【作者】 董玉英；

【导师】 王洁；

【作者基本信息】 河北医科大学 ， 病理学与病理生理学， 2006， 博士

【摘要】 目的头颈癌是全世界第六位最常见的癌症,而在发展中国家高居第三位。口腔颊癌是头颈癌中较常见的类型之一。在世界范围内,颊癌是一种常见的颊粘膜上皮性肿瘤,特别是在发展中国家,如印度、斯里兰卡、菲律宾、巴西、中国等地,尤为多见。颊癌的生存率依照年龄、性别、种族和地域的不同而不同,这种差异性说明颊癌的发病与多种因素有关。颊癌的早期检测和早期诊断已经提高了患者的生存率,但5年的50%生存率在大多数肿瘤中还是较低的。近三十年间颊癌的发病率和死亡率在发展中国家中有上升的趋势,临床上放疗和化疗的应用,并没有明显提高颊癌病人的生存率。存活的病人通常都存在面部畸形和不同程度的功能丧失,一些治愈的病人在几年内又会复发。随着疾病分子病理学的飞速发展,人们逐渐认识到上皮细胞癌变是一个多因素多阶段的过程。在癌变的不同阶段有不同基因的改变,因此,认识口腔颊癌的癌变机理,已成为多年来口腔医学研究领域的热门课题。肿瘤的发生是一个多阶段的过程,如果某些细胞内基因损伤而未被修复,则可出现细胞的异常增殖而发展成肿瘤。目前研究发现与肿瘤发生有关的基因分两大类:原癌基因和抑癌基因。细胞原癌基因激活和抑癌基因的失活,可导致细胞信号传导和细胞周期紊乱,抑制细胞凋亡,结果出现细胞异常增殖。任何一肿瘤的发生都涉及多种原癌基因的激活和抑癌基因的失活,研究发现p53的基因突变和p16基因的失活是肿瘤发生的重要因素之一。p53基因是较早被发现的抑癌基因,也是目前研究最为广泛深入的基因之一。正常的p53基因起着分子警察的作用,它监视着整个基因状况,被视为基因的卫士。若p53丢失或突变,则DNA不能被修复,细胞突变发生恶性肿瘤。p53基因是重要的肿瘤抑制基因,许多人类肿瘤都伴有不同程度的p53基因突变。很多文献报道p53基因突变是口腔颊粘膜癌变过更多还原

【Abstract】 ObjectivesSquamous cell carcinoma (SCC) of the head and neck region accounts for the sixth position of human cancer in the world, and it accounts for the third position of human tumour in some developing countries, such as India, SriLanka, the Philippines, Brazil and China. Buccal cancer is frequent type of SCC in head and neck regions. Survival rate of buccal cancer is different depending on age, gender, ethnic background, and geographic area. This variability reflects the multifactorial pathogenesis of the disease. Early detection and diagnosis could improve survival, but the overall 5-year rate of 50% is much lower than the other human cancers. The incidence and mortality of buccal cancer has been increasing in developing countries over the last three decades. Recently, although radiotherapy and chemotherapy have been used in the patients with buccal cancer, the survival rate of the patients is not obviously improved and the patients still have poor prognosis of dysfunction and disfigurement. With the rapid development of molecular pathology, it is gradually realized that carcinogenesis is a multifactorial process and different stages have different gene alterations. A great deal of attentions has attracted to identify the molecular mechanisms of buccal cancer in the last few years. It is possible to suggest certain molecular events in the development of this disease.Cancer is a multi-step process, involving many carcinogenic factors, for example: genetic damage in certain cells. If undetected by the cells’ DNA repair mechanism, it could develop a selective growth advantage and could form a tumour. It is now recognized that two types of cancer genes are enrolled, oncogenes and tumour suppressor genes. The oncogene genes are probably involved in both initiation and progression of the disease, whereas更多还原