宣威肺癌是云南特有的、死亡率极高的一种肺癌，其不断上升的死亡率迫切需要尽快发掘与之诊疗相关的生物标志物。本课题组的前期研究发现miR-4778-5p在宣威肺癌患者的肺癌组织和血浆中均显著低表达，且与肿瘤分期、患者预后相关。据此提出假设：miR-4778-5p可作为宣威肺癌的新型生物标志物，其在肺癌组织和血浆中表达水平的检测有助于宣威肺癌的诊断、分期及患者的预后判断。为证实此假设，本项目拟通过临床、细胞和动物实验研究，采用miRNA芯片、基因表达谱芯片、实时荧光定量PCR、western blot、荧光素酶报告基因实验、慢病毒载体转染、动物模型等手段，探讨miR-4778-5p作为宣威肺癌新型潜在标志物的临床应用价值，阐明其与靶基因的相互作用关系及参与宣威肺癌发生发展的分子作用机制，以期为宣威肺癌的诊断与治疗提供新途径和实验依据。

Xuanwei lung cancer, which only occurs in Yunnan province, has distinct characteristics, its rising mortality needs to explore effective biomarkers for diagnosis and treatment as soon as possible. In our previous study, we found that miR-4778-5p level was significantly decreased in both Xuanwei lung cancer tissue and plasma of Xuanwei lung cancer patients and closely associated with tumor staging and prognosis. Consequently, we speculated that miR-4778-5p may function as the potential biomarker and participate in the development of Xuanwei lung cancer. To verify this hypothesis, we intend to perform clinical, cellular and animal studies using plenty of biomedical methods, such as miRNA array, gene expression array, real-time quantitative PCR, western blot, luciferase reporter system, lentiviral transfection, animal model et al. To definite the clinical application value of miR-4778-5p as novel biomarker for Xuanwei lung cancer, ascertain its target gene and their relationship and the molecular mechanism involved in pathogenesis and progression of Xuanwei lung cancer, and provide a novel approach and theoretical basis for diagnosis and treatment of Xuanwei lung cancer.