SD-1029 inhibits signal transducer and activator of transcription 3 nuclear translocation
SD-1029 inhibits signal transducer and activator of transcription 3 nuclear translocation
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DOI：
10.1158/1078-0432.ccr-06-1330
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发表时间：
2006-11-15
影响因子：
11.5
通讯作者：
Seiden, Michael V.
中科院分区：
文献类型：
--
作者：
Duan, Zhenfeng;Bradner, James E.;Seiden, Michael V.
目的：信号转导和转录激活因子3（Stat 3）蛋白在肿瘤细胞的生存和增殖中起重要作用。最近的研究表明，异常的Stat 3激活促进了几种人类癌症的肿瘤生长和存活，因此，为靶向抗癌治疗的发展提供了一个有吸引力的途径。Stat 3是一种DNA结合转录因子，因此，其功能依赖于细胞质到核的易位。为了发现新型的Stat 3信号通路抑制剂，我们设计了一种基于细胞的筛选方法，能够识别抑制Stat 3核转位和活性的化合物，实验设计：基于细胞的荧光显微镜筛选和增强型绿色荧光蛋白-Stat 3核转位测定的定量测量用于识别新型的Stat 3抑制剂。通过蛋白质印迹和激酶体外自磷酸化测定确定所鉴定的Stat 3抑制剂对Janus激酶（Jak）、Stat 3表达和活化的影响。通过细胞增殖试验和凋亡试验评估了所识别的Stat 3抑制剂对细胞生长的影响。结果：在美国国家癌症研究所多样性集，2,000名成员的生物活性小分子库，我们确定SD-1029作为IL-6或抑癌素诱导的Stat 3核转位的微摩尔抑制剂。生化分析显示SD-1029抑制Stat 3的酪氨酰磷酸化，暗示SD-1029是Jak的抑制剂。进一步的分析表明，该化合物抑制Jak 2同工酶的酪氨酰磷酸化。抗凋亡蛋白Bcl-X-L和生存素，活化的Stat 3的靶蛋白，被SD-1029下调，导致在几个人乳腺癌和卵巢癌细胞系中诱导凋亡。SD-1029还增强了卵巢癌细胞中紫杉醇诱导的细胞凋亡。结论：这些结果表明，SD-1029直接废除了Jak-Stat 3信号通路在人类癌细胞表达组成型活性Stat，并添加到越来越多的文献，验证这一途径作为一个可行的目标，为进一步的药物开发。最后，SD-1029可能代表了一个合适的原型，用于结构优化和探索作为治疗的领导。
Purpose: Signal transducer and activator of transcription 3 (Stat3) proteins have important roles in cancer cell survival and proliferation. Recent studies show that aberrant Stat3 activation promotes tumor growth and survival in several human cancers, and thus, presents an attractive pathway for the development of targeted anticancer therapy. Stat3 is a DNA-binding transcription factor, and thus, its function depends on cytoplasmic to nuclear translocation. To discover novel inhibitors of the Stat3 signaling pathway, we designed a cell-based screening assay capable of identifying compounds that inhibit Stat3 nuclear translocation and activity.Experimental Design: Cell-based fluorescence microscope screening and quantitative measurement of enhanced green fluorescent protein - Stat3 nuclear translocation assays were used to identify novel Stat3 inhibitors. The effects of identified Stat3 inhibitors on Janus kinase (Jak), Stat3 expression, and activation were determined by Western blotting and kinase in vitro autophosphorylation assay. The effects of identified Stat3 inhibitors on cell growth was evaluated by cell proliferation assay and apoptosis assay.Results: Among the National Cancer Institute Diversity set, a 2,000-member library of bioactive small molecules, we identified SD-1029 as a micromolar inhibitor of IL-6 or oncostatin-induced Stat3 nuclear translocation. Biochemical analysis shows that SD-1029 inhibits tyrosyl phosphorylation of Stat3 implicating SD-1029 as an inhibitor of Jak. Further analysis shows that this compound inhibits tyrosyl phosphorylation of the Jak2 isoenzyme. The antiapoptotic proteins Bcl-X-L and survivin, target proteins of activated Stat3, are down-regulated by SD-1029 resulting in the induction of apoptosis in several human breast and ovarian cancer cell lines. SD-1029 also enhances apoptosis induced by paclitaxel in ovarian cancer cells.Conclusions: These results show that SD-1029 directly abrogates the Jak-Stat3 signaling pathway in human cancer cells expressing constitutively active Stat, and add to the growing literature that validates this pathway as a viable target for further drug development. Finally, SD-1029 may represent a suitable prototype for structural optimization and exploration as a therapeutic lead.