Kadry Alaa Ahmed, Adel Mai, Abubshait Samar A, Yahya Galal, Sharaky Marwa, Serya Rabah A T, Abouzid Khaled A M
Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassaia, Cairo 11566, Egypt.
Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassaia, Cairo 11566, Egypt.
Bioorg Med Chem. 2025 Jul 1;124:118173. doi: 10.1016/j.bmc.2025.118173. Epub 2025 Mar 23.
Poly(ADP-ribose) polymerase-1 (PARP-1) plays a crucial role in DNA repair, mediating approximately 90 % of ADP-ribosylation processes associated with DNA damage response. Consequently, inhibiting PARP-1 with small molecules represents a promising strategy for cancer therapy. Utilizing a structure-based design and molecular hybridization approach, we developed three novel series of spirobenzoxazinone-piperdine/salicylamide-based derivatives. These compounds were evaluated for their in vitro PARP-1 inhibitory activity, and their structure-activity relationships were analyzed. At 10 µM concentration, derivatives (18a-d) demonstrated nearly complete inhibition, and the spirocyclic derivative (7c) also achieved a considerable inhibitory effect, with IC values in the low micromolar range. The most promising compounds (7c, 18a-d) were tested for their antiproliferative activity against six cancer cell lines. Notably, compounds (7c) and (18d) exhibited significant antiproliferative effects against H1299 and FaDu cells, which correlated with their calculated logP values. These compounds were also tested against normal human skin fibroblasts (HSF), revealing a favorable safety profile compared to cancer cells. Basal anti-PARP-1 activity of the most promising compounds was validated in the HCT116 colorectal cancer cell line. Western blot analysis confirmed robust cleavage of PARP-1, indicating enzymatic inhibition and loss of PARP-1 activity. Combining these inhibitors with doxorubicin showed synergistic lethality in colony-formation assay. Finally, a molecular docking study was conducted to examine the binding modes of these compounds within the PARP-1 active site. The results demonstrated binding modes comparable to those of olaparib and other approved PARP-1 inhibitors, maintaining the key interactions necessary for activity. Based on these findings, compounds (7c) and (18d) emerge as promising candidates for further development in targeting anti-cancer drug resistance through PARP-1 inhibition.
聚（ADP - 核糖）聚合酶 -1（PARP -1）在DNA修复中起着关键作用，介导约90%与DNA损伤反应相关的ADP - 核糖基化过程。因此，用小分子抑制PARP -1是一种很有前景的癌症治疗策略。利用基于结构的设计和分子杂交方法，我们开发了三个新型的基于螺苯并恶嗪酮 - 哌啶/水杨酰胺的衍生物系列。对这些化合物的体外PARP -1抑制活性进行了评估，并分析了它们的构效关系。在10µM浓度下，衍生物（18a - d）表现出几乎完全抑制，螺环衍生物（7c）也取得了相当大的抑制效果，IC值在低微摩尔范围内。对最有前景的化合物（7c，18a - d）针对六种癌细胞系的抗增殖活性进行了测试。值得注意的是，化合物（7c）和（18d）对H1299和FaDu细胞表现出显著的抗增殖作用，这与其计算的logP值相关。还对这些化合物针对正常人皮肤成纤维细胞（HSF）进行了测试，与癌细胞相比显示出良好的安全性。在HCT116结肠癌细胞系中验证了最有前景化合物的基础抗PARP -1活性。蛋白质印迹分析证实了PARP -1的强烈切割，表明酶抑制和PARP -1活性丧失。在集落形成试验中，将这些抑制剂与阿霉素联合使用显示出协同致死性。最后，进行了分子对接研究以检查这些化合物在PARP -1活性位点内的结合模式。结果表明其结合模式与奥拉帕利和其他已批准的PARP -1抑制剂相当，维持了活性所需的关键相互作用。基于这些发现，化合物（7c）和（18d）成为通过PARP -1抑制靶向抗癌耐药性进一步开发很有前景的候选物。
