Abstract

Photodynamic therapy (PDT), which is a new method for treating tumors, has been used in the treatment of cancer. In-depth research has shown that PDT cannot completely kill tumor cells, indicating that tumor cells are resistant to PDT. Glucose regulatory protein 78 (GRP78), which is a key regulator of endoplasmic reticulum stress, has been confirmed to be related to tumor resistance and recurrence, but there are relatively few studies on the further mechanism of GRP78 in PDT. Our experiment aimed to observe the role of GRP78 in HOS human osteosarcoma cells treated with pyropheophorbide-α methyl ester-mediated photodynamic therapy (MPPα-PDT) and to explore the possible mechanism by which the silencing of GRP78 expression enhances the sensitivity of HOS osteosarcoma cells to MPPα-PDT. HOS osteosarcoma cells were transfected with siRNA-GRP78. Apoptosis and reactive oxygen species (ROS) levels were detected by Hoechst staining and flow cytometry, cell viability was detected by Cell Counting Kit-8 assay, GRP78 protein fluorescence intensity was detected by immunofluorescence, and apoptosis-related proteins, cell proliferation-related proteins, and Wnt pathway-related proteins were detected by western blot. The results showed that MPPα-PDT can induce HOS cell apoptosis and increase GRP78 expression. After successful siRNA-GRP78 transfection, HOS cell proliferation was decreased, and apoptosis-related proteins expressions was increased, Wnt/β-catenin-related proteins expressions was decreased, and ROS levels was increased. In summary, siRNA-GRP78 enhances the sensitivity of HOS cells to MPPα-PDT, the mechanism may be related to inhibiting Wnt pathway activation and increasing ROS levels.

中文翻译：

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靶向 GRP78 通过 Wnt/β-catenin 信号通路增强 HOS 骨肉瘤细胞对焦脱镁叶绿酸-α 甲酯介导的光动力治疗的敏感性

摘要

光动力疗法（PDT）是一种治疗肿瘤的新方法，已被用于治疗癌症。深入研究表明，PDT不能完全杀死肿瘤细胞，说明肿瘤细胞对PDT具有抗药性。葡萄糖调节蛋白78（GRP78）是内质网应激的关键调节因子，已被证实与肿瘤耐药和复发有关，但关于GRP78在PDT中的进一步作用机制的研究相对较少。我们的实验旨在观察GRP78在焦脱镁叶绿酸-α甲酯介导的光动力疗法（MPPα-PDT）治疗HOS人骨肉瘤细胞中的作用，并探讨GRP78表达的沉默增强HOS骨肉瘤细胞敏感性的可能机制。 MPPα-PDT。用 siRNA-GRP78 转染 HOS 骨肉瘤细胞。Hoechst染色和流式细胞仪检测细胞凋亡和活性氧（ROS）水平，Cell Counting Kit-8法检测细胞活力，免疫荧光法检测GRP78蛋白荧光强度，凋亡相关蛋白、细胞增殖相关蛋白, 和 Wnt 通路相关蛋白通过蛋白质印迹检测。结果表明，MPPα-PDT可诱导HOS细胞凋亡，增加GRP78表达。siRNA-GRP78转染成功后，HOS细胞增殖减少，凋亡相关蛋白表达增加，Wnt/β-catenin相关蛋白表达减少，ROS水平升高。综上所述，siRNA-GRP78增强了HOS细胞对MPPα-PDT的敏感性，其机制可能与抑制Wnt通路激活、增加ROS水平有关。