Division of Pediatric Infection, Changhua Christian Children's Hospital, Changhua 50006, Taiwan.
Orthopedics & Sports Medicine Laboratory, Changhua Christian Hospital, Changhua 50006, Taiwan.
Int J Mol Sci. 2022 Jan 31;23(3):1632. doi: 10.3390/ijms23031632.
Hinokitiol is a tropolone-related compound isolated from the heartwood of cupressaceous plants. It is known to exhibit various biological functions including antibacterial, antifungal, and antioxidant activities. In the study, we investigated the antitumor activities of hinokitiol against human osteosarcoma cells. The results revealed that hinokitiol treatment inhibited cell viability of human osteosarcoma U-2 OS and MG-63 cells in the MTT assay. Further study revealed that hinokitiol exposure caused cell cycle arrest at the S phase and a DNA damage response with the induction of γ-H2AX foci in both osteosarcoma cell lines. In U-2 OS cells with wild-type tumor suppressor p53, we found that hinokitiol exposure induced p53 expression and cellular senescence, and knockdown of p53 suppressed the senescence. However, in MG-63 cells with mutated p53, a high percentage of cells underwent apoptosis with cleaved-PARP expression and Annexin V staining after hinokitiol treatment. In addition, up-regulated autophagy was observed both in hinokitiol-exposed U-2 OS and MG-63 cells. As the autophagy was suppressed through the autophagy inhibitor chloroquine, hinokitiol-induced senescence in U-2 OS cells was significantly enhanced accompanying more abundant p53 expression. In MG-63 cells, co-treatment of chloroquine increased hinokitiol-induced apoptosis and decreased cell viability of the treated cells. Our data revealed that hinokitiol treatment could result in different cell responses, senescence or apoptosis in osteosarcoma cell lines, and suppression of autophagy could promote these effects. We hypothesize that the analysis of p53 status and co-administration of autophagy inhibitors might provide more precise and efficacious therapies in hinokitiol-related trials for treating osteosarcoma.
桧木醇是从柏科植物的心材中分离得到的一种三萜烯化合物。它具有多种生物学功能，包括抗菌、抗真菌和抗氧化活性。在这项研究中，我们研究了桧木醇对人骨肉瘤细胞的抗肿瘤活性。结果表明，桧木醇处理抑制了人骨肉瘤 U-2 OS 和 MG-63 细胞的 MTT 测定中的细胞活力。进一步的研究表明，桧木醇暴露导致细胞周期停滞在 S 期，并在两种骨肉瘤细胞系中诱导 γ-H2AX 焦点形成的 DNA 损伤反应。在具有野生型肿瘤抑制因子 p53 的 U-2 OS 细胞中，我们发现桧木醇暴露诱导了 p53 表达和细胞衰老，并且 p53 的敲低抑制了衰老。然而，在具有突变型 p53 的 MG-63 细胞中，在桧木醇处理后，大量细胞经历了凋亡，表现为 cleaved-PARP 表达和 Annexin V 染色。此外，在桧木醇暴露的 U-2 OS 和 MG-63 细胞中观察到自噬上调。由于自噬通过自噬抑制剂氯喹被抑制，因此 U-2 OS 细胞中桧木醇诱导的衰老明显增强，同时 p53 表达更加丰富。在 MG-63 细胞中，氯喹的共同处理增加了桧木醇诱导的凋亡并降低了处理细胞的细胞活力。我们的数据表明，桧木醇处理可能导致骨肉瘤细胞系中不同的细胞反应，衰老或凋亡，并且抑制自噬可以促进这些效应。我们假设分析 p53 状态并联合使用自噬抑制剂可能为桧木醇相关试验治疗骨肉瘤提供更精确和有效的治疗方法。
