Department of Gastroenterology, Affiliated Hospital of Hebei University of Engineering, Handan 056001, Hebei Province, China.
Department of Surgery, Affiliated Hospital of Hebei University of Engineering, Handan 056001, Hebei Province, China.
World J Gastroenterol. 2019 Apr 21;25(15):1854-1864. doi: 10.3748/wjg.v25.i15.1854.
Gastric cancer is one of the most common and deadly malignancies worldwide. Despite recent medical progress, the 5-year survival rate of gastric cancer is still unsatisfactory. 5-fluorouracil (5-Fu) is one of the first-line antineoplastic treatments for gastric cancer, as it can effectively induce cancer cell apoptosis. However, the effect of 5-Fu is limited due to drug resistance of the malignant tumor. Previous studies have reported that Sotetsuflavone from Thunb. can markedly suppress lung cancer cell proliferation by apoptosis, though its effect on gastric cancer remains unknown.
To investigate the inhibitory effect of Thunb. and to determine whether it can overcome gastric cancer cell drug resistance to 5-Fu.
Cell viability was examined to determine whether the natural extract of Thunb. induced gastric cancer cell death. The half-maximal effective concentration and the half-maximal lethal concentration were calculatede. Wound-healing and transwell assays were performed to examine gastric cancer cell motility. Clonogenic assays were performed to investigate the synergistic effects of Thunb. with 5-Fu, and apoptotic bodies were detected by Hoechst staining. Western blotting was performed to examine the expression of related proteins and to investigate the molecular mechanism of Thunb.-induced cancer cell apoptosis. The expressions of proteins, including mammalian target of rapamycin (mTOR) and p-AKT, were detected in different combinations of treatments for 48 h, then analyzed by ECL detection.
Gastric cancer cells were more sensitive to the natural extract of Thunb. compared to normal gastric epithelial cells, and the extract effectively inhibited gastric cancer cell migration and invasion. The extract improved the anti-cancer effect of 5-Fu by enhancing the chemosensitization of gastric cancer cells. Extract plus 5-Fu further reduced the expression of the drug-resistance-related proteins p-AKT and mTOR after 48 h compared to 5-Fu alone. Compared to 5-Fu treatment alone, mTOR and p-AKT expression was significantly reduced by about 50% and 75%, respectively. We also found that the natural extract of Thunb. further increased 5-Fu-induced gastric cancer cell apoptosis. Expression of apoptosis-related protein X-linked inhibitor of apoptosis protein and apoptosis inducing factor were significantly reduced and increased, respectively, in the 5-Fu-resistant gastric cancer line SGC-7901/R treated with extract plus 5-Fu, while the expression of survivin did not change.
The natural extract of Thunb. effectively inhibited gastric cancer cell growth and enhanced the anti-cancer effect of 5-Fu through the AKT-mTOR pathway.
胃癌是全球最常见和最致命的恶性肿瘤之一。尽管最近取得了医学进展，但胃癌的 5 年生存率仍然不尽如人意。5-氟尿嘧啶（5-Fu）是胃癌的一线抗肿瘤治疗药物之一，因为它可以有效诱导癌细胞凋亡。然而，由于恶性肿瘤的耐药性，5-Fu 的效果有限。先前的研究表明，来自 Thunb.的 Sotetsuflavone 可以通过凋亡显著抑制肺癌细胞的增殖，尽管其对胃癌的作用尚不清楚。
研究 Thunb. 的抑制作用，并确定其是否能克服胃癌细胞对 5-Fu 的耐药性。
通过细胞活力测定来确定 Thunb. 的天然提取物是否诱导胃癌细胞死亡。计算半最大有效浓度和半最大致死浓度。通过划痕愈合和 Transwell 测定来检测胃癌细胞的运动性。通过克隆形成实验来研究 Thunb.与 5-Fu 的协同作用，并通过 Hoechst 染色检测凋亡小体。通过 Western blot 检测相关蛋白的表达，探讨 Thunb.-诱导癌细胞凋亡的分子机制。用 ECL 检测分析不同处理组合 48 h 后，检测哺乳动物雷帕霉素靶蛋白（mTOR）和 p-AKT 等蛋白的表达。
与正常胃上皮细胞相比，胃癌细胞对 Thunb.的天然提取物更敏感，提取物有效抑制了胃癌细胞的迁移和侵袭。提取物通过增强胃癌细胞的化疗敏感性，提高了 5-Fu 的抗癌效果。与单独使用 5-Fu 相比，提取物加 5-Fu 可在 48 h 后进一步降低耐药相关蛋白 p-AKT 和 mTOR 的表达。与单独使用 5-Fu 相比，mTOR 和 p-AKT 的表达分别降低了约 50%和 75%。我们还发现，Thunb.的天然提取物进一步增加了 5-Fu 诱导的胃癌细胞凋亡。在用提取物加 5-Fu 处理的耐药性胃癌细胞系 SGC-7901/R 中，凋亡相关蛋白 X 连锁凋亡抑制蛋白和凋亡诱导因子的表达分别显著降低和增加，而存活素的表达没有改变。
Thunb. 的天然提取物通过 AKT-mTOR 通路有效抑制胃癌细胞生长，并增强 5-Fu 的抗癌作用。
