Platinum(II) Iodido Complexes of 7-Azaindoles with Significant Antiproliferative Effects: An Old Story Revisited with Unexpected Outcomes
作者:Pavel Štarha、Ján Vančo、Zdeněk Trávníček、Jan Hošek、Jarmila Klusáková、Zdeněk Dvořák
DOI:10.1371/journal.pone.0165062
日期:——
A series of platinum(II) diiodido complexes containing 7-azaindole derivatives, having the general formula cis-[PtI2(naza)2] (1–8), has been prepared and thoroughly characterized, including X-ray structure analysis of cis-[PtI2(2Me4Claza)2]∙DMF (8∙DMF; 2Me4Claza = 2-methyl-4-chloro-7-azaindole). Complexes showed high in vitro cytotoxicity against nine human cancer cell lines (IC50 ranging from 0.4 to 12.8 μM), including the cisplatin-resistant ovarian cancer cell line (A2780R; IC50 = 1.0–3.5 μM). The results of in vivo testing, using the L1210 lymphocytic leukaemia model, at the equimolar doses of Pt with cisplatin (2 mg/kg) confirmed the activity of complex 8 comparable to cisplatin. From the mechanistic point of view, evaluated ex vivo by Western blot analyses on the samples of isolated tumour tissues, the treatment of the animals with complex 8, contrary to cisplatin, decreased the levels of tumour suppressor p53 and increased significantly the amount of intracellular anti-apoptotic protein MCL-1L (37 kDa). Additionally, the active form of caspase 3 was significantly elevated in the sample of tumour tissues treated with complex 8, indicating that the activation of p53-independent cell-death pathway was initiated. The light and electron microscopy observations of the cancerous tissues revealed necrosis as a dominant mechanism of cell death, followed by scarce signs of apoptosis. The additional results (e.g. in vitro interaction experiments with selected biomolecules, cell cycle perturbations, gel electrophoretic studies on pUC19 plasmid DNA) supported the hypothesis that the complexes might be involved in the mechanism of action quite different from cisplatin.
我们制备了一系列含有 7-氮杂吲哚衍生物的铂(II)二碘络合物,通式为顺式-[PtI2(naza)2](1-8),并对其进行了全面表征,包括对顺式-[PtI2(2Me4Claza)2]∙DMF(8∙DMF;2Me4Claza = 2-甲基-4-氯-7-氮杂吲哚)进行了 X 射线结构分析。复合物对九种人类癌症细胞系(IC50 从 0.4 到 12.8 μM)显示出较高的体外细胞毒性,其中包括顺铂抗性卵巢癌细胞系(A2780R;IC50 = 1.0-3.5 μM)。使用 L1210 淋巴细胞白血病模型进行的体内测试结果表明,在铂与顺铂(2 毫克/千克)等摩尔剂量下,复合物 8 的活性与顺铂相当。从机理角度来看,通过对分离的肿瘤组织样本进行体内外 Western 印迹分析评估,与顺铂相反,用复合物 8 处理动物会降低肿瘤抑制因子 p53 的水平,并显著增加细胞内抗凋亡蛋白 MCL-1L (37 kDa)的含量。此外,在用复方 8 处理的肿瘤组织样本中,caspase 3 的活性形式明显升高,表明与 p53 无关的细胞死亡途径被激活。对癌症组织的光镜和电子显微镜观察显示,细胞坏死是细胞死亡的主要机制,其次是细胞凋亡。其他结果(如与选定生物大分子的体外相互作用实验、细胞周期扰动、pUC19 质粒 DNA 的凝胶电泳研究)支持了该复合物可能参与了与顺铂截然不同的作用机制的假设。