Baicalin Augments Hyperthermia-Induced Apoptosis in U937 Cells and Modulates the MAPK Pathway via ROS Generation
Baicalin Augments Hyperthermia-Induced Apoptosis in U937 Cells and Modulates the MAPK Pathway via ROS Generation
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DOI：
10.1159/000488263
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发表时间：
2018-03
影响因子：
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通讯作者：
S. A. Zakki;Zheng-Guo Cui;Lu Sun;Qianwen Feng;Mengling Li;H. Inadera
中科院分区：
文献类型：
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作者：
S. A. Zakki;Zheng-Guo Cui;Lu Sun;Qianwen Feng;Mengling Li;H. Inadera
背景/目的：热疗是一种广泛使用的癌症治疗工具，也是一种众所周知的细胞凋亡诱导剂。虽然类黄酮化合物黄芩苷（BCN）是一种有效的抗癌剂，对几种人类癌症，它是在人类U937骨髓单核细胞白血病细胞系的效力较低。为探讨BCN对高温诱导的U937细胞凋亡的增强作用，本研究探讨了高温与BCN联合作用对U937细胞凋亡的影响及其机制。研究方法：将U937细胞在44ºC下热处理12分钟，使用或不使用BCN（10-50 µM）预处理，然后在37 ºC下用5% CO2和95%空气孵育6小时。通过台盼蓝拒染测定分析细胞活力。用DNA片段化、荧光显微镜和流式细胞术检测细胞凋亡。流式细胞仪检测线粒体跨膜电位（MMP）、线粒体钙离子和活性氧（ROS）的产生。Western blotting检测细胞凋亡相关蛋白及信号通路的表达。结果如下：单独的热疗并没有降低细胞活力或诱导显著的细胞凋亡水平，但联合热疗和BCN治疗显着增加细胞凋亡，通过上调促凋亡蛋白和抑制抗凋亡蛋白，最终在caspase-3激活。线粒体跨膜电位显著降低，活性氧（ROS）的产生和抗氧化酶的抑制明显。此外，在联合治疗下，JNK和p38的磷酸化形式表现出表达增加，而AKT被去磷酸化。JNK-IN-8（JNK抑制剂）和NAC（ROS清除剂）消除了联合治疗的凋亡效应，显著保护了细胞，并表明高ROS生成和MAPK通路参与了潜在的分子机制。结论：这项研究提供了令人信服的证据，热疗，结合BCN，是一个有前途的治疗策略，增强细胞凋亡，并提出了一个有前途的治疗方法，癌症。
Background/Aims: Hyperthermia is a widely used therapeutic tool for cancer therapy and a well-known inducer of apoptosis. Although the flavonoid compound baicalin (BCN) is a potent anticancer agent for several human carcinomas, it is less potent in the human U937 myelomonocytic leukemia cell line. To explore any enhancing effects of BCN on hyperthermia-induced apoptosis, this study investigated the combined effects and apoptotic mechanisms of hyperthermia and BCN in U937 cells. Methods: U937 cells were heat treated at 44ºC for 12 min with or without pre-treatment with BCN (10-50 µM) and then incubated for 6 h at 37 ºC with 5% CO2 and 95% air. Cell viability was analyzed by Trypan blue exclusion assay. Apoptosis was examined by DNA fragmentation, fluorescence microscopy and flow cytometry. Generation of mitochondrial trans-membrane potential (MMP), mitochondrial calcium, and reactive oxygen species (ROS) was also detected by flow cytometry. The expression of proteins related to apoptosis and signaling pathways was determined by western blotting. Results: Hyperthermia alone did not reduce cell viability or induce notable levels of apoptosis, but combined hyperthermia and BCN treatment markedly augmented apoptosis by upregulating proapoptotic proteins and suppressing antiapoptotic proteins, culminating in caspase-3 activation. Mitochondrial transmembrane potential was significantly decreased, and generation of reactive oxygen species (ROS) and suppression of antioxidant enzymes were marked. Furthermore, with the combined treatment, the phosphorylated forms of JNK and p38 showed increased expression, whereas AKT was dephosphorylated. JNK-IN-8 (a JNK inhibitor) and NAC (a ROS scavenger) abrogated the apoptotic effects of the combined treatment, significantly protecting the cells and indicating the involvement of high ROS generation and the MAPK pathway in the underlying molecular mechanism. Conclusion: This study provides compelling evidence that hyperthermia, in combination with BCN, is a promising therapeutic strategy for enhancement of apoptosis and suggest a promising therapeutic approach for cancer.