骨肉瘤（OS）是一种常见的骨癌，主要影响儿童和青少年。顺铂（CDDP）已被证明对不同的癌症，如骨肉瘤，具有疗效，但其耐药性的发展以及重要的副作用导致了治疗失败。铜化合物等新型疗法在抗癌药物中显示出潜在的有效性，并成为通常使用的铂类化合物的替代品之一。本研究的目标是评估含有三牙腙类配体的Cu(II)阳离子配合物（简称CuHL，其化学式为[H2L=N'-(2-羟基-3-甲氧基苯甲烯)噻吩-2-卡巴酰肼]）对人骨肉瘤MG-63细胞的体外和体内抗肿瘤活性，并阐明其分子靶点。在骨肉瘤细胞株MG-63中评估了抗癌活性，包括单层培养和球体培养。CuHL在这两种模型中均显著降低了细胞存活率（IC50 2D: 2.1 ± 0.3 μM; 3D: 9.1 ± 1.0 μM）（p < 0.001）。细胞添加实验表明，铜化合物抑制了细胞增殖并导致细胞凋亡，通过流式细胞术确定。CuHL通过彗星实验显示了较大的基因毒性。轨道飞行时间质谱蛋白质组学分析鉴定了27种差异表达的蛋白质：在CuHL处理后，MG-63细胞中发现了17个蛋白质过度表达和10个蛋白质低表达。对未折叠蛋白质的应答是最受影响的生物过程。此外，对人类骨肉瘤裸鼠异种移植瘤进行了化合物的体内抗肿瘤效果评估。以每周三次、每次剂量为2 mg/kg的方式进行了为期一个月的CuHL处理，显著抑制了骨肉瘤异种移植瘤的进展，并伴随着有丝分裂指数的降低和肿瘤坏死的增加（p < 0.01）。按照相同的治疗方案给予标准的细胞毒性药物CDDP处理，未能抑制骨肉瘤的生长和进展。版权所有© 2023. 由Elsevier B.V.出版。

Osteosarcoma (OS) is a frequent bone cancer, affecting largely children and young adults. Cisplatin (CDDP) has been efficacious in the treatment of different cancer such us OS but the development of chemoresistance and important side effects leading to therapeutic failure. Novel therapies including copper compounds have shown to be potentially effective as anticancer drugs and one alternative to usually employed platinum compounds. The goal of this work is to evaluate the in vitro and in vivo antitumoral activity and dilucidate the molecular target of a Cu(II) cationic complex containing a tridentate hydrazone ligand, CuHL for short, [H2L=N'-(2-hydroxy-3-methoxybenzylidene)thiophene-2-carbohydrazide, against human OS MG-63 cells. Anticancer activity on MG-63 cell line was evaluated in OS monolayer and spheroids. CuHL significantly impaired cell viability in both models (IC50 2D: 2.1 ± 0.3 μM; 3D: 9.1 ± 1.0 μM) (p < 0.001). Addition cell studies demonstrated that copper compound inhibits cell proliferation and conveys cells to apoptosis, determined by flow cytometry. CuHL showed a great genotoxicity, evaluated by comet assay. Proteomic analysis by Orbitrap Mass Spectometry identified 27 differentially expressed proteins: 17 proteins were found overexpressed and 10 underexpressed in MG-63 cells after the CuHL treatment. The response to unfolded protein was the most affected biological process. In addition, in vivo antitumor effects of the compound were evaluated on human OS tumors xenografted in nude mice. CuHL treatment, at a dose of 2 mg/kg i.p., given three times/week for one month, significantly inhibited the progression of OS xenografts and was associated to a reduction in mitotic index and increased tumor necrosis (p < 0.01). Administration of standard-of-care cytotoxic agent CDDP, following the same treatment schedule as CuHL, failed to impair OS growth and progression.Copyright © 2023. Published by Elsevier B.V.