核仁小分子snoRD78在肺癌中的致病机制研究

lung cancer is the most common cancer in terms of both incidence and mortality, and is initiated by activation of oncogenes or inactivation of tumor suppressor genes. For non-small-cell lung carcinoma (NSCLC), prognosis is generally poor. The five-year survival rate of patients with stage IV NSCLC is about 1%. .It has become increasingly apparent that the non-protein-coding portion of the genome is of crucial functional importance: for normal development and physiology and for disease (e.g., cancer). However, we are only beginning to understand the nature and extent of the involvement of ncRNAs in disease. Other ncRNA, such as small nucleolar RNAs (snoRNA) and large intergenic non-coding RNA (lincRNA) are emerging as key elements of cellular homeostasis. Along with miRNAs, dysregulation of these ncRNA is being found to have relevance not only to tumorigenesis, but also to neurological, cardiovascular, developmental and other diseases. There is great interest in therapeutic strategies to counteract these pertubations of ncRNA. snoRNA are intermediate-sized ncRNA (60-300nt). Some snoRNA exhibit differential expression patterns in a variety of human cancers and demonstrate capability to affect cell transformation, tumorigenesis, and metastasis. Our paper published in 2010 had shown that 6 snoRNAs are differentially expressed in NSCLC in comparison with the corresponding matched tissue. We are beginning to comprehend the functional repercussions of snoRNA in the development and progression of malignancy. In this research, we focus on the role of snoRD78 (containing box C/D) in lung tumorigenesis..snoRD78 has high expression in both cell lines and tissues of lung cancer by microarry and RT-qPCR. After knockdown of snoRD78 using siRNA, cell viability has greatly been affected via MTT, FCM, soft agar colony formation unit and tumorigenicty in vivo. The preliminary data shows that snoRD78 plays important role in the tumorigenesis of lung cancer. Based on the preliminary data, we then select two good cell model (sw1573 and H226) to do further research and to explore the regulatary mechanism of snoRD78 in lung cancer, then validate in other lung cancer cell lines and clinical samples. First, we want to detect the difference of gene expression profiles betwenn siRNA-knockdown group and scrambled group using affymetrix micoarray; second, using target prediciton software (Plexy) in the website, potential targets of snoRD78 will be found, then we will compare them with the data of microarray; finally, we try to find the regulatory pathway of snoRD78 in vivo and in vitro. The major techniques used in this research are microarry, RT-qPCR, western blot, IP, construction of fluorescence reporter, gene mutation, and so on. This research will extend the new role of small ncRNAs in the disease of lung cancer and help us to understand the new way of development, progress and prognosis in lung cancer.

肺癌是全球最常见的恶性肿瘤之一，其病死率位居恶性肿瘤首位。组织或血清中small noncoding RNA(sncRNA)(如miRNA）的异常表达与多种人类恶性肿瘤密切相关。核仁小分子RNA（snoRNA）是除miRNA外另一类种类繁多的sncRNA。我们的前期研究结果表明，肺癌组织中某些snoRNA出现异常高表达，预示这些snoRNA与肺癌的发生发展相关。本研究在microarray的基础上，将研究重点针对肺癌细胞株和肺癌组织中均高表达的snoRD78（提示snoRD78可能是癌基因）。通过siRNA下调snoRD78的表达，探讨snoRD78在肺癌细胞中的生物学功能（MTT，FCM，软琼脂集落形成试验，体内成瘤实验等方法），并最终探明snoRD78在肺癌中的致病机制。本研究不仅能丰富ncRNA的功能，而且可揭示肺癌发生发展及预后等方面的机制。