Cheng Hai-bo, Bo Yun, Shen Wei-xing, Ren Xian-guo, Tan Jia-ni, Jia Zhi-rong, Xu Chang-Liang
Translational Medicine Research Center, Nanjing University of Chinese Medicine, No. 138, Xianlin Road, Nanjing, Jiangsu, People's Republic of China.
Naunyn Schmiedebergs Arch Pharmacol. 2015 Jun;388(6):623-34. doi: 10.1007/s00210-015-1107-4. Epub 2015 Mar 6.
Pancreatic cancer is a devastating disease with a poor prognosis. It ranks as the fourth or fifth most common cancer in men and women and has the lowest 5-year survival rate. Therefore, there is an urgent need to develop novel therapeutic agents for pancreatic cancer. Longikaurin E (LE), which is derived from the traditional herbal medicine Rabdosia longituba, had been reported to have anti-proliferative and pro-apoptotic properties in several types of cancers. In this study, we investigated the cytotoxic properties of LE against pancreatic cancer cells and explored the mechanism behind the observed apoptosis. Pancreatic cancer cell lines cultured in the presence of LE exhibited dose- and time-dependent growth suppression by clone formation, methylthiazoltetrazolium assay, lactate dehydrogenase cytotoxicity assay, and fluorescence-activated cell sorting analysis, respectively. In addition, these culture conditions also induced the generation of cellular reactive oxygen species (ROS). In order to determine the mechanisms underlying LE-induced cytotoxicity, we used reverse transcription polymerase chain reaction and Western blot analysis in the pancreatic cancer cell line PANC1. The results showed that the expression of Bax was noticeably upregulated and the expression levels of Bcl-2, Bcl-XL, survivin, and c-Myc were significantly downregulated. We also observed increased p38 phosphorylation and decreased phosphorylation of the PI3K/AKT pathway. Interestingly, we also found that LE activated caspase-3. However, N-acetyl-L-cysteine, a kind of antioxidant, reversed all of these cellular activities. In conclusion, this study suggested that LE induced apoptosis of pancreatic cancer cells via ROS generation to modulate the p38 and PI3K/AKT pathways and could be a promising anti-pancreatic agent.
胰腺癌是一种预后较差的毁灭性疾病。它在男性和女性中是第四或第五大常见癌症，5年生存率最低。因此，迫切需要开发针对胰腺癌的新型治疗药物。长叶香茶菜素E（LE）源自传统草药长管香茶菜，据报道在几种癌症中具有抗增殖和促凋亡特性。在本研究中，我们研究了LE对胰腺癌细胞的细胞毒性特性，并探讨了观察到的凋亡背后的机制。在LE存在下培养的胰腺癌细胞系分别通过克隆形成、甲基噻唑四氮唑法、乳酸脱氢酶细胞毒性测定和荧光激活细胞分选分析表现出剂量和时间依赖性的生长抑制。此外，这些培养条件还诱导了细胞活性氧（ROS）的产生。为了确定LE诱导细胞毒性的机制，我们在胰腺癌细胞系PANC1中使用了逆转录聚合酶链反应和蛋白质免疫印迹分析。结果表明，Bax的表达明显上调，而Bcl-2、Bcl-XL、生存素和c-Myc的表达水平显著下调。我们还观察到p38磷酸化增加，PI3K/AKT途径的磷酸化减少。有趣的是，我们还发现LE激活了半胱天冬酶-3。然而，一种抗氧化剂N-乙酰-L-半胱氨酸逆转了所有这些细胞活性。总之，本研究表明，LE通过产生活性氧来调节p38和PI3K/AKT途径诱导胰腺癌细胞凋亡，可能是一种有前途的抗胰腺癌药物。
