实时荧光定量PCR检测职业砷暴露人群p53基因损伤

目的 探讨云南某砒霜厂工人p53基因第5和第8外显子损伤与砷的代谢转化关系;建立实时荧光定量PCR检测人群基因特异DNA损伤的方法.方法 选择云南某砒霜厂一线工人37例(高暴露组)、管理和后勤人员16例(低暴露组)和当地近期无毒物接触人员25例(对照组)为研究对象,应用实时荧光定量PCR检测人群p53基因第5和第8外显子损伤,同时检测尿中总砷和有机砷含量,评价人群对砷的代谢转化与p53基因损伤的相关性.结果 高、低暴露组男性尿有机砷浓度分别为(1.18±0.76) mg/L、(0.32±0.28) mg/L,女性分别为0.23 mg/L、(0.53±0.30) mg/L;高、低暴露组男性尿总砷浓度分别为(0.48±0.37) mg/L、(0.08±0.05) mg/L,女性分别为0.11 mg/L、(0.30±0.24) mg/L.男性尿总砷和有机砷高暴露组均高于低暴露组(P＜0.05),对照组均低于检出值下限0.02 mg/L.p53基因第5外显子实时荧光定量PCR检测的Ct相对值,男性高暴露组高于男性对照组(P＜0.05),Ct相对值随尿中有机砷含量上升有升高趋势(rs=0.355, P=0.011);p53基因第8外显子Ct相对值,男性低暴露组高于对照组(P＜0.05),但男性高暴露组与低暴露组、对照组比较,差异均无统计学意义,Ct相对值与尿中有机砷含量无相关性.结论 职业砷暴露可能致p53基因第5和第8外显子损伤,砷的代谢转化可能在第5外显子损伤中起关键作用;实时荧光定量PCR用于检测人群基因特异DNA损伤切实可行.

Real-time PCR Used to Detect p53 Gene Damage in Workers Exposed to Arsenic

OBJECTIVE: To evaluate the relationship between the metabolism of arsenic and the damage of exon 5 and 8 of p53 gene from workers in a arsenic mill, and with real-time PCR technique, to establish the method probing the gene-specific DNA damage in people. METHODS: By real-time PCR, the damages of exon 5 and 8 of p53 gene were probed in 37 workers exposed highly to, 16 manager and logistic employees exposed less to an arsenic mill in Yunnan province, and also 25 local people who did not contact with any white arsenic in near past time. At the same time, the urinary total and organic arsenic of workers were detected. The correlation between metabolism of arsenic and damage of p53 gene was evaluated. RESULTS: Total urinary arsenic concentrations were (1.18 +/- 0.76) mg/L and (0.32 +/- 0.28) mg/L for high and low exposed male workers, and 0.23 mg/L, (0.53 +/- 0. 30) mg/L for high and low exposed females. Organic urinary arsenic concentrations were (0.48 +/- 0.37) mg/L and (0.08 +/- 0.05) mg/L for high and low exposed males, and 0.11 mg/L, (0.30 +/- 0.24) mg/L for high and low exposed females. The total and organic urinary arsenic of high exposed group was higher than that of control male (P < 0.05), all in control group were lower than 0.02 mg/L for reference. The Ct relative value of exon 5 of p53 gene in high exposed group was higher than that in control male (P < 0.05), and the increased tendency of Ct relative value of exon 5 of p53 gene was found in workers with organic arsenic concentration going up (r(s) = 0.355, P = 0.011). The Ct relative value of exon 8 of p53 gene in low exposed group was higher than that in control male (P < 0.05), but the difference between high exposed and low exposed or reference's was not obvious (P > 0.05). CONCLUSION: The damages in exon 5 and 8 of p53 gene in workers exposed to arsenic may be induced. The metabolism of arsenic may be very important in the damage of exon 5. It is feasible for real-time PCR technique used to detect gene-specific DNA damage in people.