Functional analysis of miRNA in pituitary adenoma

微RNA （miRNA）属于非编码RNA，是一种长度在20 ~ 25个碱基之间的单链RNA。近年来的研究揭示了其在基因表达中的分子功能，但对垂体腺瘤中激素调控基因的调控却知之甚少。在这项研究中，我们强调了通过几种mirna调节GH或PRL的信号级联。首先分析大鼠垂体腺瘤细胞中GH3 mRNA和miRNA的表达谱，并与对照大鼠正常垂体（RPC）进行比较，筛选出调节GH或PRL表达的mRNA和miRNA的负相关。随后，转染mi-RNA的互补序列，目的是敲除，并通过ELISA研究评估GH或PRL的分泌。最后进行微阵列分析来分析信号级联。在过表达多于RPC的miRNA中，没有一个miRNA与gh相关mRNA呈负相关。同时，rno-miR-494、-146a表达减少，与mRNA呈负相关。另外，与PRL表达密切相关的rno-miR-101b、-191和-194过表达。在具有这些互补序列的敲除细胞中，rno- mir -101b敲除GH3细胞可提高PRL分泌。同样在cDNA芯片分析中，GH3细胞在敲低rno-miR-101b后上调prl产生相关信号。总之，rno-miR-101b是调节PRL生成的miRNA。

Micro-RNA (miRNA) is belonged to non-coding RNA, which is single-stranded RNA ranging20 to 25 bases. Recent studies have disclosed its molecular function in gene expression, however, the regulation on genes regarding hormonal regulation in pituitary adenoma has been little discussed. In this study, we highlighted on signaling cascades that regulate GH or PRL by several miRNAs.Firstly, profiling of mRNA and miRNA in rat pituitary adenoma cells, GH3 was analyzed comparing rat normal pituitary (RPC) as the control and followed by selection of the negative correlation of mRNA and miRNA among those regulate GH or PRL expression. Subsequently, complimentary sequence for the mi-RNA was transfected aiming to knock-down and secretion of GH or PRL was evaluated with ELISA study. Microarray analysis was finally performed to analyze signal cascades.In miRNA that over-expressed more than RPC, none of miRNA had no negative correlation with GH-related mRNA. Meanwhile, rno-miR-494, -146a were expressed decreasingly and had negative correlation with mRNA. Separately, rno-miR-101b, -191, and -194, closely relating to PRL expression, were over-expressed. In knock-down cells with thosecomplimentary sequences, PRL secretion was elevated by rno-miR-101b-knock down GH3 cells. Also in cDNA microarray analysis, GH3 cells up-regulated PRL-production-related signalsafter knock-down of rno-miR-101b.In conclusion, rno-miR-101b is a miRNA regulating PRL production.