【作者】 张振伟；

【导师】 蒋仲敏；

【作者基本信息】 济南大学 ， 外科学， 2012， 硕士

【摘要】 食管癌是消化系统最常见的恶性肿瘤之一，我国是食管癌高发地区，其中以食管鳞状上皮细胞癌(ESCC)为主，占90%以上。目前临床工作中对食管癌的早期诊断及判断疗效的方法较多，但还存在着种种不足，如:特异性低、敏感性差、操作繁琐、为有创伤性检查等等。早期诊断、早期治疗及合理判断治疗效果是提高其生存率的关键。因此寻找一种便捷有效的诊断及判断治疗效果的方法是当前临床的一个迫切要求,其中针对肿瘤特异性分子标志物的研究已成为近年来肿瘤研究的热点。Bmi-1和Mel-18基因同属于PCG（Polycombgroup,PcG）基因家族成员，Bmi-1作为一种原癌基因，可经多种途径促进细胞的转化和肿瘤的形成，现有研究结果已证实其在多种肿瘤中呈过度表达，如非小细胞肺癌、胃癌、乳腺癌、大肠癌等，目前已成为各种肿瘤的研究热点。Mel-18与Bmi-1结构存在65%的同源性，决定了其功能上的相似性，Mel-18被发现在霍奇金淋巴瘤中存在高表达，但近年来的研究表明Mel-18更多的表现为抑癌基因的作用，当前已被证实在白血病及乳腺癌、胃癌等实体瘤中存在低表达。二者在食管癌中的表达及研究国内外较少报道。因此，本实验尝试检测Bmi-1及Mel-18mRNA在人食管鳞状癌细胞株和正常人食管上皮细胞株以及正常食管组织和食管鳞癌组织中的表达，探讨其在食管鳞癌发生、发展中的作用及其临床意义，以期为食管鳞癌的防治提供新的依据。材料与方法人食管鳞癌细胞株ECA-109和TE-1，一株正常人食管上皮细胞株Het1A，均由山东省千佛山医院中心实验室提供。53例食管鳞癌手术标本及配对癌旁正常食管组织标本（距肿瘤5cm以上）取自山东大学附属千佛山医院胸外科2010年3月-2011年5月期间的手术患者，采用逆转录多聚酶链反应（RT-PCR）方法检测细胞及两组标本中Bmi-1和Mel-18的表达，分析其在肿瘤中的表达情况与各临床病理因素（性别、肿瘤部位、分化程度、浸润深度、淋巴结转移、临床分期）的关系，以探讨Bmi-1和Mel-18在食管鳞癌中表达的相关性。结果1.2株食管鳞癌细胞株中Bmi-1的表达均呈高表达，2株食管鳞癌细胞株中Mel-18的表达均呈低表达。2.Bmi-1在53例食管鳞癌组织中的表达水平明显高于其在癌旁正常食管组织中的表达，表达差异有显著性(P<0.05)。Bmi-1在淋巴结转移组的表达量明显高于无淋巴结转移组的表达量；Bmi-1基因在临床分期Ⅰ、Ⅱ和Ⅲ/ⅣA期患者中的相对表达值依次升高；肿瘤侵及纤维膜组Bmi-1的表达高于未侵及纤维膜组，以上三组表达差异均有统计学意义(P<0.05)；Bmi-1mRNA在不同性别、肿瘤部位、分化程度的表达均无明显差异(P>0.05)。3.食管鳞癌组织中的Mel-18mRNA表达水平低于癌旁正常食管组织，差异具有显著性（P<0.05）。Mel-18mRNA在食管癌不同性别、肿瘤部位的表达均无明显差异(P>0.05)。侵及纤维膜组Mel-18mRNA的表达低于未侵及纤维膜组的表达，低分化组Mel-18表达低于中高分化组，但两实验组差异均无统计学意义(P>0.05)。Mel-18基因在临床分期Ⅰ、Ⅱ和Ⅲ/ⅣA期患者中的表达值依次降低（P<0.05），有淋巴结转移组Mel-18基因的表达明显低于无淋巴结转移组的表达，差异有统计学意义(P<0.05)。4.Bmi-1和Mel-18在食管鳞癌组织中的表达呈负相关。结论1.Bmi-1在食管鳞癌细胞株中呈高表达，在食管鳞癌组织中表达较正常食管组织中强，Mel-18在食管鳞癌细胞株中呈低表达，在食管鳞癌组织中表达较正常食管组织中弱，表达差异有统计学意义。提示Bmi-1、Mel-18与食管鳞癌的发生可能存在密切联系。2.Bmi-1与Mel-18在有无淋巴结转移组和不同TNM分期中的表达差异均具有显著性，且Bmi-1随着肿瘤浸润深度的深入表达增加，提示Bmi-1与Mel-18表达差异与食管鳞癌的进展及淋巴结转移状况密切相关。3.Bmi-1的表达与Mel-18的表达呈负相关，提示两者可能在食管鳞癌的发生、侵袭与转移过程中发挥不同作用。4.Bmi-1与Mel-18有望成为食管癌特异性的分子标志物，作为病理TNM分期、食管癌的临床诊断及预后判断的补充。更多还原

