我们在国内外率先报道：RACK1是优于任何目前常用的评价乳腺癌预后参考指标的蛋白；通过miRNA芯片结合软件分析和预实验结果推断：miR-320家族参与RACK1表达的调节。但miR-320家族与RACK1之间的调节关系及其对乳腺癌侵袭转移的作用和机制、miR-320家族表达的调节等问题尚不清。本研究拟采用荧光素酶报告基因系统确定RACK1与miR-320家族直接作用的存在，使用miR-320前体和抑制剂转染等法，通过体内、外实验两方面研究，明确miR-320与RACK1的相互调节、表达及与乳腺癌侵袭转移和病人预后的关系；并揭示其参与乳腺癌侵袭和转移的分子机制；用ChIP-PCR和启动子报告基因等方法，确定调控miR-320家族成员的转录因子和阐释miR-320-RACK1涉及的相关分子通路。从而为临床预测乳腺癌转移和预后提供新的生物学指标及有效的治疗靶点。

We have reported for the first time that RACK1 is a superior independent predictor for poor clinical outcome in breast carcinoma. Through analysis of miRNA-array and our recent preliminary experiments, we presume that miR-320 family may participate in regulation of RACK1 expression. However, many problems still remain unclear. The present project firstly is to definite RACK1 mRNA is direct target of miR-320 family using luciferase reporter assay. Then we investigate the regulation of miR-320 to RACK1 expression、associations of their expressions with invasion/ metastasis and patients prognosis of breat carcinoma, and involved mechanism(s) both in vitro and in vivo, using miR-320x precursor or antagomiR-320x transfection etc. Moreover, utilizing ChIP-PCR and promoter reporter ssatlstem analysis etc., we will determine the regulatory factor of miR-320 family and signaling pathway of miR-320-RACK1. Thus,this research would provide new predictive biomarker of tumor metastasis and patients prognosis and new ulility therapic strategy for breast carcinoma.