【摘要】 目的　为了探讨日本血吸虫所致肝癌和直肠癌的病因学。方法　用PCR -SSCR和DNA序列分析直肠癌伴有晚期血吸虫患者P53 基因的突变类型 ,来自同一医院直肠癌不伴有晚期血吸虫患者作为对照。结果　在直肠癌伴有晚期血吸虫病的 2 2个患者中 ,有 10个病例共发现 13个突变即两个缺失和 11个取代 ,在 11个取代突变中有 9个转换和 2个颠换 ,并且 11个取代突变中有 7个发生在CpG核苷酸排列部位。而在 2 2个直肠癌不患有血吸虫的病例中。它们中仅有 3个发生在CpG核苷酸排列部位。结论　直肠癌伴有晚期血吸虫患者 ,在CpG核苷酸排列部位的取代突变显著性高于直肠癌不患血吸虫病患者 (P <0 .0 5 )。在晚期血吸虫直肠癌患者中 ,点突变频繁的发生在p5 3基因外显子 7的 2 48号密码子 ,显示了日本血吸虫是一个内源性的遗传毒性因子。更多还原

【Abstract】 Objective To understand the etiology and molecular pathogenesis of rectal cancer in patients with schistosomiasis japonicum. Methods Mutation in p53 tumor suppressor gene were examined in 44 Chinese patients with rectal cancer,including 22 cases with advanced schistosomiasis japonicum and 22 cases without schistosomiasis with PCR-SSCP and DNA sequence analysis. Results In schistosomal rectal cancer(SRC),13 mutations were found in 10 cases,which included 11 base-pair substitutions and two deletions.Of 11 base substitutions,nine were transitions and two were transversitons and seven of them were located at CpG dinucleotides.In non-schistosomal rectal cancer(NSRC),13 substitutions,10 were transitions and three were transversions and three of them were located at CpG dinucleotides. Conclusion The proportion of base pair substitutions at CpG dinucleotides was higher in SRC than in SRC.These observations suggest that the mutations in SRC are the result of genotoxic agents produced endogenously through the course of schistosomiasis japonica.更多还原