PCNA AND P53 EXPRESSION IN ORAL LEUKOPLAKIA WITH DIFFERENT DEGREES OF KERATINIZATION EXPRESSÃO DO PCNA E P53 EM LEUCOPLASIAS DE MUCOSA JUGAL COM DIFERENTES GRAUS DE QUERATINIZAÇÃO

ABSTRACTRESUMO PCNA AND P53 EXPRESSION IN ORAL LEUKOPLAKIAWITH DIFFERENT DEGREES OF KERATINIZATION EXPRESSAO DO PCNA E P53 EM LEUCOPLASIAS DE MUCOSA JUGAL COM DIFERENTESGRAUS DE QUERATINIZACAO Melaine de Almeida LAWALL 1 , Marcelo Macedo CRIVELINI 2 1- DDS, MSc, Graduate Student, Department of Oral Pathology, Dental School, State University, Aracatuba, Sao Paulo, Brazil.2- DDS, MSc, PhD, Associate Professor, Department of Oral Pathology, Dental School, State University, Aracatuba, Sao Paulo, Brazil. Corresponding address: Rua Sao Goncalo, no6-73. Vila Altinopolis - Bauru - SP - Cep.: 17012-170 - Telephone number: (14) 3234-6120Cel phone: (14) 9735-8727 - e-mail address: melainelawall@yahoo.com.br Received: March 07, 2006 - Modification: June 01, 2006 - Accepted: June 14, 2006 eukoplakias are oral lesions that may have many clinical and histological aspects and they are usually associated withmalignancy when dysplastic alterations are shown. However, these transformations may occur in non-dysplastic lesions thatshow harmless clinical aspect. For this reason, the proposal was to study the p53 and PCNA immunohistochemical expressionin non-dysplastic leukoplakias, trying to correlate the results only with the epithelial keratinization degree. For this, 24 le ukoplakiasdegrees I, II and III of Grinspan were used, all of them located in oral mucosa. Most of the leukoplakias showed p53 and PCNAexpression in their different keratinization degrees. The p53 marking was confined to the basal and parabasal layers, while thePCNA marking occurred in practically all epithelial layers. The expression pattern of these markers was histologically andstatistically similar between the lesions with these keratinization variations. It was evident that non-dysplastic epithelium ofleukoplakias showed submicroscopical signs of alterations that lead to malignant transformation, and that the keratinizationdegree did not correlate to a greater risk of this event.