Aberuyi Narges, Rahgozar Soheila, Khosravi Dehaghi Zohreh, Moafi Alireza, Masotti Andrea, Paolini Alessandro
Department of Biology, Faculty of Science, University of Isfahan.
Department of Pediatric-Hematology-Oncology, Sayed-ol-Shohada Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
Onco Targets Ther. 2017 Jul 10;10:3373-3380. doi: 10.2147/OTT.S140488. eCollection 2017.
The aim of this work was to study the correlation between the expressions of the and genes at the mRNA and protein levels in children with acute lymphoblastic leukemia (ALL) and the effects of this association on multidrug resistance (MDR).
Sixty-nine children with de novo ALL and 25 controls were enrolled in the study. Mononuclear cells were isolated from the bone marrow. The mRNA levels of and were measured by real-time polymerase chain reaction (PCR). Samples with high mRNA levels were assessed for respective protein levels by Western blotting. Following the first year of treatment, persistent monoclonality of T-cell gamma receptors or immunoglobulin H (IgH) gene rearrangement was assessed and considered as the MDR. The tertiary structure of ABCA2 was predicted using Phyre2 and I-TASSER web systems and compared to that of ABCA3, which has been previously reported. Molecular docking was performed using DOCK 6.7.
Real-time quantitative PCR (qRT-PCR) showed high levels of and mRNAs in 13 and 17 samples, respectively. Among them, five and eight individuals demonstrated high levels of ABCA2 and ABCA3, respectively. Response to chemotherapy was significantly decreased (=0.001) when the mRNA and protein of both genes were overexpressed compared to individuals with high transcriptional levels of either or alone. Close similarity between ABCA2 and ABCA3 structures was revealed by protein tertiary structure prediction, whereas molecular docking analysis suggested similar binding of chemotherapy drugs and therefore a potentially similar role in determining the MDR.
Our findings suggested, for the first time, that quantification of the protein level of ABCA2 and ABCA3 transporters had a prognostic impact on pediatric ALL MDR. Furthermore, the tertiary structure of ABCA2 was predicted for the first time, and docking analysis revealed a possible compensatory effect between ABCA2 and ABCA3 transporters, which may contribute to the efflux of cytotoxic drugs and, ultimately, to chemoresistance.
本研究旨在探讨急性淋巴细胞白血病（ALL）患儿中ABCA2和ABCA3基因在mRNA和蛋白质水平的表达相关性，以及这种关联对多药耐药（MDR）的影响。
本研究纳入69例初发ALL患儿和25例对照。从骨髓中分离单个核细胞。采用实时聚合酶链反应（PCR）检测ABCA2和ABCA3的mRNA水平。对mRNA水平高的样本进行蛋白质印迹法检测相应蛋白质水平。治疗1年后，评估T细胞γ受体或免疫球蛋白H（IgH）基因重排的持续单克隆性，并将其视为MDR。使用Phyre2和I-TASSER网络系统预测ABCA2的三级结构，并与先前报道的ABCA3的三级结构进行比较。使用DOCK 6.7进行分子对接。
实时定量PCR（qRT-PCR）显示，分别有13例和17例样本中ABCA2和ABCA3的mRNA水平较高。其中，分别有5例和8例个体ABCA2和ABCA3蛋白水平较高。与仅ABCA2或ABCA3转录水平高的个体相比，当两个基因的mRNA和蛋白均过表达时，化疗反应显著降低（P=0.001）。蛋白质三级结构预测显示ABCA2和ABCA3结构高度相似，而分子对接分析表明化疗药物的结合相似，因此在确定MDR方面可能具有相似作用。
我们的研究结果首次表明，ABCA2和ABCA3转运蛋白的蛋白质水平定量对儿童ALL的MDR具有预后影响。此外，首次预测了ABCA2的三级结构，对接分析揭示了ABCA2和ABCA3转运蛋白之间可能存在的补偿作用，这可能有助于细胞毒性药物的外排，并最终导致化疗耐药。
