Investigation of regulatory mechanism of homeostasis using functional nucleic acids.

骨桥蛋白（OPN）是细胞外基质蛋白的一员，其调节多种细胞功能，包括粘附、迁移、肿瘤细胞侵袭和炎症反应。骨桥蛋白结合各种细胞表面受体，整合素和CD44。我们先前已经证明，中和性抗OPN抗体可以改善小鼠模型中的类风湿性关节炎和伴刀豆球蛋白A（ConA）诱导的肝炎，因此OPN可能是各种炎性疾病的潜在治疗靶点。最近，一种称为RNA干扰（RNAi）的技术已经成功地适用于哺乳动物细胞，使得RNAi可以成为沉默基因表达和功能的有力工具。因此，我们确定了靶向OPN的小干扰RNA（OPN siRNA）是否可用于疾病控制。首先，我们证明了OPN siRNA对外源性和内源性OPN表达的沉默作用。接下来，我们评估了OPN siRNA治疗或预防OPN介导的疾病的潜力。 ...更多信息 S. Matrigel法<TM>显示OPN siRNA能显著抑制小鼠刘易斯肺癌细胞和人纤维肉瘤细胞HT 1080的侵袭。使用ConA诱导的肝炎模型，其是T细胞介导的肝病的良好表征的小鼠模型，我们已经表明OPN siRNA预处理可以抑制肝组织损伤，如血清ALT水平所反映的。重要的是，血清ALT水平与肝脏OPN mRNA表达水平密切相关。这些发现表明，用OPN siRNA沉默OPN表达可能代表治疗肿瘤侵袭和炎性肝病的新方法。为了提高siRNA靶向OPN mRNA的功能，我们构建了一系列新型siRNA，并对其进行了各种化学修饰。只有一个siRNA分子显示出与标准siRNA相当的抑制效果，尽管大多数含有化学修饰的siRNA复合物对抑制效果起负面作用。此外，我们进行了寡核苷酸阵列分析，以研究与siRNA治疗相关的综合基因表达谱。发现一些基因的表达谱响应于siRNA处理而特异性改变。少

Osteopontin(OPN) is a member of extracellular matrix proteins which regulate a variety of cell functions including adhesion, migration, tumor cell invasion, and inflammatory responses. OPN binds to the various cell surface receptors, integrins and CD44. We have previously demonstrated that the neutralizing anti-OPN antibody could ameliorate rheumatoid arthritis and concanavalin A(ConA)-induced hepatitis in murine models and thus OPN could be a potential therapeutic target for various inflammatory diseases. Recently, a technique known as RNA interference (RNAi) has been successfully adapted to mammalian cells so that RNAi can be a powerful tool to silencing gene expression and function. Therefore, we determined whether small interfering RNA targeting OPN (OPN siRNA) can be useful for disease control. First, we demonstrated the silencing effect of OPN siRNA against exogeneous and endogeneous OPN expression. Next, we evaluated OPN siRNA's potential to treat or prevent OPN-mediated disease … More s. In Matrigel^<TM> assay, invasion of mouse Lewis lung carcinoma and HT1080 human fibrosarcoma cells was significantly inhibited by OPN siRNA. Using a ConA-induced hepatitis model that is a well-characterized murine model of T cell-mediated liver diseases, we have shown that OPN siRNA pretreatment could inhibit the liver tissue damage as reflected by the serum ALT levels. Importantly, serum ALT levels well correlated with the liver OPN mRNA expression levels. These findings suggest that silencing OPN expression with OPN siRNA may represent a new approach for the treatment of tumor invasion and inflammatory liver diseases. To improve the siRNA function targeting OPN mRNA, we constructed a series of novel siRNAs to which various chemical modifications were introduced. There was only one siRNA molecule, which showed the inhibitory effect comparable to the standard siRNA although most of the siRNA complexes containing the chemical modifications negatively functioned on the suppression effect. Furthermore, we carried out oligonucleotide array analysis to investigate comprehensive gene expression profile associated with siRNA treatment. It was found that the expression profiles of some genes specifically changed in response to the siRNA treatment. Less