Department of Internal Medicine, School of Medical Science, Hematology and Hemotherapy Center, University of Campinas, 13083-970 Campinas, SP, Brazil.
BMC Med Genomics. 2010 Jul 15;3:30. doi: 10.1186/1755-8794-3-30.
Myelodysplastic syndromes (MDS) are a group of clonal hematological disorders characterized by ineffective hematopoiesis with morphological evidence of marrow cell dysplasia resulting in peripheral blood cytopenia. Microarray technology has permitted a refined high-throughput mapping of the transcriptional activity in the human genome. Non-coding RNAs (ncRNAs) transcribed from intronic regions of genes are involved in a number of processes related to post-transcriptional control of gene expression, and in the regulation of exon-skipping and intron retention. Characterization of ncRNAs in progenitor cells and stromal cells of MDS patients could be strategic for understanding gene expression regulation in this disease.
In this study, gene expression profiles of CD34+ cells of 4 patients with MDS of refractory anemia with ringed sideroblasts (RARS) subgroup and stromal cells of 3 patients with MDS-RARS were compared with healthy individuals using 44 k combined intron-exon oligoarrays, which included probes for exons of protein-coding genes, and for non-coding RNAs transcribed from intronic regions in either the sense or antisense strands. Real-time RT-PCR was performed to confirm the expression levels of selected transcripts.
In CD34+ cells of MDS-RARS patients, 216 genes were significantly differentially expressed (q-value <or= 0.01) in comparison to healthy individuals, of which 65 (30%) were non-coding transcripts. In stromal cells of MDS-RARS, 12 genes were significantly differentially expressed (q-value <or= 0.05) in comparison to healthy individuals, of which 3 (25%) were non-coding transcripts.
These results demonstrated, for the first time, the differential ncRNA expression profile between MDS-RARS and healthy individuals, in CD34+ cells and stromal cells, suggesting that ncRNAs may play an important role during the development of myelodysplastic syndromes.
骨髓增生异常综合征（MDS）是一组克隆性血液病，其特征为无效造血，骨髓细胞形态学证据显示发育不良，导致外周血细胞减少。微阵列技术允许对人类基因组的转录活性进行精细的高通量映射。非编码 RNA（ncRNA）由基因内含子区域转录，参与许多与基因表达的转录后控制以及外显子跳跃和内含子保留相关的过程。MDS 患者祖细胞和基质细胞中 ncRNA 的特征可能对理解该疾病中的基因表达调控具有战略意义。
在这项研究中，使用 44k 组合内含子-外显子寡核苷酸芯片比较了 4 例难治性贫血伴环形铁幼粒细胞（RARS）亚组 MDS 患者的 CD34+细胞和 3 例 MDS-RARS 患者的基质细胞与健康个体的基因表达谱，该芯片包括编码基因外显子的探针，以及来自顺式或反式内含子的非编码 RNA 转录物的探针。进行实时 RT-PCR 以确认所选转录物的表达水平。
与健康个体相比，MDS-RARS 患者的 CD34+细胞中 216 个基因的表达显著差异（q 值≤0.01），其中 65 个（30%）为非编码转录物。在 MDS-RARS 的基质细胞中，与健康个体相比，有 12 个基因的表达显著差异（q 值≤0.05），其中 3 个（25%）为非编码转录物。
这些结果首次证明了 MDS-RARS 与健康个体的 CD34+细胞和基质细胞之间的差异 ncRNA 表达谱，表明 ncRNA 可能在骨髓增生异常综合征的发展过程中发挥重要作用。
