山东胃癌高低发人群Lewis基因多态性分析

应用PCR产物直接测序的方法,检测山东省胃癌高发的临朐人群和低发的苍山人群中Lewis基因多态性T59G的分布,旨在探讨山东临朐和苍山地区胃癌发病率显著不同的内在原因,为阐明临朐地区胃癌高发的机制提供实验依据。结果表明,T59G突变个体在临朐和苍山人群中的分布频率分别为34.5%和31.6%,差别无统计学意义,P＞0.05,OR为1.14 （95% CI,0.59~2.19）。提示就此点突变而言,临朐人群和苍山人群为同一人群,具有极其相似的遗传背景;T59G不能作为区分临朐和苍山人群的遗传标志,与这两个地区胃癌发病的区别没有相关性。 Abstract:To explore the cause leading to the difference in incidence of gastric cancer between Linqu and Cangshan populations,Shandong Province,and to provide evidence for the possible mechanism of high incidence of gastric cancer in Linqu County,the distribution of T59G mutation in Lewis gene was screened between Linqu and Cangshan populations by PCR-sequencing.The frequency of individuals with T59G mutation was 34.5% in Linqu population and 31.6% in Cangshan population,respectively,with no significant difference,P＞0.05,and OR is 1.14 (95% CI,0.59~2.19).This suggests that Linqu and Cangshan populations may share the same genetic background.T59G mutation of Lewis gene could not be used as a genetic marker for Linqu and Cangshan populations and is not relevant to the difference in incidence of gastric cancer between them.     

化学致癌作用靶基因的分离与测序

采用新的差异表达基因显示法,从一对处于不同癌变阶段的人类胃粘膜上皮细胞,显示和分离出了差别表达的基因。其中8个基因片段克隆于质粒DNA,荧光标记测序分析并在基因库中查找比较,发现其中一个基因与人类“真核蛋白合成启动因子”EIF-4γ)97.5％同源,另一个与大鼠SX1基因有86.2％的同源。其余6个为未报道基因序列。由于这对细胞的差别是化学致癌物MNNG所致,这些新分离的基因可能即为化学致癌剂的靶基因,与细胞的癌变相关。     

人胃癌细胞株BGC-823 DNA二轮转化细胞基因组文库的构建及其转化基因的克隆

以人胃癌细胞株BGC-823 DNA二轮转化的鼠成纤维细胞为材料,用λ噬菌体EMBL_3,作克隆载体,构建了转化细胞的基因组文库。用~(32)P标记的人Alu重复顺序和原癌基因c-Ha-ras为探针,对100万基因文库噬斑进行原位杂交筛选,找出了两个可以同时与上述探针杂交的阳性克隆。经对两个阳性克隆DNA进行分子杂交表明,它们均含有来自人胃癌细胞株BGC-823的转化基因Ha-ras,进一步运用质粒载体pBR322对这一转化基因进行次级克隆,并进行了限制性内切酶图谱的初探,从而为研究胃癌转化基因的结构、DNA序列及与原癌基因的异同奠定了基础。     

山东临朐胃癌高发人群和北京人群Lewis血型抗原相关SE基因多态性分析

为探讨宿主的遗传背景和幽门螺杆菌（Helicobacter pylori,H.pylori）相关胃癌的易感性之间的关系,本文采用PCR产物直接测序和PCR-RFLP的方法,检测142例山东临朐县胃癌高发人群个体（包括69例癌症患者和73例非癌个体）和93例北京正常对照个体SE基因多态性的分布特点。结果显示：sew/sew基因型在山东非癌个体和北京人群之间的分布差异具有统计学意义（P＜0.01,OR=3.06,95% CI,1.28~7.30）,sew/sew基因型在山东癌症病人和非癌个体之间分布频率无显著性差异,H.pylori感染状况与SE基因型的分布也无关联性。提示：sew/sew纯合突变在山东临朐人群中分布频率较高,可能为临朐人群的遗传标记之一。 Abstract:To study the relation between host genetic backgroud and the susceptibility to H.pylori associated gastric cancer,PCR-sequencing and PCR-RFLP were used to screen SECRETOR gene polymorphisms in 142 subjects including 69 cancer patients and 73 non-cancer individuals from high-risk area of gastric cancer in Shandong and 93 control individuals from Beijing.Results showed that the difference in sew/sew distribution between non-cancer individuals and Beijing population was significant(P＜0.01,OR is 3.06,95% CI,1.28~7.30),but that between cancer patients and non-cancer individuals was not with significance.SE gene polymorphism was not relevant to H.pylori infection.We concluded that Shandong population from high-risk area of gastric cancer shared a high distribution of sew/sew genotype,which could be considered as one of the genetic markers.