Wei Zhiyuan, Chen Yan, Liu Guoshi, Deng Siyu, Wang Zhiyong, Zou Fan
Department of Orthopedics, Gaoxin Branch of The First Affiliated Hospital, Nanchang University, Nanchang, PR China.
Drug Dev Res. 2025 Sep;86(6):e70158. doi: 10.1002/ddr.70158.
Osteosarcoma (OS) is a common malignant bone tumor, frequently associated with impaired osteogenic differentiation of tumor cells. Recent studies have suggested that the NOTCH signaling pathway plays a crucial role in maintaining tumor cell stemness and may influence their differentiation status. This study investigates the role of NOTCH2, a key receptor in the NOTCH family, in regulating osteogenic differentiation in OS. By analyzing public datasets, we compared the expression patterns and functional relevance of NOTCH1-4 in OS and identified NOTCH2 as the most significant. Using MG-63 and Saos-2 OS cell lines, we found that NOTCH2 silencing suppressed cell proliferation, invasion, and stem-like properties, while promoting osteogenic differentiation under inductive conditions. This was accompanied by increased expression of osteogenic markers. Further experiments demonstrated that Importazole, an Importin-β inhibitor, blocked the nuclear translocation of NOTCH2. Treatment with Importazole alone inhibited OS cell proliferation and invasion, reduced stem-like features, and enhanced osteogenic differentiation. When combined with NOTCH2 knockdown, Importazole exerted a synergistic effect, further inhibiting tumor progression and promoting differentiation. In vivo, xenograft models confirmed that the combination treatment more effectively suppressed tumor growth and induced osteoblast-like characteristics compared to either intervention alone. These findings indicate that NOTCH2 is a critical regulator of OS cell behavior, and that targeting NOTCH2 - especially in combination with Importazole - may offer a promising therapeutic strategy to promote differentiation and suppress tumor progression in OS.
骨肉瘤（OS）是一种常见的恶性骨肿瘤，常与肿瘤细胞成骨分化受损有关。最近的研究表明，NOTCH信号通路在维持肿瘤细胞干性方面起着关键作用，并可能影响其分化状态。本研究探讨NOTCH家族中的关键受体NOTCH2在调节骨肉瘤成骨分化中的作用。通过分析公共数据集，我们比较了NOTCH1-4在骨肉瘤中的表达模式和功能相关性，并确定NOTCH2最为显著。使用MG-63和Saos-2骨肉瘤细胞系，我们发现NOTCH2沉默可抑制细胞增殖、侵袭和干细胞样特性，同时在诱导条件下促进成骨分化。这伴随着成骨标志物表达的增加。进一步的实验表明，输入蛋白-β抑制剂Importazole可阻断NOTCH2的核转位。单独使用Importazole处理可抑制骨肉瘤细胞增殖和侵袭，减少干细胞样特征，并增强成骨分化。当与NOTCH2敲低联合使用时，Importazole发挥协同作用，进一步抑制肿瘤进展并促进分化。在体内，异种移植模型证实，与单独的任何一种干预相比，联合治疗更有效地抑制肿瘤生长并诱导成骨样特征。这些发现表明，NOTCH2是骨肉瘤细胞行为的关键调节因子，靶向NOTCH2——尤其是与Importazole联合使用——可能为促进骨肉瘤分化和抑制肿瘤进展提供一种有前景的治疗策略。
