Cojocneanu Roxana, Braicu Cornelia, Raduly Lajos, Jurj Ancuta, Zanoaga Oana, Magdo Lorand, Irimie Alexandru, Muresan Mihai-Stefan, Ionescu Calin, Grigorescu Mircea, Berindan-Neagoe Ioana
Research Center for Functional Genomics and Translational Medicine, Iuliu Hatieganu University of Medicine and Pharmacy, 23 Marinescu Street, 400015 Cluj-Napoca, Romania.
Department of Surgery, The Oncology Institute "Prof. Dr. Ion Chiricuta", 400015 Cluj-Napoca, Romania.
Cancers (Basel). 2020 Mar 31;12(4):843. doi: 10.3390/cancers12040843.
An increasing number of studies suggest the implication of microRNAs (miRNAs) in colorectal (CRC) carcinogenesis and disease progression. Nevertheless, the basic mechanism is not yet clear. We determined plasma miRNA expression levels using Agilent microarray technology followed by overlapping with The Cancer Genome Atlas (TCGA) tissue data and a qRT-PCR validation step and analysis of the altered miRNA signatures to emphasize new mechanistic insights. For TGCA dataset, we identified 156 altered miRNAs (79 downregulated and 77 upregulated) in colorectal tissue samples versus normal tissue. The microarray experiment is based on 16 control samples, 38 CRC plasma samples from colorectal cancer patients who have not undergone chemotherapy, and 17 chemo-treated samples. In the case of the analysis of CRC cancer versus healthy control we identified 359 altered miRNAs (214 downregulated and 60 upregulated), considering as the cutoff value a fold-change of ±1.5 and < 0.01. An additional microarray analysis was performed on plasma from untreated colorectal cancer ( = 38) and chemotherapy-treated colorectal cancer patients ( = 17), which revealed 15 downregulated miRNAs and 53 upregulated miRNAs, demonstrating that the plasma miRNA pattern is affected by chemotherapy and emphasizing important regulators of drug resistance mechanisms. For the validation of the microarray data, we selected a panel of 4 miRNAs from the common miRNA signatures for colon and rectal cancer (miR-642b-3p, miR-195-5p and miR-4741). At the tissue level, the expression levels were in agreement with those observed in colorectal plasma. miR-1228-3p, the top upregulated miRNA in CRC, was chosen to be validated on tissue and plasma samples, as it was demonstrated to be downregulated at tissue level in our patient cohort. This was confirmed by TCGA data and was one example of ta ranscript that has a different expression level between tumor tissue and plasma. Developing more efficient investigation methods will help explain the mechanisms responsible for miRNAs released in biofluids, which is the most upregulated transcript in colorectal plasma samples and which can function as a prediction tool within the oncological field.
越来越多的研究表明，微小RNA（miRNA）与结直肠癌（CRC）的致癌作用和疾病进展有关。然而，其基本机制尚不清楚。我们使用安捷伦微阵列技术测定血浆miRNA表达水平，随后与癌症基因组图谱（TCGA）组织数据进行比对，并通过qRT-PCR验证步骤以及对改变的miRNA特征进行分析，以强调新的机制见解。对于TCGA数据集，我们在结直肠组织样本与正常组织中鉴定出156个改变的miRNA（79个下调和77个上调）。微阵列实验基于16个对照样本、38个未接受化疗的结直肠癌患者的CRC血浆样本以及17个化疗处理样本。在分析CRC癌症与健康对照时，我们将±1.5的倍数变化和<0.01作为截断值，鉴定出359个改变的miRNA（214个下调和60个上调）。对未治疗的结直肠癌患者（n = 38）和化疗治疗的结直肠癌患者（n = 17）的血浆进行了额外的微阵列分析，结果显示有15个miRNA下调和53个miRNA上调，这表明血浆miRNA模式受化疗影响，并强调了耐药机制的重要调节因子。为了验证微阵列数据，我们从结肠癌和直肠癌的常见miRNA特征中选择了一组4个miRNA（miR-642b-3p、miR-195-5p和miR-4741）。在组织水平上，表达水平与在结直肠血浆中观察到的一致。miR-1228-3p是CRC中上调最明显的miRNA，由于在我们的患者队列中其在组织水平被证明下调，因此被选择在组织和血浆样本上进行验证。这得到了TCGA数据的证实，并且是一个在肿瘤组织和血浆之间具有不同表达水平的转录本的例子。开发更有效的研究方法将有助于解释生物流体中释放的miRNA的机制，这是结直肠血浆样本中上调最明显的转录本，并且可以在肿瘤学领域用作预测工具。