【Abstract】 Esophageal cancer is the most common malignancy in the digest system. China is a high-incidence areas in the word. Among them, esophageal squamous cell carcinoma (ESCC) dominated, accounting for about90%.There are many traditional clinical diagnosis methods and histologic markers to detect this disease are commonly used today,but there are a variety of insufficients such as low specificity, poor sensitivity, operation trouble, traumatic check, et al. Diagnosis and treatment of ESCC at an early stage and reasonably judge therapeutic efficacy can conspicuously improve survival. So, there is an urgent need to seek a simple and effective way of diagnosis and prognostication for ESCC patients,and the research of cancer specific molecular markers has become a hot spot in recent years. Both Bmi-1and Mel-18belong to the Polycomb group, As an oncogene, Bmi-1plays an important role in cell proliferation and human oncogenesis. Overexpression of Bmi-1has been observed in a variety of human cancers,such as non-small cell lung cancer, gastric carcinoma, breast cancer, colorectal cancer,et al. Bmi-1has become a research focus in the tumor therapy field. The Mel-18gene product is structurally highly similar to Bmi-1protein,and there is a functional similarity too. One study has shown that Mel-18is overexpressed in Hodgkin’s Lymphoma,but more researches have shown that Mel-18plays a role as a suppressor gene in most tumors. There is low expression of Mel-18gene not only in hematological malignancies, but also in solid tumors, including breast and gastric carcinomas. Study of Bmi-1and Mel-18expression in esophageal cancer have reported fewer. We investigated the expression of Bmi-1and Mel-18in Esophageal Squamous cell Carcinoma cells strains and tissues to explore the expression and clinical significance of Bmi-1and Mel-18in Esophageal Squamous cell Carcinoma, with the hope to provid the new theoretical basis for esophageal cancer prevention and control strategy.Materials and MethodsTwo squamous esophageal cell lines and a strain of normal esophageal epithelial cell lines were provided by Qianfoshan Hospital of Shandong University center lab. Esophageal squamous cell carcinoma and corresponding normal tissues of53patients were obtained from Department of Chest Surgery, Qianfoshan Hospital of Shandong University. The reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression of Bmi-1and Mel-18in three strains of cell lines,cancer tissue and corresponding normal tissue in the53cases,then analyzed the association between their expression and the clinical parameters of the tumors (gender, tumor location, histological differentiation,invasive depth,clinical stage, lymph node metastases).The association between Bmi-1and Mel-18expression was also analyzed.Results1. The analysis revealed significantly overexpression of Bmi-1in2squamous esophageal cell lines and low expression of Mel-18in the2squamous esophageal cell lines.2. There was significantly increased expression of Bmi-1in carcinoma tissues than in corresponding normal tissues (P<0.05). The difference of expression in the groups with and without lymph node metastases was significant (P<0.05); The expression levels of Bmi-1were rose consequently in TNM stage Ⅰ, Ⅱ and Ⅲ/IVA(P<0.05);The expression in invasion fiber membrane group was significantly higher than that without invasion(P<0.05); There was no relation between Bmi-1expression and any clinicopathological parameters, such as gender,tumor location, histological differentiation (P>0.05).3. There was significantly decreased expression of Mel-18in carcinoma tissues than in corresponding normal tissues (P<0.05).There was no relation between Mel-18expression and any clinicopathological parameters, such as gender,tumor location, histological differentiation and invasive depth (P>0.05). The expression levels of Mel-18 in TNM stage Ⅰ, Ⅱ,Ⅲ/ⅣA were reduced consequently (P<0.05). The difference of expression in the groups with and without lymph node metastases was significant (P<0.05).4. The expression of Bmi-1is negatively correlated the expression of Mel-18(P<0.05).Conclusions1. The Bmi-1mRNA expression was significantly Overexpression in squamous esophageal cell.The Bmi-1mRNA expression levels was significantly higher in53carcinoma tissues than corresponding normal tissues. The mRNA expression of Mel-18was significantly low expression in squamous esophageal cell. The Mel-18mRNA expression levels was significantly lower in53carcinoma tissues than corresponding normal tissues. These results suggested that Bmi-1and Mel-18may play a important role in the progression of esophageal squamous cell carcinoma.2. The expression of Bmi-1and Mel-18in different TNM stages and lymph node metastasis group have significant difference,and the expressions of Bmi-1were positively correlated with the depth of tumor invasion, suggest the expression differences of Bmi-1and Mel-18and the tumor stage and lymph node status of esophageal squamous cell carcinoma are closely related.3. The expression of Bmi-1and Mel-18is a certain negative correlation, Bmi-1and Mel-18may have a mutual effect in the occurrence,development, invasion and metastasis of esophageal squamous cell carcinoma.4. It is possible that Mel-18could be used as a definite diagnosis and evaluating prognosis marker of Esophageal Squamous cell carcinoma.更多还原