SOX2激活Wnt/β-catenin信号通路在新疆哈萨克族食管癌发生发展中的机制研究

Xinjiang Kazak is a high incidence of esophageal cancer in China, and its pathogenesis is still unclear.Previous studies have found that Kazak's esophageal cancer is associated with abnormal activation of Wnt/β-catenin signaling pathway, but the regulatory mechanism of its abnormal activation is not clear.Studies have shown that SOX2(sex determining region Y-box 2), as a new type of oncogene, activates the Wnt signaling pathway by combining the β-catenin, and plays a carcinogenic role in a variety of tumors.The purpose of this study is to verify the important role of Wnt/β-catenin signaling pathway in Kazak esophageal cancer at the tissue, cell and animal levels.The relationship between SOX2 and β-catenin was analyzed by immunohistochemistry, Western-blot, immunofluorescence, immunoprecipitation, cell function test and subcutaneous tumor formation in nude mice. It was discussed whether SOX2 triggers the abnormal activation of Wnt signaling pathway, thereby promoting tumor proliferation, invasion and metastasis.And we screened SOX2 related genes and apoptotic proteins by high throughput sequencing and apoptotic protein chips.The purpose of this study is to explore the specific targets for the clinical treatment of Kazak's esophageal cancer.

新疆哈萨克族是我国食管癌高发民族，其发病机制尚不清楚。前期研究发现哈萨克族食管癌与Wnt/β-catenin信号通路的异常激活相关，但其异常激活的调控机制尚不明确。研究表明，SOX2（sex determining region Y-box 2）作为一种新型致癌基因，通过结合β-catenin激活Wnt信号通路，在多种肿瘤中起致癌作用。本研究拟在组织、细胞、动物水平验证Wnt/β-catenin信号通路在哈萨克族食管癌中发挥的重要作用；通过免疫组化、western-blot、免疫荧光、免疫共沉淀、细胞功能实验及裸鼠皮下成瘤等分析SOX2与β-catenin的关系，探讨SOX2能否触发Wnt信号通路的异常激活，从而促进肿瘤增殖、侵袭及转移；运用高通量测序和凋亡蛋白芯片筛选出与SOX2相关的基因和凋亡蛋白。旨在探寻哈萨克族食管癌临床治疗的特异性靶点。

食管鳞状细胞癌是我国主要的食管癌类型，具有发病率高、预后差的特点。本课题围绕“SOX2经由Wnt/ꞵ-catenin信号通路促进食管鳞状细胞癌增殖、侵袭的机制”这一科学问题，从四个层面，2个角度即肿瘤增殖、迁移和侵袭，运用多种研究方法包括单细胞测序数据库分析联合生信分析技术；临床组织病理进行免疫组化检测；应用慢病毒转染干预SOX2、ꞵ-catenin表达构建TE-1食管鳞癌细胞稳转株，通过Transwell侵袭实验、免疫共沉淀技术、免疫荧光、荧光素酶报告实验、RT-PCR、western blot等验证SOX2、ꞵ-catenin促进食管鳞癌的增殖、侵袭和EMT；SOX2与ꞵ-catenin相互正向调节，并通过SOX2/Wnt/ꞵ-catenin信号轴形成正向反馈环路调节食管鳞癌的增殖、侵袭；抑制SOX2可经由Wnt/ꞵ-catenin信号轴抑制ꞵ-catenin部分抑制食管鳞癌的增殖、侵袭和EMT；应用裸鼠皮下成瘤方法，验证了抑制SOX2能通过Wnt/ꞵ-catenin信号通路抑制ꞵ-catenin表达抑制肿瘤的增殖、EMT，进而说明SOX2是食管鳞癌的重要靶向基因。同时单细胞测序分析发现SOX2仅在上皮细胞表达的特点可能为SOX2作为针对食管鳞癌上皮细胞治疗的靶点基因而深入开展研究工作，研究方案按计划执行。本项目的出发点来源于本人前一个国自然项目中对食管鳞癌蛋白组学的研究，发现了包含SOX2、β-catenin等多个在食管鳞癌中高表达的蛋白标志物。因此，本项目在探讨主线“SOX2/Wnt/β-catenin信号轴”的前提下还探索了蛋白组学中发现的其他蛋白标志物在食管鳞癌中的表达和初步作用。其中缺氧相关蛋白及维甲酸通路蛋白在食管鳞癌和癌旁组织中具有显著的表达差异，说明其可能在食管鳞癌的发病和进展中具有潜在作用，也为探索食管鳞癌治疗的新方法提供了理论依据。