Cell type-specific, topoisomerase II-dependent inhibition of hypoxia-inducible factor-1α protein accumulation by NSC 644221
Cell type-specific, topoisomerase II-dependent inhibition of hypoxia-inducible factor-1α protein accumulation by NSC 644221
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DOI：
10.1158/1078-0432.ccr-06-2301
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发表时间：
2007-02-01
影响因子：
11.5
通讯作者：
Melillo, Giovanni
中科院分区：
文献类型：
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作者：
Creighton-Gutteridge, Mark;Cardellina, John H., II;Melillo, Giovanni
目的：发现和开发缺氧诱导因子-1 (HIF-1) 小分子抑制剂对于开发新的癌症治疗药物来说是一种有吸引力但具有挑战性的策略。在此，我们报告了一种新型 HIF-1 α 三环甲酰胺抑制剂 NSC 644221。 实验设计：我们研究了新型化合物 NSC 644221 抑制 HIF-1 α 的机制。结果：NSC 644221 抑制 U251-HRE 和 U251-HRE 中 HIF-1 依赖性而非组成型荧光素酶表达。 分别观察U251-pGL3细胞以及低氧诱导U251细胞中血管内皮生长因子mRNA的表达。 NSC 644221 以时间和剂量依赖性方式抑制 HIF-1 α 蛋白表达，但不抑制 HIF-1 β 蛋白表达。有趣的是，在蛋白酶体抑制剂 MG132 或 PS341 存在的情况下，NSC 644221 无法抑制 HIF-1 α 蛋白的积累，但如在环己酰胺存在或使用 [S-35] 蛋氨酸进行脉冲追踪标记的情况下进行的实验所示，它不会直接影响 HIF-1 α 的降解。相反，相对于未治疗的对照，NSC 644221 降低了 HIF-1 α 翻译速率。通过特定的小干扰 RNA 沉默拓扑异构酶 (topo) II α（而非拓扑异构酶 I），可完全阻断 NSC 644221 抑制 HIF-1 α 的能力。所提供的数据显示，NSC 644221 抑制 HIF-1 α 需要 topo II。此外，尽管 NSC 644221 在大多数测试的细胞系中诱导 p21 表达、γ H2A.X 和 G(2)-M 停滞，但它仅在不同的细胞亚群中抑制 HIF-1 α，从而增加了通路特异性“抵抗”的可能性。 癌细胞中的 HIF-1 抑制。结论：NSC 644221 是一种新型 HIF-1 抑制剂，具有用作分析工具和治疗剂的潜力。我们的数据为追求 NSC 644221 作为 HIF-1 抑制剂的临床前开发提供了强有力的理由。
Purpose: The discovery and development of small-molecule inhibitors of hypoxia-inducible factor-1 (HIF-1) is an attractive, yet challenging, strategy for the development of new cancer therapeutic agents. Here, we report on a novel tricyclic carboxamide inhibitor of HIF-1 alpha, NSC 644221.Experimental Design: We investigated the mechanism by which the novel compound NSC 644221 inhibited HIF-1 alpha.Results: NSC 644221 inhibited HIF-1 -dependent, but not constitutive, luciferase expression in U251-HRE and U251-pGL3 cells, respectively, as well as hypoxic induction of vascular endothelial growth factor mRNA expression in U251 cells. HIF-1 alpha, but not HIF-1 beta, protein expression was inhibited by NSC 644221 in a time- and dose-dependent fashion. Interestingly, NSC 644221 was unable to inhibit HIF-1 alpha protein accumulation in the presence of the proteasome inhibitors MG132 or PS341, yet it did not directly affect the degradation of HIF-1 alpha as shown by experiments done in the presence of cyclohexamide or pulse-chase labeling using [S-35] methionine. In contrast, NSC 644221 decreased the rate of HIF-1 alpha translation relative to untreated controls. Silencing of topoisomerase (topo) II alpha, but not topo I, by specific small interfering RNA completely blocked the ability of NSC 644221 to inhibit HIF-1 alpha. The data presented show that topo II is required for the inhibition of HIF-1 alpha by NSC 644221. Furthermore, although NSC 644221 induced p21 expression, gamma H2A.X, and G(2)-M arrest in the majority of cell lines tested, it only inhibited HIF-1 alpha in a distinct subset of cells, raising the possibility of pathway-specific "resistance" to HIF-1 inhibition in cancer cells.Conclusions: NSC 644221 is a novel HIF-1 inhibitor with potential for use as both an analytic tool and a therapeutic agent. Our data provide a strong rationale for pursuing the preclinical development of NSC 644221 as a HIF-1 inhibitor.