XRCC1基因多态性与辐射致染色体损伤的关系

Study of Relationship between Polymorphisms of XRCC1 and Radiation Exposure Induced Chromosome Damage

目的探讨XRCC1基因的多态性与辐射致染色体损伤程度的关系,从基因水平探讨辐射损伤的修复机制。方法选择从事放射线工作工龄>1 a、出现染色体损伤的人员(224名)作为病例组,根据染色体畸变类型和细胞畸变率将病例分为轻度和重度损伤组,采用1∶1配对设计,从放射人员健康检查中选择与病例组同性别、同民族、年龄相差≤5岁、与病例组在同一工作岗位、工龄相差≤1 a无染色体损伤和血象异常的人员为对照组。盐析法提取基因组DNA,采用多聚酶链反应—限制性片段长度多态性分析技术(PCR-RFLP)检测基因型。结果XRCC1226304、27466、28152、36189位点各基因型及等位基因频率在轻度损伤组与对照组分布比较,差异均无统计学意义(P>0.05)。重度损伤组携带26304位点T等位基因的频率高于对照组,差异有统计学意义(P<0.01),携带26304CT/TT基因型的放射线工作者发生染色体重度损伤的风险是携带其他基因型个体的1.89倍,其他3个位点的等位基因和基因型频率两组分布比较,差异均无统计学意义(P>0.05)。结论XRCC126304位点T等位基因为染色体损伤的危险因素,携带26304CT/TT基因型的放射线接触者易发生染色体损伤且损伤程度重。该研究未发现XRCC127466、28152、36189位点基因多态性与辐射导致的染色体损伤程度有关联。

Objective To study of the relationship between polymorphisms of XRCC1 and radiation exposure induced chromosome damage. Methods 224 radiation exposed workers suffering from chromosome damage were selected as case group. The chromosome damages were classified as mild and severe groups according to damage degree. Applying 1 ： 1 pair matching case-control design, 224 workers with normal chromosome, hemogram, and similar cumulative radiation exposure matched in sex, age （± 5 years）, nationality, type of job, and working age（≤ 1 year）were selected as controls. The common information of subjects was investigated. The method of whole blood tiny culture was used for chromosome analysis. DNA was extracted from veinal blood by means of a saturated salting out procedure. The polymerase chain reactionrestriction fragment length polymorphism（PCR-RFLP）technique was applied to detect the sites of XRCC1. Results There was no significant difference in frequencies of XRCC1 26304, 27466, 28152, 36189 genotypes and alleles between mild damage and control. Frequency of 26304 CT/TT in severe damage group was significantly higher than that of control（OR= 1.89,95% CI 1.10～3.26）. The frequencies of XRCC1 26304T allele in severe damage group and controls were 35.98% and 22.43% respectively, the difference was statistically significant （P〈0.01）. Conclusions The polymorphism of XRCC1 26304 was associated with chromosome damage. The chromosome damage was easy-to-occur in workers with 26304 CT/TT when exposed to radiation. The relationship between polymorphism of XRCC1 27466, 28152, 36189 sites and chromosome damage was not found in this study.