Agnoletto Chiara, Brunelli Laura, Melloni Elisabetta, Pastorelli Roberta, Casciano Fabio, Rimondi Erika, Rigolin Gian Matteo, Cuneo Antonio, Secchiero Paola, Zauli Giorgio
Department of Morphology, Surgery and Experimental Medicine and LTTA Centre, University of Ferrara, Ferrara, Italy.
Institute of Pharmacological Researches, IRCCS "Mario Negri", Milano, Italy.
Oncotarget. 2015 Feb 10;6(4):2385-96. doi: 10.18632/oncotarget.2960.
B-chronic lymphocytic leukemia (B-CLL) patients harboring p53 mutations are invariably refractory to therapies based on purine analogues and have limited treatment options and poor survival. Having recently demonstrated that the mitochondria-targeting small molecule sodium dichloroacetate (DCA) exhibits anti-leukemic activity in p53wild-type B-CLL cells, the aim of this study was to evaluate the effect of DCA in p53mutated B-CLL cells and in p53mutated/null leukemic cell lines. DCA exhibited comparable cytotoxicity in p53wild-type and p53mutated B-CLL patient cell cultures, as well as in p53mutated B leukemic cell lines (MAVER, MEC-1, MEC-2). At the molecular level, DCA promoted the transcriptional induction of p21 in all leukemic cell types investigated, including p53null HL-60. By using a proteomic approach, we demonstrated that DCA up-regulated the ILF3 transcription factor, which is a known regulator of p21 expression. The role of the ILF3/p21 axis in mediating the DCA anti-leukemic activity was underscored by knocking-down experiments. Indeed, transfection with ILF3 and p21 siRNAs significantly decreased both the DCA-induced p21 expression and the DCA-mediated cytotoxicity. Taken together, our results emphasize that DCA is a small molecule that merits further evaluation as a therapeutic agent also for p53mutated leukemic cells, by acting through the induction of a p53-independent pathway.
携带p53突变的B细胞慢性淋巴细胞白血病（B-CLL）患者对基于嘌呤类似物的治疗总是无效，治疗选择有限且生存率低。最近已证明，靶向线粒体的小分子二氯乙酸钠（DCA）在p53野生型B-CLL细胞中具有抗白血病活性，本研究的目的是评估DCA对p53突变的B-CLL细胞以及p53突变/缺失白血病细胞系的作用。DCA在p53野生型和p53突变的B-CLL患者细胞培养物以及p53突变的B白血病细胞系（MAVER、MEC-1、MEC-2）中表现出相当的细胞毒性。在分子水平上，DCA促进了所有研究的白血病细胞类型中p21的转录诱导，包括p53缺失的HL-60。通过蛋白质组学方法，我们证明DCA上调了ILF3转录因子，这是一种已知的p21表达调节因子。敲低实验强调了ILF3/p21轴在介导DCA抗白血病活性中的作用。事实上，用ILF3和p21 siRNA转染显著降低了DCA诱导的p21表达和DCA介导的细胞毒性。综上所述，我们的结果强调，DCA是一种小分子，通过诱导一条不依赖p53的途径发挥作用，作为一种治疗药物，对p53突变的白血病细胞也值得进一步评估。
