上皮组织特异性转录因子ESE3的异常胞质定位在食管上皮早期癌变过程中的作用与分子机制

China is a country with a high incidence and mortality of esophageal squamous carcinoma, therefore it is very important to explore its pathogenesis. Our previous work has found that the epithelial-specific transcription factor ESE3 was transferred to cytoplasm in esophageal moderate and high grade epithelial dysplasia and cacinoma cells, which implied that the abnormal cytoplasmic localization of ESE3 protein may be an early event of esophageal epithelial transformation. This is not reported in previous studies. Therefore, we planned to used esophageal tissue and sera samples with various pathological stages accumulated in our high incidence area cohort study, to screen the ratio of abnormal ESE3 cytoplasmic localization and the serum ESE3 level using immunohistochemistry and ELISA respectively, and clarify the potential correlation between ESE3 abnormalities and the early stage of esophageal epithelial transformation. For detection abnormal cytoplasmic localization, CREM1 inhibition agent leptomycin B, the PKC inhibitor were used to treat esophageal squamous carcinoma cells with ESE3 abnormal cytoplasmic localization to observe ESE3 cytoplasmic localization, then, PKC phosphorylation sites was confirmed to construct ESE3 cloning with specific phosphorylation mutation, and its influence on tumor growth was detected. Researching the effect and and molecular mechanisms of ESE3 abnormal cytoplasmic location in the carcinogenesis of esophageal epithelium is very important in the early diagnosis and intervention for esophageal squamous cell carcinoma.

我国是全球食管癌发病率和死亡率最高的国家之一，研究其发病机制非常重要。我们前期工作发现，上皮特异性转录因子ESE3在中重度异常增生及癌变的食管上皮中发生异常的胞质定位，而在正常食管上皮定位于细胞核，这提示ESE3异常胞质定位可能是食管上皮癌变的早期分子事件。这在既往的研究中没有报道。因此,我们计划应用在食管癌高发地区建立的研究队列，在不同病理阶段的食管癌前病变和癌变组织、血清样本中，利用免疫组化和ELISA的方法检测ESE3的定位和水平, 利用CREM1抑制剂leptomycin B、PKC抑制剂处理出现ESE3异常胞质定位的食管鳞癌细胞系，观察ESE3定位是否发生改变，进一步确定PKC磷酸化ESE3的位点，构建磷酸化位点突变的ESE3基因克隆，检测其对肿瘤生长的影响。通过研究ESE3异常胞质定位在食管上皮癌变的作用及机制，对于食管鳞癌的早期诊断及干预具有非常重要的意义。

食管鳞癌是我国常见的恶性肿瘤之一，其发病机制尚不明确。ESE3是ETS转录家族的一员，仅表达在上皮组织中。本研究旨在探讨ESE3在食管鳞癌发生发展中的作用。免疫组化发现ESE3在正常组织中定位于细胞核，而在食管早期鳞癌及癌组织中定位于细胞浆；同时，在正常上皮细胞（HEEpiC和）和食管鳞癌细胞（TE1, EC9706, KYSE150, KYSE410）中证实了这一发现，提示我们ESE3细胞的定位改变可能是食管鳞癌发生的早期事件。基于此，通过在EC9706和KYSE150中外源性过表达ESE3，我们发现外源性的ESE3主要定位于细胞核，此定位的改变，导致细胞的增殖能力、集落形成、细胞侵袭和迁移能力下降，进一步表明ESE3在食管鳞癌的发生发展过程中起到重要作用。为了探究ESE3定位改变的机制，应用actinomycin D,lepmycin B以及p38 MAPK,PKC,CKII磷酸化激酶抑制剂等工具药物处理食管鳞癌细胞系，我们发现ESE3的定位改变并非这些常见的出核机制所致，将进一步探讨ESE3定位改变的机制。总之，ESE3通过定位的改变在食管鳞癌发生发展中起重要作用，参与调控食管鳞癌的增殖和迁移、侵袭等功能。