Managit Chittima, Sakurai Hiroaki, Saiki Ikuo
Department of Pharmaceutical Technology, Faculty of Pharmacy, Srinakharinwirot University, Nakhonnayok 26120, Thailand.
Department of Cancer Cell Biology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
Oncol Lett. 2017 Apr;13(4):2791-2798. doi: 10.3892/ol.2017.5748. Epub 2017 Feb 17.
Tumor necrosis factor-α (TNF-α) and TNF-related apoptosis-inducing ligand (TRAIL) are promising candidates for cancer treatment due to their ability to induce apoptosis through death receptor stimulation. However, their usage may be limited due to the resistance of cancer cells to TNF-α- and TRAIL-induced apoptosis. Currently, there is interest in screening for natural products that can sensitize cancer cells to TNF-α- and TRAIL-induced apoptosis for their use in combination with TNF-α or TRAIL. It was previously reported that the bark extract of Thevetia peruviana showed a reversal effect on TRAIL-resistance in human gastric adenocarcinoma cell lines. In the present study, the effects of the ethanolic extract of T. peruviana flowers on TNF-α- and TRAIL-induced apoptosis of human cervical cancer HeLa cells were investigated by determining cell viability and apoptosis using a WST-1 cell proliferation assay and immunoblot analysis, respectively. The ethanolic extract of T. peruviana flowers promoted TNF-α and TRAIL-mediated cell death through the activation of the caspase cascade, poly(ADP-ribose) polymerase and BH3-interacting domain death agonist cleavage. Combined treatment using the extract plus TNF-α resulted in downregulation of anti-apoptotic protein, including myeloid cell leukemia sequence-1, B-cell lymphoma-extra large (Bcl-XL), X-linked inhibitor of apoptosis protein and survivin, while the combined treatment with TRAIL downregulated Bcl-XL. Thus, the ethanolic extract of T. peruviana flowers has potential in sensitizing the TNF-α- and TRAIL-induced apoptosis of HeLa cells via the intrinsic and extrinsic pathways.
肿瘤坏死因子-α（TNF-α）和肿瘤坏死因子相关凋亡诱导配体（TRAIL）因其能够通过刺激死亡受体诱导细胞凋亡，而成为癌症治疗的有前景的候选药物。然而，由于癌细胞对TNF-α和TRAIL诱导的凋亡具有抗性，它们的使用可能会受到限制。目前，人们有兴趣筛选能够使癌细胞对TNF-α和TRAIL诱导的凋亡敏感的天然产物，以便与TNF-α或TRAIL联合使用。先前有报道称，黄花夹竹桃的树皮提取物对人胃腺癌细胞系中的TRAIL抗性具有逆转作用。在本研究中，通过分别使用WST-1细胞增殖测定法和免疫印迹分析来测定细胞活力和凋亡，研究了黄花夹竹桃花乙醇提取物对人宫颈癌HeLa细胞TNF-α和TRAIL诱导凋亡的影响。黄花夹竹桃花乙醇提取物通过激活半胱天冬酶级联反应、聚（ADP-核糖）聚合酶和BH3相互作用结构域死亡激动剂的切割，促进了TNF-α和TRAIL介导的细胞死亡。提取物加TNF-α的联合处理导致抗凋亡蛋白下调，包括髓样细胞白血病序列-1、B细胞淋巴瘤-超大（Bcl-XL）、X连锁凋亡抑制蛋白和生存素，而与TRAIL的联合处理则下调了Bcl-XL。因此，黄花夹竹桃花乙醇提取物具有通过内在和外在途径使HeLa细胞对TNF-α和TRAIL诱导的凋亡敏感的潜力。
