Abstract: BACKGROUND ＆ AIM： To explore the significance and interaction of telomerase activation and expression of proliferating cell nucleus antigen (PCNA) in arsenic_induced skin lesion from coal burning. MATERIALS AND METHODS： Using telomeric repeat amplification protocol(TRAP) assay and ABC immunohistochemical technique, the level of telomerase activation and PCNA expression were evaluated in 29 skin lesions of arseniasis patients and 10 cases of normal skin. RESULTS： The positive rates of telomerase in cancerous skins and skins with general pathological changes(dermatitis，hyperkeratosis and pigmentation) were 90.9％ and 0.0％，respectively. In these 2 groups, the positive rates of PCNA were 90.9％ and 16.7％，respectively. The differences in telomerase and PCNA rates between the 2 skin groups were both statistically significant(P<0.01). The telomerase and PCNA were negative in 10 cases of normal skin. There was a positive relationship between telomerase activation and PCNA expression(r=0.659， P<0.01). The two indexes had concordance(P>0.05) and the rate was 82.8％. CONCLUSION: The increase of telomerase activation and PCNA expression were important during the course of arsenic_induced skin carcinogenesis. There was concordance between the two. Combined measurements of telomerase activation and PCNA expression would be helpful in the diagnosis of skin carcinoma induced by arsenic.

Key words: telomerase, proliferating cell nucleus antigen, arseniasis, coal, skin lesion