Université Clermont Auvergne, INSERM, U1240 Imagerie Moléculaire et Stratégies Théranostiques, 63000, Clermont-Ferrand, France; Laboratoire de Développement Chimique, Galénique et Pharmacologique des Médicaments, Faculté de Pharmacie de Monastir, Université de Monastir, 5000, Monastir, Tunisia.
Université Clermont Auvergne, INSERM, U1240 Imagerie Moléculaire et Stratégies Théranostiques, 63000, Clermont-Ferrand, France.
Eur J Med Chem. 2018 Oct 5;158:51-67. doi: 10.1016/j.ejmech.2018.08.060. Epub 2018 Aug 23.
Due to an abundant chondrogenic, poorly vascularized and particularly hypoxic extracellular matrix, chondrosarcoma, a malignant cartilaginous tumour, is chemo- and radio-resistant. Surgical resection with wide margins remains the mainstay of treatment. To address the lack of therapy, our strategy aims to increase anticancer drugs targeting and delivery in the tumour, by leveraging specific chondrosarcoma hallmarks: an extensive cartilaginous extracellular matrix, namely the high negative fixed charge density and severe chronic hypoxia. A dual targeted therapy for chondrosarcoma was investigated by conjugation of a hypoxia-activated prodrug (HAP) to quaternary ammonium (QA) functions which exhibit a high affinity for polyanionic sites of proteoglycans (PGs), the major components of the chondrosarcoma extracellular matrix. Based on preclinical results, an imidazole prodrug, ICF05016, was identified and provided the basis for a lead optimization study. A series of 27 QA-phosphoramide mustard conjugates, differing by the type of QA function and the length of the alkyl linker, was yielded by a common multi-step sequence involving phosphorylation of a key 2-nitroimidazole alcohol. Then, a screening was realized by surface plasmon resonance technology to assess biomolecular interactions between QA derivatives and aggrecan, the most abundant PG in chondrosarcoma. Results revealed that affinity depends more on the type of QA function, than on the linker length. Moreover, the presence of a benzyl group enhanced affinity to aggrecan. Twelve compounds were shortlisted and evaluated for antiproliferative activity (i.e., growth inhibiting concentration 50), under normoxic and hypoxic conditions using the human extraskeletal myeloid chondrosarcoma cell line (HEMC-SS). For all prodrugs, hypoxic selectivity was maintained and even increased, compared with the lead. From this study, compound 31f emerged as the most effective PG-targeted HAPs with a dissociation constant of 2.10 μM in the SPR experiment, a hypoxia cytotoxicity ratio of 24 and an efficient reductive cleavage under chemical and enzymatic conditions.
由于软骨肉瘤的细胞外基质富含软骨生成细胞、血管较少且特别缺氧，因此对化疗和放疗具有抗性。广泛切除肿瘤仍然是治疗的主要方法。为了解决缺乏治疗方法的问题，我们的策略旨在通过利用软骨肉瘤的特定特征来增加抗癌药物在肿瘤中的靶向性和输送：广泛的软骨细胞外基质，即高负固定电荷密度和严重的慢性缺氧。通过将缺氧激活前药 (HAP) 与季铵 (QA) 功能结合，研究了软骨肉瘤的双重靶向治疗，QA 功能对软骨肉瘤细胞外基质中主要成分蛋白聚糖 (PG) 的聚阴离子位点具有高亲和力。基于临床前结果，确定了一种咪唑前药 ICF05016，并为后续的优化研究提供了基础。通过涉及关键 2-硝基咪唑醇磷酸化的常见多步序列，产生了 27 种 QA-磷酰胺 mustard 缀合物，这些缀合物通过 QA 功能的类型和烷基连接体的长度而有所不同。然后，通过表面等离子体共振技术进行筛选，以评估 QA 衍生物与软骨肉瘤中最丰富的 PG 聚集蛋白聚糖之间的生物分子相互作用。结果表明，亲和力更多地取决于 QA 功能的类型，而不是连接体的长度。此外，苄基的存在增强了与聚集蛋白聚糖的亲和力。在有氧和缺氧条件下，使用人 extraskeletal 髓样软骨肉瘤细胞系（HEMC-SS），通过表面等离子体共振技术对 12 种化合物进行了抗增殖活性（即生长抑制浓度 50）的筛选。对于所有前药，与先导化合物相比，缺氧选择性保持甚至增加。从这项研究中，化合物 31f 脱颖而出，成为最有效的 PG 靶向 HAPs，在 SPR 实验中的解离常数为 2.10μM，缺氧细胞毒性比为 24，在化学和酶条件下具有有效的还原裂解。
