Development of novel therapy against human liposarcoma using siRNAlibrary

真核细胞中RNA干扰（RNAi）的发现是近年来分子和细胞生物学研究的重大突破。RNAi机制在基因调控、基因组防御、染色质结构和动力学中发挥生物学功能。今天，RNAi对动物新型疾病模型的发展产生了巨大的影响。此外，小干扰RNA（small interfering RNA，siRNA）作为RNA沉默的触发分子，有可能成为治疗多种疾病的重要工具。所有已知的人类粘液样和圆细胞脂肪肉瘤（myxoid and round cell liposarcomas，MLS/RCLS）都与染色体易位有关。本研究利用慢病毒siRNA文库筛选MLS/RCLS肿瘤发生相关基因，并对MLS/RCLS肿瘤发生相关基因进行筛选，筛选出与MLS/RCLS肿瘤发生相关的基因。我们用慢病毒siRNA文库感染人粘液样脂肪肉瘤细胞株，克隆了部分基因。到25个核苷酸的非编码小RNA，主要起基因调节作用。microRNAs（miRNAs）在细胞增殖、凋亡和分化中发挥重要作用。在几种人类恶性肿瘤中已经描述了异常的miRNA表达，并且肿瘤抑制功能已经归因于这类新的小调控RNA。尽管有这些知识，但缺乏关于MLS/RCLS中miRNA的信息。在本项目中，我们尝试利用微阵列技术鉴定TLS-CHOP的下游miRNA。我们发现了一些调节TLS-CHOP的miRNA。有趣的是，我们转染了一些由TLS-CHOP调控的miRNA，抑制了MLS/RCLS细胞系的肿瘤生长。这些数据表明，一些miRNA成为MLS/RCS的药物靶标。

The discovery of RNA interference (RNAi) in eukaryotic cells is a major breakthrough in the recent progress of the molecular and cellular biology. RNAi machineries exert biological functions in gene regulation, genome defense, chromatin architecture and dynamics. Today, RNAi has had an enormous impact on the development of novel disease models in animals. In addition, small interfering RNAs (siRNAs), the trigger molecules for RNA silencing, are likely to become invaluable tools for the treatment of various diseases.All of known human myxoid and round cell liposarcomas (MLS/RCLS) are associated with chromosomal translocations. These chromosomal translocations lead to gene fusions that encode chimeric oncoproteins consisting of an N terminus contributed by one of two related genes, TLS (also known as FUS) or EWS, and a C terminus contributed by the CHOP (also called GADD153) gene.In this project, we tried to identify the genes that implicated with tumorigenesis of MLS/RCLS using Lentiviral siRNA library. We infected human myxoid liposarcoma cell lines with Lentiviral siRNA library and we cloned some genes.On the other hand, MicroRNAs (miRNAs) are a family of 21. to 25-nucleotide, noncoding small RNAs that primarily function as gene regulators. MicroRNAs (miRNAs) have been suggested to play important roles in cell proliferation, apoptosis, and differentiation. And aberrant miRNA expression has been described for several human malignancies and tumour suppressor functions have been ascribed to this new class of small regulatory RNAs. Despite this knowledge, there is a lack of information regarding miRNA in the MLS/RCLS. In this project, we have tried to identify downstream miRNA of TLS-CHOP using microarray. And we identified some miRNAthat regulated TLS-CHOP. Interestingly, we transfected some of miRNA that regulated by TLS-CHOP, suppressed tumor growth MLS/RCLS cell lines. These data suggested that some miRNA become drugable target for MLS/RCS.