The Ca2⁺/calmodulin-mediated phosphatase activity of calcineurin (CN) integrates calcium-mediated signaling with gene expression programs involved in the control of essential cellular processes in health and disease, such as the immune response and the pathogenesis of cancer progression and metastasis. In addition, CN is the target of the immunosuppressive drugs cyclosporine A (CsA) and FK-506 which are the cornerstone of immunosuppressant therapy. Unfortunately, long-term administration of these drugs results in severe side effects. Herein, we describe the design, synthesis and evaluation of new synthetic compounds that are capable of inhibiting NFATc activity in a dose-dependent manner, without interfering on CN phosphatase activity. These compounds were designed using the structure-based pharmacophore model of a peptide-derived PxIxIT sequence binding to calcineurin A subunit. Moreover, these compounds inhibit NFATc-dependent cytokine gene expression, secretion and proliferation of human T CD4⁺ cells. More importantly, compound 5a reduces tumor weight and shows a tendency to reduce tumor angiogenesis in an orthotopic immunocompetent mouse model of triple negative breast cancer, suggesting that 5a has tumor suppressor activity. These findings validate compound 5a as an agent with therapeutic activity against CN-NFATc and highlight its potential as a tool for drug development with therapeutic purposes.

Ca2 ⁺/钙调蛋白介导的钙调神经磷酸酶活性 (CN) 将钙介导的信号传导与基因表达程序相结合，这些基因表达程序参与控制健康和疾病中的基本细胞过程，例如免疫反应和癌症进展和转移的发病机制。此外，CN 是免疫抑制药物环孢素 A (CsA) 和 FK-506 的靶点，它们是免疫抑制治疗的基石。不幸的是，长期服用这些药物会导致严重的副作用。在此，我们描述了能够以剂量依赖性方式抑制 NFATc 活性而不干扰 CN 磷酸酶活性的新合成化合物的设计、合成和评估。这些化合物是使用肽衍生的 PxIxIT 序列与钙调磷酸酶 A 亚基结合的基于结构的药效团模型设计的。此外，这些化合物抑制人 T CD4 的 NFATc 依赖性细胞因子基因表达、分泌和增殖⁺细胞。更重要的是，在三阴性乳腺癌原位免疫活性小鼠模型中，化合物5a降低了肿瘤重量并显示出减少肿瘤血管生成的趋势，这表明5a具有肿瘤抑制活性。这些发现证实了化合物5a作为对 CN-NFATc 具有治疗活性的药物，并突出了其作为具有治疗目的的药物开发工具的潜力。