Sifakis Emmanouil G, Lambrou George I, Prentza Andriana, Vlahopoulos Spiros, Koutsouris Dimitris, Tzortzatou-Stathopoulou Fotini, Chatziioannou Aristotelis A
School of Electrical and Computer Engineering, National Technical University of Athens, Athens, Greece.
First Department of Pediatrics, University of Athens, Choremeio Research Laboratory, Athens, Greece.
J Clin Bioinforma. 2011 Dec 20;1:36. doi: 10.1186/2043-9113-1-36.
It has been shown previously that glucocorticoids exert a dual mechanism of action, entailing cytotoxic, mitogenic as well as cell proliferative and anti-apoptotic responses, in a dose-dependent manner on CCRF-CEM cells at 72 h. Early gene expression response implies a dose-dependent dual mechanism of action of prednisolone too, something reflected on cell state upon 72 h of treatment.
In this work, a generic, computational microarray data analysis framework is proposed, in order to examine the hypothesis, whether CCRF-CEM cells exhibit an intrinsic or acquired mechanism of resistance and investigate the molecular imprint of this, upon prednisolone treatment. The experimental design enables the examination of both the dose (0 nM, 10 nM, 22 uM, 700 uM) effect of glucocorticoid exposure and the dynamics (early and late, namely 4 h, 72 h) of the molecular response of the cells at the transcriptomic layer.
In this work, we demonstrated that CCRF-CEM cells may attain a mixed mechanism of response to glucocorticoids, however, with a clear preference towards an intrinsic mechanism of resistance. Specifically, at 4 h, prednisolone appeared to down-regulate apoptotic genes. Also, low and high prednisolone concentrations up-regulates genes related to metabolism and signal-transduction in both time points, thus favoring cell proliferative actions. In addition, regulation of NF-κB-related genes implies an inherent mechanism of resistance through the established link of NF-κB inflammatory role and GC-induced resistance. The analysis framework applied here highlights prednisolone-activated regulatory mechanisms through identification of early responding sets of genes. On the other hand, study of the prolonged exposure to glucocorticoids (72 h exposure) highlights the effect of homeostatic feedback mechanisms of the treated cells.
Overall, it appears that CCRF-CEM cells in this study exhibit a diversified, combined pattern of intrinsic and acquired resistance to prednisolone, with a tendency towards inherent resistant characteristics, through activation of different molecular courses of action.
先前研究表明，糖皮质激素在72小时时对CCRF - CEM细胞具有双重作用机制，呈剂量依赖性，包括细胞毒性、促有丝分裂以及细胞增殖和抗凋亡反应。早期基因表达反应也表明泼尼松龙具有剂量依赖性双重作用机制，这在治疗72小时后的细胞状态中有所体现。
在本研究中，我们提出了一个通用的计算微阵列数据分析框架，以检验CCRF - CEM细胞是否表现出内在或获得性耐药机制的假设，并研究泼尼松龙治疗后其分子印记。该实验设计能够在转录组层面同时考察糖皮质激素暴露的剂量（0 nM、10 nM、22 μM、700 μM）效应以及细胞分子反应的动力学（早期和晚期，即4小时、72小时）。
在本研究中，我们证明CCRF - CEM细胞对糖皮质激素的反应可能具有混合机制，然而，明显倾向于内在耐药机制。具体而言，在4小时时，泼尼松龙似乎下调凋亡基因。此外，低浓度和高浓度泼尼松龙在两个时间点均上调与代谢和信号转导相关的基因，从而促进细胞增殖作用。另外，NF - κB相关基因的调控暗示了一种内在耐药机制，这是通过已确立的NF - κB炎症作用与糖皮质激素诱导的耐药之间的联系实现的。此处应用的分析框架通过识别早期反应基因集突出了泼尼松龙激活的调控机制。另一方面，对糖皮质激素长时间暴露（72小时暴露）的研究突出了处理后细胞稳态反馈机制的作用。
总体而言，本研究中的CCRF - CEM细胞似乎对泼尼松龙表现出多样化的内在和获得性耐药组合模式，通过激活不同的分子作用过程，具有内在耐药特征的倾向。
