Induction of thyroid cancer cell apoptosis by a novel nuclear factor κB inhibitor, dehydroxymethylepoxyquinomicin
Induction of thyroid cancer cell apoptosis by a novel nuclear factor κB inhibitor, dehydroxymethylepoxyquinomicin
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DOI：
10.1158/1078-0432.ccr-04-0463
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发表时间：
2004-10-15
影响因子：
11.5
通讯作者：
Yamashita, S
中科院分区：
文献类型：
--
作者：
Starenki, DV;Namba, H;Yamashita, S
目的：这项研究的目的是确定一种新的选择性核因子κ B的作用，（NF-κ B）抑制剂脱羟甲基表氧喹诺霉素（DHMEQ）在体外和体内甲状腺癌细胞中的作用，并进一步阐明这种化疗剂作用的分子机制。在体外实验中，通过流式细胞术分析膜联蛋白，蛋白质印迹法检测caspase的活化。对于体内研究，将雌性nu/nu小鼠皮下异种移植。甲状腺肿瘤。以8 mg/kg/天的剂量腹膜内注射DHMEQ溶液，持续两周。每周两次监测肿瘤大小，并通过末端脱氧核苷酸转移酶介导的缺口末端标记染色确定肿瘤标本中的细胞凋亡。用DHMEQ处理基本上抑制了p65和p50 NF-κ B亚单位向细胞核的移位、RelA/p65的DNA结合活性、凋亡抑制剂（IAP）家族蛋白质cIAP-1、cIAP-2、和XIAP，以及核因子κ B α抑制剂的从头合成。在0.1至5 μ g/ml的浓度水平下，DHMEQ诱导半胱天冬酶介导的凋亡反应，该反应可被c-Jun NH 2-末端激酶抑制剂SP 600125消除，但不能被促分裂原活化蛋白/细胞外信号调节激酶激酶或p38抑制剂消除。相反，正常人甲状腺细胞对DHMEQ诱导的细胞凋亡有抵抗力。在较高剂量的DHMEQ，我们观察到的坏死样杀死正常和恶性甲状腺细胞，这是抵抗丝裂原活化蛋白激酶抑制剂。在裸鼠DHMEQ实质上抑制肿瘤的生长，没有明显的副作用，并观察到与DHMEQ.Conclusions治疗的肿瘤的组织切片中的凋亡细胞的数量增加：我们的研究结果显示了潜在的有用性的新型NF-κ B抑制剂，DHMEQ，在未来的治疗策略，用于治疗甲状腺癌，不响应传统的方法。
Purpose: The objective of the study was to determine the effects of a novel selective nuclear factor kappaB (NF-kappaB) inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), in thyroid carcinoma cells in vitro and in vivo and to additionally elucidate the molecular mechanisms underlying the action of this chemotherapeutic agent.Experimental Design: In the in vitro experiments, the induction of apoptosis by DHMEQ in various human thyroid carcinoma cell types was determined by flow cytometry analysis of annexin-V binding and the caspase activation by Western blotting. For the in vivo study, female nu/nu mice were xenografted with s.c. FRO thyroid tumors. DHMEQ solution was injected i.p. at a dose of 8 mg/kg/day for two weeks. Tumor dimensions were monitored twice weekly, and apoptosis in tumor specimens was determined by terminal deoxynucleotidyl transferase-mediated nick end labeling staining.Results: Treatment with DHMEQ substantially inhibited the translocation of p65 and p50 NF-kappaB subunits to the nucleus, the DNA-binding activity of the RelA/p65, NF-kappaB-dependent expression of the inhibitor of apoptosis (IAP)-family proteins, cIAP-1, cIAP-2, and XIAP, and the de novo synthesis of inhibitor of nuclear factor kappaB alpha. At concentration levels ranging from 0.1 to 5 mug/ml, DHMEQ induced a caspase-mediated apoptotic response that could be abrogated by the c-Jun NH2-terminal kinase inhibitor SP600125 but not by either mitogen-activated protein/extracellular signal-regulated kinase kinase or p38 inhibitors. In contrast, normal human thyrocytes were resistant to DHMEQ-induced apoptosis. At higher doses of DHMEQ we observed the necrotic-like killing of both normal and malignant thyrocytes, which was resistant to mitogen-activated protein kinase inhibitors. In nude mice DHMEQ substantially inhibited tumor growth without observable side effects, and increased numbers of apoptotic cells were observed in the histologic sections of tumors treated with DHMEQ.Conclusions: Our results show the potential usefulness of the novel NF-kappaB inhibitor, DHMEQ, in future therapeutic strategies for the treatment of thyroid cancers that do not respond to conventional approaches.