新lncRNA-TIL1H结合ILF3蛋白促进骨肉瘤转移及其分子机制

Osteosarcoma (OS) treatment often fails due to development of metastasis, but the mechanism is unclear. Recent studies show that long noncoding RNAs (lncRNA) plays key role in cancer metastasis. In previous study we found new lncRNA-TIL1H was overexpressed in high metastatic OS cell lines and primary tumors of OS patient with lung metastasis compared to low metastatic OS cell lines and primary tumors of OS patient without metastasis, respectively. Overexpression of lncRNA-TIL1H stimulates invasion of OS cells and increases ILF3 expression. In addition, we found that lncRNA-TIL1H interacts with ILF3 and overexpression of ILF3 increase cMYC expression. Interestingly, animal study show overexpression of cMYC can stimulates OS cell lung metastasis. Based on results from previous study, we hypothesized that lncRNA-TIL1H can stimulates OS metastasis via ILF3 regulation for cMYC expression. In this study, we will use animal models to confirm the lncRNA-TIL1H effects on OS metastasis and evaluate the possibility of lncRNA-TIL1H as a therapeutic target for treatment of OS metastasis. Also, we will use RNAi, RNA-pull-down, RNA binding protein immunoprecipitation and qRT-PCR methods to investigate the lncRNA-TIL1H how to regulate the ILF3 and cMYC expression in vitro. By this research, we are hoping to reveal molecular mechanism of OS metastasis and to provide a new therapeutic target for treatment of OS metastasis.

转移是骨肉瘤治疗失败的重要原因，但其机制尚不清楚。新近研究表明长非编码RNA（lncRNA)与肿瘤转移密切相关。我们前期研究发现新的lncRNA-TIL1H在高转移骨肉瘤细胞和肺转移患者的骨肉瘤组织中高表达；过表达lncRNA-TIL1H促进骨肉瘤细胞的侵袭以及促癌基因ILF3；lncRNA-TIL1H与ILF3结合；过表达ILF3促进cMYC表达；过表达cMYC促进骨肉瘤的转移。据此，我们推测lncRNA-TIL1H可能通过ILF3调控cMYC表达，进而促进骨肉瘤的转移。本课题拟通过细胞和动物实验，应用RNAi、RNA-pull-down、RNA结合蛋白免疫共沉淀和定量RT-PCR等技术，重点研究lncRNA-TIL1H在骨肉瘤转移中的关键作用及其调控ILF3/cMYC的分子机制。该研究不仅有助于揭示骨肉瘤转移的新的分子机制，还有望为临床骨肉瘤转移的治疗提供新的靶点。

转移是骨肉瘤治疗失败的重要原因，但其机制尚不清楚。研究表明长编码RNA（lncRNA）与肿瘤转移密切相关。我们通过前期研究推测IncRNA-TIL1H在可能通过ILF3调控cMYC表达，进而促进骨肉瘤的转移。本课题中通过细胞实验和动物实验，应用RNAi、RNA结合蛋白免疫共沉淀和定量RT-PCR等技术，重点研究了IncRNA-TIL1H在骨肉瘤转移中的关键作用及其调控ILF3/cMYC的分子机制。通过动物实验发现过表达lncRNA-TIL1H 促进骨肉瘤肺转移，而且还发现敲低c-MYC可以有效地抑制由lncRNA-TIL1H过表达促进的骨肉瘤肺转移。通过细胞实验我们发现过表达的lncRNA-TIL1H增加了cMYC和ILF3的表达，然而sh-ILF3抑制了被lncRNA-TIL1H增加的cMYC的表达，ILF3的表达以lncRNA-TIL1H的浓度增加而增加。相反, ILF3的表达以lncRNA-TIL1H的浓度减少而减少。进一步，我们发现过表达的lncRNA-TIL1H抑制了miR-let-7的表达，然而shILF3增加了被lncRNA-TIL1H抑制的miR-let-7的表达。lncRNA-TIL1H促进了ILF3和cMYC RNA的结合。这些结果说明了lncRNA-TIL1H通过ILF3调控cMYC的表达，进而促进骨肉瘤的肺转移，有望成为诊治骨肉瘤肺转移的新靶点。