flotillin-1通过NF-κB通路调控上皮细胞间质化促进早期宫颈癌淋巴结转移的分子机制研究

Cervical cancer remains a heavy burden of disease and healthy economics of women in China, and lymph node metastasis is the most import prognostic high risk factor for patients with cervical cancer. However, the molecular mechanism of lymph node metastasis of cervical cancer is largely unclear, and there is neither reliable biomarker to accurately predict the risk of lymph node metastasis nor therapeutic target until now. We have already demonstrated that elevated expression of flotillin-1 protein is highly associated with lymph node metastasis and poor prognosis of patients with early-stage cervical cancer, and flotillin-1 succeeds in promoting invasion and mobility of cervical cancer cells in vitro through its regulating of a key process of cancer metastasis-epithelial–mesenchymal transition (EMT). Moreover, further investigation revealed NF-κB pathway is activated by flotillin-1 in cervical cancer cells as well. In the current study, we plan to establish an in vivo model of cervical cancer lymph node metastasis and employ multiple inhibitor interferes, transfection of dominant-negative mutant and immunoprecipitation, to investigate the hypothesis that flotillin-1 may activate NF-κB pathway through TNFR or EGFR, and then regulate EMT process which promotes lymph node metastasis in early-stage cervical cancer. Finally, we will validate this hypothesis with clinical cancer tissue samples. The fulfillment of the current study is expected to elucidate the molecular mechanism of lymph node metastasis in early stage cervical cancer promoted by flotillin-1 protein, and to provide a theoretical basis for the searching of clinical reliable biomarkers to predict the risk of lymph node metastasis as well as novel therapeutic target in earl-stage cervical cancer.

宫颈癌仍是我国妇女沉重的疾病和卫生经济负担，而淋巴结转移则严重影响着患者的预后。但因其分子机制不明，目前尚缺乏能有效预测转移风险的分子标记物，也无特异的治疗靶点。我们前期研究发现，flotillin-1蛋白高表达与早期宫颈癌的淋巴结转移及患者不良预后密切相关；flotillin-1能通过调控肿瘤转移的关键事件——上皮细胞间质化(EMT)过程促进宫颈癌细胞在体外的侵袭和迁移，其机制可能与NF-κB通路密切相关。本研究拟进一步建立宫颈癌淋巴结转移的体内模型并通过抑制剂干预、导入负性突变体、免疫共沉淀等方法证实flotillin-1可能通过TNFR或EGFR途径激活NF-κB通路调控EMT过程从而促进宫颈癌的淋巴结转移，并在临床标本中加以验证。本研究可进一步明确flotillin-1促进早期宫颈癌淋巴结转移的分子机制，为寻找能有效预测早期宫颈癌淋巴结转移风险的分子标记物和治疗新靶点提供理论依据。

宫颈癌仍是我国妇女沉重的疾病和卫生经济负担，而淋巴结转移则严重影响着患者的预后。但因其分子机制不明，目前尚缺乏能有效预测转移风险的分子标记物，也无特异的治疗靶点。我们前期研究发现，flotillin-1蛋白高表达与早期宫颈癌的淋巴结转移及患者不良预后密切相关；flotillin-1能通过调控肿瘤转移的关键事件——上皮细胞间质化(EMT)过程促进宫颈癌细胞在体外的侵袭和迁移，其机制可能与NF-κB通路密切相关。本项目通过一系列shRNA沉默、过表达、抑制剂干预、导入负性突变体、免疫共沉淀等方法证实flotillin-1蛋白在体外对NF-κB通路关键分子蛋白表达水平和核定位有显著影响，flotillin-1蛋白激活NF-κB通路依赖脂阀的完整性，但与原先的科学假说不同，flotillin-1蛋白对NF-κB通路及EMT现象和宫颈癌细胞侵袭迁移以及淋巴管形成的调控可能并不是通过TNFR或EGFR途径；进一步在不同flotillin-1蛋白表达水平的宫颈癌细胞中通过全转录组测序和生物信息学分析，发现血管抑制素-2（VASH2）可能是flotillin-1的重要下游靶基因，并发现VASH2在宫颈癌细胞和有淋巴结转移的宫颈癌组织中呈异常高表达，且VASH2能在体外能促进宫颈癌细胞的增殖、迁移、侵袭和新生淋巴管形成，并能在宫颈癌细胞中介导EMT过程，提示flotillin-1可能是通过调控VASH2的表达进而激活NF-κB通路，介导EMT过程并最终促进宫颈癌的淋巴结转移。本研究可望进一步明确flotillin-1促进早期宫颈癌淋巴结转移的分子机制，为寻找能有效预测早期宫颈癌淋巴结转移风险的分子标记物和治疗新靶点提供理论依据。