CAFs是肿瘤微环境的最主要成员，对肿瘤发展、远处转移产生重要影响。研究CAFs的活化、活性维持是揭示CAFs功能的关键。前期工作发现乳癌CAFs中miR-200s/205明显下调，关键靶转录因子TCF4、TCF12、Fli-1、KLF12可能与CAF功能有关，且CAFs存在ECM基因异常。故，本项目提出miR-200s/205调控TCF4等关键转录因子、促进并维持CAFs活性、参与ECM重塑，推动乳腺癌细胞增殖和侵袭。拟采用过表达和干扰技术明确miR-200s/205与靶基因正反调控关系、维持CAFs活性；3D共培养、胶收缩、ECM成分分析、天狼星红染色等研究miR-200s/205及靶基因参与ECM重塑；3D共培养、裸鼠成瘤、Transwell等研究ECM对不同亚型乳癌细胞增殖、浸润。研究结果将揭示miR-200s/205对乳癌CAFs活性维持、ECM重塑、促肿瘤发展新机制

Cancer-associated fibroblasts (CAFs) are a major member in the tumor stroma and play an important role in the tumor development and metastasis. The activity, especially its maintenance of CAFs is a key for understanding CAFs’ functions. Our previous studies found that miR-200 family and miR-205 are down-regulated in breast cancer CAFs compared with NFs by miRNA-array, and those miRNAs possibly play a role in the activation of CAFs and ECM remodeling. Some of important transcriptors (TCF4、TCF12、Fli-1、KLF12) may associated with CAFs’ function. Here, we hypothesis that miR-200s/205 activate and maintain the activity of CAFs to remodel the ECM and enhance tumor growth and invasion. The activity of CAFs and the relationship between miRNAs and their targets will be detected under either the overexpression and siRNA silence of miR-200s/205 or their key targets. The remodeling of ECM will be checked by 3D co-culture, fibroblast contraction assay, and Picric acid Sirius red staining. The tumor cells proliferation and invasion will be analysis by 3D co-culture, nude mouse, Transwell assay. Our results will disclose a novel potential mechanism of miR-200s/205 in activation and maintenance of CAFs, remodeling of ECM and promoting development of breast cancer.