This, in turn, led to rapid and significant apoptosis (>90% of cells) and growth inhibition in vitro (90% reduction in viable cell mass) and in vivo (75% reduction in tumor allograft wet weight). In summary, we have demonstrated that mouse cancer cells are vulnerable to direct telomerase interference using novel murine telomerase targeting constructs; this approach can now be used to study the true therapeutic potential of telomerase interference in mouse spontaneous cancer models.