PITX2已被发现与多种肿瘤中的发生发展关系密切。本课题组前期实验发现PITX2高表达与食管鳞癌患者放化疗抵抗性密切相关。但是PITX2在食管癌中过表达的机理尚未完全阐明。miRNA是一类内源性，非编码短链RNA，参与多种生物学功能。课题组通过预实验发现miR-644a靶向PITX2参与诱导食管癌细胞放化疗抵抗性的可能性。本项目通过基因表达调控，细胞实验，动物模型及人体食管癌组织标本探讨miR-644a, PITX2及其下游靶基因与食管癌放化疗敏感性的关系和作用机制，分析和总结与食管癌患者放化疗有关的高危的分子指标，为今后临床治疗提供参考。

PITX2 have been reported to be associated with the development and progression of several human cancers. Our previous study have elucidated that high PITX2 was closely associated with chemoradioresistance in human esophageal squamous cell carcinoma (ESCC). However, the exact mechanism of PITX2 overexpression in human ESCC is largely unknown. miRNAs (miRNA) are endogenous non-coding short RNAs, which could regulate a variety of process. Our study first found that miR-644a could target directly PITX2, which might involved in the regulation of chemoradioresistance in human ESCC. In this study, we tried to identify the relationship of miR-644a, PITX2 and its target genes with ESCC chemoradiotherapy sensitivity and the underlying mechanism involved, and summarize the high risk of biomarker closely related to the ESCC chemoradioresistance, providing some references for clinical treatment in the future.