Transcription and expression of excision repair cross complementing 1 in endemic arsenism caused by coal-burning / 中国地方病学杂志

ABSTRACT

Objective 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.