作者:Hamish S. Sutherland、In Young Hwang、Elaine S. Marshall、Brent S. Lindsay、William A. Denny、Catherine Gilchrist、Wayne R. Joseph、Debra Greenhalgh、Emma Richardson、Philip Kestell、Angela Ding、Bruce C. Baguley
DOI:10.1007/s10637-011-9744-z
日期:2012.10
Purpose The human tumour suppressor protein p53 is mutated in nearly half of human tumours and most mutant proteins have single amino acid changes. Several drugs including the quinazoline derivative 1 (CP-31398) have been reported to restore p53 activity in mutant cells. The side chain of 1 contains a styryl linkage that compromises its stability and we wished to explore the activity of analogues containing more stable side chains. Methods Reactivation of p53 function was measured by flow cytometry as the ability to potentiate radiation-induced G1-phase cell cycle arrest and by western blotting to determine expression of p21WAF1. DNA binding was measured by competition with ethidium and preliminary pharmacological and xenograft studies were carried out. Results Screening of analogues for potentiation of radiation-induced G1-phase cell cycle arrest using NZOV11, an ovarian tumour cell line containing a p53R248Q mutation, demonstrated that the (2-benzofuranyl)-quinazoline derivative 5 was among the most active of the analogues. Compound 5 showed similar effects in several other p53 mutant human tumour cell lines but not in a p53 null cell line. 5 also potentiated p21WAF1 expression induced by radiation. DNA binding affinity was measured and found to correlate with p53 reactivation activity. Plasma concentrations of 5 in mice were sufficient to suggest in vivo activity and a small induced tumour growth delay (7 days) of NZM4 melanoma xenografts was observed. Conclusion Compound 5 restores p53-like function to a human tumour cells lines expressing a variety of mutant p53 proteins, thus providing a basis for the design of further new drugs.
目的 在近一半的人类肿瘤中,人类肿瘤抑制蛋白 p53 发生突变,大多数突变蛋白只有一个氨基酸发生变化。据报道,包括喹唑啉衍生物 1(CP-31398)在内的几种药物可恢复突变细胞中 p53 的活性。1 的侧链含有苯乙烯基连接,影响了其稳定性,因此我们希望探索含有更稳定侧链的类似物的活性。方法 通过流式细胞术测量 p53 功能的重激活,即增强辐射诱导的 G1 期细胞周期停滞的能力,并通过 Western 印迹法测定 p21WAF1 的表达。通过乙啶竞争法测定 DNA 结合,并进行了初步的药理学和异种移植研究。结果 使用含有 p53R248Q 突变的卵巢肿瘤细胞系 NZOV11 对类似物进行筛选,以确定其对辐射诱导的 G1 期细胞周期停滞的增效作用,结果表明(2-苯并呋喃基)-喹唑啉衍生物 5 是活性最高的类似物之一。化合物 5 在其他几种 p53 突变的人类肿瘤细胞系中也显示出类似的作用,但在 p53 缺失的细胞系中却没有。5 还能增强辐射诱导的 p21WAF1 的表达。对 DNA 结合亲和力进行了测量,发现它与 p53 的重新激活活性相关。5 在小鼠体内的血浆浓度足以表明其体内活性,并观察到 NZM4 黑色素瘤异种移植物的肿瘤生长略有延迟(7 天)。结论 化合物 5 能使表达多种突变 p53 蛋白的人类肿瘤细胞系恢复类似 p53 的功能,从而为设计进一步的新药物提供了基础。