远处转移是乳腺癌患者死亡的主要原因。近期研究发现蛋白激酶ULK1的表达与乳腺癌淋巴结转移状态呈负相关，但其具体作用及调控机制不清楚。本项目预实验发现高转移人乳腺癌细胞中过表达ULK1显著抑制其迁移和侵袭能力。ULK1能结合并磷酸化胞泌复合体亚基Exo70且敲低Exo70极大削弱ULK1对乳腺癌细胞迁移和侵袭的抑制作用。我们拟：1）进一步通过裸鼠原位移植转移模型验证ULK1对乳腺癌转移的调控作用；2）鉴定Exo70上的ULK1磷酸化位点，并利用这些位点的点突变以及特异性识别这些位点的磷酸化抗体，从分子、细胞、动物和临床多个水平深入探讨ULK1调控乳腺癌转移的分子机制，即通过磷酸化Exo70抑制乳腺癌细胞的迁移和侵袭；3）探讨高转移乳腺癌中ULK1表达降低的调控机制。希望通过本项目，为乳腺癌提供预后判断指标和治疗新靶点。

Distant metastasis is the leading cause of death among breast cancer patients. Recent studies revealed that the expression of protein kinase ULK1 was negatively correlated with the lymph node status of breast cancer, but the role of ULK1 and the mechanisms involved were unknown. Preliminary studies of this project found that, overexpression of ULK1 significantly inhibited migration and invasion of human breast cancer cells with highly metastatic potential. ULK1 bound and phosphorylated exocyst complex subunit Exo70, and the inhibitory effects of ULK1 on the migration and invasion of breast cancer cells were greatly impaired by knocking down endogenous Exo70. We will: 1) verify the regulatory role of ULK1 in breast cancer metastasis using metastatic model in nude mice via orthotopic implantation; 2) identify Exo70 phosphorylation sites by ULK1, and employ loss or gain of function mutants of these sites and specific antibodies recognizing these phosphorylated sites in molecular, cellular, animal and clinical experiments to reveal the regulatory mechanisms of ULK1 in breast cancer metastasis, that is, inhibiting cell migration and invasion by phosphorylating Exo70; 3) explore how ULK1 expression was down-regulated in highly metastatic breast cancer. All these in this project will provide prognostic indicators and new therapeutic targets for breast cancer.