Flavopiridol disrupts STAT3/DNA interactions, attenuates STAT3-directed transcription, and combines with the Jak kinase inhibitor AG490 to achieve cytotoxic synergy
Flavopiridol disrupts STAT3/DNA interactions, attenuates STAT3-directed transcription, and combines with the Jak kinase inhibitor AG490 to achieve cytotoxic synergy
复制标题
DOI：
10.1158/1535-7163.mct-05-0235
复制
发表时间：
2006-01-01
影响因子：
5.7
通讯作者：
Bible, KC
中科院分区：
文献类型：
--
作者：
Lee, YK;Isham, CR;Bible, KC
上调的信号转导子和转录激活子 (STAT) 介导的信号传导被认为有助于多种实体癌和血液癌的发病机制。因此，最近提出抑制 STAT 介导的信号传导作为治疗癌症的潜在新治疗方法。之前已经证明，泛细胞周期蛋白依赖性激酶抑制剂黄酮吡醇与 DNA 结合，并且在某些情况下似乎通过该过程杀死癌细胞，我们评估了黄酮吡醇可能因此破坏 STAT3/DNA 相互作用、减弱 STAT3 定向转录并下调 STAT3 下游多肽（包括抗凋亡多肽 Mcl-1）的假设。 SDS-PAGE/免疫印迹和逆转录-PCR分别用于评估RNA和多肽水平。 DNA纤维素亲和层析和核洗脱测定用于评估flavopiridol破坏STAT3/DNA相互作用的能力。使用 STAT3 荧光素酶报告基因测定来检查黄酮吡多减弱 STAT3 介导的转录的能力。使用集落形成测定来评估弗拉吡多和 AG490 之间的细胞毒性协同作用。发现 Flavopiridol 可 (a) 破坏 STAT3/DNA 相互作用（DNA 纤维素亲和层析和核洗脱测定），(b) 减弱 STAT3 定向转录（STAT3 荧光素酶报告基因测定），以及 (c) 在转录水平下调 STAT3 下游抗凋亡多肽 Mcl-1（逆转录 PCR 和 SDS-PAGE/免疫印迹）。此外，黄吡醇（而不是微管抑制剂紫杉醇）可以与STAT3通路抑制剂AG490联合，在A549人非小细胞肺癌细胞中实现细胞毒协同作用。总的来说，这些数据表明，黄酮吡多可以有针对性地减弱 STAT3 定向转录，因此可在临床上用于开发结合黄酮吡多和 STAT3 信号通路其他抑制剂的化疗方案。
Up-regulated signal transducers and activators of transcription (STAT)-mediated signaling is believed to contribute to the pathogenesis of a variety of solid and hematologic cancers. Consequently, inhibition of STAT-mediated signaling has recently been proposed as a potential new therapeutic approach to the treatment of cancers. Having shown previously that the pan-cyclin-dependent kinase inhibitor flavopiridol binds to DNA and seems to kill cancer cells via that process in some circumstances, we evaluated the hypothesis that flavopiridol might consequently disrupt STAT3/DNA interactions, attenuate STAT3-directed transcription, and down-regulate STAT3 downstream polypeptides, including the antiapoptotic polypeptide Mcl-1. SDS-PAGE/immunoblotting and reverse transcription-PCR were used to assess RNA and polypeptide levels, respectively. DNA cellulose affinity chromatography and a nuclear elution assay were used to evaluate the ability of flavopiridol to disrupt STAT3/DNA interactions. A STAT3 luciferase reporter assay was used to examine the ability of flavopiridol to attenuate STAT3-directed transcription. Colony-forming assays were used to assess cytotoxic synergy between flavopiridol and AG490. Flavopiridol was found to (a) disrupt STAT3/DNA interactions (DNA cellulose affinity chromatography and nuclear elution assay), (b) attenuate STAT3-directed transcription (STAT3 luciferase reporter assay), and (c) down-regulate the STAT3 downstream antiapoptotic polypeptide Mcl-1 at the transcriptional level (reverse transcription-PCR and SDS-PAGE/immunoblotting). Furthermore, flavopiridol, but not the microtubule inhibitor paclitaxel, could be combined with the STAT3 pathway inhibitor AG490 to achieve cytotoxic synergy in A549 human non-small cell lung cancer cells. Collectively, these data suggest that flavopiridol can attenuate STAT3-directed transcription in a targeted fashion and may therefore be exploitable clinically in the development of chemotherapy regimens combining flavopiridol and other inhibitors of STAT3 signaling pathways.