Semaphorin 4C 通过活化整合素α5β1建立宫颈癌淋巴结转移前微环境的研究

Lymph nodes are initial sites of Cervical cancer metastasis, yet whether the lymph node microenvironment actively promotes tumor metastasis remains unknown. In preliminary studies, we found that Cervical carcinoma associated LECs（lymphatic endothelial cells）highly express and secrete Semaphorin 4C(Sema4C), which could promote LECs proliferation, movement and tube sprouting. Besides, secrete Sema4C could be detected in the serum of patient by ELISA and had a positive correlation with lymph node metastasis. Yet applicant found that highly expression of Sema4C in metastatic lymph node LECs and therefore, this project intends to further clarify the role of Sema4C plays in the metastasis microenvironment in draining lymph nodes, by establishing nude mice animal model, using protein Sema4C local or systemic, imitating pre-metastasis niche of sentinel lymph nodes and detecting changes of lymphatic vessel density and adhesion ability, to explore the mechanism of Sema4C establishing pre-metastasis niche of sentinel lymph nodes in cervical carcinoma. The aim of this study was to reveal a series of molecular changes of sentinel lymph node before lymph node metastasis in patients with cervical cancer,.to provide a new choice for the Intraoperative lymph node imaging and clinical treatment.

淋巴结是宫颈癌转移的第一站，前哨淋巴结微环境是否参与促进肿瘤转移尚不清楚。申请者所在课题组利用激光捕获和表达谱芯片发现Semaphorin 4C(Sema4C)在人宫颈癌相关淋巴管内皮细胞（LEC）中高表达，并意外发现其具有分泌型，在人的血清中被检测到和淋巴结转移正相关。申请者初步实验发现Sema4C在宫颈癌淋巴结转移的淋巴管内皮细胞中高表达，因此，本项目拟进一步明确Sema4C在淋巴结转移前微环境中发挥的作用，利用裸鼠建立动物模型，局部或全身使用蛋白Sema4C，模拟肿瘤转移前淋巴结内淋巴管变化，检测淋巴管密度和粘附能力的改变，探讨Sema4C建立宫颈癌淋巴结转移前微环境的机制。旨在揭示宫颈癌淋巴结转移前前哨淋巴结一系列分子改变，为术中淋巴结显影和临床治疗提供新的选择。

淋巴结是宫颈癌转移的第一站，前哨淋巴结微环境是否参与促进肿瘤转移尚不清楚。申请者所在课题组利用激光捕获和表达谱芯片发现Semaphorin 4C(Sema4C)在人宫颈癌相关淋巴管内皮细胞（LEC）中高表达，并意外发现其具有分泌型，在人的血清中被检测到和淋巴结转移正相关。申请者初步实验发现Sema4C在宫颈癌淋巴结转移的淋巴管内皮细胞中高表达，并进一步在临床切片证实Sema4C 在宫颈癌前哨淋巴结内淋巴管内皮细胞高表达高分泌，并且共表达plexinB2和integrin α5β1，证实Sema4C和integrin α5β1可能是前哨淋巴结内新生淋巴管的一种标志；体内利用宫颈癌细胞株SiHa 左侧腹股沟旁皮下注射成瘤建立动物模型，发现在成瘤第7天前哨淋巴结内淋巴管开始增多并高表达Sema4C和integrin α5β1，并证实Sema4C和PlexinB2结合后通过PI3K-AKT信号通路激活Integrinα5β1并促进淋巴管新生。体外进一步发现integrin α5β1 活化后的内皮细胞能够粘附表达VCAM-1配体的肿瘤细胞，体内将进一步证实integrin α5β1 活化后的内皮细胞能够捕获经过淋巴结内淋巴管的表达VCAM-1配体的转移性肿瘤细胞。探讨 Sema4C/ Plexin B2/ integrin α5β1 在宫颈癌淋巴结转移中的机制，为术前评估已发生微环境改变的淋巴结和术后监测可能富集残存肿瘤细胞淋巴结提供显影、检测及阻断靶点，为临床宫颈癌治疗提供了新的思路。