RNA helicase DDX3: a novel therapeutic target in Ewing sarcoma
RNA helicase DDX3: a novel therapeutic target in Ewing sarcoma
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DOI：
10.1038/onc.2015.336
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发表时间：
2016-05-19
期刊：
影响因子：
8
通讯作者：
Loeb, D. M.
中科院分区：
文献类型：
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作者：
Wilky, B. A.;Kim, C.;Loeb, D. M.
RNA解旋酶DDX 3在乳腺癌和肺癌中具有致癌活性，并且是复杂mRNA转录物（包括编码关键细胞周期调节蛋白的那些转录物）翻译所必需的。我们试图确定DDX 3在肉瘤细胞中的表达和功能，并研究新型小分子DDX 3抑制剂RK-33的抗肿瘤活性。利用各种肉瘤细胞系、异种移植物和人类组织微阵列，我们在mRNA和蛋白水平上测量DDX 3表达，并评估RK-33在肉瘤细胞系中的细胞毒性。为了研究DDX 3在尤文肉瘤中的作用，我们使用DDX 3特异性小发夹RNA（shRNA）产生稳定的DDX 3敲低尤文肉瘤细胞系，并评估致癌活性。使用同量异序质量标签定量蛋白质组学方法将DDX 3敲低和RK-33处理的尤文肉瘤细胞与野生型细胞进行比较，以鉴定受DDX 3抑制影响的靶蛋白。总体而言，我们发现DDX 3在许多人肉瘤亚型中的高表达与非恶性间充质细胞相比，并且通过RNA干扰敲低DDX 3抑制尤文肉瘤细胞中的致癌活性。用RK-33治疗优先对肉瘤细胞具有细胞毒性，包括耐化疗的尤文肉瘤干细胞，同时保留非恶性细胞。对RK-33的敏感性与DDX 3蛋白表达相关。RK-33处理抑制小鼠中表达高DDX 3的人尤文肉瘤异种移植物的生长，而没有明显的毒性。DDX 3抑制改变了尤文肉瘤细胞蛋白质组，特别是涉及DNA复制，mRNA翻译和蛋白酶体功能的蛋白质。这些数据支持进一步研究DDX 3在肉瘤中的作用，将RK-33推进到尤文肉瘤临床试验，并开发RNA解旋酶抑制作为一种新的抗肿瘤策略。
RNA helicase DDX3 has oncogenic activity in breast and lung cancers and is required for translation of complex mRNA transcripts, including those encoding key cell-cycle regulatory proteins. We sought to determine the expression and function of DDX3 in sarcoma cells, and to investigate the antitumor activity of a novel small molecule DDX3 inhibitor, RK-33. Utilizing various sarcoma cell lines, xenografts and human tissue microarrays, we measured DDX3 expression at the mRNA and protein levels, and evaluated cytotoxicity of RK-33 in sarcoma cell lines. To study the role of DDX3 in Ewing sarcoma, we generated stable DDX3-knockdown Ewing sarcoma cell lines using DDX3-specific small hairpin RNA (shRNA), and assessed oncogenic activity. DDX3-knockdown and RK-33-treated Ewing sarcoma cells were compared with wild-type cells using an isobaric mass-tag quantitative proteomics approach to identify target proteins impacted by DDX3 inhibition. Overall, we found high expression of DDX3 in numerous human sarcoma subtypes compared with non-malignant mesenchymal cells, and knockdown of DDX3 by RNA interference inhibited oncogenic activity in Ewing sarcoma cells. Treatment with RK-33 was preferentially cytotoxic to sarcoma cells, including chemotherapy-resistant Ewing sarcoma stem cells, while sparing non-malignant cells. Sensitivity to RK-33 correlated with DDX3 protein expression. Growth of human Ewing sarcoma xenografts expressing high DDX3 was inhibited by RK-33 treatment in mice, without overt toxicity. DDX3 inhibition altered the Ewing sarcoma cellular proteome, especially proteins involved in DNA replication, mRNA translation and proteasome function. These data support further investigation of the role of DDX3 in sarcomas, advancement of RK-33 to Ewing sarcoma clinical trials and development of RNA helicase inhibition as a novel anti-neoplastic strategy.