ABSTRACT
Objective To determine the protein expression of P14ARF,MDM2 and mutant type P53 (P53mt) in skin specimens of coal-burning-type of endemic arseniasis patients and to reveal the molecular mechanism of the disease.Methods Sixty skin specimens from 60 endemic arseniasis patients including 35 of skin lesions patients,19 of precancerous lesion and 6 of skin cancer and 9 normal skin specimens from non-cancer patients were studied.Expression of P14~,MDM2 and P53mt was evaluated by immunohistochemistry using corresponding monoclonal antibodies.Results There was significant difference in the positive rates of P14ARF,MDM2 and P53mt among the 4 groups(x2 =9.39,6.21,20.64,all P ＜ 0.05).The positive rates of P14ARF in precancerous lesion and skin cancer specimens were 46.1％ (6/19) and 33.3％ (2/6),respectively,which were significantly lower than that of the normal skin specimens [88.9％(8/9),all P ＜ 0.05].Decreased expression of P14ARF was correlated with the development of dermopathy (P ＜ 0.05).The positive rates of MDM2 and P53mt in skin lesions,precancerous lesion and skin cancer specimens were 54.2％ ( 19/35 ),63.2％ (10/19),66.7％ (4/6) and 25.7％(9/35),73.7％(14/19),83.3％(5/6),respectively,which were significantly higher than those of the control (0,0,all P＜ 0.05).The expression of MDM2 and P53mt increased with the development of dermopathy(all P ＜ 0.05).Conclusions P53mt protein in skin tissue of coal-burning-type of endemic arseniasis patients is over expressed.Abnormal expression of P14ARF and MDM2 may be one of the reasons lead to abnormal cell cycle control disorders and may play a role in the development of endemic arseniasis.