Ur Rahman Muhammad Saif, Zhang Ling, Wu Lingyan, Xie Yuqiong, Li Chunchun, Cao Jiang
Clinical Research Center.
Cardiovascular Key Laboratory of Zhejiang Province, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, People's Republic of China.
Drug Des Devel Ther. 2017 Aug 22;11:2431-2441. doi: 10.2147/DDDT.S145719. eCollection 2017.
Severe side effects are major problems with chemotherapy of gastric cancer (GC). These side effects can be reduced by using sensitizing agents in combination with therapeutic drugs. In this study, the low/nontoxic dosage of glaucocalyxin B (GLB) was used with other DNA linker agents mitomycin C (MMC), cisplatin (DDP), or cyclophosphamide (CTX) to treat GC cells. Combined effectiveness of GLB with drugs was determined by proliferation assay. The molecular mechanisms associated with cell proliferation, migration, invasion, cell cycle, DNA repair/replication, apoptosis, and autophagy were investigated by immunoblotting for key proteins involved. Cell cycle and apoptosis analysis were performed by flow cytometry. Reactive oxygen species level was also examined for identification of its role in apoptosis. Proliferation assay revealed that the addition of 5 µM GLB significantly sensitizes gastric cancer SGC-7901 cells to MMC, DDP, and CTX by decreasing half-maximal inhibitory concentration (IC) by up to 75.40%±5%, 45.10%±5%, and 52.10%±5%, respectively. GLB + drugs decreased the expression level of proteins involved in proliferation and migration, suggesting the anticancer potential of GLB + drugs. GLB + MMC, GLB + CTX, and GLB + DDP arrest the cells in G/G and G/S phase, respectively, which may be the consequence of significant decrease in the level of enzymes responsible for DNA replication and telomerase shortening. Combined use of GLB with these drugs also induces DNA damage and apoptosis by activating caspase/PARP pathways and increased production of reactive oxygen species and increased autophagy in GC cells. GLB dosage sensitizes GC cells to the alkylating agents via arresting the cell cycle and enhancing cell death. This is of significant therapeutic importance in the reduction of side effects associated with these drugs.
严重的副作用是胃癌（GC）化疗的主要问题。通过将增敏剂与治疗药物联合使用，可以减少这些副作用。在本研究中，低/无毒剂量的蓝萼甲素（GLB）与其他DNA连接剂丝裂霉素C（MMC）、顺铂（DDP）或环磷酰胺（CTX）联合用于治疗GC细胞。通过增殖试验确定GLB与药物的联合有效性。通过对关键蛋白进行免疫印迹，研究了与细胞增殖、迁移、侵袭、细胞周期、DNA修复/复制、凋亡和自噬相关的分子机制。通过流式细胞术进行细胞周期和凋亡分析。还检测了活性氧水平，以确定其在凋亡中的作用。增殖试验表明，添加5µM GLB可使胃癌SGC-7901细胞对MMC、DDP和CTX显著敏感，半最大抑制浓度（IC）分别降低高达75.40%±5%、45.10%±5%和52.10%±5%。GLB + 药物降低了参与增殖和迁移的蛋白质的表达水平，表明GLB + 药物具有抗癌潜力。GLB + MMC、GLB + CTX和GLB + DDP分别使细胞停滞在G/G期和G/S期，这可能是负责DNA复制的酶水平显著降低和端粒酶缩短的结果。GLB与这些药物联合使用还通过激活半胱天冬酶/PARP途径诱导DNA损伤和凋亡，并增加GC细胞中活性氧的产生和自噬。GLB剂量通过阻滞细胞周期和增强细胞死亡使GC细胞对烷化剂敏感。这在减少与这些药物相关的副作用方面具有重要的治疗意义。
