Emergency Hospital, Mansoura University, Mansoura 35516, Egypt.
Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt; Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Tabuk, Tabuk 71491, Saudi Arabia.
Life Sci. 2018 Apr 1;198:87-93. doi: 10.1016/j.lfs.2018.02.027. Epub 2018 Feb 21.
Oleuropein is considered as a new chemotherapeutic agent in human hepatocellular carcinoma (HCC) while, its exact underlying molecular mechanism still not yet explored. In addition, cisplatin is a standard anticancer drug against solid tumors with toxic side effects. Therefore, we conducted this study to assess antitumor activity of oleuropein either alone or in combination with cisplatin against HepG2, human HCC cell lines, via targeting pro-NGF/NGF signaling pathway.
HepG2 cells were treated with cisplatin (20, 50, 100 μM) and oleuropein (100, 200, 300 and 400 μM) as well as some of the cells were treated with 50 μM cisplatin and different concentrations of oleuropein. Gene expressions of nerve growth factor (NGF), matrix metalloproteinase-7 (MMP-7) and caspase-3 were evaluated by real time-PCR. In addition, protein levels of NGF and pro-form of NGF (pro-NGF) were measured by ELISA while, nitric oxide (NO) content was determined colorimetrically.
Cisplatin treatment showed a significant elevation of NO content and pro-NGF protein level with a marked reduction of NGF protein level in addition to the upregulation of caspase-3 along with downregulation of MMP-7 gene expressions in a dose-dependent manner. However, the combination of 50 μM cisplatin and 200 μM oleuropein showed the most potent effect on the molecular level when compared with oleuropein or cisplatin alone.
Our results showed for the first time that the anti-tumor activity of oleuropein against HCC could be attributed to influencing the pro-NGF/NGF balance via affecting MMP-7 activity without affecting the gene expression of NGF. Concurrent treatment with both oleuropein and cisplatin could lead to more effective chemotherapeutic combination against HCC.
橄榄苦苷被认为是人类肝癌（HCC）的一种新的化疗药物，但其确切的潜在分子机制尚未被探索。此外，顺铂是一种针对实体瘤的标准抗癌药物，具有毒副作用。因此，我们进行了这项研究，以评估橄榄苦苷单独或与顺铂联合治疗 HepG2 人肝癌细胞系的抗肿瘤活性，通过靶向前神经生长因子/神经生长因子信号通路。
用顺铂（20、50、100 μM）和橄榄苦苷（100、200、300 和 400 μM）处理 HepG2 细胞，部分细胞用 50 μM 顺铂和不同浓度的橄榄苦苷处理。实时 PCR 检测神经生长因子（NGF）、基质金属蛋白酶-7（MMP-7）和半胱天冬酶-3 的基因表达。此外，通过 ELISA 测定 NGF 和前神经生长因子（pro-NGF）的蛋白水平，通过比色法测定一氧化氮（NO）含量。
顺铂处理以剂量依赖性方式显著增加了 NO 含量和 pro-NGF 蛋白水平，同时显著降低了 NGF 蛋白水平，并且上调了 caspase-3，下调了 MMP-7 基因表达。然而，与单独使用橄榄苦苷或顺铂相比，50 μM 顺铂和 200 μM 橄榄苦苷联合使用在分子水平上显示出最强的效果。
我们的研究结果首次表明，橄榄苦苷对 HCC 的抗肿瘤活性可能归因于通过影响 MMP-7 活性而影响 pro-NGF/NGF 平衡，而不影响 NGF 的基因表达。同时使用橄榄苦苷和顺铂可能导致针对 HCC 的更有效的化疗联合。
