循环miRNA广泛参与了口腔肿瘤细胞的恶性转化过程，但循环miRNA对于肿瘤的功能调控机制的研究始终没有取得有效突破。"循环miRNA以配体结合方式与肿瘤组织受体蛋白直接作用并发挥调控功能"是新发现的循环miRNA的调控模式，对于这种作用机制的证明，不仅可以阐明循环miRNA在肿瘤发生、发展中的功能作用模式，也将拓展人们对于"细胞间信号交流"的认识。针对目前循环miRNA作用机制研究中存在的主要问题，本研究拟以循环miRNA与肿瘤表皮生长因子受体(EGFR)的相互作用研究为切入点，通过对于二者相互作用规律和生物学效应的深入研究，期望发现并证实一种新型"循环miRNA介导的肿瘤细胞EGFR信号激活机制"，研究其对于肿瘤生物学行为的影响。在此基础上，初步探索并验证循环miRNA靶向干预治疗手段对于提高肿瘤EGFR靶向治疗的有效性，为新型肿肿瘤靶向治疗药物的研发及临床转化应用提供直接的实验证据。

Circulating miRNAs are extensively involved in malignant transformation of tumor cells, but the regulatory mechanism of circulating miRNA has not been well illustrated. It is a novel theory that miRNA can directly bind to tumor cells receptors and play a regulatory function like a ligand. The verification of this theory allows us not only to clarify the regulatory mechanism of circulating miRNAs, but also will expand the understanding of "cell-cell communication". In the present study, the interactions between circulating miRNAs and epidermal growth factor receptor (EGFR) are going to be investigated to confirm the ligand like binding of specific miRNAs to EGFR and subsequent effects on the tumor cells biological behavior. This study is capable to reveal the molecular basis and the binding rules between circulating miRNAs and EGFR, and will provide experimental evidence for the development of some novel tumor-targeted therapies.