环状RNA-circFBLIM1促进肝细胞癌生长与转移的机制研究.

Recent studies have shown that circular RNA (circRNA) could act as competing endogenous RNA (ceRNA) to bind micro RNA (miRNA) and regulate the expression and function of target gene. Through a high-throughput circRNA microarray，we found that circFBLIM1 was highly expressed in hepatocellular carcinoma (HCC). Functional experiments showed that knockdown of circFBLIM1 inhibited proliferation and invasion of HCC. Further experiments revealed that circFBLIM1 mostly distributed in the cytoplasm, indicating that circFBLIM1 might function as a ceRNA to sequester miRNA, leading to the liberation of corresponding miRNA-targeted transcript. Bioinformatics analysis predicted potential binding sites of miR-346 within circFBLIM1 sequence. And potential binding sites of miR-346 were also found in FBLIM1 3’UTR sequence. Therefore, we propose a scientific hypothesis that circFBLIM1 rescues the inhibition of FBLIM1 by sponging miR-346 to promote the growth and metastasis of HCC. The purpose of this project is to investigate the role of circRNA in HCC. Using circFBLIM1 as the starting point, we used in vitro cell molecular biology and in vivo animal imaging techniques, combined with microarray, bioinformatics analysis and clinical specimen analysis to investigate the role and molecular mechanism of circFBLIM1 in the growth and metastasis of HCC. This project would provide a new theoretical basis for the occurrence and development of HCC and a new target for the treatment of HCC and has important clinical guidance value.

新近研究表明，环状RNA可作为竞争性内源性RNA（ceRNA）吸附miRNA，从而调控靶基因的表达及其功能。环状RNA主要位于胞浆，具有比一般ceRNA更多的miRNA应答元件且更高效。本项目前期发现环状RNA-circFBLIM1在肝细胞癌中表达升高，且主要位于胞浆，将其敲低可抑制肝细胞癌的生长与转移，提示其可能作为ceRNA吸附miRNA而发挥作用。生物信息学预测发现circFBLIM1和FBLIM1基因序列上均存在miR-346结合位点。由此我们提出科学假说：circFBLIM1通过吸附miR-346，解除miR-346对FBLIM1的沉默效应，从而促进肝细胞癌的生长与转移。本项目拟采用体外细胞分子生物学和体内动物成像等技术，结合基因芯片、生物信息学及临床标本分析，探讨circFBLIM1在肝细胞癌生长与转移中的作用及其分子机制，为肝细胞癌的发生发展和治疗靶点选择提供新的实验依据。

环状RNA（circRNA）是一类非编码RNA，已被证明在肿瘤发生中起重要作用。然而，尚不清楚circRNA如何调节肝细胞癌的进展。在这项研究中，我们对肝细胞癌组织进行了circRNA微阵列分析，以鉴定出差异表达的circRNA。对HCC细胞系和组织进行了定量RT-PCR分析（qRT-PCR），发现环状RNA-circFBLIM1在肝细胞癌中表达升高，且主要位于胞浆，将其敲低可抑制肝细胞癌的生长与转移，提示其可能作为ceRNA吸附miRNA而发挥作用。生物信息学预测发现circFBLIM1和FBLIM1基因序列上均存在miR-346结合位点，同时该项目发现circ0097009显着上调。我们通过一系列实验研究了circ0097009在肝癌中的功能，这些实验包括细胞增殖、侵袭和小鼠异种移植实验。此外，荧光素酶测定实验和RNA免疫沉淀测定法被用于探究circ0097009、miRNA-1261和SLC7A11在肝癌中的相互作用。微阵列分析和qRT-PCR证实，在HCC组织和细胞系中，circRNA circ0097009明显上调。敲除circ0097009可抑制HCC细胞的增殖和侵袭。荧光素酶报告基因分析表明，circ0097009和SLC7A11直接与miR-1261结合。随后的实验表明，circ0097009和SLC7A11通过与miR-1261的结合相互调节其表达。circ0097009是竞争性内源RNA（ceRNA），可通过与miR-1261结合调节HCC中SLC7A11（癌细胞铁死亡的关键调节因子）的表达。circ0097009可用作肝细胞癌的诊断生物标志物和肝细胞癌治疗的潜在靶标。本项目采用体外细胞分子生物学和体内动物成像等技术，结合基因芯片、生物信息学及临床标本分析，探讨circFBLIM1和circ0097009在肝细胞癌生长与转移中的作用及其分子机制，为肝细胞癌的发生发展和治疗靶点选择提供新的实验依据。