Terpenoids-enriched fraction of Celastrus orbiculatus sensitizes gemcitabine by disrupting Chk1/RAD51-mediated DNA damage response in pancreatic cancer
Terpenoids-enriched fraction of Celastrus orbiculatus sensitizes gemcitabine by disrupting Chk1/RAD51-mediated DNA damage response in pancreatic cancer
复制标题
南蛇藤中富含萜类化合物的部分通过破坏胰腺癌中 Chk1/RAD51 介导的 DNA 损伤反应来使吉西他滨敏感
DOI：
10.1007/s42764-021-00055-w
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Tao Li
中科院分区：
文献类型：
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作者：
Zhao Yang;Jiang Zhuangzhuang;Ni Tengyang;Jiang Wei;Zhou Kehui;Liu Yuping;Liu Yanqing;Tao Li
南蛇藤是一种传统中药材，其茎具有显着的抗炎和抗肿瘤活性。在本研究中，我们制备了富含萜类化合物的组分，称为 TTC（C. orbiculatus 的总萜类化合物），并通过靶向 DNA 损伤反应来探索 TTC 作为吉西他滨敏化剂在胰腺癌治疗中的潜力。最初，我们表征了 TTC 的化学特征。使用 EdU 掺入测定，TTC 和成分萜类化合物通过抑制 AsPC-1 和 BxPC-3 细胞的增殖显示出抗肿瘤作用。接下来，我们量化了 TTC 和吉西他滨之间的相互作用，其在低于 IC50 浓度下产生协同效应。此外，在吉西他滨存在的情况下，TTC 可以进一步阻止 S 期进入或诱导更高程度的细胞凋亡。值得注意的是，通过单细胞凝胶电泳和中期扩散分析，我们观察到 TTC 在两个 PC 细胞中引起 DNA 断裂。我们还排除了暴露于 TTC 时 DNA 的氧化损伤。从机械角度来看，TTC 废除了 Chk1/RAD51，促进 γH2AX 的积累，并逆转吉西他滨引发的复制应激相关的 DNA 损伤反应。 TTC 通过蛋白酶体降解破坏核 Chk1 和 RAD51 负载的稳定性。此外，p53 缺失的 AsPC-1 细胞中热点突变体 p53（R175H、R248W 和 R273H）的异位表达显示 RAD51 表达增加，这可能会受到 TTC 的影响。在 mCherry-BxPC-3 细胞的原位小鼠模型中，我们证实了 TTC 与吉西他滨联合使用的体内抗转移功效。这些数据让我们深入了解 TTC 和参与 DNA 损伤和修复的分子如何有效地多靶点并赋予吉西他滨对胰腺癌的化学敏感性。
The stem of Celastrus orbiculatus, a traditional Chinese herbal medicine exhibits prominent anti-inflammatory and anti-tumor activities. In the present study, we prepared terpenoids-enriched fraction termed TTC (Total Terpenoids of C. orbiculatus) and explored the potentials of TTC as a sensitizer of gemcitabine by targeting DNA damage response in treatment of pancreatic cancer. Initially, we characterized the chemical profile of TTC. TTC and constitutional terpenoids showed antitumor effects through prohibiting the proliferation of AsPC-1 and BxPC-3 cells using EdU incorporation assay. Next, we quantified the interaction between TTC and gemcitabine which produced synergistic effects under sub-IC50 concentrations. Moreover, TTC could further block S-phase entry or induce higher extent of apoptosis in the presence of gemcitabine. Of note, we observed that TTC caused DNA breaks in two PC cells assayed by single cell gel electrophoresis and metaphase spreading. We also ruled out the oxidative damage of DNA upon TTC exposure. Mechanically, TTC abrogated Chk1/RAD51, promoted accumulation of γH2AX and reversed replication stress associated DNA damage response triggered by gemcitabine. TTC destabilized nuclear Chk1 and RAD51 loading via proteasomal degradation. Additionally, the ectopic expression of hotspot mutant p53 (R175H, R248W and R273H) in p53-null AsPC-1 cells displayed increased expression of RAD51, which could be compromised by TTC. In an orthotopic mouse model of mCherry-BxPC-3 cells, we confirmed the in vivo anti-metastatic efficacy of TTC in combination with gemcitabine. These data provide insight into how TTC and molecules involved in DNA damage and repair could be effectively multi-targeted and confer chemosensitivity to gemcitabine toward pancreatic cancer.