Triptolide induces the expression of miR-142-3p: a negative regulator of heat shock protein 70 and pancreatic cancer cell proliferation.
Triptolide induces the expression of miR-142-3p: a negative regulator of heat shock protein 70 and pancreatic cancer cell proliferation.
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DOI：
10.1158/1535-7163.mct-12-1231
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发表时间：
2013-07
影响因子：
5.7
通讯作者：
Saluja AK
中科院分区：
文献类型：
--
作者：
MacKenzie TN;Mujumdar N;Banerjee S;Sangwan V;Sarver A;Vickers S;Subramanian S;Saluja AK
胰腺导管腺癌（PDAC）是最致命的恶性肿瘤之一，对目前的化疗具有耐药性。我们以前发现雷公藤内酯醇在体外抑制PDAC细胞生长，并在体内阻断转移扩散。雷公藤内酯醇下调热休克蛋白70（HSP 70），一种在几种肿瘤类型中上调的分子伴侣。本研究探讨雷公藤甲素抑制热休克蛋白70的机制。随着microRNA（miRNAs）越来越被认为是基因表达的负调节因子，我们测试了雷公藤甲素是否通过miRNAs调节HSP70。在这里，我们发现雷公藤内酯醇，以及槲皮素，但不是吉西他滨，上调miR-142 - 3p在PDAC细胞（MIA PaCa-2，Capan-1，和S2 - 013）。与对照组相比，miR-142 - 3p的异位表达抑制了细胞增殖（通过电细胞基质阻抗传感测量），并降低了HSP 70的表达（通过实时PCR和免疫印迹测量）。我们证明了miR-142 - 3p直接与HSP70的3'UTR结合，并且这种相互作用对于HSP70过表达挽救miR-142 - 3p诱导的细胞死亡是重要的。我们发现miR-142 - 3p独立于热休克因子1调节HSP70。此外，雷公藤甲素的水溶性前药Minnelide在体内诱导了miR-142 - 3 p的表达。这是第一次描述癌症中miRNA介导的HSP70调节机制，使miR-142 - 3p成为PDAC治疗干预的有吸引力的靶点。
Pancreatic ductal adenocarcinoma (PDAC), one of the deadliest malignancies, is resistant to current chemotherapies. We previously showed that triptolide inhibits PDAC cell growth in vitro and blocks metastatic spread in vivo. Triptolide downregulates heat shock protein 70 (HSP70), a molecular chaperone upregulated in several tumor types. This study investigates the mechanism by which triptolide inhibits HSP70. As microRNAs (miRNAs) are becoming increasingly recognized as negative regulators of gene expression, we tested whether triptolide regulates HSP70 via miRNAs. Here we show that triptolide, as well as quercetin but not gemcitabine, upregulated miR-142-3p in PDAC cells (MIA PaCa-2, Capan-1, and S2-013). Ectopic expression of miR-142-3p inhibited cell proliferation, measured by Electric Cell-substrate Impedance Sensing, and decreased HSP70 expression, measured by real-time PCR and immunoblotting, compared with controls. We demonstrated that miR-142-3p directly binds to the 3’UTR of HSP70, and that this interaction is important as HSP70 overexpression rescued miR-142-3p-induced cell death. We found that miR-142-3p regulates HSP70 independently of heat shock factor 1. Furthermore, Minnelide, a water soluble prodrug of triptolide, induced the expression of miR-142-3p in vivo. This is the first description of an miRNA-mediated mechanism of HSP70 regulation in cancer, making miR-142-3p an attractive target for PDAC therapeutic intervention.