长链非编码RNA-X53654在放射性肺损伤中的功能研究

放射性肺损伤是胸部肿瘤放疗最主要的并发症和剂量限制性毒性反应，其发生机制至今尚未完全明确。长度大于200nt的长链非编码RNA（LncRNA）参与调控机体多种重要生命过程，但其与电离辐射所致机体损伤的关系鲜见报道。前期研究筛选鉴定的LncRNA -X53654与放射性肺损伤发生、发展负相关；抑制该基因可增加支气管上皮细胞Beas-2B的放射敏感性，引起细胞周期G2/M期阻滞，诱导细胞凋亡；提示X53654可能在放射性肺损伤发生、发展中起关键调控作用。本研究拟采用动物和细胞模型，通过重组真核质粒转染、RNA干扰、Northern blot、real-time PCR、Western blot等手段，从动物、细胞、分子水平深入研究X53654在放射性肺损伤中的功能，初步确定上下游作用分子及调控通路。预期本研究将从LncRNA这个新的角度揭示放射性肺损伤的相关机制，为其临床防治提供新的研究思路。

Radiation-induced lung injury is a common dose-limiting complication of thoracic radiotherapy, but until now its underlying molecular mechanisms and signaling pathways are insufficiently understood. Long non-coding RNAs (lncRNAs) are a novel class of messenger RNA (mRNA)-like transcripts . LncRNAs are usually more than 200 nucleotides in length and lacking an open reading frame. They have been regarded as primary genetic regulators of several important biological processes in the last decades. However, regarding ionizing irradiation induced lung injury, the deregulation and biological function of lncRNAs remains largely unknown. In our preliminary study, lncRNA-X53654 was identified as negatively correlated with the initiation and progression of radiation-induced lung injury via high throughput lncRNA microarray screening, bioinformatics analysis, and real-time PCR confirmation. Increased radiosensitivity, obvious cell cycle G2 / M phase arrest and subG1 apoptotic peak were also been observed in bronchial epithelial cell line Beas-2B with knockdown X53654 gene. Based on these data, we proposed a hypothesis that X53654 might play a key role in the development of radiation-induced lung injury. In the present study, C57BL/6 mice and pulmonary cell lines are used to construct radiation induced lung injury models. The precise biological functions, definite downstream effectors and regulatory pathway(s) of X53654 gene in radiation-induced lung injury are to be identified from different level, using methods such as recombinant eukaryotic plasmid transfection, RNA interference, Northern blot , real-time PCR, and Western blot etc.. It will provide novel mechanisms of radiation-induced lung injury in regards to the concept of LncRNAs.