Autophagic cell death of malignant glioma cells induced by a conditionally replicating adenovirus
Autophagic cell death of malignant glioma cells induced by a conditionally replicating adenovirus
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DOI：
10.1093/jnci/djj161
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发表时间：
2006-05-03
影响因子：
10.3
通讯作者：
Kondo, Seiji
中科院分区：
文献类型：
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作者：
Ito, Hideaki;Aoki, Hiroshi;Kondo, Seiji
背景：条件复制腺病毒（CRAds）可以在癌细胞中选择性复制并引起癌症特异性细胞裂解；因此，它们被认为是一种很有前途的癌症治疗方法。方法：为了阐明CRAds诱导癌症特异性细胞死亡的机制，我们用端粒酶逆转录酶启动子（hTERT-Ad）或对照非复制腺病毒（AdGFP）调控的CRAds感染正常人成纤维细胞（MRC5，端粒酶阴性）、人恶性胶质瘤（U373-MG和U87-MG）、人宫颈癌（HeLa）和人前列腺癌（PC3）细胞（端粒酶均阳性）。通过检测细胞形态、酸性囊泡细胞器的发育以及微管相关蛋白1轻链3从细胞质形式向自噬体膜形式的转化，评估Ad-GFP和htert - ad感染细胞的非凋亡性自噬；western blot检测自噬相关分子——哺乳动物雷帕霉素靶蛋白（mTOR）的信号传导。我们还比较了裸鼠皮下注射Ad-GFP或hTERT-Ad后皮下胶质瘤的生长情况。采用Kaplan-Meier法和Cox-Mantel log-rank分析比较腹腔内注射Ad-GFP或hTERT-Ad治疗的胸腺瘤小鼠颅内胶质瘤的存活率。所有统计检验均为双侧检验。结果：hTERT-Ad诱导肿瘤细胞和皮下胶质瘤的肿瘤特异性自噬细胞死亡。hTERT-Ad诱导的自噬与hTERT-Ad感染动力学相关。与GFP-Ad或未治疗相比，hTERT-Ad治疗的肿瘤细胞和皮下胶质瘤中的mTOR信号通路受到抑制，这表明mTOR下游靶标p70S6激酶（p70SW）的磷酸化降低。与GFP-Ad治疗（n = 7）(平均肿瘤体积= 200 mm（3), 95% CI = 149至251 mm(3)）相比，hTERT-Ad治疗小鼠（n = 7）在第7天(体积差= 161 mm（3), 95% CI = 126至197 mm(3)）减缓了皮下胶质瘤的生长(平均肿瘤体积= 39 mm(3), 95% CI = 23至54 mm(3))；P
Background: Conditionally replicating adenoviruses (CRAds) can be engineered to replicate selectively in cancer cells and cause cancer-specific cell lysis; thus they are considered a promising cancer therapy. Methods: To elucidate the mechanisms by which CRAds induce cancer-specific cell death, we infected normal human fibroblasts (MRC5, telomerase negative), human malignant glioma (U373-MG and U87-MG), human cervical cancer (HeLa), and human prostate cancer (PC3) cells (all telomerase positive) with CRAds regulated by the human telomerase reverse transcriptase promoter (hTERT-Ad) or control nonreplicating adenoviruses (AdGFP). Nonapoptotic autophagy was assessed in Ad-GFP- and hTERT-Ad-infected cells by examining cell morphology, the development of acidic vesicular organelles, and the conversion of microtubule-associated protein 1 light chain 3 from the cytoplasmic form to the autophagosome membrane form; signaling via mammalian target of rapamycin (mTOR), an autophagy-associated molecule, was monitored by western blot analysis. We also compared the growth of subcutaneous gliomas in nude mice that were treated by intraturnoral injection with Ad-GFP or hTERT-Ad. Survival of athymic mice carrying intracranial gliomas treated by intraturnoral injection with Ad-GFP or hTERT-Ad was compared by using the Kaplan-Meier method and the Cox-Mantel log-rank analysis. All statistical tests were two-sided. Results: hTERT-Ad induced tumor-specific autophagic cell death in tumor cells and in subcutaneous gliomas. hTERT-Ad-induced autophagy was associated with hTERT-Ad infection kinetics. The mTOR signaling pathway was suppressed in tumor cells and in subcutaneous gliomas treated with hTERT-Ad compared with GFP-Ad or no treatment as shown by reduced phosphorylation of mTOR's downstream target p70S6 kinase (p70SW). hTERT-Ad treatment of mice (n = 7) slowed growth of subcutaneous gliomas (mean tumor volume = 39 mm(3), 95% confidence interval [CI] = 23 to 54 mm(3)) compared with GFP-Ad treatment (n = 7) (mean tumor volume = 200 mm(3), 95% CI = 149 to 251 mm(3)) at day 7 (volume difference = 161 mm(3), 95% CI = 126 to 197 mm(3); P