基于M13噬菌体的循环肿瘤细胞高效分离富集与分析新策略

肿瘤细胞从原发肿瘤脱落进入血液循环系统形成循环肿瘤细胞（CTCs）是导致肿瘤转移和复发的重要因素。外周血中CTCs的存在预示肿瘤可能发生转移。因此，CTCs检测在肿瘤分期诊断、疗效评估、预后判断等方面具有重大意义，但血液中CTCs含量稀少，使CTCs分离检测极具挑战。本项目拟从噬菌体多肽文库筛选获取针对前列腺癌、乳腺癌的CTCs识别肽，并将其展示于M13噬菌体表面，以组装噬菌体的界面捕获CTCs，并利用CTCs识别肽的高亲和力及噬菌体纳米仿生拓扑结构协同实现CTCs的高效分离；将内切蛋白酶识别肽展示于噬菌体表面，通过定点酶切实现CTCs可控无损释放；以展示CTCs识别肽和SERS标签的噬菌体为检测探针，实现信号放大的CTCs分型分析。本项目有望发展新型的CTCs分离富集体系，并建立其检测新方法和新策略，实现CTCs的高效分离、无损释放及高灵敏检测，为肿瘤转移预警及预后分析提供有益参考。

Circulating tumor cells (CTCs) shedding into bloodstream from primary tumor is the key factor for the initiation of tumor metastasis and recurrence. The detection of CTCs in peripheral blood usually indicates the possibility of metastasis. Therefore, CTCs detection is of great importance for the cancer staging diagnosis, therapeutic effect evaluation and prognosis. These cells, however, are extraordinarily rare, bringing much challenge in the isolation and detection of CTCs. This project aims at conquering the drawbacks of the conventional CTCs detection approach and developing novel strategies for CTCs detection with high capture efficiency, nondestructive releasement and high sensitivity. The main content of this project includes: .(1) obtaining CTCs-recognition peptides specifically aiming at prostate cancer and breast cancer via biopanning from phage peptide libraries and display these peptides on the surface of M13 phages for the construction of CTCs capturing surface. By the merit of the high affinity of CTCs-recognition peptides and the bio-inspired nanoscale topological structure of M13 phages, CTCs separation with high efficiency would be achieved; (2) expressing endopeptidase substrate on the surface of phages in order to achieve the controllable and nondestructive release of CTCs; (3) decorating phages with CTCs-recognition peptide and SERS detection tag to construct SERS detection probes for CTCs typing and analysis with amplified signals. .This project will provide beneficial information for the early-warning of tumor metastasis and prognosis.