Mohamed Mervat S, Abdelhamid Abdou O, Almutairi Fahad M, Ali Ayat G, Bishr Mai K
Department of Biochemistry, Faculty of Science, University of Tabuk, Saudi Arabia; Department of Chemistry, Biochemistry Speciality, Faculty of Science, Cairo University, Egypt.
Department of Chemistry, Organic Chemistry Speciality, Faculty of Science, Cairo University, Egypt.
Bioorg Med Chem. 2018 Feb 1;26(3):623-629. doi: 10.1016/j.bmc.2017.12.026. Epub 2017 Dec 20.
In the rapidly expanding era of cancer target therapy, regulators of apoptosis are emerging as attractive therapeutic targets. X-linked inhibitor of apoptosis (XIAP) is of specific interest owing to its characteristic overexpression in a wide variety of neoplasms, with a resultant survival advantage for tumor cells and treatment resistance. In this study, we examined three pyrazolo [3,4-d] pyridazine derivatives (PPDs) through molecular modeling and studied their modes of interaction with XIAP-BIR3 domain. PPD-1, which possessed the highest binding affinity with XIAP, was tested on A549 (lung cancer cell line); HCT-116 (colorectal carcinoma cell line); HEPG2 (liver carcinoma cell line), HFB4 (normal human skin melanocyte cell line) and WI-38 (human embryonic lung fibroblasts). In comparison to cisplatin as a positive control, PPD-1 yielded remarkable cytotoxicity on all cancer cell lines, with the highest anti-tumor activity on A549 and a favorable therapeutic ratio. Flow cytometry studies concluded that PPD-1 treatment induces Sub G1 and G2/M cell cycle arrest and apoptosis. The percentage of apoptotic cells in PPD-1 treated A549 cells was considerably higher than that in untreated cells (10.06% vs 0.57%, respectively). To further investigate the mechanism of induction of apoptosis by PPD-1, Real time-PCR was used to quantify the expression levels of key apoptotic regulators. Significant overexpression of the effector capsase-3, pro-apoptotic bax and tumor suppressor gene p53 were noted as compared to untreated cells (7.19 folds, 7.28 folds, and 5.08 folds, respectively). Moreover, PPD-1 inhibited the expression of the anti-apoptotic bcl-2 gene to 0.22 folds. These findings demonstrate that PPD-1 treatment disrupts the Bcl-2/BAX balance in lung cancer cell lines, leading to apoptosis induction possibly through intrinsic mitochondria-dependent pathway. These novel insights elucidate the mechanism of PPD-1 cytotoxicity in lung cancer cell lines and offer a promising therapeutic approach that needs further study.
在癌症靶向治疗迅速发展的时代，细胞凋亡调节因子正成为有吸引力的治疗靶点。X连锁凋亡抑制蛋白（XIAP）因其在多种肿瘤中特征性的过表达而备受关注，这使得肿瘤细胞具有生存优势并产生治疗抗性。在本研究中，我们通过分子建模研究了三种吡唑并[3,4-d]哒嗪衍生物（PPDs），并研究了它们与XIAP-BIR3结构域的相互作用模式。与XIAP具有最高结合亲和力的PPD-1在A549（肺癌细胞系）、HCT-116（结肠癌细胞系）、HEPG2（肝癌细胞系）、HFB4（正常人皮肤黑素细胞系）和WI-38（人胚肺成纤维细胞）上进行了测试。与作为阳性对照的顺铂相比，PPD-1对所有癌细胞系均产生显著的细胞毒性，对A549具有最高的抗肿瘤活性和良好的治疗指数。流式细胞术研究表明，PPD-1处理可诱导亚G1期和G2/M期细胞周期阻滞及细胞凋亡。PPD-1处理的A549细胞中的凋亡细胞百分比显著高于未处理细胞（分别为10.06%和0.57%）。为进一步研究PPD-1诱导细胞凋亡的机制，采用实时定量PCR来定量关键凋亡调节因子的表达水平。与未处理细胞相比，效应半胱天冬酶-3、促凋亡蛋白bax和肿瘤抑制基因p53显著过表达（分别为7.19倍、7.28倍和5.08倍）。此外，PPD-1将抗凋亡蛋白bcl-2基因的表达抑制至0.22倍。这些发现表明，PPD-1处理破坏了肺癌细胞系中的Bcl-2/BAX平衡，可能通过内源性线粒体依赖性途径导致细胞凋亡诱导。这些新见解阐明了PPD-1在肺癌细胞系中的细胞毒性机制，并提供了一种有前景的治疗方法，需要进一步研究。
