Shu Rongbing, Yu Zhuanyi, Wu Jianmin, Cheng Qiuxin, Peng Zhihao, Zhou Huaqiang, Zhao Min
Department of Orthopedic, Yingtan People's Hospital, Yingtan, 335000, Jiangxi, China.
J Orthop Surg Res. 2025 Jan 31;20(1):124. doi: 10.1186/s13018-024-05412-5.
Osteosarcoma (OS) is a highly invasive bone tumor that frequently metastasizes to the lungs. This study aims to investigate the role of the Id-1 gene in OS invasion and metastasis, and its relationship with the Snail gene.
This study included tissue samples from 12 non-metastatic osteosarcomas and 9 metastatic osteosarcoma patients to examine the expression of Id-1 and Snail using RT-qPCR and analyze their correlation. In cell-based experiments, four osteosarcoma cell lines (Saos-2, U2OS, MG-63, and 143B) and the human osteoblast cell line hFOB 1.19 were cultured. The expression of Id-1 and Snail was evaluated by RT-qPCR and Western blotting.Cells were randomly divided into the Control group, sh-NC group, and sh-Id-1 group using lentiviral infection. Transwell invasion and scratch assays were used to assess cell migration and invasion. WB was employed to detect the expression of Id-1, Snail, and epithelial-mesenchymal transition (EMT)-related proteins (E-cadherin, vimentin, and N-cadherin) in the OS cells of each group. In animal experiments, Tumor formation in each group was evaluated by injecting cells subcutaneously into mice. An osteosarcoma lung metastasis model was established by injecting infected cells into the tibia of mice. Tumor growth and lung metastasis were observed using HE staining. The expression of Id-1, Snail, and EMT-related proteins in osteosarcoma and lung tissues from each group of mice was assessed using Western blot and immunohistochemistry.
The expression of Id-1 and Snail was significantly higher in osteosarcoma tissues than in normal bone tissues, and the expression of Id-1 was positively correlated with that of Snail. In cell experiments, downregulation of Id-1 reduced Snail expression and significantly inhibited EMT, as well as the migration and invasion of OS cells (P < 0.05). In animal experiments, compared to the Control group, the sh-Id-1 group mice was no significant change in body weight, but the tumor volume was significantly reduced, and fewer lung metastatic nodules (P < 0.05). HE staining indicated decreased nuclear atypia, reduced invasion and destruction, fewer new blood vessels, and less calcification in the sh-Id-1 group tumors. Immunohistochemistry and WB results showed upregulation of E-cadherin and downregulation of vimentin, N-cadherin, Id-1, and Snail in the sh-Id-1 group (P < 0.05).
Downregulation of Id-1 inhibits the EMT process by reducing Snail expression, effectively suppressing the growth, invasion, and lung metastasis of OS.
骨肉瘤（OS）是一种具有高度侵袭性的骨肿瘤，常转移至肺部。本研究旨在探讨Id-1基因在OS侵袭和转移中的作用及其与Snail基因的关系。
本研究纳入了12例非转移性骨肉瘤和9例转移性骨肉瘤患者的组织样本，采用RT-qPCR检测Id-1和Snail的表达，并分析它们的相关性。在细胞实验中，培养了四种骨肉瘤细胞系（Saos-2、U2OS、MG-63和143B）以及人成骨细胞系hFOB 1.19。通过RT-qPCR和蛋白质免疫印迹法评估Id-1和Snail的表达。利用慢病毒感染将细胞随机分为对照组、sh-NC组和sh-Id-1组。采用Transwell侵袭实验和划痕实验评估细胞迁移和侵袭能力。运用蛋白质免疫印迹法检测各组OS细胞中Id-1、Snail和上皮-间质转化（EMT）相关蛋白（E-钙黏蛋白、波形蛋白和N-钙黏蛋白）的表达。在动物实验中，通过将细胞皮下注射到小鼠体内评估每组的肿瘤形成情况。通过将感染细胞注射到小鼠胫骨建立骨肉瘤肺转移模型。采用苏木精-伊红（HE）染色观察肿瘤生长和肺转移情况。运用蛋白质免疫印迹法和免疫组织化学评估每组小鼠骨肉瘤和肺组织中Id-1、Snail和EMT相关蛋白的表达。
骨肉瘤组织中Id-1和Snail的表达显著高于正常骨组织，且Id-1的表达与Snail呈正相关。在细胞实验中，Id-1的下调降低了Snail的表达，并显著抑制了EMT以及OS细胞的迁移和侵袭（P<0.05）。在动物实验中，与对照组相比，sh-Id-1组小鼠体重无显著变化，但肿瘤体积显著减小，肺转移结节减少（P<0.05）。HE染色显示sh-Id-1组肿瘤细胞核异型性降低、侵袭和破坏减少、新生血管减少且钙化减少。免疫组织化学和蛋白质免疫印迹结果显示sh-Id-1组E-钙黏蛋白上调，波形蛋白、N-钙黏蛋白、Id-1和Snail下调（P<0.05）。
Id-1的下调通过降低Snail的表达抑制EMT过程，有效抑制了OS的生长、侵袭和肺转移。
