Lian Qiujian, Liu Hu, Li Jingyan, Luo Cheng, Liu Chang, Zhao Haonan, Dai Peijun, Wang Bingxuan, Zhou Huipeng, Jiang Xin, Wang Zhiwei, Qiao Suchi
Department of Orthopedics, Fuzhou Second General Hospital, Fuzhou, Fujian, 350007, China.
Department of Orthopedics, The Third Affiliated Hospital of Naval Medical University, Shanghai, 201805, China.
J Exp Clin Cancer Res. 2025 May 24;44(1):159. doi: 10.1186/s13046-025-03417-4.
The prognosis of osteosarcoma has improved little over the past few decades, with radioresistance being a contributing factor. Effective radiosensitizing targets and novel mechanisms for treating osteosarcoma are urgently needed. Research on the impact of regulating differentiation levels on the radiosensitivity of malignant tumors is limited. This study aimed to explore the efficacy of ITGB3 as a novel radiosensitizing target in osteosarcoma and to explore whether the modulation of osteogenic differentiation plays a role in mediating the radiosensitizing effect.
RNA sequencing was utilized to screen for potential targets that affect the radiosensitivity of osteosarcoma. In vitro assays examining cell viability, apoptosis, proliferation, migration, and invasion were conducted to verify the radiosensitizing effect of ITGB3-knockdown (KD). Furthermore, in vivo validation was performed by constructing mouse models with subcutaneous and orthotopic tibial tumors. Rescue experiments involving siRNAs and molecular inhibitors were performed to explore and validate the mechanisms through which ITGB3-KD exerts a radiosensitizing effect in vitro and in vivo. Additionally, osteogenic differentiation cultures of osteosarcoma cells were conducted as auxiliary validation for the radiosensitizing mechanism.
ITGB3-KD had a radiosensitizing effect on osteosarcoma in vitro by inhibiting cell viability, proliferation, migration, and invasion and promoting apoptosis. ITGB3-KD radiosensitized osteosarcoma in vivo in subcutaneous and orthotopic tibial tumor models. ITGB3-KD upregulated the JNK/c-JUN pathway, and rescue experiments with a JNK inhibitor revealed that the activation of this pathway was crucial for the upregulation of osteogenic markers such as RUNX2, OCN, and OPN, as well as for promoting apoptotic pathways. siRNA-based rescue experiments indicated that the upregulation of RUNX2 mediated the proapoptotic radiosensitizing effects of ITGB3-KD. Culture in osteogenic differentiation medium promoted osteosarcoma radiosensitization by enhancing the osteogenic differentiation status, working synergistically with ITGB3-KD.
Our findings indicate that ITGB3-KD enhances radiosensitivity in osteosarcoma by promoting osteogenic differentiation and apoptosis through activation of the JNK/c-JUN/RUNX2 pathway, identifying ITGB3 as a candidate therapeutic target and implicating JNK/c-JUN/RUNX2 signaling as a modulatory axis for improving the response to radiation of osteosarcoma.
在过去几十年中，骨肉瘤的预后改善甚微，放射抗性是一个影响因素。迫切需要有效的放射增敏靶点和治疗骨肉瘤的新机制。关于调节分化水平对恶性肿瘤放射敏感性影响的研究有限。本研究旨在探讨整合素β3（ITGB3）作为骨肉瘤新型放射增敏靶点的疗效，并探讨成骨分化的调节在介导放射增敏效应中是否起作用。
利用RNA测序筛选影响骨肉瘤放射敏感性的潜在靶点。进行体外实验检测细胞活力、凋亡、增殖、迁移和侵袭，以验证ITGB3基因敲低（KD）的放射增敏作用。此外，通过构建皮下和原位胫骨肿瘤小鼠模型进行体内验证。进行涉及小干扰RNA（siRNA）和分子抑制剂的挽救实验，以探索和验证ITGB3-KD在体外和体内发挥放射增敏作用的机制。此外，进行骨肉瘤细胞的成骨分化培养作为放射增敏机制的辅助验证。
ITGB3-KD通过抑制细胞活力、增殖、迁移和侵袭以及促进凋亡，在体外对骨肉瘤具有放射增敏作用。在皮下和原位胫骨肿瘤模型中，ITGB3-KD在体内使骨肉瘤对放疗敏感。ITGB3-KD上调了c-Jun氨基末端激酶（JNK）/c-JUN途径，用JNK抑制剂进行的挽救实验表明，该途径的激活对于上调成骨标志物如RUNX2、骨钙素（OCN）和骨桥蛋白（OPN）以及促进凋亡途径至关重要。基于siRNA的挽救实验表明，RUNX2的上调介导了ITGB3-KD的促凋亡放射增敏作用。在成骨分化培养基中培养通过增强成骨分化状态促进骨肉瘤放射增敏，与ITGB3-KD协同作用。
我们的研究结果表明，ITGB3-KD通过激活JNK/c-JUN/RUNX2途径促进成骨分化和凋亡，从而增强骨肉瘤的放射敏感性，确定ITGB3为候选治疗靶点，并表明JNK/c-JUN/RUNX2信号传导是改善骨肉瘤放疗反应的调节轴。
