EGFR-TKIs耐药是制约其临床疗效的主要难题。近来研究表明EGFR-TKIs耐药与EGFR胞吞机制的异常有关。我们前期发现EHD1高表达与NSCLC患者EGFR-TKIs耐药密切相关；在EGFR-TKIs敏感株PC9细胞中过表达EHD1可显著降低细胞对EGFR-TKIs的敏感性，但作用机制尚待阐明。鉴于EHD1是调控细胞膜受体蛋白胞吞转运的膜转运蛋白，我们推测EHD1通过调控突变型EGFR胞吞转运及信号传导，进而调节EGFR-TKIs耐药。本项目从细胞、裸鼠及人体组织标本着手，拟采用基因转染、siRNA等技术进一步明确EHD1在EGFR-TKIs耐药中的作用。通过免疫荧光、IP、内吞及循环实验、GST pull-down等方法探讨EHD1对突变型EGFR胞吞转运和下游信号传导通路的调控作用及其分子机制。本项目将为临床探索肺腺癌患者EGFR-TKIs耐药机制提供新理论、新靶点。

EGFR-TKIs resistance is the neck of clinical therapy in lung adenocarcinoma. It was found that EGFR-TKIs resistance was correlated with the endocytic/recycling of EGFR. In our previous study, a higher level of EHD1 expression in EGFR-TKIs resistant NSCLC was observed, and by transfecting EHD1 into PC9 cells drug sensitivity can be discounted, but the specific mechanism has not been elucidated. EHD1 is a protein regulating membrane receptor trafficking. We postulated EHD1 is involved in EGFR-TKIs resistance by regulating the endocytic/recycling of mt-EGFR and its downstream signal transduction. Therefore, we are planning to study the mechanism of EHD1 regulating mutation-EGFR endocytosis by starting with cell lines, xenograft models and cancer tissues from NSCLC patients by using gene transfection and siRNA. By means of immunofluorescence, IP, the endocytic cycle experiment, GST pull-down, we aim to explore the mechanism of endocytic/recycling of EGFR and its downstream signaling of EGFR pathway and of its being involved in developing EGFR-TKIs resistance. This study may provide new theoretical basis and molecular target in overcoming EGFR-TKIs resistance for the patients of lung adenocarcinoma.