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Expression of apoptotic and cell proliferation regulatory proteins in actinic cheilitis
A Martínez1, U Brethauer, I G Rojas
1Department of Oral Pathology, College of Dentistry, Universidad de Concepción, Chile. almartin@udec.cl
Background:
Actinic cheilitis (AC) is a pre-malignant lesion caused by ultraviolet (UV) radiation. The apoptotic proteins p53, bax, bcl-2, and the proliferation marker Ki-67, are known to play an important role in UV-exposed skin and carcinomas, therefore, these markers were assessed in AC and compared with normal lip and oral mucosa.
Methods:
AC (n = 13), normal lip (n = 7) and oral mucosa (n = 6) biopsies were stained immunohistochemically for p53, bax, bcl-2 and Ki-67, to determine their expression and distribution.
Results:
p53 was over-expressed in AC as compared with normal lip and oral mucosa (P < 0.003). Although bcl-2 expression was higher in AC than in oral mucosa (P < 0.002), it was significantly reduced as compared with normal lip (P < 0.04). Bax expression remained unchanged, and Ki-67 was significantly increased in AC and normal lip as compared with oral mucosa (P < 0.05).
Conclusion:
The results suggest that DNA-damaged cells by UV radiation in AC are eliminated by apoptosis.
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