Abstract：
MicroRNAs (miRNAs) are short non-coding RNAs that function in post-transcriptional gene silencing and mRNA regulation. Although the number of nucleotides of miRNAs ranges from 17 to 27, they are mostly made up of 22 nucleotides. The expression of miRNAs changes significantly in cancer, causing protein alterations in cancer cells by preventing some genes from being translated into proteins. In this research, a structural analysis of 587 miRNAs that are differentially expressed in myeloid cancer was carried out. Length distribution studies revealed a mean and median of 22 nucleotides, with an average of 21.69 and a variance of 1.65. We performed nucleotide analysis for each position where Uracil was the most observed nucleotide and Adenine the least observed one with 27.8% and 22.6%, respectively. There was a higher frequency of Adenine at the beginning of the sequences when compared to Uracil, which was more frequent at the end of miRNA sequences. The purine content of each implicated miRNA was also assessed. A novel motif analysis script was written to detect the most frequent 3-7 nucleotide (3-7n) long motifs in the miRNA dataset. We detected CUG (42%) as the most frequent 3n motif, CUGC (15%) as a 4n motif, AGUGC (6%) as a 5n motif, AAGUGC (4%) as a 6n motif, and UUUAGAG (4%) as a 7n motif. Thus, in the second part of our study, we further characterized the motifs by analyzing whether these motifs align at certain consensus sequences in our miRNA dataset, whether certain motifs target the same genes, and whether these motifs are conserved within other species. This thorough structural study of miRNA sequences provides a novel strategy to study the implications of miRNAs in health and disease. A better understanding of miRNA structure is crucial to developing therapeutic settings.
摘要：
MicroRNAs（miRNA）是短的非编码RNA，在转录后基因沉默和mRNA调节中起作用。尽管miRNA的核苷酸数量范围为17至27，但它们大多由22个核苷酸组成。miRNA的表达在癌症中显著改变,通过阻止一些基因被翻译成蛋白质来引起癌细胞中的蛋白质改变。在这项研究中,对髓样癌中差异表达的587种miRNA进行了结构分析.长度分布研究显示平均和中位数为22个核苷酸，平均值为21.69，方差为1.65。我们对每个位置进行了核苷酸分析，其中尿嘧啶是观察到的最多的核苷酸，腺嘌呤是观察到的最少的核苷酸，分别为27.8％和22.6％。分别。与尿嘧啶相比，在序列开始时腺嘌呤的频率更高，这在miRNA序列的末端更为常见。还评估了每个涉及的miRNA的嘌呤含量。编写新的基序分析脚本以检测miRNA数据集中最常见的3-7个核苷酸(3-7n)长基序。我们检测到CUG(42%)是最常见的3n基序，CUGC(15%)作为4n主题，AGUGC(6%)作为5n主题，AAGUGC（4％）作为6n主题，和UUUAGAG（4%）为7n基序。因此，在我们研究的第二部分，我们通过分析这些基序是否在我们的miRNA数据集中的某些共有序列上对齐来进一步表征基序，某些基序是否针对相同的基因，以及这些基序在其他物种中是否保守。这种对miRNA序列的彻底结构研究为研究miRNA在健康和疾病中的意义提供了新的策略。更好地理解miRNA结构对于开发治疗环境至关重要。
