摘要目的 观察燃煤污染型地方性砷中毒(简称燃煤型砷中毒)患者外周血中切除修复交叉互补基因1(ERCC1)mRNA和皮肤组织中ERCC1蛋白表达情况,探讨其在砷致病或致癌机制中的作用.方法 依据<地方性砷中毒诊断标准>(WS/T 211-2001),选择贵州省兴仁县燃煤型砷中毒病区110例砷中毒患者为病例组,依据其发砷分为3组:＜2、2～＜4、≥4 mg/kg组,分别为31、31、48例,以距病区约13 km的非砷污染村36例健康居民为对照组.在知情同意原则下收集上述观察对象头发、外周血,采用二乙氨基二硫代甲酸银(Ag-DDC)法检测发砷、实时荧光定量PCR技术检测外周血中ERCC1 mRNA的表达情况.利用自愿手术治疗的62例砷中毒患者皮肤标本,依据其发砷分为3组:＜2、2～＜4、≥4 mg/kg组,分别为16、20、26例,同时依据皮肤病理学诊断分为一般皮肤病变组、癌前病变组、癌变组,分别为32、19、11例,以某医院经病理学诊断无异常的13例非肿瘤手术患者皮肤组织为对照组,采用免疫组织化学法检测皮肤组织中ERCC1蛋白的表达情况.结果 发砷＜2、2～＜4、≥4mg/kg组患者外周血中ERCC1 mRNA相对表达中位数(四分位间距)分别为0.7156(0.2158～1.2405)、0.5772(0.0843～1.1234)和0.5490(0.1895～0.8431),与对照组[1.5128(1.0000～2.1295)]比较,差异有统计学意义(P均＜0.05).发砷＜2、2～＜4、≥4 mg/kg组患者皮肤组织中ERCC1蛋白阳性表达率分别为87.5%、80.0%和77.0%,发砷2～＜4和≥4 mg/kg组与对照组(100.0%)比较,差异有统计学意义(P均＜0.05);在一般皮肤病变组、癌前病变组和癌变组患者皮肤组织中ERCC1蛋白阳性表达率分别为84.4%、79.0%和72.8%,与对照组(100.0%)比较,差异均有统计学意义(P均＜0.05).结论 燃煤砷污染可导致人体ERCC1基因转录及蛋白质表达水平异常,可能通过影响受损DNA的切除,继发性抑制DNA修复,促进砷中毒乃至皮肤癌的发生、发展.

abstractsObjective To study the transcription and expression of excision repair cross complementing 1(ERCC1) in the peripheral blood and the skin tissue in coal-burning borne endemic arsenism, and to explore the role of arsenism in its pathogenic or carcinogenesis mechanism. Methods According to "Endemic arsenism diagnostic criteria" (WS/T 211-2001), 110 arsenism patients were chosen as case group in Xingren county,Guizhou province and they were divided into 3 groups according to their hnir arsenic: ＜ 2(31 cases),2 ～＜ 4(31 cases),≥4 mg/kg(48 cases), respectively. Another 36 healthy residents about 13 km away from the endemic area were chosen as healthy control group. Under the principle of informed consent, hair samples were collected for arsenic analysis by Ag-DDC and blood samples were collected to determine mRNA expression levels of ERCCI by real-time fluorescence quantitative PCR. At the same time, skin tissue samples were collected from the voluntary surgical treatment of 62 patients with endemic arsenism as case group which were divided into 3 groups according to their hair arsenic: ＜ 2(16 cases), 2 ～＜ 4(20 cases) and ≥4 mg/kg(26 cases), respectively, and these patients were also divided into general pathological changes (32 cases), precancerous (19 cases) and cancerous groups( 11cases), respectively, according to their skin pathologic diagnosis of skin lesions. Another 13 cases pathologically normal without skin cancer surgery from a certain hospital were chosen as control group. Skin samples were collected to detect the ERCC1 protein by immunohistochemical method. Results The mRNA levels of ERCC1 were 0.7156(0.2158 ～ 1.2405),0.5772(0.0843 ～ 1.1234) and 0.5490(0.1895 ～ 0.8431 ), respectively, among ＜ 2, 2 ～＜ 4and ≥4 mg/kg groups, which were lower than the mRNA levels of ERCC1 in the control group[1.5128(1.0000 ～2.1295)], and the difference was statistically significant(all P ＜ 0.05). The expression rate of ERCC1 protein were 87.5%, 80.0% and 77.0%, respectively, among ＜ 2, 2 ～＜ 4 and ≥4 mg/kg groups. The expression rate of ERCC1 protein in 2 ～＜ 4 and ≥4 mg/kg groups were lower than the rate in the control group(100.0%), and the difference was statistically significant (all P ＜ 0.05). The expression rate of ERCC1 protein were 84.4%, 79.0%and 72.8%, respectively, among general pathological changes, precancerous and cancerous groups compared with the control group( 100.0% ), and the difference was statistically significant(all P ＜ 0.05). Conclusions Arsenic from coal-burning can lead to abnormal ERCC1 gene transcription and protein expression, which may inhibit DNA repair through influencing the removal of damaged DNA and promoting the incidence of arsenism development and even skin carcinogenesis.